NTSB Factual Report

History of the Flight

On January 22, 2004, about 1148 eastern standard time, a Piper PA-23-160, N4293P, crashed in a residential area while returning to land at West Palm Beach County Park Airport, Lantana, Florida, while on a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The airplane was destroyed and the private-rated pilot and one passenger received fatal injuries. The flight originated from West Palm Beach County Park Airport, the same day, about 1137.

After departure from West Palm Beach County Park Airport, the pilot of N4293P contacted the FAA, West Palm Beach International Airport Departure Control, and requested visual flight rules flight following for a flight to Everglades City, Florida. The pilot was given a transponder code. Shortly after this, the pilot reported to the controller that he needed to return to the West Palm Beach County Park Airport. The controller approved this and told the pilot that radio frequency change was approved. Shortly after this, the pilot transmitted on the Unicom frequency for the West Palm Beach County Park Airport, that he was 4 miles southwest of the airport, inbound for landing "on one engine".

A flight instructor and dual student located in a Cessna 152 at the end of runway 27, who were awaiting takeoff, reported hearing the pilot of N4293P transmit on the Unicom frequency that he was 3 miles southwest of the airport, returning to the airport on one engine. They then heard the pilot report entering downwind for runway 27. They looked and observed the airplane abeam the end of runway 27 at about 400 feet altitude. The airplane then turned base leg for runway 27 and continued to lose altitude. The pilot then "overshot" the final turn for runway 27, to the north, while at an altitude of about 100-150 feet. The bank angle increased to 50-60 degrees and the nose of the airplane dropped to a low attitude. The airplane was now at about 50 feet altitude and descended in this attitude into the neighborhood. They then observed a ball of flame and smoke coming from the scene.

The NTSB obtained from the West Palm Beach International Airport Authority, recordings of transmissions made by the pilot of N4293P on the West Palm Beach County Park Airport Unicom frequency , 122.7 MHz. The recordings showed that the pilot transmitted he was "four miles to the southwest inbound on one engine". A short time later, he transmitted that he was "three point five miles southwest". The pilot's final transmission was when the pilot reported "downwind for two seven".

Recorded radar data from the FAA, West Palm Beach International Airport Approach Control showed that after takeoff from West Palm Beach County Park Airport the pilot climbed to 3,000 feet while maintaining a southwesterly heading. The pilot then made a left turn back to the airport and began a descent from which he entered downwind for runway 27 at an altitude of between 400 and 500 feet, while about 1/4 mile south of the runway, at a groundspeed of between 95 and 105 knots. The pilot turned onto base leg at an altitude of about 300 feet, while about 1/2 mile from the arrival end of runway 27, at an approximate groundspeed of between 75 and 80 knots. The last radar contact showed the airplane at an altitude of 82 feet at a groundspeed of 66 knots.

Personnel Information

The pilot held an FAA private pilot certificate with airplane single engine land, airplane multiengine land, airplane single engine sea, and instrument airplane ratings, last issued on July 10, 1993. The pilot held an FAA third class medical certificate, issued on March 22, 2002, with limitations that the holder wear corrective lenses for distant vision and possess glasses for near vision while exercising the privileges of the certificate. On the application for this medical certificate the pilot reported he had 2,500 total flight hours and that he had flown 40 flight hours in the previous 6 months. Examination of the pilot's logbook showed that at the time of the accident he had accumulated about 2,754 total flight hours and 2,435 total flight hours in the Piper PA-23-160. The pilot had accumulated about 20 total flight hours, all in the PA-23-160, in the previous 90 days. The pilot received a biennial flight review on January 16, 2002.

Airplane Information

The airplane was a Piper Aircraft Corporation model PA-23-160, serial number 23-1793, manufactured in 1959. At the time of the accident the airplane had accumulated about 6,334 total flight hours. The airplane was last inspected on December 4, 2003, about 20 flight hours before the accident, when it received an annual inspection. The airplane was equipped with two Lycoming O-360-A1D, 180 horsepower engines. The left engine was overhauled on December 6, 2002, about 114 flight hours before the accident. The right engine was overhauled on June 21, 1999, about 396 flight hours before the accident. The airplane was equipped with two Hartzell HC-C2YK-2, two-bladed propellers.

Meteorological Information

The Palm Beach International Airport, 1153 surface weather observation was winds from 310 degrees at 6 knots, visibility 10 statute miles, sky few clouds at 2,500 feet and scattered clouds at 10,000 feet, temperature 72 degrees F, dew point temperature 57 degrees F, and altimeter setting 30.15 inHg. Palm Beach International Airport is located about 5 miles north of the accident site.

Wreckage and Impact Information

The airplane crashed in the yard of a house located at 1812 Crest Drive, Lake Worth, Florida. The main wreckage came to rest at position 26 degrees 35.440 minutes North latitude and 080 degrees 04.572 West longitude. Examination of the accident site showed the airplane collided with a tree at about the 20-foot level. Several tree limbs up to 2 inches in diameter were cut from the tree. The airplane continued on about a 236-degree heading and collided with cable television lines. The airplane then touched down on the ground, collided with another tree, and turned around, coming to rest on a 110-degree heading. The nose landing gear, left wing, left propeller, right engine, and right propeller separated from the airplane during the accident sequence. All of these components were found within 15 feet of the main wreckage. The right propeller had television cables wrapped around it. A postcrash fire erupted and consumed the cabin and inboard right wing.

All components of the airplane which are necessary for flight were located on or around the main wreckage of the airplane. Continuity of the aileron, elevator, rudder, rudder trim, and elevator trim systems was established. All separation of control cables was consistent with overload separation or fire damage. The elevator trim was found in the neutral position. The rudder trim was found in the neutral position. The wing flap actuator was found extended to the flaps 21 degree extended position. The landing gear was found in the extended position.

Examination of the airframe fuel system showed that the fuel selectors in the cockpit were in the full forward or main tank position. The left main fuel tank contained about 30 gallons of blue aviation fuel. The right main fuel tank was consumed by the postcrash fire. The left and right fuel valves located in the wings were found in the outboard tank position and the cables between the cockpit fuel selector handles and the valves had sustained impact damage. The left engine fuel strainer contained blue aviation fuel and no contamination. The right fuel strainer was consumed by the postcrash fire. All fuel lines in the left wing and engine were unobstructed. The fuel lines in the right wing were consumed by fire. The left wing outboard fuel tank cap was in place after the accident. The left wing inboard tank fuel cap separated during the accident and was found lying near the wreckage. There were no fuel stains on the wing around the left inboard tank filler neck. The left wing electric fuel pump operated normally after the accident. The right wing electric fuel pump had sustained post crash fire damage and could not be tested.

The left engine remained attached to the engine firewall after the accident. The propeller separated from the engine during the crash sequence when the propeller flange separated from the engine crankshaft in bending overstress. Postcrash examination of the engine showed it rotated and continuity of the crankshaft, camshaft, valve train, and accessory drives was established. Each cylinder produced compression. The right magneto condenser wire had sustained postcrash heat damage and had grounded. When the lead was insulated the magneto operated normally on a test bench. The condenser potting material had oozed from the condenser consistent with exposure to heat from the postcrash fire. The left magneto had also sustained postcrash heat damage to the condenser and wire. When this was corrected the magneto operated normally on a test bench. The spark plugs had a light gray deposit, consistent with normal engine operation. The engine oil pump was intact. The engine-driven fuel pump operated normally. The carburetor remained attached to the engine and operated normally in postcrash testing. The propeller governor rotated freely after the accident and pumped oil. The vacuum pump rotated freely when removed from the engine. The exhaust pipes had dry, tan colored deposits.

Examination of the right engine showed it separated from the firewall during the accident and was found lying forward of the remains of the right wing. The propeller separated from the engine during the crash sequence when the propeller flange separated from the engine crankshaft in bending overstress. The engine was rotated and continuity of the crankshaft, camshaft, valve train, and accessory drives was established. The No. 3 and 4 cylinders produced compression. The No. 1 and 2 cylinders had sustained impact damage and would not produce compression. The No. 1 and 2 cylinders were removed from the engine and no perish anomalies with the pistons, rings, or cylinders were found. Both magnetos had sustained post crash fire and could not be tested. The spark plugs had a light gray deposit, consistent with normal engine operation. The carburetor was separated from the engine, had sustained postcrash fire damage, and could not be tested. The engine-driven fuel pump had sustained postcrash fire damage and could not be tested. The engine oil pump was intact. The vacuum pump rotated freely when removed from the engine. The propeller governor had impact and postcrash fire damage. The gears within the governor were intact. The exhaust pipes had dry , tan colored deposits.

Examination of the left propeller showed it had separated from the engine during the crash. The engine propeller flange was still attached to the propeller. The propeller spinner was still in place on the propeller. Both propeller blades were bent aft 30-40 degrees at the midspan. The blades were found in the low pitch position. Disassembly of the propeller showed the No. 1 blade pitch change pin had sheared in overstress. The No. 2 blade pitch change pin was intact. There was not damage to the low pitch stops.

Examination of the right propeller showed it had separated from the engine during the crash. The engine propeller flange was still attached to the propeller. The propeller spinner had mostly been burned away by the post crash fire. The right propeller had television cables wrapped around it. The blades were partially consumed by the post crash fire. Both pitch change pins had sheared off in overload. Both propeller blades had moved to the reverse range after the pins sheared. Disassembly showed damage on the blade ends consistent with the blades being in the low pitch range at the time of the accident.

Medical and Pathological Information

Postmortem examination of the pilot and passenger was conducted by the Office of the Medical Examiner, West Palm Beach, Florida. The cause of death for the pilot was reported as inhalation of products of combustion and thermal injuries. The cause of death for the passenger was reported as multiple blunt traumatic injuries. Postmortem toxicology testing on specimens obtained from the pilot were performed by the FAA BioAeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, and the Wuesthoff Reference Laboratory, Melbourne, Florida. The tests were negative for ethanol and drugs. The test were positive for caffeine, carbon monoxide, and cyanide. Postmortem toxicology testing on specimens obtained from the passenger was performed by Wuesthoff Reference Laboratory, Melbourne, Florida. The tests were negative for ethanol, drugs, and carbon monoxide.

Tests and Research

Recordings of the Unicom frequency at the Palm Beach County Park Airport were obtained from the West Palm Beach International Airport Authority and were sent to the audio laboratory of the National Transportation Safety Board. The good quality digital recordings were examined to document any engine or propeller sounds that could be heard during radio transmissions from the accident aircraft. There were three radio transmissions identified as originating from the accident aircraft. The first radio transmission occurred when the pilot called four miles to the southwest inbound on one engine. The next transmission occurred a minute later when the pilot reported that he was three point five miles southwest. The final radio transmission from the accident aircraft occurred a few minutes later when the pilot reported downwind for two seven.

The radio transmissions were examined on an audio spectrum analyzer to identify any background sound signatures that could be associated with either of the aircraft’s engines or the propellers. The first radio transmission contained sound signatures that were associated with one engine/propeller operating at approximately 2460 rpm. The 82Hz primary tone was identified with strong third and fourth harmonic sound signatures. The second radio transmission contained two sets of sound signatures. One set could be associated with an engine/propeller running at approximately 2470 rpm. The other signature if it was produced by an engine/propeller was rotating at approximately 2718 rpm. The 1st signature was associated with strong 3rd and 4th harmonics. The 2nd signature had no harmonics associated with the fundamental frequency. The last radio transmission contained a sound signature that could be associated with an engine/propeller rotating at about 2085 rpm. This sound signature had only the 4th harmonic present. No background aircraft warning tones or alarms were heard in any of the radio transmissions.

The Owner's Handbook for the Piper PA23-160 showed that the stall speed for the airplane with wing flaps down and engine power off is 53 knots. Stall speed would increase about 25 percent at a bank angle of 50 degrees and 40 percent at a bank angle of 60 degrees. This would increase stall speed to between 66 and 74 knots at the reported bank angle of 50-60 degrees used by the pilot of N4293P.

Additional Information

The airplane wreckage was released by the NTSB on March 10, 2004, to David E. Gourgues, Senior Surveyor, LAD, Inc., Orlando, Florida.

NTSB Probable Cause

The pilot's inadequate control of the aircraft by his use of an excessive bank angle, and his failure to maintain airspeed which resulted in a stall and a loss of control following a loss of power in one engine. The reason for the loss of the engine power was not determined.