During postaccident interviews, a St. Louis police officer
who had provided security to one of the passengers on the accident airplane2
stated that the pilot and two passengers arrived at CPS about 1140 on the day
of the accident and then spent the day attending four campaign functions. Later
that day, the pilot asked this security officer to take him back to the airport
early so that he could prepare for the flight to EIW. The security officer stated
that the pilot contacted the St. Louis Automated Flight Service Station (AFSS)
to obtain a weather briefing during the drive back to CPS.3
The security officer also stated that the pilot then contacted the fixed-base
operator (FBO) at CPS and asked to have the airplane's wing tanks topped off
The security officer reported that after arriving at
CPS about 1835, the pilot went into the FBO to check the weather on the
computer and pay for the fuel. The security officer stated that when he
asked the pilot if they were going to be able to make the flight to EIW,
the pilot indicated that he did not anticipate that the weather would cause
any problems with the flight and stated, "I've seen better days, but I've
seen a lot worse." The security officer stated that the two passengers
arrived at the airport about 1845 and then boarded the airplane. He stated
that the pilot was seated in the left front seat but that he could not
tell where the two passengers were seated.
At 1918:19, the pilot contacted St. Louis TRACON. At 1918:48, when the airplane
was at approximately 2,200 feet, the St. Louis TRACON Low West (LW) controller
informed the pilot of N8354N that he had radar contact with the airplane and
instructed the pilot to turn left to a heading of 180° and climb to 2,600
feet. The pilot acknowledged these instructions. At 1920:00, the controller
instructed the pilot to turn left to a heading of 150° and maintain 2,600
At 1920:07, the pilot stated, "five four November we're having some problems
uh with primary attitude indicator we'd like uh little bit...higher climb."7
The LW controller responded that he would be able to issue him a higher altitude
"in about two miles." At 1920:51, the controller asked the pilot to state the
airplane's altitude. The pilot replied, "we're at three thousand six hundred."
The controller responded, "okay the uh assigned altitude was two thousand six
hundred but climb and maintain four thousand." The pilot responded, "we got
our hands full right now." At 1921:08, the controller stated, "uh roger you
in some sort of difficulty." The pilot responded, "we got a primary attitude
indicator that's not uh reading properly having to try and fly off of copilot
[the right-side attitude indicator]." At 1921:20, the controller advised the
pilot to try and fly the airplane level on any heading and told him that he
would try to get him to as high an altitude as possible. The pilot responded,
At 1921:35, the LW controller told the pilot to fly "straight ahead" and stated
that he would get him to visual flight rules (VFR) conditions. At 1921:52, the
controller instructed the pilot to climb to and maintain 4,000 feet and to "let
me know when you get on top [of the clouds]."8
The pilot acknowledged the instruction. At 1922:00, the controller asked another
pilot, whose airplane was at 5,000 feet, if he was on top of the clouds, and
the pilot responded that he was not.9
At 1922:33, the controller reported to N8354N, "I don't have much hope for getting
you on top uh people say it's like about twelve five [12,500 feet]." At 1922:50,
the pilot stated that he wanted to head toward Jefferson City Memorial Airport
(JEF), Jefferson City, Missouri, because he understood that the weather conditions
were better there. The controller then asked the pilot if his "instrument" was
showing a heading of 150°, and the pilot responded "well the compass is
showing due south one eight zero [180°]."10
At 1923:12, the controller instructed the pilot to turn to a heading of 120°,
and the pilot acknowledged the instruction.11
At 1923:39, the LW controller told the pilot to "climb and maintain seven thousand
[feet] at pilot discretion." The pilot acknowledged the instruction and added
"we would like to go direct to jefferson city if possible." The controller responded,
"say jefferson city."12
The pilot responded, "that's right jefferson city." At 1923:55, the controller
stated, "in that case turn right heading two seven zero." The pilot then acknowledged
the turn instruction and confirmed the assigned altitude.13
At 1925:12, the LW controller informed the pilot that "it appears you're heading
northwest but uh you're basically in a good direction." At 1928:36, the LW controller
asked the pilot if he was still having "attitude problems." The pilot replied,
"the attitude problems are continuing." ATC radar data indicate that at this
time, the airplane's altitude had reached 7,400 feet and that the airplane had
entered a left turn to the southeast.14
The data show that the airplane then descended slightly and that its altitude
varied between 7,000 and 7,200 feet. At 1929:31, the pilot stated, "we're gonna
need some vectors somewhere where we can get down [to] VFR [conditions]."15
The LW controller stated that he would check around for other weather conditions
and that, in the meantime, the pilot should "just go straight ahead...doesn't
make any difference what direction that is just go straight ahead." At 1930:17,
the controller told the pilot that the weather at Columbia Regional Airport,
Columbia, Missouri, was 7,000 feet overcast with 7 miles visibility and light
rain. The controller told the pilot that the further west he went the better
the weather was going to be. He then asked the pilot if he wanted to head west.
At 1930:35, the pilot responded, "that would be great." This was the pilot's
At 1930:37, the LW controller told the pilot to "make a slow
right turn as much as you can the standard rate...as much as you can to make
this a stabilized affair."16
ATC radar data show that after this instruction was issued, the airplane entered
a right turn. ATC radar data further show that at 1931:17, the airplane had
descended to approximately 6,500 feet. At 1931:22, the controller told the pilot
to stop the turn and to fly straight ahead.17
At 1932:28, the controller unsuccessfully tried to contact N8354N. At 1932:34,
the controller transmitted, "november three five uh five four november radar
The accident occurred at night in dark lighting conditions.
The location of the accident site was 38° 18.653' north latitude, 90°
30.125' west longitude at an elevation of about 826 feet mean sea level.
The pilot, age 44, held a commercial pilot certificate with
airplane multiengine land and instrument airplane ratings and a private pilot
certificate with airplane single-engine and multiengine land19
and single-engine sea ratings. The pilot's most recent FAA second-class airman
medical certificate was issued on January 21, 2000, and contained the limitation
that he wear corrective lenses.
The last entry in the pilot's logbooks was dated April 27, 2000. Investigators
used the pilot's logbooks, campaign flight logs, and flight logs from other
airplanes the pilot had flown20
to estimate the pilot's total flight experience. The pilot's estimated total
flight time at the time of the accident was about 1,829.7 hours, including about
735 hours of multiengine flight time, of which 513 hours were in a Cessna 335.
The pilot's estimated total night flight time was about 460.5 hours, of which
157.4 hours were in a Cessna 335.
The pilot's estimated total actual instrument flight time was about 87.6 hours,
of which 22.4 hours were in a Cessna 335.21
His estimated total simulated instrument flight time was about 65.2 hours, of
which 1 hour was in a Cessna 335. Records indicate that the pilot's most recent
instrument proficiency checkride was on September 21, 1999. Flights recorded
in the pilot's logbook that contained the remark "partial panel flight" totaled
to about 12.3 hours,22
none of which were in a Cessna 335.
The pilot's estimated flight time in the 90 days before the accident
flight was about 93.6 hours, of which 81.3 hours were in a Cessna 335.
The pilot's estimated flight time in the 30 days before the accident flight
was about 38 hours, of which 32.4 hours were in a Cessna 335.
According to the pilot's personal physician, the pilot was in "excellent
health" during the 12 months before the accident. He reported that the
pilot had no acute illnesses; did not take any medications; and did not
use alcohol, tobacco, or caffeine. Family and friends reported that the
pilot exercised on a regular basis, preferring to run or walk in the mornings.
Friends also reported that he would not have flown if he were tired. Further,
they stated that he had been known to cancel trips when the weather conditions
A review of training records shows that the pilot received
an insurance "checkout" from a flight instructor in the accident airplane
between November 21 and December 6, 1997. The checkout consisted of 15
hours of flight time, during which the pilot was exposed to systems training
and IMC, normal, and emergency procedures. The pilot logged 2.5 hours of
this flight time as instrument training and 7.5 hours as night flight time.
From May 15 through 17, 1998, the pilot attended and completed a Systems and
Operational Procedures Training Seminar held by Twin Cessna Flyer, Defiance,
Ohio. According to the course materials, the course's primary purpose was to
"help the pilot/owner of twin Cessna aircraft prevent emergencies and accidents
through increased knowledge of aircraft systems and operational procedures."
The course included 3 days of classroom and lab instruction. The instruction
covered the following information: systems--knowledge, operation, and maintenance;
normal and emergency procedures; decision-making and judgment; and proficiency
flying. A portion of the course manual titled, "Normal and Emergency Operating
Procedures," covered the twin Cessna's vacuum system.23
The course manual also contained a Twin Cessna Checklist, which included performing
a vacuum system check as part of the engine start and shutdown procedures. Further,
a copy of the Pilot Operating Handbook Supplement that outlined the engine start
and shutdown procedures, which includes the performance of a vacuum system check,
was distributed to and discussed with the attendees as they were reviewing the
Pilot's 72-Hour History
Coworkers, friends, and the pilot's sister provided
information to Safety Board investigators about the pilot's activities
during the 72 hours before the accident. On October 13, 2000, the pilot
was reported to have arrived at his office in Rolla, Missouri, sometime
between 1430 and 1600 and to have departed about 1800. From about 2000
to 2200, the pilot was reportedly at his home visiting with the caretakers
of his farm. The pilot reportedly drove the caretakers and their family
back to their house and arrived back home between 2230 and 2300.
On October 14th, the pilot was seen at his home between 0930 and 1000,
where he was getting ready for a trip. According to the pilot's sister,
he flew N8354N from Rolla to Columbia, Missouri, where he attended a football
game. According to a campaign schedule, the pilot was scheduled to depart
Columbia at 1405 and arrive in Creve Coeur, Missouri, at 1450. According
to the pilot's sister, after arriving at Creve Coeur, the pilot departed
for Cuba, Missouri, and then continued on to Rolla.
On October 15th, the pilot attended church in Rolla. About 1208, the
pilot sent an e-mail to a friend stating that he had flown for the campaign
almost every day recently, that he had slept soundly at home the night
before, that he was over a cold, that he had run the day before after not
having run in over a week, that he was heading for Kansas City that afternoon,
and that he was returning to Jefferson City that night. The caretaker's
wife reported that the pilot called her from his office between 1000 and
1300. The pilot's sister reported the he departed Rolla about 1400 to pick
up their parents in St. Louis to fly them to Kansas City. According to
a campaign schedule, the pilot was scheduled to depart Creve Coeur at 1445
and arrive in Kansas City at 1615. The pilot was then scheduled to depart
Kansas City at 2045 and arrive in Jefferson City at 2135, where he was
expected to spend the night.
On October 16th, the pilot was scheduled to depart JEF at 1025 and
arrive at CPS at 1110. According to a security officer, the airplane actually
arrived at CPS about 1140. Both the pilot and passengers proceeded to scheduled
campaign events. That afternoon the pilot called his office and stated
that he was running behind schedule and that he would not be in the office
that day as he had previously planned. The pilot's sister reported that
the pilot visited the campaign office in the afternoon where he checked
the weather on a computer before leaving for the next campaign event about
1645. About 1815, the pilot asked one of the security officers to take
him back to the airport early so that he could prepare for the flight to
One of the accident airplane's passengers was a licensed
pilot. On August 25, 1997, he obtained a private pilot certificate with
an airplane single-engine land rating. On May 16, 1999, he obtained an
instrument airplane rating. He held a third-class medical certificate with
the limitation that he must wear lenses for distant vision and possess
glasses for near vision. He owned and flew a Beechcraft B33 Debonair. Members
of the security detail and other pilots who had traveled previously with
this passenger stated that although he was a licensed pilot, he normally
sat in the back of the airplane when there were other passengers on board
or when he needed to prepare for his next campaign event.
Air Traffic Controller
The St. Louis TRACON LW controller, age 54, was hired by the
FAA in 1968. Before being hired by the FAA, he was an air traffic controller
in the U.S. Air Force for 3 1/2 years. The controller's first assignment with
the FAA was at the Chicago O'Hare International Airport (ORD), Chicago, Illinois,
ATCT. He worked at the ORD ATCT from 1968 until 1970 or 1971.24
The controller then went to work at the Rockford, Illinois, ATCT until 1977.
He then worked at the ORD TRACON until 1980, at which time, he left to work
at the St. Louis TRACON. The controller held an airline transport pilot certificate
with an airplane multiengine land rating, a commercial glider certificate, and
a certified flight instructor glider certificate. He held type ratings for Falcon-20,
-50, and -900 series airplanes. He reported that his total flight time was approximately
6,800 hours. On the day of the accident, he was assigned to work from 1550 to
2355; however, he arrived at the facility about 1520. The controller had been
working at the LW position for about 45 minutes before handling the accident
The controller stated that after starting his shift, during his briefing, he
was informed that level 1 through level 3 weather existed in the area.25
He reported that he selected level 2 and level 3 on his computer display and
that it indicated that only level 2 weather existed in the area. The controller
reported that air traffic in his area of responsibility was "typical and routine."
The accident airplane, N8354N, a Cessna 335,26
serial number (S/N) 335-0063, was manufactured by the Cessna Aircraft Company
in 1980. Airplane records show that the pilot's business (a law firm) purchased
the airplane on November 27, 1997. The airplane had six previous owners. The
last entry in the Airframe Maintenance Record (logbook), dated September 28,
2000, shows that, at that time, the airplane had 2,299.4 total hours of operation.
The accident airplane was equipped with two Continental TSIO-520-EB8
engines (left engine S/N 271477-R and right engine S/N 271478-R), which
the Rebuilt Engine Logs indicate were zero-time, factory-rebuilt engines
that were installed on the airplane on August 27, 1997. The last entry
in the Rebuilt Engine Logs, also dated September 28, 2000, shows that,
at that time, the left engine had operated about 489.7 hours and the right
engine had operated about 475.5 hours since remanufacture. The accident
airplane was equipped with a 400B Nav-o-matic Autopilot system. Maintenance
records show that a WX-11 Stormscope system was installed in the airplane
on December 31, 1991, and that on November 19, 1998, it was repaired and
According to airplane maintenance records, the last transponder, altimeter,
static system check was performed on May 22, 2000, and the last annual
inspection was accomplished on August 21, 2000, at a total airframe time
of 2,257 hours.
Assuming that about 30 pounds of baggage were on board27
and that the airplane's main fuel tanks were full, the airplane did not exceed
its operational weight and balance limitations.
Cessna 335 Vacuum System
According to the Cessna 335 Maintenance Manual, the Cessna
335 vacuum system consists of a dry vacuum pump28
on each engine, two pressure relief valves, a manifold air filter,29
vacuum-operated instruments, and necessary plumbing. The pump outlets (pressure
sides) are routed to deicing equipment and primarily exhausted into the engine
nacelle. Vacuum lines are routed from the vacuum pumps through the nacelles
to the relief valves mounted in each wing root area. From the relief valves,
additional vacuum lines are routed through the inboard portion of the wing then
through the cabin to the vacuum manifold (located on the left side of the forward
cabin bulkhead), which has check valves to prevent reverse flow in the event
that either vacuum pump fails.
Hoses are routed from the vacuum manifold to the vacuum system instruments,
which include a heading indicator, an attitude indicator, and a vacuum gage
for the standard installation. The heading indicator is an air-driven, gyro-controlled
directional indicator designed to provide stable heading references. The attitude
indicator has a fixed-airplane silhouette and a pitch-and-roll display that
moves behind the airplane.30
The movement of the display is guided by the attitude of the actual airplane
in relation to a single air-driven gyroscope. The vacuum gage indicates the
amount of vacuum in the system and the operational status of each pump and has
red indicator buttons that will extend in the event of a pump failure.
The Cessna 335 Pilot's Information Manual states the following about
the vacuum system:
Each vacuum pump pulls a vacuum on the common manifold; exhausting
the air overboard. The maximum amount of vacuum pulled on the manifold
by each vacuum pump is controlled to a preset level by each pressure relief
valve. Should either of the pumps fail, a check valve is provided in each
end of the manifold to isolate the inoperative vacuum pump from the system...The
vacuum pressure being applied to the gyros is constantly presented on the
suction gage. This gage also provides failure indicators for the left and
right vacuum pumps. These indicators are small red buttons located in the
lower portion of the suction gage which are spring-loaded to the extended
(failed) position. When normal vacuum is applied in the manifold, the failure
buttons are pulled flush with the gage face. Should insufficient vacuum
occur on either side, the respective red button will extend. No corrective
action is required by the pilot, as the system will automatically isolate
the failed vacuum source, allowing normal operation on the remaining operative
According to Cessna delivery documents, the airplane was manufactured and delivered
to the first owner with complete left-side flight instrumentation.31
The vacuum-driven instruments installed on the left side of the instrument panel
consisted of a horizontal situation indicator that incorporated a heading indicator
(S/N W7153B) and an attitude indicator (S/N A4118K). The pitot-static instruments
installed on the left side of the instrument panel included an encoding altimeter,
an airspeed indicator, and a vertical speed indicator. The only electrically
driven navigation instrument on the left panel was the turn and bank indicator.
Cessna's delivery documents show that the only flight instrument installed on
the right side of the instrument panel at the time of manufacture was a pitot-static
altimeter. Before the pilot's business purchased the airplane, a second attitude
indicator and its respective vacuum system plumbing and fittings were installed
on the right side of the instrument panel.32
Accident Airplane Maintenance History
Sigma-Tek records show that the attitude indicator/flight
in the airplane at the time of the accident was an overhauled unit that it had
shipped to the most recent previous owner in 1996.34
According to airplane maintenance records, in December 1999, this instrument
was removed to clean the pitch slip rings and was then reinstalled in the airplane.
According to airplane maintenance records, the factory-new vacuum pumps were
installed on the left and right engines on March 28 and April 10, 1997, respectively.35
According to an airframe and powerplants mechanic who worked on the airplane,
the pilot contacted him on September 25, 2000, and stated that he thought his
left engine vacuum pump had failed. The mechanic stated that he discussed the
issue with the pilot and requested that he bring the airplane in for repairs.
The mechanic stated that the pilot brought the airplane in on September 27th
and that on September 28th, he removed and replaced the left engine vacuum pump.36
The mechanic reported that he performed a postmaintenance operational check
on both vacuum pumps and that the pumps operated normally.
The mechanic also reported that on September 29, 2000, he removed the right
side attitude indicator for overhaul37
and installed a placard on the instrument panel that stated, "CO-PILOTS HORIZON
GYRO REMOVED FOR O/H 9/29/00." The mechanic stated that the pilot had called
him on October 9th or 10th to check on the status of the right-side attitude
indicator (referred to here as the "co-pilot's horizon gyro"). According to
the mechanic, during this conversation, the pilot told him that since the removal
of the part, the vacuum gage had been reading lower than "what he was accustomed
to seeing." The mechanic stated that he explained to the pilot that "the removed
instrument is a restriction on the vacuum system and since it had been removed,
that was the most likely reason for the lower reading."
The mechanic stated that he reinstalled the right-side attitude indicator
on October 11th and checked its and the vacuum system's operation. He reported
that he was satisfied with the operation of both and that he removed the
placard for the attitude indicator. The mechanic reported that he informed
the pilot of the work that had been done and told him to monitor the vacuum
gage reading on his next flight to see if the lower than usual reading
he had reported earlier had been corrected by reinstalling the overhauled
attitude indicator. The mechanic stated that the pilot did not inform him
if the lower than usual vacuum gage reading had been corrected by the reinstallation
of the overhauled attitude indicator.
The mechanic also reported that on September 29, 2000, he removed the electric
pitch trim servo for overhaul and installed a placard on the instrument panel
that stated, "PITCH TRIM SERVO REMOVED FOR O/H 9/29/00." The mechanic reported
that the pilot questioned whether or not he could use the autopilot with the
servo removed. The mechanic stated that to answer the pilot he called an autopilot
repair station and was informed that "the system could be used but it would
put more load on the pitch servo itself."38
The mechanic reported that on October 11th, he reinstalled the electric pitch
trim servo and determined that it was still inoperative. He reported that he
contacted the overhaul facility and was instructed to return the unit for further
repairs. The mechanic reported that he again installed a placard on the instrument
panel stating, "PITCH TRIM SERVO REMOVED FOR REPAIR 10/11/00."
Cessna Service Bulletins
Service Bulletin MEB99-19
On October 4, 1999, the Cessna Aircraft Company issued
Service Bulletin (SB) MEB99-19 to do the following:
Add vacuum system check procedures for the Pilots Operating
Handbook, Owners Manual and Aircraft Flight Manual. These procedures are
being added to the existing Engine Start and Shutdown procedures to detect
for a possible defective vacuum system check valve or failed vacuum pump
prior to flight. Non-compliance with this Service Bulletin may allow a
defective vacuum system check valve or failed vacuum pump to go unnoticed
which could result in a pilot using instruments for flight that are not
providing proper information due to a malfunctioning and/or failed vacuum
system....the revisions shall be reviewed and incorporated as soon as possible,
but no later than the next 100 hours of operation or 4 months, whichever
In part, SB MEB99-19 describes the engine start and shutdown procedures
AFTER FIRST ENGINE IS STARTED:
With throttles set at 1000 RPM or higher:
1. Suction Gage - CHECK (reading in green arc)
2. Check that the red vacuum failure button in the
suction gage for that engine is flush with the gage face, prior to starting
the opposite engine.
a. If failure button remains extended (not flush with
gage face), a vacuum source failure has occurred.
b. If both failure buttons are flush with face of gage,
a vacuum system check valve is defective.
AFTER SECOND ENGINE IS STARTED:
With throttles set at 1000 RPM or higher:
1. Suction Gage - CHECK (reading in green arc)
2. Check that the red vacuum failure button in the
suction gage for the engine is flush with the gage face.
a. If failure button remains extended (not flush with
gage face), a vacuum source failure has occurred.
1. Shut down engine that was started first.
a. The red vacuum failure button for that engine in
the suction gage should extend.
b. If the failure button for the shutdown engine remains
flush with the face of the gage, a vacuum system check valve is defective.
2. With throttle set at 1000 RPM or lower on the running
engine, check that the red vacuum failure button in the suction gage for
that engine is flush with the gage face.
a. If the red vacuum failure button for the running
engine extended when the first engine was shutdown, a vacuum system check
valve and/or pump is defective.
Cessna Aircraft Company records indicate that SB MEB99-19
was mailed to the registered owner of N8354N on October 4, 1999. During
postaccident interviews, pilots who had flown with the accident pilot reported
that he used these procedures routinely. A portion of the procedures outlined
in the SB was found in the wreckage.
Service Bulletin MEB00-5
On October 2, 2000, the Cessna Aircraft Company issued
SB MEB00-5 to do the following:
Provide inspection and replacement intervals for the vacuum
system manifold check valve. Non-compliance with this Service Bulletin
may allow a defective vacuum manifold check valve to go unnoticed which
could result in: a pilot using instruments for flight that are not providing
proper information, and/or a de-ice system not properly inflating the boots
due to a malfunctioning and/or failed manifold check valve....shall be
accomplished within the next 100 hours of operation or 12 months, whichever
occurs first. Refer to Airborne Product Reference Memo No. 39 (or latest
revision) for possible subsequent inspections and valve replacement intervals.
Airborne Product Reference Memo No. 39 applied to N8354N
because it had a 1H5 Series vacuum check valve manifold installed in it.
The memo states the following:
The...components supplied by Airborne for use in aircraft pneumatic
systems are manufactured with elastomeric components that deteriorate with
age. As these components age, it is increasingly important to periodically
assure their proper operation, thus avoiding unscheduled system problems
and aircraft downtime...It is recommended that beginning five years from
date of manufacture, the serviceability of these components be verified
every twelve months in accordance with the procedure provided on the applicable
Airborne Technical Service Instruction. It is further recommended that
these pneumatic system check valve manifolds and check valves be replaced
ten years from date of manufacture...The 1H5 series check valve manifold
provides a means of coupling dual vacuum sources. More importantly, the
1H5 check manifold provides a means of isolating these dual vacuum sources
in the event that one of the sources is not in operation....The `flapper-type'
check valves are spring loaded in the closed position. As airflow is pulled
through the manifold, the check valves open allowing airflow through the
instruments. If airflow through a check valve is stopped (i.e., vacuum
source taken out of operation), the check valve will close in order to
allow the pneumatic system to properly function utilizing the lone operating
Cessna Aircraft Company records indicate that SB MEB00-5
was mailed to the registered owner of N8354N on October 2, 2000. It is
unknown if the pilot/owner of N8354N received this SB. The mechanics that
routinely performed maintenance on N8354N stated that they did not have
any discussions with the pilot regarding SB MEB00-5.
About 1602 on the day of the accident, the pilot contacted
the St. Louis AFSS for a weather briefing. According to a recording of the conversation,
the pilot requested the weather for the first leg of the planned flight (from
CPS to EIW) with a scheduled departure time of 1730 and a planned cruising altitude
of between 5,000 and 9,000 feet. He also requested weather for the second leg
of the proposed flight (from EIW to JEF) with a scheduled departure time of
2030. The briefer indicated that there was a low-pressure system and a stationary
front over southern Missouri. The briefer also indicated that there was an extensive
area of IFR conditions north of the front, that an AIRMET (airmen's meteorological
current for the area, and that a large band of rain showers extended over the
area. The briefing included the current conditions for airports along the route
of flight, the forecast for southern Missouri, winds aloft data, and available
pilot reports. The briefer reported that the cloud tops were expected to be
at approximately 25,000 feet. After receiving this information, the pilot stated
that he would call back for an update and to file his flight plans.
About 1811, the pilot contacted the St. Louis AFSS for an updated weather
briefing and to file his IFR flight plans. The pilot told the briefer that
the first leg of the flight would take 1 hour and that there were 4.5 hours
of fuel and three people on board. The briefer informed the pilot that
the current weather conditions at CPS were wind 010° at 9 knots; visibility
2 miles with rain and mist; broken cloud ceiling at 600 and 1,000 feet,
2,500 feet overcast; temperature 15° Celsius (C); and dew point 14°
C. The briefer reported that an area of low pressure was moving into New
Madrid along with a stationary front. The briefer further reported that
there was a chance of moderate rime or mixed icing above 12,500 feet and
that there were several thunderstorms along and around the pilot's intended
route of flight. The briefer then informed the pilot that the St. Louis
winds aloft for 3,000 feet were 050° at 10 knots and that the winds
at 6,000 feet were light and variable. The briefer informed the pilot that
near New Madrid, the winds aloft were light and variable at 3,000 feet
and 200° at 12 knots for 6,000 feet.
The briefer asked the pilot if he wanted to file an altitude for the
flight plan, and the pilot responded, "7,000 feet." The pilot then changed
his previous estimated departure time from 1830 to 1845 and stated that
he wanted to fly directly to EIW. The pilot then filed a flight plan for
the flight from EIW to JEF. The briefer then informed the pilot that he
would be flying too low for ice but that it was "naturally gonna be a little
bumpy in that semi cumulus type form stuff ah so ah you know maybe bases
and tops if you happen to find em." The weather briefing ended about 1827.
A National Weather Service National Center for Environmental Prediction regional
surface analysis chart showed that the main weather features at the surface
within the hour of the accident included a low-pressure system over southern
Missouri, a cold front to the southwest of the low-pressure system, a stationary
front to the east of the low-pressure system, and a trough40
of low pressure to the south of the low pressure system, extending southward
into Arkansas. A second weather system, identified as a trough of low pressure,
was approaching the area to the northwest. A high-pressure system was identified
over Wisconsin, with a ridge of high-pressure extending over Iowa, northern
Missouri, and eastern Kansas.
The CPS (located 28 miles northeast of the accident site) special surface
weather observation for 1920 was as follows:
wind from 020 degrees at 12 knots gusting to 16 knots, visibility
2 miles in light rain and mist, ceiling broken at 600 feet, broken at 1,200
feet, and overcast at 3,200 feet, temperature 15 degrees C (59 degrees
[Fahrenheit] F), dew point 14 degrees C (57 degrees F), altimeter 30.06
inches [mercury] Hg. Remarks; automated observation, precipitation since
1853 was reported at 0.04 of an inch.
The CPS special surface weather observation for 1953
was as follows:
wind from 030 degrees at 11 knots, visibility
2 1/2 miles in moderate rain and mist, ceiling broken at 800 feet, overcast
at 1,200 feet, temperature 15 degrees C (59 degrees F), dew point 14 degrees
C (57 degrees F), altimeter 30.06 inches Hg. Remarks; automated observation...precipitation
since 1853 was reported at 0.14 of an inch.
The Spirit of St. Louis Airport (SUS), Chesterfield,
Missouri (located 23 miles north-northwest of the accident site), special
surface weather observation for 1854 was as follows:
wind from 030 degrees at 7 knots, tower visibility
3/4 mile in moderate rain and mist, ceiling broken at 800 feet, temperature
15 degrees C (59 degrees F), dew point 14 degrees C (57 degrees F), altimeter
30.05 inches Hg. Remarks; automated observation, surface visibility 3 miles,
ceiling 50 feet variable to 1,300 feet...precipitation since last hour
0.08 inches, 6-hour precipitation 0.79 of an inch.
The SUS special surface weather observation for 1946
was as follows:
wind from 040 degrees at 11 knots, tower visibility
2 mile in light rain and mist, ceiling broken at 800 feet, overcast at
1,400 feet, temperature and dew point 14 degrees C (57 degrees F), altimeter
30.05 inches Hg. Remarks; automated observation, surface visibility 5 miles,
ceiling 600 feet variable to 1,100 feet, precipitation since last hourly
observation 0.08 inches.
Weather stations surrounding the destination airport
(EIW) and the airport to which the pilot asked to be diverted (JEF) were
reporting visual meteorological conditions around the time of the accident.
The closest upper air data site was in Springfield, Missouri,
located 136 miles southwest of the accident site. The sounding41
this site indicated a low-level inversion about 3,500 feet to 5,000 feet, which
was saturated up to 8,700 feet with drier air above. The sounding showed a northeast
wind flow of 10 to 30 knots from the surface to below the inversion, with winds
backing to the north and northwest above the inversion at speeds of 20 to 25
knots. The sounding indicated that the freezing level was 12,654 feet.
WRECKAGE AND IMPACT INFORMATION
The accident site was located in a heavily wooded area
near Hillsboro, Missouri. The initial terrain impact occurred along the
slope of a heavily wooded hillside. The impact resulted in a crater that
measured approximately 10 feet long by 5 feet wide and was approximately
4 feet deep at the center.
Sixteen trees were struck, including a stand of trees that were completely
severed along the airplane's path. The remaining trunk of each severed
tree was splintered toward the southwest, about 240°. Several trees
were contacted before the airplane severed the stand of trees, and the
first identifiable tree strike occurred about 144 feet east-northeast of
the impact crater. The distance from the first tree strike to the stand
of trees was about 64 feet, and the distance from the stand of trees to
the impact crater was about 80 feet. The distance between the impact crater
and the furthest piece of wreckage was about 900 feet. An aerial search
of the accident site did not reveal any aircraft parts in the area of the
flightpath leading to the initial tree impact or in the area beyond the
furthest piece of recovered wreckage.
The wing tips, nose, tail, and some or all of the flight control surfaces
were found at the wreckage site. The first piece of fuselage wreckage (nose
gear door) was located near the first trees in the stand of trees. Pieces
of the right wing tip fuel tank were located 120 feet east-northeast of
the impact crater in the area of the initial tree strike; pieces of the
left wing tip fuel tank were located 45 feet southwest of (past) the impact
crater. Portions of the right wing structure were located in line with
the flightpath, slightly to the right of the impact crater. Most of the
left wing structure was found further southwest of the crater than the
right wing structure. A large portion of the left engine was located approximately
300 feet southwest of the impact crater, and it was suspended in a tree
about 60 feet from the ground. The right engine crankshaft was located
approximately 900 feet southwest of the crater, in the area that marked
the southwestern boundary of the debris field.
The wreckage field was divided into 30 zones of various sizes, depending
on the aircraft wreckage density. The wreckage was surveyed, documented,
and then moved to the Missouri National Guard Armory in Festus, Missouri,
for further examination. Approximately 70 to 80 percent of the airplane
was recovered. With the exception of the horizontal stabilizers and the
aft upper fuselage skin, the airframe structure separated into small (between
6 inches by 6 inches and 12 inches by 12 inches) and medium (between 12
inches by 12 inches and 24 inches by 24 inches) size pieces of debris.
A laser-based measuring device was used to document
the accident site. Data from the laser survey were used to create a three-dimensional
model of the airplane's flightpath through the trees. The model and the
inspection of the accident site revealed that the airplane was in a 16°
to 18° right-wing-down attitude during its entry into the trees. (See
No evidence of an in-flight fire or in-flight structural failure was
noted. All of the examined fracture surfaces exhibited evidence of overload
Figure 1. Diagram showing
the side-view of the broken tree tops, construction lines that connect
the trees along the direction of travel, and attitude lines with respect
to a horizontal plane. Each vertical line represents the base and top of
a remaining tree.
MEDICAL AND PATHOLOGICAL INFORMATION
Because of the condition of the pilot's remains, no
autopsy was performed. Toxicological samples (muscle tissue) from the pilot
were sent to the FAA's Toxicology and Accident Research Laboratory, Oklahoma
City, Oklahoma, for examination. The pilot's toxicological results were
negative for alcohol and drugs.
The accident was not survivable.
A person who lives near the accident site reported the accident
to the Jefferson County 911 Dispatch shortly after it occurred.42
Members of the Goldman Fire District, the Jefferson County Sheriff's Department,
and the Missouri State Highway Patrol responded to the site of the accident.
After which time, a search of the local area was initiated. Because of the condition
of the wreckage, the poor weather conditions, the rough terrain, and dark lighting,
emergency response efforts were suspended until the next morning.
TESTS AND RESEARCH
Vacuum System and Cockpit Instrument Component Examination
Components and pieces of wreckage identified as being
part of the accident airplane's vacuum system and cockpit instrumentation
were inspected at the Safety Board's Materials Laboratory in Washington,
Vacuum Gage System Failure Indicator Buttons
Both the left and right vacuum gage system failure
indicator buttons (a red plastic spherical cap inside a 1.25-inch-long
brass tube) were located. The indicator buttons did not have any markings
to indicate with which vacuum pump they were associated. The tip of the
end of the red cap on one of the indicators was slightly recessed (.029
inch) from the end of the brass tube, and this position is at almost the
fully retracted position. The midportion of the brass tube was slightly
flattened, and one side of the tube was bent over the end of the cap. The
red cap of the second indicator tube was protruding 0.082 inch beyond the
edge of the brass, which is in the midportion of its full extension range.
The central portion of the second indicator tube and cap was flattened
at almost the same position as the first tube.
Vacuum Check Valve Manifold
Three pieces of the vacuum check valve manifold were
found. Two of the pieces were the end caps of the manifold, both of which
had B-nuts attached to them. One of the B-nuts was found with a flattened
aluminum tube attached. The third piece was the center portion of the manifold.
The portion of the data plate that remained on the center section contained
no useful markings. Both end caps are normally attached to the center section
with rivets; pieces of the rivets were found in the end caps. The internal
"flapper-type" check valves and springs were not located.
Left Engine Vacuum Pump
Three pieces of the left engine vacuum pump were found:
the mounting flange/pump base, which remained attached to the engine accessory
case; the pump housing; and the pump housing back flange. (See figure 2
for a diagram of a Cessna 335 vacuum pump.) Fragments of rotor pieces,
between 1 and 2 inches long, were recovered. The pieces contained short
scratches and gouges in the direction of rotor rotation and other scuff
marks and scratches in random directions.
No intact rotor vanes were recovered.
The pump mounting was removed from a fragment of the engine case. The drive
shaft end coupling did not rotate when light manual force was applied. After
it was disassembled, it was determined that the coupling did not rotate because
of a fractured braze43
joint between the shaft assembly and the shaft disc. Examination of the braze
joint revealed no evidence of rotational scoring. The drive shaft/coupling assembly
was further disassembled. The drive coupling, flex coupling (shear coupling),
and driven coupling were intact. Four of the six pin shaft drive pins were bent
toward one side (not in the direction of rotation) at varying angles. The pump
housing was slightly flattened, and no internal rotational score marks were
visible around the circumference. The base of the pump housing contained three
marks, which encompassed one half of the circumference. All three marks showed
metal dislocation toward the same side of the housing. Once the coupling was
removed, the carbon bearing under the base of the pump was found broken on the
same side. The outside of the pump housing contained numerous impact marks.
Wood and dirt were found embedded within the cooling fins.
Right Engine Vacuum Pump
The right engine vacuum pump was found in two main
pieces: the mounting flange and the pump. The drive coupling was found
loose from the other components, and two of its pins were missing. The
flex coupling (shear coupling) was not recovered. The driven coupling remained
attached to the pump assembly and was found intact with pieces of wood
embedded between the coupling driven end and the mounting flange. The pump
was opened and an even distribution of wear was noted. The interior surface
of the drive cap showed no evidence of complete circumferential or lateral
marks. Short scratches and gouges were found in the direction of rotation.
The rotor was found broken into five major pieces with smaller fragments.
The periphery of the rotor was not damaged. The six vanes were found intact
with slight chips missing from the outboard corner at the driven end of
two of the vanes. The cooling fins sustained impact damage on the side
of the pump opposite the OUT port.
Left-Side Attitude Indicator
The following components from the left-side attitude
indicator/flight director were identified in the wreckage: the gyroscopic
rotor, the rotor case cap, two pieces of the rotor case, the instrument
face display (including the roll ring), and pieces of the instrument case
frame. (See figure 3 for a photograph of an exemplar attitude indicator
and its components.) The model of the attitude indicator installed on the
accident airplane contained an arm that provides mechanical linkage from
the rotor housing to the pilot's display. This arm was located on a fragment
of the instrument case frame.
Figure 3. Photograph
of an exemplar attitude indicator and its components.
Examination of the interior diameter of the rotor case
revealed faint, unevenly spaced diagonal scratches. The measured angle
between the scratches and the direction of rotation was between 4.0°
and 5.2°. The scratches were consistent with the direction of rotation
of the rotor and with the direction the rotor was moving when it exited
the case. No other circumferential score marks were found on the inner
surface of the case that paralleled the direction of rotation.
Diagonal marks were found on the end of the rotor. Nearly all of the
other scratches on the cap were oriented across the direction of rotation
at various angles. The center fastener hole on the cap was ripped, with
more than half of the periphery remaining. The width of the tears matched
the width of the gouges in the rotor. The exterior of the cap contained
scratches that resembled the width and approximate locations of the motion-limiting
stop wires mounted on an exemplar instrument.
Damage on the facial roll ring resembled the shape of the triangular
airplane support housing and the roll index that had been fixed to the
instrument case. The relative positions of the damage resembling the triangular
support and roll index were on the top and bottom of the ring, respectively,
when it was placed at an inverted display of attitude. The face of the
instrument was placed behind that of an exemplar instrument and, using
the damage on the roll ring for alignment, the marks were within 2°
of a wings-level inverted attitude. (See figure 4.)
Figure 4. Photograph
showing the face of the accident airplane's primary attitude indicator
behind that of an exemplar instrument.
Right-Side Attitude Indicator
The following components from the right-side attitude
indicator were found: the gyroscopic rotor, the rotor case cap, two pieces
of the rotor case, the instrument face display, and portions of the instrument
case frame. The instrument display was found separated into three pieces:
the football-shaped facial card, the background horizon, and the roll ring.
Two pieces of the rotor case contained light diagonal surface scratches
that measured between 2.0° and 5.1° from the direction of rotation.
The scratches were consistent with the direction of rotation of the rotor
and with the direction the rotor was moving when it exited the case. The
lower left corner of the surface contained heavier scuff marks, and the
lower edges of the scuff marks were at an angle of about 6°, right
end up, from the direction of rotation. A scratch located over the scuffed
area was perpendicular to the direction of rotation.
The end of the gyroscopic rotor and the rotor case cap contained light
diagonal marks. No complete circumferential marks were found around the
surface of the rotor. The interior of the rotor case cap did not contain
an imprint of the rotor like the one observed on the cap from the left-side
attitude indicator. The material from around the central fastener hole
was found displaced to one side, and the cap had an impression on one edge.
Marks on the facial card were matched up with the airplane silhouette
in both pitch and roll. Depending on the placement of the airplane, the
marks ranged between a 8.4° to 11.8° right-wing-down position at
between a -11° to -13° (nose-down) pitch. A paper tracing of the
airplane housing cover was moved along the ring. When lined up, one set
of marks indicated a 5° right-wing-down position. A second set of pitch-and-roll
markings were found on other fragments. The other set of marks were offset
to the right of the path that the pitch display would normally travel,
and alignment in this plane could only have occurred if the parts had been
released from the normal assembly.
After the accident, fuel samples were taken from the truck
that refueled the accident airplane before its departure from CPS and from the
airplane's fuel supply tank. Fuel testing conducted by the Missouri State Highway
Patrol Crime Laboratory and Phillips 66 Company revealed no problems with the
An aircraft performance study was conducted by the
Safety Board using FAA airport surveillance radar data obtained from the
St. Louis Lambert International Airport, St. Louis, Missouri, and from
the Scott Air Force Base, Belleville, Illinois. Air route surveillance
radar data from the FAA's St. Louis Air Route Traffic Control Center and
weather data, including winds aloft information, were also used.
At 1920:07, when the pilot first declared that he was having a problem
with the airplane's primary attitude indicator, the airplane was climbing
through an altitude of 3,000 feet. (See figure 5 for a plot of the ground
track for the accident airplane's last 12 minutes of flight.) The calculated
indicated airspeed of the airplane during the climb was between 140 and
150 knots. The airplane leveled off slightly and then continued to climb
at a slower climb rate as it turned left to a heading of approximately
150° by 1921:10. The airplane remained on this heading for about 2
At 1923:55, the St. Louis LW controller instructed the pilot to turn
right to a heading of 270°, and, at 1924:04, the controller instructed
the pilot to climb to and maintain 7,000 feet. The airplane began the climb
and turned right maintaining about a 3.5°-per-second heading change.
Calculations show that this turn required an airplane bank angle of 30°
and that the airspeed increased to greater than 150 knots. The turn was
completed at an altitude of about 5,000 feet, and the airplane continued
the climb at 120 knots. By 1928:00, the airplane reached 7,000 feet at
a heading of about 300° as the airspeed accelerated to 150 knots. At
1928:30, the airplane began a left turn to the southeast to a heading of
about 140° at an altitude that varied between 7,100 and 7,400 feet.
The calculated bank angle in the turn was about 25°.
Figure 5. Ground
track of the accident airplane's last 12 minutes of flight.
Following the LW controller's instruction to make a
slow right turn at 1930:37, the airplane began turning to the right. Calculations
reveal that, during the turn, the airplane descended to about 6,800 feet
while maintaining an airspeed of about 150 knots. The airplane then descended
to about 6,500 feet and then climbed at over 3,000 feet per minute (fpm)
for the next several seconds. The airspeed was calculated to be about 120
knots during the climb, with a bank angle of approximately 25°. At
1931:31, the airplane reached its maximum altitude of 7,700 feet.
After reaching 7,700 feet with a calculated pitch angle of 15.5°
nose up with a 25° right bank, the airplane began a steep descent.
The last radar return occurred at 1931:57, when the airplane was at 2,700
feet. At this point, the calculated descent rate was about 26,000 fpm,
the calculated airspeed was greater than 300 knots, and the airplane was
at approximately a 60° nose-down attitude.
One purpose for instrument training and maintaining
instrument proficiency is to prevent a pilot from being misled by several
types of hazardous illusions that are peculiar to flight. Under IFR conditions,
an aircraft's attitude can only be determined accurately by observing and
interpreting the flight instruments and rejecting the bodily sensations
associated with the aircraft's movement, which can be exacerbated by head
movements. Practice and experience in instrument flying are necessary to
help pilots ignore or overcome false sensations.
The FAA Instrument Flying Handbook (FAA-H-8083-15) describes one of
the major illusions leading to spatial disorientation as follows:
The pilot has been in a turn long enough for the fluid in the
ear canal to move at the same speed as the canal. A movement of the head
in a different plane, such as looking at something in a different part
of the cockpit, may set the fluid moving, thereby creating the strong illusion
of turning or accelerating on an entirely different axis...This action
causes the pilot to think the aircraft is doing a maneuver that it is not.
The disoriented pilot may maneuver the aircraft into a dangerous attitude
in an attempt to correct the aircraft's perceived attitude.
For this reason, it is important that pilots develop an instrument
cross-check or scan that involves minimal head movement.
The Aeronautical Information Manual
the coriolis illusion as the "most overwhelming of all illusions in flight"
and states that it "may be prevented by not making sudden, extreme head movements,
particularly while making prolonged constant rate turns under IFR conditions."45
Partial Panel and Instrument Meteorological Conditions Flight Training
The Instrument Airplane Rating Practical Test Standard
for 2000 requires that the instrument rating applicant do the following:
exhibit the knowledge of recognizing whether an attitude indicator and/or
heading indicator is inaccurate or inoperative,
advise anytime the aircraft is unable to comply with a clearance, and
demonstrate a nonprecision instrument approach without gyro attitude and
Title 14 CFR Section 61.57, "Recent Flight Experience:
Pilot in Command [PIC]," Paragraph (c), "Instrument Experience," states
that to act as PIC under IFR, or in weather conditions less than the minimums
prescribed for VFR, the person must have accomplished the following, within
the preceding 6 months:
performed and logged under actual or simulated instrument conditions,
either in flight in the appropriate category of aircraft for the instrument
privileges sought or in a flight simulator or flight training device that
is representative of the aircraft category for the instrument privileges
at least six instrument approaches;
holding procedures; and
intercepting and tracking courses through the use
of navigation systems.
FAA Procedures and Guidance Regarding ATC Handling of Aircraft in Emergency
FAA Order 7110.65, "Air Traffic Control," Chapter 10,
"Emergencies," provides controllers with the following guidance on recognizing
and handling emergency situations:
10-1-1 Emergency Determinations
An emergency can be either a Distress
or an Urgency
condition as defined in the "Pilot/Controller Glossary."...If...you are in
doubt that a situation constitutes an emergency or potential emergency, handle
it as though it were an emergency....Because of the infinite variety of possible
emergency situations, specific procedures cannot be prescribed. However, when
you believe an emergency exists or is imminent, select and pursue a course
of action which appears to be most appropriate under the circumstances and
which most nearly conforms to the instructions in this manual.
10-1-2 Obtaining Information
Obtain enough information to handle the emergency intelligently.
Base your decision as to what type of assistance is needed on information
and requests received from the pilot because he/she is authorized by 14
[CFR] Part 91 to determine a course of action.
10-1-3 Providing Assistance
Provide maximum assistance to aircraft in distress.
Enlist the services of available radar facilities...as well as their emergency
services and facilities, when the pilot requests or when you deem necessary.
Further, FAA Order 7110.65 contains procedures that enable
ATC to render assistance by minimizing pilot workload during inadvertent operation
in IMC. Specifically, Paragraph 10-2-9, "Radar Assistance Techniques,"49
states the following:
Use the following techniques to the extent possible
when you provide radar assistance to a pilot not qualified to operate in
a. Avoid radio frequency changes except when necessary
to provide a clear communications channel.
b. Make turns while the aircraft is in VFR conditions
so it will be in a position to fly a straight course while in IFR conditions.
c. Have pilot lower gear and slow aircraft to
approach speed while in VFR conditions.
d. Avoid requiring a climb or descent while in
a turn if in IFR conditions.
e. Avoid abrupt maneuvers.
f. Vector aircraft to VFR conditions.
FAA Order 7110.65 also specifies other procedures and
techniques for assisting pilots in difficulty, including "no-gyro" vector
procedures, which provide a defined method for controllers to issue heading
changes to aircraft that have a defective gyroscopic instrument, such as
an attitude indicator. The procedure entails the pilot making turns at
no greater than the standard rate when instructed to do so by the controller.
Further, instead of providing the pilot with headings to be flown, the
controller should observe the radar track and issue control instructions
"turn right/left" or "stop turn" as appropriate.
The pilot received current and adequate weather information
before conducting the accident flight.
Instrument meteorological conditions (IMC) prevailed
at the time of the accident, which occurred at night in dark lighting conditions,
turbulence, and rain.
The pilot was properly certificated and qualified to operate a multiengine
airplane in IMC in accordance with applicable Federal regulations. However,
because the pilot made no pilot logbook entries during the 6 months preceding
the accident, it could not be determined if he met the instrument currency
requirements to act as pilot-in-command in IMC.
The airplane was properly certificated and equipped in accordance with
Federal regulations and approved procedures.
The pilot remained in contact with air traffic control (ATC) facilities
and a transponder code was transmitted to ground-based radar sites throughout
the flight, indicating that the airplane did not experience an in-flight
Examination of the airframe and engines did not reveal any preexisting
mechanical failures or malfunctions in the structure or powerplants.
There was no evidence that medical issues or pilot
fatigue contributed to the accident.
Radar data, ATC transmissions, and other evidence indicate
that the pilot lost control of the airplane at 7,700 feet as he was making
a climbing right turn.
Examination and distribution of the wreckage revealed
that the airplane remained intact and was in an upright attitude when it
contacted trees at a velocity of over 300 knots and then impacted rocky
Role of Malfunctioning Attitude Indicator
The pilot indicated to ATC several times that he was having
problems with the airplane's primary attitude indicator. He also told ATC that
he was trying to use the right-side attitude indicator, which indicates that
the airplane did not experience a total vacuum system failure. Examination of
the wreckage revealed rotational marks in the left and right engine vacuum pumps,
which indicates that they were most likely functioning at the time of impact.
Further, one of the vacuum gage system failure indicator buttons exhibited evidence
of having been in almost the fully retracted position (the other indicator button
was found in the partially retracted position), which indicates that adequate
vacuum existed for the airplane's instruments to operate.50
On the basis of the examination of the left-side (primary) attitude
indicator, it was determined that the rotor was most likely spinning, but
not at a high enough rpm to keep the display erect (the wreckage fragments
of the left-side attitude indicator clearly aligned in an inverted attitude),
indicating that this attitude indicator was not displaying properly at
the time of impact. Although the pilot reported that his primary attitude
indicator had failed and examination of the attitude indicator supported
that such a failure had occurred, the investigation could not determine
the cause of the failure in that instrument.
On the basis of the examination of the right-side attitude indicator,
it was determined that the rotor was spinning, the display was erect when
the airplane made initial contact with the trees, and the attitude it displayed
was consistent with the airplane's attitude when it struck the trees (as
determined by an inspection of the accident site and a three-dimensional
model of the airplane's flightpath through the trees), indicating that
this attitude indicator was functioning properly until the time of impact.
After first reporting that the primary attitude indicator was malfunctioning,
the pilot continued flight for about 11 minutes, including two controlled
heading changes, indicating that the pilot had functioning cockpit instruments
and that he could control the airplane. Further, in the event that an instrument
malfunction occurs, instrument flight rules (IFR)-qualified pilots are
trained to use other relevant instruments, which evidence indicates were
operating on the accident airplane (the right-side attitude indicator).
Therefore, the loss of the primary attitude indicator alone does not explain
why the pilot lost control of the airplane and crashed.
However, the right-side attitude indicator was not large and would
have been several feet to the right of the pilot. Therefore, using the
right-side attitude indicator would have resulted in the pilot making frequent,
rapid head movements to cross-check that instrument with the other instruments.
The pilot's head movements most likely caused him to experience spatial
disorientation. Further, the rain conditions in which the pilot was maneuvering
would have increased the noise level in the cockpit, and the presence of
turbulence would have made it more difficult to control the airplane with
failed instrumentation, both of which would likely have exacerbated the
pilot's spatial disorientation.
Air Traffic Controller Actions
The procedures in FAA Order 7110.65, "Air Traffic Control,"
Paragraph 10-2-9, "Radar Assistance Techniques," do not directly apply to situations
in which IFR aircraft experience instrument failures. However, a reasonable
and prudent controller would be expected to use such procedures in these situations.51
Pilots who conduct flights under IFR compensate for the absence of visual cues
by using aircraft attitude information obtained from instruments such as a heading
indicator, an attitude indicator, and a turn coordinator. If these instruments
or their power sources fail, it can be difficult for the pilot to maintain control
of the aircraft. Services provided by a radar ATC facility can replace some
of the information provided by gyroscopic instruments, such as course and turn
A review of the ATC recording revealed that when the pilot first stated
that he was having some problems with the airplane's primary attitude indicator
at 1920:07, a great deal of background noise was also recorded, which made
the pilot's comment unclear and likely prevented the controller from hearing
this portion of the pilot's transmission. During that transmission, the
pilot also asked to be assigned a higher altitude, which could be heard
clearly on the ATC recording. At 1920:16, the controller responded to this
request, stating, "I'll have a higher climb in about two miles."
At 1920:11, the pilot again indicated that he was having a problem
with the airplane's primary attitude indicator. At 1921:20, the controller
advised the pilot to try and fly the airplane level on any heading and
told him that he would try to get him to as high an altitude as possible.
The controller's instructions were prudent for handling an airplane in
At 1922:50, the pilot made his first request to be diverted to Jefferson City
Memorial Airport (JEF). In response, the controller issued the pilot a heading
would not have directed the airplane toward JEF, rather it would have directed
the airplane toward EIW. This action and the controller's postaccident statement
that he was surprised when the pilot asked to be diverted the second time (at
1923:46) because he thought the pilot wanted assistance to continue to EIW indicates
that the controller did not understand or hear the pilot's first request. At
1923:39, the controller issued a climb clearance to the pilot, stating, "climb
and maintain seven thousand at pilot discretion." The controller's use of the
phrase, "at pilot discretion," allowed the pilot to initiate a climb at any
point or rate that he wished to help prevent him from having to make a climbing
turn, which indicates that the controller recognized the seriousness of the
situation and used good operating practices for assisting a pilot flying an
airplane with instrument difficulty. Radar data indicate that the pilot elected
to initiate the climb immediately after receiving the clearance from the controller.
After the pilot's second request (at 1923:46) that he wanted to divert to JEF,
the controller responded, stating, "in that case turn right heading two seven
the pilot asked the controller to confirm the assigned altitude, and, the controller
responded, "climb and maintain seven thousand." Radar data indicate that the
airplane continued to climb after this transmission and started the turn that
the pilot had requested.
After this exchange, the controller directed his attention to another
airplane for about 1 minute. At 1925:12, the controller informed the pilot
of N8354N that "you're basically going in a good direction." ATC radar
indicate that for about 3 1/2 minutes after this transmission, the airplane
flew on a course and at an altitude consistent with the controller's instructions.
At 1928:36, the controller asked the pilot, "you have
any more attitude problems," and the pilot responded, "the attitude problems
are continuing." ATC radar show that the airplane entered a left turn to
the southeast as the pilot was making this statement. At 1929:31, the pilot
requested "vectors...[to] get down VFR." During postaccident interviews,
the controller stated that he became concerned when the pilot requested
vectors to VFR conditions and that, in his opinion, the pilot did not convey
a sense of urgency until he made this request. Further, the controller
stated that after the pilot made this request, he observed N8354N's target
on the radar turn left back into "weather," at which point, he became very
At 1929:41, the controller instructed the pilot of
N8354N to "just go straight ahead...doesn't make any difference what direction
that is just go straight ahead." Although the controller did not advise
the pilot of the southeasterly turn or attempt to determine why the pilot
was deviating from his intended destination (JEF), he did start applying
no-gyro vector procedures, which was an appropriate and prudent response.
ATC radar show that after the controller made this instruction, the airplane
appeared to be stabilized on the southeasterly course at a level altitude
for about 1 minute. While on this course, the controller continued to issue
no-gyro vector instructions, stating, "make a slow right turn as as much
as you can the standard rate." ATC radar data indicate that the airplane
started to make a slow right turn after this instruction. At 1931:22, the
controller continued issuing no-gyro vector instructions, stating, "just
stop your turn and go straight ahead you're doing fine." ATC radar show
that, shortly thereafter, the airplane began its rapid descent.
In summary, although the controller continued to issue
specific compass heading instructions to the pilot after he determined
that the airplane's primary attitude indicator was malfunctioning at 1920:11,
ATC radar data show that the pilot made the turns as instructed and flew
straight and level for several minutes after making the turns. Therefore,
the Safety Board determined that these turn instructions did not cause
or contribute to the pilot's spatial disorientation. Further, although
the controller did not give the pilot the information about his southeasterly
heading or try to determine why the pilot made the turn and given that
the pilot responded to the controller's instructions, the Board determined
that this omission did not cause or exacerbate the pilot's spatial disorientation.
Therefore, the controller's actions were not considered to be a contributing
The National Transportation Safety Board determines
that the probable cause of this accident was the pilot's failure to control
the airplane while maneuvering because of spatial disorientation. Contributing
to the accident were the failure of the airplane's primary attitude indicator
and the adverse weather conditions, including turbulence.