Accident Details
Probable Cause and Findings
The incorrect use of an abbreviated callsign by the TRACON sector radar controller to issue a descent clearance to N434PA and the sector controllers failure to detect that the clearance had been read back with the full callsign by the pilot of N304PA. Also causal was the pilots failure to question a clearance that descended them below the published Minimum En route Altitude (MEA). Contributing to the accident was the failure of both the Center and TRACON controllers to properly respond to the aural and visual Minimum Safe Altitude Warning System (MSAW) alert.
Aircraft Information
Registered Owner (Historical)
Analysis
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 pub...
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# LAX04FA205