Aircraft Was Part Of The Tehachapi, CA Independence Day
Celebration
The NTSB has finished its investigation of an accident which
occurred on July 4th in Tehachapi, CA, in which an Aero Vodochody
L-29 went down after a low pass over towns the 4th of July parade,
fatally injuring both people on board.
The NTSB lists the probable cause of the accident as the
pilot’s failure to maintain clearance from terrain while
performing a low altitude maneuver.
HISTORY OF FLIGHT
On July 4, 2009, about 1329 Pacific daylight time, an Aero
Vodochody L-29 airplane, N97869, was substantially damaged when it
impacted terrain while maneuvering near Tehachapi, California. The
airplane was registered to and operated by the pilot. The
commercial pilot/owner and an airline transport pilot also on board
were killed. Visual meteorological conditions prevailed and no
flight plan was filed for the personal flight. The local flight
originated from the Tehachapi Municipal Airport (TSP), Tehachapi,
about 1300.
Several witnesses located adjacent to the accident site reported
observing three jet airplanes overflying the area on a westerly
heading at an estimated altitude of about 500 feet above ground
level (agl). The accident airplane was observed trailing the other
two airplanes. The witnesses reported that the three airplanes
initiated a right turn to a northerly heading and the accident
airplane made a sharp right climbing turn to join up with the other
two airplanes. Subsequently, the accident airplane pitched upwards
and rolled to the left over the other two airplanes, transitioning
from the right side to the left side. Witnesses further reported
that the accident airplane completed the roll in a nose low
attitude and descended into terrain where a post-crash fire
ensued.
The pilot of the lead formation
airplane reported that the flight departed “single
ship” and joined up in an extended trail position with about
500 to 800 feet of separation. The flight climbed to an altitude of
5,000 feet mean sea level (msl) and overflew the city on a westerly
heading. Following the overhead pass, the flight initiated a
climbing left turn to 6,000 feet msl. The lead pilot stated that he
rolled out on a heading of approximate 190 degrees and then
reversed the turn to the right “to complete a 90/270 degree
turn in order to return for a pass over the city.” The lead
pilot further stated that the number two airplane was to join up on
his left wing and that the number three airplane (the accident
airplane) was to join up on his right wing. As the lead pilot
initiated the right turn, the number two airplane joined up to his
left. As the flight was rolling through a heading of about 290
degrees, "…number three passed me by on the right and got
ahead of me. I continued turning and then observed number three
pull up and begin a left roll over the formation.” The lead
pilot added that he waited for number three to join up. A few
seconds later, the lead pilot “called for a check in.”
The pilot of number two responded, however, no response was
obtained from the number three airplane.
The pilot of the number two airplane reported that after flying
over the city, “…we turned north as part of a
racetrack pattern and after passing abeam the runway at TSP, the
lead pilot called for a rejoin to fingertip formation. I took the
left side as we prepared to turn south for a flyover in
fingertip.” The pilot stated that they were at an altitude of
between 1,500 and 2,000 feet agl. He further reported, "[I] noticed
from my peripheral vision that #3 was approaching the right wing
position faster than normal. I lost sight when #3 was directly
opposite me on the other side of Lead. Shortly thereafter I saw #3
climb up and toll to the left. I lost sight of it when it passed in
front of lead.” The pilot added that “I cannot confirm
who was flying during and after the rejoin attempt, but assume #3
went up and to the left to dissipate speed from the
rejoin.”
PERSONNEL INFORMATION
It could not be determined which of the pilots was
manipulating the flight controls when the accident occurred.
Therefore, for the purposes of this report, the pilot/registered
owner seated in the front seat is referred to as the first pilot
and the pilot seated in the rear seat is referred to as the second
pilot.
First Pilot/Registered Aircraft Owner
The pilot, age 42, who was seated in the front seat, held a
commercial pilot certificate with airplane single-engine land,
multi-engine land, and instrument ratings. A second-class airman
medical certificate was issued on March 20, 2009, with no
limitations stated. The pilot's logbook was not recovered for
examination. The pilot reported on his most recent medical
certificate application; he had accumulated 3,300 total flight
hours.
Second Pilot
The pilot, age 62, who was seated in the rear seat, held an airline
transport pilot certificate with an airplane multi-engine rating
and a commercial pilot certificate with an airplane single-engine
land rating. He also possessed a flight instructor certificate with
airplane single-engine land, multi-engine land, and instrument
ratings. A second-class airman medical certificate was issued on
February 19, 2009, with the limitations stated of "must wear
corrective lenses." The flight instructor's logbook was not
recovered for examination. The pilot reported on his most recent
medical certificate application; he had accumulated 18,900 total
flight hours.
AIRCRAFT INFORMATION
The two-seat, dual flight control, low-wing, retractable-gear
airplane, serial number (S/N) 2847, was manufactured in 1968. It
was powered by a single M701c-500 turbine engine, rated at 800
pounds of thrust. An experimental airworthiness certificate was
issued on October 6, 1994. The airframe and engine logbooks were
not located during the investigation.
File Photo
METEOROLOGICAL INFORMATION
A review of recorded data from the weather observation station
located at TSP revealed at 1300, conditions were: wind from 300
degrees at 11 knots gusting to 14 knots, visibility 10 statute
miles, clear sky, temperature 29 degrees Celsius, dew point 4
degrees Celsius, and an altimeter setting of 30.14 inches of
Mercury.
WRECKAGE AND IMPACT INFORMATION
Examination of the accident site by a Federal Aviation
Administration (FAA) inspector revealed that the airplane impacted
an open field and residential road about 4 miles southwest of TSP.
The wreckage debris path measured approximately 285 feet in length,
oriented on a northerly heading. All major components of the
airplane were located within the wreckage debris path. The wreckage
was recovered to a secure location for further examination.
MEDICAL AND PATHOLOGICAL INFORMATION
The Kern County Coroner conducted an autopsy on the owner/first
pilot on July 6, 2009. The medical examiner determined that the
cause of death was “...Multiple Blunt Force
Injuries.”
The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City,
Oklahoma, performed toxicology tests on the first pilot. According
to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs
were tested. The toxicology report showed positive results for
6.766 (ug/ml, ug/g) Acetaminophen detected in blood, an unspecified
amount of Dihydrocodeine detected in the liver, 0.084 (ug/ml, ug/g)
Hydrocodone detected in the Liver. Dihydrocodeine and Hydrocodone
were not detected in the blood.
A family member of the first pilot reported that he was
prescribed Hyrodrocodone for back pain, however, was not actively
taking it.
The Kern County Coroner conducted an autopsy on the second pilot
on July 6, 2009. The medical examiner determined that the cause of
death was “...Multiple Blunt Force Injuries.”
The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City,
Oklahoma, performed toxicology tests on the second pilot. According
to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs
were tested. The toxicology test was positive for 0.662 (ug/ml) of
Cyanide, which was detected in the blood.
TESTS AND RESEARCH
The recovered wreckage of the airplane was examined on
July 28, 2009, at the facilities of Aircraft Recovery Services,
Chino, California.
Examination of the recovered wreckage revealed that the left
wing remained attached to the center fuselage section. The right
wing was separated from the center fuselage section at the wing
root by wreckage recovery personnel. Extensive fire damage was
observed around the right wing attach point.
The left wing was mostly intact and exhibited fire damage. The
outboard four feet of the left wing was separated. The inboard and
outboard flap assemblies remained attached to the wing. The inboard
portion of the left aileron remained attached to its mounts and the
outboard portion of the aileron was separated. The left main
landing gear was observed in the retracted position. The left wing
auxiliary fuel tank was separated from the wing and was severely
crushed.
The right wing was intact and exhibited fire damage. The leading
edge was crushed aft to the forward wing spar about 5 feet inboard
of the wingtip. The inboard and outboard flaps remained attached to
the wing. The right aileron remained attached to its mounts. The
right main landing gear was observed in the retracted position. The
right wing auxiliary fuel tank was separated from the wing and was
severely crushed.
The forward portion of the fuselage from the nose of the
airplane to bulkhead number 10 (aft of the rear seat) was
fragmented into multiple pieces and exhibited fire damage. The
center section of the fuselage was intact and exhibited severe fire
damage. The rear section of the fuselage was separated from the
center section of the fuselage near bulkhead number 19 (forward of
the wing flap assemblies). The empennage was partially separated
from the rear fuselage section at the base of the vertical
stabilizer. The left air brake assembly remained attached to the
fuselage and was observed in the extended position. The right air
brake fuselage attach brackets were impact damaged and separated
from the fuselage. The right air brake hydraulic actuator was
observed in the "extended" position. The engine was separated from
the fuselage. The structure surrounding the fuselage was severely
deformed and torn.
The horizontal stabilizer remained attached to the vertical
stabilizer. The elevator remained attached to the horizontal
stabilizer via all mounts. The elevator exhibited fire and impact
damage. The rudder and tail cone assembly were separated from the
vertical stabilizer.
Flight control continuity was established from the elevator and
rudder control torque tubes forward to the center fuselage section.
The elevator and rudder control torque tubes were fractured in
multiple areas. The fractures were consistent with impact related
damage and fire damage. Continuity was established from the left
and right wing root to the ailerons. Remains of the forward and
rear cockpit controls were recovered and exhibited impact related
damage. All major components of the cockpit flight control system
were located. The recovered components exhibited impact damage.
Instruments displaced from the instrument panels were located
within the recovered wreckage debris. The airspeed indicator
faceplate and indicating needle (position unknown) was displaced
from the instrument housing. The needle on the airspeed indicator
was observed indicating 0.7 mach. The engine power percentage gauge
was observed at a reading of about 90 percent.
No pre impact mechanical anomalies were noted with the recovered
airframe.
The engine was separated into multiple sections. The compressor
section was partially intact. Four of the seven combustion chambers
were separated from the engine. The compressor wheel exhibited
severe impact thermal damage. Rotational scoring and rub marks were
observed on the compressor housing and compressor wheel shaft. The
turbine section was displaced and impact damaged. The turbine wheel
was intact. All of the turbine wheel blade tips were bent opposite
the direction of rotation. The turbine wheel was displaced against
the stator assembly. A majority of the stator vanes were separated.
Rotational scoring marks were observed around the turbine wheel on
the casing.
No pre impact anomalies were noted with the recovered portions
of the engine.