CHI94FA128
CHI94FA128

HISTORY OF FLIGHT

On April 4, 1994, at 1313 hours mountain daylight time, a Piper PA-23-250 Aztec, N5399Y, owned by James W. Furman of Alliance, Nebraska, impacted level terrain 10.5 miles southwest of Alliance, Nebraska. The airplane was destroyed. The instrument rated private pilot and the non-pilot passenger received fatal injuries. Instrument meteorological conditions (snow and fog) prevailed at the time of the accident, and an IFR flight plan was filed. The flight was conducted under 14 CFR Part 91, and originated from Mitchell, South Dakota, at 1130 hours.

The airplane was refueled with 66.7 gallons of 100LL aviation gasoline at Alliance (AIA) prior to the original departure on April 4, 1994. The airplane was reported as "topped off." It was refueled with 50.6 gallons of 100LL aviation gasoline at Mitchell, South Dakota, prior to the return trip, and again was reported as "topped off." The fuel capacity of the airplane was 144 gallons.

The pilot reported executing a missed approach at Alliance Municipal Airport and was cleared to his alternate, Scottsbluff Municipal Airport, Scottsbluff, Nebraska when the Denver Air Route Traffic Control Center (ARTCC) reported radar contact was lost.

ARTCC radar data was plotted to reproduce a ground track. This track was produced both on a data chart, and also overlayed onto a low altitude sectional chart depicting ground path as compared to the Victor-100 Airway. This ground path was consistently south of Victor-100 while inbound to the AIA VOR, and circuitous after passing AIA VOR. The ground track did not follow the published VOR-30 approach course. The ground track after the pilot stated he did not break out did not follow the published missed approach procedure.

PERSONAL INFORMATION

The 33 year old pilot held private pilot certificate number 506749759, with privileges for single and multiengine flight. He had a total time of 191 hours at the time of the accident, with 97 hours in the accident airplane. He held a third class medical certificate without limitations. His most recent flight review took place on April 1, 1994, 3 days before the accident, and was performed in the accident airplane. This was a flight check for his instrument-airplane rating, and was the second attempt to complete this checkride. The failure had occurred on March 24, 1994. According to the Designated Pilot Examiner who administered both flight checks, the failure was due to the applicant's inability to satisfactorily perform holding maneuver entries. The examiner stated during an interview on April 7, 1994, that the pilot tended to become overloaded by radio communications when combined with aircraft control and navigation duties, although his ability to perform the required maneuvers was satisfactory on April 1, 1994.

A co-owner of the airplane stated that the pilot was both cautious, and not comfortable flying without another pilot on board. The same owner reported that the pilot did not use the autopilot.

Prior to the accident flight, the pilot had accrued 34.5 hours of simulated instrument flight, and 2.5 hours of actual instrument flight.

AIRCRAFT INFORMATION

The airplane was a Piper PA-23 Aztec, serial number 27-2474, and had accrued 2835 hours at the time of the accident. The last inspection performed was an annual inspection performed on February 22, 1994, 26 flight hours prior to the accident. Both engines had total times of 2835 hours. The left engine had accrued 420 hours since overhaul. The right engine had accrued 1900 hours since overhaul.

The airplane was equipped with hydraulic flaps which were extended and retracted by a single actuating cylinder located on the right flap.

The airplane had an Altimatic II Autopilot (Model AK090).

The autopilot had been diagnosed on June 4, 1992 with 2 discrepancies:

(1) "Autopilot causes aircraft to climb when on." (2) "Altitude hold inop."

The corrective action listed was:

"No bench check or repair capability"

No other maintenance actions were located which concerned the autopilot system.

One of the owners of the airplane indicated that in June 1993, the autopilot was tested by himself. He stated that it would work, then climb. The rotary on/off knobs would engage between the 2 and 4 o'clock positions.

The Altimatic II Operating Instructions state "to disengage the Altimatic, rotate the Pitch and Roll knobs on the Console counterclockwise to the "OFF" position."

SECTION IV - EMERGENCY PROCEDURES of the Pilot Operating Handbook states:

1. In event of a malfunction, turn both pitch and roll servo knobs completely counterclockwise, disengaging both axes of altimatic from the control system.

2. Altimatic may be overpowered by exertion of 16 +/- 3 pounds of force on either control wheel for roll servo, and 14 +/- 3 pounds of force fore or aft on either control wheel for pitch servo.

METEOROLOGICAL CONDITIONS

Instrument meteorological conditions prevailed at the time of the accident, with the destination airport observation reporting a ceiling of 400 foot obscured with 1/2 mile visibility in blowing snow and fog. Winds were reported from 360 degrees at 20 knots gusting to 30 knots. Within the previous hour, several aircraft had attempted to land at Alliance, were unable, and had executed missed approaches. The Denver ARTCC sector 31 controller who was working the accident airplane stated that at the time he cleared the accident airplane to Scottsbluff (the requested alternate) to hold, there were "8 or 9 holding, with no ice reports." One aircraft was holding at Scottsbluff at that time.

A weather report provided to N5399Y by Huron AFSS while obtaining his IFR clearance included "the Huron radar are indicating a widespread area of a coverage of 1/10 coverage of heavy rain showers 7/10 coverage of light rain with snow increasing in intensity from 95 miles east of Huron to 95 miles west of Huron the area is 85 miles wide from north to south of that line with cell movement from 270 at 20 max tops 22,000 feet 21 miles south of Huron..." (See appended ZDV-ARTCC-128 Formal Accident Package dated April 4, 1994)

A "Weathermation" forecast dated April 04, 1994 at 1251z, which was located in the airplane read as follows: AIA: Unavailable BFF: 13z 25 SCT C60 OVC 3615G25 CHC 3RW- 21z C30 OVC 0120G30 OCNL C15 OVC 3R-S-F 02z IFR CIG S WIND

The AIA recorded observations (SA) were:

1815z SP W5X 1S-F /32/31/3620/977 1850z RS W4X 1/2SF/30/29/3620/979 1915z SP E7OVC 11/2S-F/30/28/3619/982

The time of the accident was 1913z.

The closest precision approach was located at Scottsbluff, Nebraska, 40 nautical miles on a heading of 242 degrees magnetic from Alliance. Weather observations (SA) at Scottsbluff were:

RS 1750z M2OVC 1/4S-F 090/32/32/3512/980/PRFSRR SP 1805z M8OVC 1S-F 3615/982 RS 1850z M13BKN 36BKN 65OVC 1S-F 100/32/30/0116/983 SP 1935z 18SCT M37OVC 15 0220/987

No icing reports were received from aircraft below 10,000 feet msl.

A Center Weather Advisory (CWA01) was in effect from 041745z to 041945z in an area bounded by LAR-PUB-LAA-BFF-LAR for airspeed fluctuation of +/- 10-15 kts due to strong and shifting low level winds with strong winds aloft. (See appended, ZDV-ARTCC-128 Formal Accident Package dated April 4, 1994) AIDS TO NAVIGATION

The flight was conducted on an instrument flight plan. The destination airport, Alliance (AIA), was served by non-precision VOR and NDB approaches, with both straight in and circling Minimum Descent Altitudes of 4420 msl. Required weather minimums for these approaches were 500 foot ceilings and 1 statute mile visibility. There were no reports before or after the accident of discrepancies with these navaids.

The alternate airport, Scottsbluff, Nebraska (BFF), was served by a precision Instrument Landing System (ILS) approach with weather minimums of 200 foot ceilings and 1/2 statute mile visibility. Several aircraft had successfully completed this approach. At the time of the accident, there was one aircraft in holding awaiting clearance to begin the ILS to Scottsbluff.

COMMUNICATIONS

Communications were maintained with N5399Y throughout the flight until the point where radar contact was lost. However, at several points during the flight, Denver ARTCC controllers were required to make numerous calls to N5399Y prior to receiving a response. Several times the response was that he heard the controller "loud and clear," and several times he stated he was having trouble hearing the transmissions.

At 1026, N5399Y received a weather brief from Huron AFSS. At 1202, Denver ARTCC attempted to contact N5399Y, and had another aircraft relay that he was radar contact. The other aircraft stated that N5399Y was attempting to respond to Denver ARTCC, but that Denver was not receiving. At 1212, N5399Y had difficulty understanding Denver ARTCC.

Between 1224:27 and 1230:17, Denver Center attempted to provide N5399Y with his clearance to perform the VOR 30 approach to the Alliance Airport. Another aircraft relayed the clearance. The final acknowledgement of this approach clearance occurred at 1230:17, at which time, according to the ARTCC radar data, N5399Y had already crossed the VOR. Radar data indicates that for the next 17 minutes, N5399Y flew a circuitous path in the vicinity of the VOR, and descended below radar coverage at 1247:47. Between 1245:30 and 1249:07, the Denver ARTCC controller, attempted to contact N5399Y with no response.

At 1255:19, N5399Y again appeared on the radar, and again flew a circuitous pattern generally southwest of the VOR. At 1258:48, Denver ARTCC contacted N5399Y, who stated that he was going to Scottsbluff for an alternate. Between 1259:06 and 1301:14 numerous calls are made by Denver and not acknowledged. At 1300:36, the radar plot shows the aircraft in a left turn. At 1301:21, N5399Y responded, "I think we're having some engine problems with our right engine." Between 1301:36 and 1302:37, five calls are made to N5399Y with no response. At 1302:54, N5399Y stated he "is headed for Scottsbluff." Radar plots show N5399Y in the second complete 360 degree turn of a left spiral.

At 1304:07, N5399Y stated he "is having trouble maintaining altitude." The radar plot shows that at the time of this transmission N5399Y had been in a left spiral for 3 minutes 30 seconds. The last radar return received was at 1303:10 at an altitude of 5800 feet. At 1304:52, N5399Y stated he was down to 5000 feet. No further transmissions were received.

AERODROME INFORMATION

The destination airport was an uncontrolled airport serviced with a National Weather Service observation station and an observer employed by a serving commuter airline. Approach radar services are provided by Denver ARTCC, and pilots are required to cancel IFR at the completion of an approach or announce their missed approach. The available runways are served with Runway End Identifier Lights (REIL) and Medium Intensity Runway Lights (MIRL) which can be pilot controlled. The VOR is located at the airport. The VOR monitored "in-service" at the time of the accident. No other aircraft reported abnormalities with the AIA VOR.

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest at position N41-54-20 W102-56-20. This position was 202 degrees magnetic at 10.5 nautical miles from the Alliance Municipal Airport. The terrain was flat, open rangeland with no trees or shrubs. Most wreckage was contained within a radius of 40 feet, with only a few light pieces of glass, 1 small aluminum piece, and a fuel cap between 40 and 100 feet.

The cabin roof and aft cabin structure was collapsed into the forward cockpit area, and the nose and instrument panel had been crushed aft to the front seats.

The airplane was oriented with the nose pointing 260 degrees magnetic, with the empennage folded over the nose, pointing 250 degrees magnetic. The wings remained attached and were oriented with the right wingtip pointed 350 degrees magnetic and the left wing pointed 170 degrees magnetic. Both wings, the horizontal and vertical stabilizer and flight control surfaces were present. The leading edges of both wings exhibited upward and aft accordion type crushing. The left wing measured 3 feet 9 inches from leading edge to trailing edge. The normal chordline distance is 6 feet.

The horizontal and vertical stabilizers had mud splatters which began at the leading edges and continued along the entire surfaces to the trailing edges.

The rudder trim cables were determined to be intact from the cockpit to the rudder. The elevator trim cables were intact from the elevator to the cockpit floor. Aileron and elevator trim cable continuity was unable to be determined forward of the crushed cockpit floor. All primary control cables were intact.

The left engine nacelle was oriented at an angle of 15 degrees down. The right wing top surface was oriented at an angle of 47 degrees down. Both engines were buried in wet mud to the firewalls. The ground to the right front of each engine exhibited a slash mark which extended forward at an angle of 30 degrees to the wing leading edge from the right side propeller blade. Both propeller blades exhibited chordwise scratches. The right propeller mounting flange was bent outward approximately 40 degrees from its normal plane of rotation, and the bolt holes exhibited elongation. The right propeller blades exhibited permanent deformation toward the cambered side for the inboard 2/3 of their length.

Both left and right propeller governors were broken from their mounts. The right governor was not located.

The fuel tanks in both wings were ruptured. There was a fuel smell present at the crash site. When the right engine was removed from the ground, a large amount of a clear liquid which smelled like gasoline drained out. The t-fitting at the left electric boost pump was full of fuel. The lines to the left engine driven fuel pump was full of fuel. The left carburetor was broken open and destroyed.

The flap actuator piston lower rod end attachment was broken. The actuator was in the flaps fully extended position, and hydraulic fluid was present in both the extension and retraction sides of the cylinder. The hydraulic lines were intact. The flap connecting torque tube was in the extended (40 degree) position. The hydraulic reservoir was below the level of the flap actuator cylinder when the wreckage came to rest. The position of the flap selector handle could not be determined.

The autopilot roll control knob was found turned to the 3 o'clock position, and the pitch control knob was rotated to the 2:30 clock position. These knobs are labeled "off" at the 7:30 clock position and "on" at the 5:30 clock position. According to Piper and other Aztec owners, the autopilot would engage when these knobs are rotated between 2 o'clock and 4 o'clock. The "trim turn" knob was found in the 12 o'clock (centered) position, and the "pitch cont" knob was in the 9 o'clock (centered) position. The pilot operating handbook, and the placard on the control head state that the "Altimatic pilot may be overpowered manually."

The attitude indicator artificial horizon faceplate was not located within its case. The backing plate for the visual horizon exhibited a distinct metallic bend around the sphere gimbal plate which corresponded to a left angle of bank of approximately 45 degrees. Internal inspection of the gyroscopic attitude indicator revealed rotational scoring marks on the inside of the instrument case.

Inspection of the directional gyro revealed rotational score marks inside the case. The directional gyro indicated a heading of 275 degrees.

Rotation of both vacuum pump drive shafts resulted in a discharge of air. Disassembly of the vacuum pumps revealed all carbon vanes to be intact and free to move within their respective slots.

The electrically powered turn indicator was trapped with the needle indicating a right 1 1/2 standard rate turn, with the balance ball deflected 1 ball width left. The inside of the turn indicator case displayed rotational scoring marks corresponding to the rotating wheel. The electrical connection rotating "points" were intact and exhibited no indications of burning or arcing.

The landing gear was in the up (retracted) position and the gear doors were closed. The landing gear handle was in the "up" position.

Inspection of the pitot tube revealed dirt impacted inside the ram air tube.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on both occupants by R. C. Blevins, M.D., of Western Pathology Consultants, P.C., of Scottsbluff, Nebraska, on April 5, 1994. The cause of death was stated as multiple blunt trauma. No pre-accident anomalies were detected.

Toxicological results were negative for Carbon Monoxide, and all other substances tested.

SURVIVAL ASPECTS

The airplane was not equipped with shoulder harnesses or upper body restraints. Livable volume was not maintained within the cockpit.

The Emergency Locator Transmitter (ELT) operated and assisted in location of the wreckage.

TESTS AND RESEARCH

The hydraulic flap actuator was tested to determine if it would free fall to the extended position as found in the wreckage. The actuator remained in the retracted position throughout the test. Procedures are enclosed.

Inspection of the engine spark plugs revealed no anomalies and a black, sooty appearance. Rotation of the engine drive shafts resulted in compression at all cylinders in the left engine, and all but 1 cylinder (which had impact damage) on the right engine.

Both left and right magnetos on both engines produced spark on all leads. Removal of all accessories and inspection of mounting pads revealed no drive anomalies. Rotation of both engine propeller shafts resulted in rotation of the accessory drive gears at the vacuum pumps.

The pitot tube was removed and 12 volt DC power was applied across the wire leads, resulting in the pitot tube becoming hot.

ADDITIONAL DATA/INFORMATION

Parties to the investigation were the Federal Aviation Administration, represented by the Lincoln, Nebraska Flight Standards District Office, and Textron-Lycoming Corporation.

The airplane was released to the owner's representative on April 6, 1994. The aircraft maintenance records were returned to the owner's representative on September 22, 1994.

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