1.1 HISTORY OF FLIGHT

On May 10, 2004, about 2051, Pacific daylight time, a Piper PA-44-180, N304PA, collided with mountainous terrain at Julian, California. The airplane was operated by Pan Am International Flight Academy under the provisions of 14 CFR Part 91. Both private pilots were fatally injured and the airplane was destroyed. Visual meteorological conditions prevailed and an instrument flight plan had been filed. The flight originated at Deer Valley, Arizona.

The airplane was on an IFR flight from Phoenix Deer Valley Airport, Phoenix, Arizona, to McClellan-Palomar Airport, Carlsbad, California. The airplane took off from Deer Valley at 1932 Pdt and the cleared route of flight was; Gila Bend, V66, Imperial, V458, Julian, then direct to Palomar. N304PA was number four in a train of five company airplanes flying the same route. The time separation between each airplane was about 5 to 10 minutes. The airplane directly ahead of N304PA was N434PA.

Review of Air Traffic Control communications and radar data shows that the flight crew of N304PA contacted the San Diego North Radar (SDNR) controller at 2043:48 Pdt, reporting level at 8,000. The SDNR controller instructed the pilot to fly heading 260 after Julian and intercept the (Palomar) localizer. The pilot read back the clearance. At 2045:47, the SDNR controller told the pilot of N434PA, another Piper Seminole ahead of N304PA and flying the same route, to descend to 6,000 feet. The pilot of N434PA acknowledged the clearance. At 2047:55, the SDNR controller transmitted, "Seminole four papa alpha descend and maintain five thousand two hundred." The pilot of N304PA responded, "Down to five thousand two hundred for three zero four papa alpha." According to information provided by the approach controller, this clearance was intended for N434PA. The controller did not recognize that the clearance had been acknowledged by N304PA rather than N434PA. At 2048:19, the pilot of N434PA transmitted, "…for four three four papa alpha?" (The beginning of the transmission was blocked by another transmission from the SDNR controller to an uninvolved aircraft.) The SDNR controller replied, "No. Duke six romeo tango heading one nine zero maintain eight thousand."

At 2049:55, the pilot of N304PA reported that he had ATIS information Zulu at Palomar, and the SDNR controller responded, "Seminole three zero four papa alpha thank you very much." According to radar data, at that time N304PA was descending through about 6,600 feet. At 2050:27, the SDNR controller again cleared N434PA to descend and maintain 5,200 feet. The pilot read back the clearance, and the SDNR controller then transmitted, "Seminole four three four papa alpha is five miles from escon. Cross escon three thousand five hundred or above cleared ILS 24 at Palomar." The pilot of N434PA acknowledged.

At 2052, the controller-in-charge (CIC) of the area including the SDNR sector received a call from San Diego automated flight service station (AFSS) reporting that they were receiving a strong emergency locater transmitter (ELT) signal in the area of the Julian VOR. The AFSS specialist asked the CIC to have controllers check with aircraft in the area in order to begin localizing the source. The CIC contacted the controllers at both the San Diego West and North sectors to attempt to locate the ELT signal. At 2053:23, the SDNR controller transmitted, "Seminole four papa alpha can you uh come up on one two one point five and check for an ELT please?" There was no response. The SDNR controller then made two more attempts to contact N304PA without success. He then transmitted, "Seminole four three four papa alpha how do you hear?" The pilot of N434PA replied, "four three four papa alpha five by five." The SDNR controller then instructed the pilot of N434PA to contact Palomar tower, and the pilot acknowledged.

Between 2054:21 and 2055:36, the SDNR controller made five more unsuccessful attempts to contact N304PA. At 2058:34, the pilot of N6ZP asked, "SoCal six zulu papa just for my own heart did you get a hold of that Seminole?" The SDNR controller responded, "No uh we're checking right now uh I don't uh we don't know where it is right now uh last we saw of him he was just five southeast of Julian same route that you were four papa alpha."

There was no further contact with N304PA.

1.5 PERSONNEL INFORMATION

1.5.1 Flightcrew

The occupants consisted of two private pilots, both with recently acquired instrument and multi-engine ratings. The intension of the flight was to build flight experience. The normal practice at the academy was for one pilot to be pilot-in-command on the outbound leg and the other pilot to be the pilot-in-command on the return leg of the trip.

A review of Federal Aviation Administration (FAA) airman records, Okalahoma City, Okalahoma, revealed the occupant-1 held a private pilot certificate issued on April 12, 2004, with ratings for single-engine land, multi-engine land, and instrument ratings for airplanes. Occupant-1 held a first-class medical certificate issued on July 10, 2003, with the restriction that he must wear corrective lenses. Occupant-2 held a private pilot certificate issued on April 30, 2004, with ratings for single-engine land, multi-engine land, and instrument ratings for airplanes. Occupant-2 held a first class medical certificate issued on November 18, 2003, with the limitation of wearing corrective lenses for distant vision.

Occupant-1's flight logbook was not recovered or examined by the Safety Board investigator. Occupant-1's accumulated flight time was calculated from flight and training records provided by Pan Am International Flight Academy, which may not be all inclusive of his flight experience. The Pan Am International Flight Academy records revealed that the pilot had approximately 174.8 total hours of flight time with 21.6 hours of that in multi-engine aircraft. He had approximately 46.8 hours of simulated instrument time in an airplane and 12.2 hours of night flying.

Examination of occupant-2's flight logbook revealed he had 239.8 hours of total flight time, 51.3 hours of multi-engine time, 50.4 hours of simulated instrument time in an airplane, and 37.2 hours of night flying.

1.5.2 ATC Controllers

The Safety Board ATC Group Chairman conducted detailed controller interviews, which are described in the ATC Group Factual Report section in the Official Docket of this accident. The San Diego North Radar Controller was certified in this position in October 1975. The San Diego Area Controller-in-Charge was certified in this position in March 1992. The San Diego North Radar Handoff Controller was certified in this position in February 1999. The San Diego Area Supervisor West Radar Controller became supervisor in 1999 and is qualified in the North, West, and South Bay sectors. The Los Angeles Sector 9 Radar Controller has been certified in this position since January 2003. Los Angeles Area E Controller-in-Charge has been certified in this position since April 1989.

1.6 AIRCRAFT INFORMATION

The airplane was a Piper PA-44-180, serial number 4496123, which was a twin engine, four seat, equipped aircraft. The airplane was powered by two Lycoming O-360 engines with Hartzell propellers. Examination of the engine and airframe maintenance logbooks revealed a total airframe and engine time of 2,467.8 hours when it underwent its last maintenance inspection on May 4, 2004. The airplanes maintenance was conducted under the direction of the Pan Am International Flight Academy's Progressive Inspection Program. The airplanes flight record log revealed that the airplane had accumulated 17 hours of hobbs time since May 4th.

The airplanes flight record log that is kept with the airplane has entries for both occupants, with occupant-1 listed first with the "flight hobbs out" field entered as 3129.5, the "flight hobbs in" field blank, and the dispatch block initialed. The last entry, which was occupant-2, had all flight time and dispatch fields blank. The airplane discrepancy sheet in the airplane flight record log listed a discrepancy that was reported by the previous flight crew on 5/6/04 at a recorded "flight hobbs in" as 3129.5. This discrepancy was described as the right main landing gear light inoperative. Corrective maintenance action was recorded in the discrepancy log and flight record log. No other maintenance action or flight crews are listed between the last recorded flight on 5/6/04 and the accident flight entries.


1.7 METEOROLOGICAL INFORMATION

The closest weather reporting station to the accident site was Ramona, California, which is located 18 miles to the northwest at an elevation of 1,390 feet. Ramona reported that at 2053 Pdt the winds were out of the south at four knots, visibility was 10 statute miles, the sky was overcast at 2,000 feet agl, the temperature was 15C, dew point 10C, and an altimeter setting of 29.87Hg.

A remote Automated Weather Station (RAWS) was located 4 nautical miles south of the accident location. This stations elevation was 4,239 feet, and provided information about winds and relative humidity. The 2110 Pdt observation indicated winds were out of the west-southwest near 14 knots, gusting to 22 knots. The relative humidity was 100% (temperature and dew point were 9C).

Astronomical calculations show that sunset occurred at 1942 Pdt. At 2051 the moon was on a true bearing from the accident location of 73.9 degrees and 60.2 degrees below the horizon.

A detailed weather description can be found in the Meteorological Factual Report section in the Official Docket for this accident.

1.8 AIDS TO NAVIAGTATION

1.8.1 Information Available to the flight crew

The published L-3 IFR En route Low Altitude chart used for instrument navigation depicts airway V458 feeding into the Julian (JLI) VOR on a 295 course (115 radial) and has a minimum en route altitude (MEA) of 7,700 feet.

The published ILS RWY 24 instrument approach to McClellan-Palomar (CRQ) depicts the approach feeder radial 258 leaving the Julian (JLI) VOR with a corresponding minimum en route altitude (MEA) of 6,800 feet until the GENTA intersection. GENTA intersection is on the JLI 258 radial and 14.3 DME (distance measuring equipment). The depicted minimum safe altitude (MSA) for aircraft approaching the Oceanside VOR (OCN) from the east within a 25 nautical mile radius is 6,800 feet.

The published RNAV (GPS) RWY 24 approach to McClellan-Palomar (CRQ) depicts a minimum safe altitude (MSA) of 7,400 feet for all quadrants around the airport.

1.8.2 ATC and Radar Information

Until about 2043, N304PA was receiving IFR ATC service from ZLA sector 9, which controls all airspace above 7,000 feet southeast of Julian (JLI) along V458. The aircraft was therefore still in Los Angeles Center (ZLA) airspace when the descent from 8,000 feet began, although the pilot was in contact with the Southern California TRACON (SCT) San Diego North Radar (SDNR) controller. ZLA's radar data for this area is provided by an ARSR-4 radar system located on top of Mount Laguna, which is 18 miles southeast of the accident site at 6,200 feet elevation and provided excellent coverage of N304PA's flight path. According to recorded ZLA automation data, a Minimum Safe Altitude Warning (MSAW) alert on N304PA was presented to the ZLA sector 9 controller at 2049:03. The aircraft's data block remained on the ZLA sector 9 display until the radar controller forced it off at 2050:07. The Minimum Safe Altitude Warning (MSAW) alert was being presented to the controller throughout that period. The last altitude displayed to the ZLA 9 controller in a full data block was 6,800 feet, although the target would have continued to be displayed as a limited data block (with only a beacon code and altitude) for the remainder of the flight. The ZLA minimum IFR altitude for the area southeast of JLI is 8,000 feet.

The San Diego North Radar sector uses an ASR-9 radar system located at MCAS Miramar, which is about 32 miles from the accident site. According to controller statements, it is not uncommon for the system to miss targets at 8,000 feet along the route followed by N304PA. However, recorded data shows that there were no missing targets for the last 5 minutes of the flight before the aircraft descended below 6,100 feet and went out of radar coverage.

At the time of the accident, the SDNR radar controller and associate were also responsible for the Miramar and Del Mar sectors. According to controller statements this is a normal configuration for the late evening time period. The two San Diego area controllers characterized their workload as moderate.

1.8.3 Minimum Safe Altitude Warning System Operation (MSAWS)

Los Angeles Center (ZLA) and Southern Californian TRACON (SCT) both are equipped with minimum safe altitude warning software designed to alert controllers when an aircraft is in danger of colliding with terrain or defined obstructions. As noted above, the two systems are not identical in performance. The en route and terminal systems use dissimilar terrain databases and different algorithms for predicting when an aircraft may come too close to the ground or to a man-made object such as an antenna.

En route MSAW documentation is contained in FAA documents MD-316, "Adaptation," and MD-321, "Automatic Tracking." In the en route system, airspace is divided into three-dimensional polygons with a minimum alerting altitude assigned to each polygon in accordance with IFR terrain clearance requirements. In general, if an aircraft operating under instrument flight rules descends below the minimum altitude established for the polygon, a minimum safe altitude warning will be generated and the controller will be alerted. (There are special cases where alerts are intentionally suppressed, such as when an aircraft is known to be landing.) The ZLA minimum IFR altitude for the area along V458 southeast of JLI is 8,000 feet. When N304PA descended below 7,800 feet, the MSAW system activated and provided a visual alert to the sector 9 controller. The alert continued until N304PA struck the terrain, although recorded automation data shows that the controller dropped the data block from the display when the aircraft descended through 6,800 feet.

ARTS IIIE MSAW documentation is contained in FAA documents MD-643, "Site Adaptation," and MD-644, "MSAW and Altitude Tracking." Terrain and obstacle data for ARTS IIIE is held in the form of a matrix consisting of two-nautical-mile square boxes, with a maximum terrain/obstacle elevation assigned to each box. The MSAW software monitors tracked aircraft with valid mode C and produces alerts based on both current and predicted terrain/obstacle clearance. If an aircraft is currently within 500 feet of the alerting altitude for the box it is in, or is predicted through extrapolation of current altitude and rate of descent to be within 300 feet of terrain or obstacles in 30 seconds, an aural and visual alert is generated to all controllers that are displaying the aircraft's full data block. At SCT, this alert consists of a five second beeping alert tone at the affected sector as well as a flashing red "LA" above the aircraft's data block that continues until the alert terminates. Alerts terminate when the aircraft's terrain clearance increases beyond MSAW alert parameters, no valid mode C altitude data is available from the aircraft, or when radar contact is lost. The minimum aural alarm volume level is restricted, and cannot be silenced by using the volume control.

The SCT MSAW system generated two predicted alerts at 2050:46 and 2050:51. According to FAA MSAW documentation, two consecutive predicted alerts will initiate an MSAW warning to the controller working the affected aircraft. Collectively, these alerts would have caused a 5 second aural alert to the SDNR sector beginning at 2050:51, along with a flashing red "LA" in N304PA's data block from 2050:51 until about 2051:06. The aircraft then descended below radar coverage, the track went into coast status, and the alert terminated.

More detail concerning the ATC Facility, Radar, and the MSAW system is located in the ATC Group Factual Report section in the Official Docket of this accident.

1.12 WRECKAGE AND IMPACT INFORMATION

The accident site is located about 200 yards south of the Julian VOR station, along a ridgeline on the top of Volcan Mountain, at an elevation of 5,537 feet. The accident site coordinates were 33 degrees 08.341 minutes North latitude and 116 degrees 35.072 West longitude. Falling away, down slope on both sides of the ridgeline, are mature cedar and oak trees, half of which were charred and blackened from the previous years brush fires.

The first identified point of impact (FIPOI) is the sheared top of a 75 foot tree about 100 feet from the wreckage, bearing 100 degrees magnetic. The tree is located on descending terrain from the wreckage and the sheared treetop is level with the airplane wreckage. Along the same bearing are a series of split and broken trees, disturbed tree stumps, and large branches, descending towards the final location of the wreckage. The outboard section of the left wing was located in a tree about 15 feet to the north of the FIPOI and exhibited distinct semicircular leading edge crush indentations.

The main wreckage consisted of the right wing and engine nacelle, cockpit, empennage, tail, and left wing engine nacelle. The cockpit was completely crushed aft, leaving no occupiable space, with the instrument panel twisted inverted and parallel with the ground. The hobbs meter on the instrument panel read 3132.1. The occupants were found on the ground about 6 feet forward of and in line with the cockpit wreckage. Occupant-1 was on the left and occupant-2 was on the right as viewed from the cockpit. The right wing was attached to the fuselage and exhibited numerous areas of semicircular crush zones along the wings leading edge. Clear bluish fluid was found in the right nacelle fuel tank. The right engine had separated from the nacelle and rested in a heavy bush 51 feet directly inline with the nacelle. The empennage had numerous creases and dents. The vertical stabilizer exhibited semicircular crushed areas along the leading edge. The vertical stabilizer was detached from the empennage at the airframe mounting brackets and rested next to the empennage. The horizontal stabilizer was folded flat over the resting the vertical stabilizer. The left inboard wing section, nacelle, and engine had separated from the wing root and laid inverted next to the cockpit. Clear bluish liquid was found in the left nacelle fuel tank. The left wing spar fracture face had 45 degree fracture surfaces, were light gray in color, and had matted grainy surfaces.

All flight control surfaces and balance weights were present and attached to their respective lifting surfaces. All flight control cables were traced from their linkages in the cockpit to their flight control bell cranks. The left aileron cables were separated and exhibited broom-strawing of the strand bundles. The engine control cables were traced from the throttle quadrant to their respective engine components. Both propellers were found under a bush about 9 feet forward of the main wreckage. Examination of both propellers showed similar signatures; torsional shearing of the crankshaft, blade tip curling, leading edge polishing, sinusoidal curves in the blades trailing edge, and twisting towards low pitch.

The engines were examined on scene. Both engines exhibited similar characteristics. The spark plugs were light gray in color, similar gaps, round electrodes, and had no mechanical damage. The engines were rotated and thumb compression achieved on all cylinders. All valves lifted the appropriate amount and in firing order. The oil suction screens were clear of debris. Three of the four magnetos achieved sparks on all posts, the remaining magneto from the right engine was found in pieces and was not testable. The vacuum pumps were disassembled and the impellers found intact. Bluish fluid that has the consistency of aviation gasoline was found in the fuel pumps and carburetor fuel lines.

1.13 MEDICAL AND PATHOLOLOGICAL INFORMATION

The San Diego County Medical Examiner completed autopsies on both pilots. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological analysis from samples obtained during the autopsies. The results of the analysis from both pilots specimens were negative for carbon monoxide, cyanide, ethanol, and listed drugs.

The medical examiners report documents the injuries to the extremities of occupant-1 to be: left distal radius fracture, right distal thumb fracture, left humerus fracture, left distal femur fracture, and right proximal tibia fracture. The documented injuries to the extremities of occupant-2 were; Bilateral sternoclavicular separation, bilateral ankle fractures, comminuted fractures of the left tibia and fibula, left calcaneus fracture, multiple right metatarsal fractures, and left wrist fracture dislocation and proximal ulna fracture.

1.18 ADDITIONAL INFORMATION

The wreckage was released by the Safety Board investigator-in-charge on May 10, 2003.