| by |
Eric Gourley and the NTSB |
Read the NTSB report here.
Eyewitness Account
After 33 years of accident-free flying, I experienced
the worst horror I have yet seen around 1:30 PST this Thanksgiving Day. I had flown the
Twin Comanche from Mariposa to Carson City, a trip I have made many times over the years,
to pick up my brother for the Thanksgiving holiday. We grabbed a quick bite to eat in town
after I arrived at O04 and returned to the airport and headed promptly for the Comanche
parked in front of the old Carson City terminal building. As we were walking toward the
plane, I noticed an Aztec departing runway 27 and I was somewhat surprised to see it
already several hundred feet in the air as it climbed to the west only a few hundred feet
in front of me. Having learned to fly at Carson City in the early 60s and having
flown twins out of the same airport for many years, even on a cool day with slightly less
the standard conditions, the density altitude was still very close to 4000 feet. The
Aztec, in short, had more altitude than I usually see for a twin departing Carson City.
What made me look on, I don't know. But right before my eyes the most tragic Vmc
demonstration I could ever have imagined unfolded in a matter of no more than four or five
seconds. I would estimate the Aztec was close to 300 feet AGL as it passed my brother and
me about midfield. Suddenly the synchronous sound of the engines changed and the plane
pitched up slightly. It became obvious that an engine had lost power and a lot of it. I
watched in horror as the right wing began to rise and shouted to my brother, "Oh, my
God." The Aztec continued in its roll to the left, went inverted, and then at
that point the tail pointed vertical towards the sky as the nose aimed at the ground and
the uncontrolled plane continued its leftward spin towards the ground. It disappeared
behind the row of hangars southwest of the field and perpendicular to the runway. Although
the actual impact was not visible to me, it appeared the Aztec had made about one total
turn in the spin and was inverted on its path to terra firma. A flat thud came from the
hangar area as smoke began to rise from behind the hangars.
I have seen other accidents at
a farther distance before, and I knew this one was not minor. Several people near the
hangars began running toward the crash site, so I ran to a pay phone only 50 feet away
to call 911. But before I could get the first digits dialed, I could hear the fire
department on the field responding. My brother and I ran past the hangars to be stopped by
a deputy sheriff who sped onto the scene. We couldn't see much from where we were at
that point. The plane had struck the second row of hangars and a huge cloud of black smoke
was bellowing skyward as the fire crew dragged their hose toward a mangled charcoal
hangar. I gave my business card to the deputy, told him with regret that I was a
corporate pilot, multiengine instructor, and aircraft mechanic, and that I had
unfortunately been closer than anyone else in seeing the entire drama unfold. I told him
to have the NTSB contact me if they needed a witness. After waiting for about an hour as
the emergency crews suppressed the fire and removed the victims, my brother and I flew
back to Mariposa since we didn't want to be in the way.
I have never been more alert
on takeoff in the Twin Comanche in my life. I also had a pit in my stomach that made
Thanksgiving dinner anything but digestible, especially since the rumor had circulated
that there were probably four people in the plane. I doubt that any survived.
Much attention will be given to why the engine failed in the
investigation. However, what was so vividly clear to me was the inappropriate handling of
the engine failure. I could see no smoke coming from the engine. I may have seen something
fly off of the engine. Because the good engine was drowning out the anemic engine, it was
hard to tell what kind of failure it was. I think I heard a couple of pops. What I
can't understand is why the pilot at first pitched up. The plane appeared to me to be
unusually high and slow (below blue line at least) before the event occurred. Instead of
pitching forward, and instead of pulling power on the right (the good engine), the pilot
apparently panicked and tried to make the plane stay in the air when it was already well
behind the envelope. If I had had a video of this accident, I would make multiple copies
and spend some serious time analyzing pilot actions with my multiengine students when a
powerplant fails immediately after takeoff. I sincerely believe the Aztec may have been
able to land on the remaining available runway if swift and positive actions had taken
place in the correct manner. At the worst the Aztec would have landed under control
outside the airport boundary with the occupants having some chance of survival. Witnessing
this terrible accident on this Thanksgiving day is something I wish had never been. But
every fleeting second, every detail of the roll inverted, every futile command I shouted
to a pilot who could not hear me to get the nose down and pull the power back, and the
desperate hope that somehow the plane would recover the very last second will remain
indelible in my mind forever.
Is it possible to give pilots training in real life situations such as this one without
jeopardizing safety? Can the simulator gurus come up with an inexpensive, virtual reality
training package that can take us pilots through these critical emergencies so we would
handle them as perfunctorily as shaving our face with a razor every day?
My heart goes out to the pilot and the occupants of the Aztec. I wish I were a magician
capable of recreating the entire drama with a successful outcome. As it is, I learned more
in four or five seconds about an engine failure after take off, than I have after years
and years of flying. But there has to be a less expensive way.
— Eric Gourley
Probable Cause Report by the
National Transportation Safety Board
Accident occurred NOV-27-97 at CARSON CITY, NV
Aircraft: Piper PA-23-250, registration: N6933Y
Injuries: 4 Fatal.
NTSB Identification: LAX98FA048
Witnesses reported that the aircraft's engines sounded normal as the aircraft climbed
at an unusually steep angle after takeoff to about 300 feet agl, then stalled, rolled to
the left, and spun into a hangar. One witness reported that as the aircraft rolled over he
could see that the nose baggage door on the right side of the nose was open and folded
back in front of the windshield as the aircraft continued to roll. The pilot had 487 hours
total flying time with 23 hours in multiengine aircraft. He had received an 8.6 hour
checkout in the accident aircraft 2 weeks prior to the accident.
History Of Flight
On November 27, 1997, at 1235 hours Pacific standard time, a Piper PA-23-250, N6933Y,
rolled inverted during the takeoff initial climb and impacted a hangar at the Carson City,
Nevada, airport. The aircraft was destroyed and the commercial pilot and three passengers
were fatally injured. Visual meteorological conditions prevailed for the personal flight.
The flight was originating at the time and was destined for Nacadoches, Texas.
A private pilot witnessed the takeoff from near the midfield location adjacent to
runway 27. The runway is 5,900 feet long and the airport elevation is 4,697 feet. The
witness reported that the accident aircraft lifted off prior to reaching his location and
passed in front of him at 30 - 50 feet agl. The nose gear had retracted and the main gear
was in transit. The engines sounded normal. As the aircraft continued west over the
runway, the witness sensed that something was wrong as the aircraft reached 150 - 200 feet
agl, it yawed slightly, and appeared to mush. The nose pitched up and the aircraft rolled
to the left, then the nose dropped and the aircraft disappeared behind a parked aircraft
in a vertical dive and he heard the impact in the hangar. When the aircraft pitched up and
rolled to the left, he had a view of the top of the aircraft from the rear and could see
that the nose baggage door on the right side of the nose was open. As the aircraft
continued to roll, the baggage door appeared to fold back over the nose in front of the
windshield but it did not come off. He did not observe anything fall from the aircraft and
the engine sound was normal except that there was what the witness termed a "Doppler
shift" as the aircraft spun toward the ground.
Another witness, a commercial pilot who was on the midfield ramp about 200 feet south
of the runway edge, also reported that the engines sounded normal as the aircraft passed
midfield. His attention was attracted to the aircraft by its abnormally steep climb angle.
However, this witness reported hearing a pop - pop sound which he attributed to one of the
aircraft's engines immediately before the nose pitch up and "VMC roll".
Another pilot/witness observed the aircraft climbing out at a very steep angle and
stated, "As we continued to watch the plane continued up on a steep angle, until the
plane stalled. At the stall the plane nosed down to the left and went directly down into a
[hangar]."
Still another witness reported that the aircraft appeared to climb normally to about
200 feet agl and then it "appeared to zoom upward at an excessive rate for about 100
ft. more and then nosed over in a dive straight for the ground."
Another commercial pilot, who did not witness the accident, reported landing at Carson
City about 1130 behind the landing Aztec and taxiing behind the aircraft to the
(unattended) self-fueling pumps. He said that there were two young men in the aircraft and
he spoke to the one who was the pilot. The pilot said that he had rented the aircraft in
Southern California and had flown to Santa Rosa to pick up his brother. They were now
picking up his mother and girlfriend and going to Texas. While they were talking a car
drove up with the two women. The other young man, who did not appear knowledgeable about
airplanes, asked the pilot where to load the baggage. The pilot said to put the heavy bags
up front and the second man loaded approximately two to four pieces of luggage in the nose
baggage compartment. It appeared that the pilot fueled all the tanks of the accident
aircraft to capacity. This pilot fueled his aircraft after the pilot of the accident
aircraft fueled his and recalled clearing the pump which read about 109 gallons.
(According to the facility operator, there is only one grade of fuel sold at the
self-fueling facility, 100LL.) This pilot then took off about 1200 while the accident
aircraft was still on the fueling ramp and returned to Stead Airport and reported no
problem with the fuel.
A modest amount of burned luggage residue was found in the area of the nose baggage
compartment at the accident site. Two separate foot searches of the runway environs failed
to locate any items from the aircraft. The husband of the pilot's mother brought her to
the airport and helped load luggage. He reported through a friend of the family that the
group only had about 20 pounds of soft luggage. He reported that he only helped load the
baggage and did not operate the baggage door.
No fuel sample was retained by the fuel pump operator (Texaco). However, refueling
records for the time following the refueling of the accident aircraft (attached), show
three other aircraft were fueled after the accident aircraft and no abnormalities were
reported. The records show that the pilot added 119.6 gallons. The clock times on the
record are erroneous.
Personnel Information
The pilot was employed as a flight engineer at a supplemental air carrier. The pilot's
logbook was located in the wreckage with fire damage. It indicated total flying time of
484 hours as of November 15, 1997. The pilot's multiengine airplane rating was issued June
26, 1997, after 7.2 hours of instruction and check ride in a Beech BE-95. On August 1,
1997, the pilot logged 1.9 hours in a Piper PA-34-200 and 2.3 hours in a Beech BE-58. On
November 14 and 15, 1997, the pilot flew 8.6 hours during his checkout in the accident
aircraft.
One of the two flight instructors who performed the checkout in the accident aircraft
said that they do not normally simulate engine failures on takeoff or do Vmc
demonstrations during checkout of a rated pilot. They did do slow flight, steep turns, and
stalls, as well as a high altitude airport landing and takeoff. They also practiced engine
out procedures by retarding the mixture control while in cruise flight. This instructor
considered the pilot a "very good pilot" who flew well and kept the airplane
under control.
There were no further entries in the pilot's logbook after November 15. The Safety
Board investigator, using a DUATS, no wind, flight plan, estimated that the pilot flew an
additional 3.1 hours in the accident aircraft while en route from Pomona, California, to
Santa Rosa, California, to Carson City preceding the accident.
Aircraft Information
The aircraft's weight and balance at the time of the accident was estimated by the
Safety Board investigator using postaccident weights of the occupants provided by the
Coroner's office, together with baggage and fuel weights reported from other sources. The
initial calculation indicated that the takeoff center of gravity position was 100.32
inches aft of datum. However, a subsequent examination of the aircraft weighing record
dated October 29, 1997, revealed an error in the calculation which caused the empty weight
center of gravity position to be reported 2.4 inches aft of the true position. After
compensating for this error, the calculation showed the takeoff weight of the accident
aircraft was 4,730 pounds and the center of gravity was at 98.5 inches aft of datum.
According to the weight and balance documents, the maximum takeoff weight is 5,200 pounds
and the center of gravity limits (at 4,730 pounds) are 95.3 to 100.5 inches.
In the operator's "Flight Squawk Record" document, squawk number 2, dated
September 15, 1997, is "door ajar lt inop." The corrective action, dated
September 16, 1997, is "adjusted fwd baggage compartment door switch. Light works
good." According to the operator, the door ajar light was located on the glareshield
in front of the right seat passenger.
Meteorological Conditions
According to a deputy from the Carson City Sheriff's Department, weather at Carson City
at the time of the accident was clear and sunny, calm wind, and temperature in the mid
40-degree Fahrenheit range.
Wreckage And Impact Information
The aircraft impacted in the roof of a "Porta-Hangar" single aircraft,
T-hangar located approximately 1,000 feet from the departure end of runway 27 and 200 feet
south of the runway centerline. The hanger, in the center row of three rows of
"Porta-Hangar's" was identified as B6 and is located at latitude 39 degrees
11.13 minutes north, and longitude 119 degrees 44.26 minutes west (GPS). There was a fire
following impact with the ground and the entire aircraft was destroyed by the fire. Burned
debris associated with the aircraft was found on the floor of the hangar approximately in
the planform of the aircraft with the fuselage aligned approximately 300 degrees. A Cessna
T210 aircraft was stored in the hangar and was also destroyed.
The fuselage was oriented with the nose in the northwest corner of the hangar and the
skeletal remains of the empennage about 25 feet southeast near the center of the hangar
door. The aluminum components of the fuselage were consumed by fire except for the area
under the cabin floor in proximity of the wing center section structure. The instrument
panel, switches, and radios were destroyed by impact damage and fire. The cabin area was
identifiable by the steel tube truss cabin structure, seat frames, and lower fuselage in
proximity of the wing center section. The cabin floor beneath the pilot's seat was
buckled. The pilot's seat remained attached to the right rail and was detached from the
left rail. The aft travel seat stop was in place on the left rail and the seat was
positioned forward of the stop. The engine power levers were bent to the right side. The
throttle and propeller controls were approximately in the mid-range position with the
left-hand engine controls forward of the right hand engine.
The nose baggage door latch handle and recess assembly, and the latch operating shafts
were located in the nose area of the wreckage. The handle was approximately 1/4-inch open
at the locking end and solidified molten metal had filled the cavity between the handle
and the recess fixture. The track for the nose baggage door hold-open rod was found
crushed with the slot in the track.
The landing gear were in the retracted position. The flight controls were continuous
from the cockpit to the empennage and the aileron cables outboard of the nacelles had been
disturbed by rescue personnel. According to the representative from The New Piper Aircraft
Company, the threads exposed on the trim tab actuators corresponded to neutral rudder trim
and approximately 2 degrees nose down elevator trim. The flaps and flap actuator were
destroyed by impact and fire damage.
The wing center section, engine nacelle structure, and engines remained attached to the
fuselage. The wings were consumed by fire outboard of the engine nacelles; however,
residue on the hangar floor associated with wing approximated the wing planform. The fuel
selector valves in the nacelles were positioned to the outboard tank position and were
heat damaged.
Both engines remained attached to their respective engine mounts and remained aligned
with the fuselage. The engine sumps and induction systems of both engines were destroyed
by impact and fire. The right engine fuel servo assembly was destroyed by fire. The
throttle valve in the left servo assembly, although damaged by impact and fire, was near
the closed position. The fuel distribution manifold was intact on the top of the engines,
however, no fuel was present. The engine fuel supply lines and engine mounted fuel pumps
were destroyed by fire. The exhaust systems were destroyed by impact. The magnetos and
ignition harness wires on both engines were damaged by fire.
Both propellers remained attached to their respective engines and were in the feathered
position. The actuator arms of both propeller governors, however, were in the low pitch
position. The blades of the left propeller were free to rotate in the hub and the blades
of the right propeller would not rotate in the hub.
The blades of the right propeller were bent aft approximately 15 degrees about 12
inches inboard of the blade tip. The R1 blade of the right propeller exhibited one gouge
in the leading edge approximately 1/4 inch and no chordwise striations. Approximately 20
percent of the R2 blade tip was consumed by fire. The leading edge inboard of the melted
portion contained three gouges of approximately 1/4 inch and light chordwise and diagonal
striations.
The L1 blade of the left propeller was bent aft about 90 degrees between the root and
the midspan location. The blade had two gouges in the leading edge, one approximately 1/4
inch and the other of approximately 3/8 inch. The L2 blade was bent forward approximately
60 degrees and 12 inches inboard of the tip. The blade had one gouge on the face side of
the leading edge near the tip and approximately 1 to 2 inches of the blade tip trailing
edge was absent.
According to a deputy of the Washoe County Sheriff's Department who was present when
the occupants were removed from the aircraft, the pilot's mother and brother were seated
in the number 5 and 6 seats, respectively. The number 3 and 4 seats were empty and the
other female passenger was in the right front seat. There was a modest amount of personal
belongings in the nose area and, in the cabin, only a pillow and a jacket were found.
The engines were disassembled and inspected by the Safety Board at the facilities of
Textron Lycoming on January 21 and 22, 1998. The sumps were consumed by fire on both
engines and the data plates were absent. The engines were identified by metal tags affixed
at the accident site. The fuel, induction air, ignition, and exhaust systems could not be
examined due to impact and fire damage. The engines were mechanically continuous, the
valves functioned and accessory case gears rotated when the crankshaft was turned. The oil
pump gears were intact. The internal mechanical components of the engines were in place
and undamaged except for the effects of heat generated by the postaccident fire. The
crankcase and connecting rod bearings were gray and unscored, although tin plating on some
of the bearings had melted and run in localized areas of high temperature. The connecting
rod journals were smooth, shiny, and unscored, although several journals exhibited a blue
appearance in areas of high temperature. The spark plugs were clean and gray except for
the number 1, 3, and 5 cylinder plugs on the left engine which were covered with shiny
black oil. The fuel injectors were clear except the number 1 injector on the left engine
and the number 2 injector on the right engine which were blocked. The number 4 and 6
injectors on the right engine were partially blocked. The oil filters were opened and the
elements were charred. There were no metal particles in the filter elements. The propeller
governors, when removed from the engine, turned freely and pumped oil.
The propellers were disassembled and inspected by the Safety Board at Hartzell
Propeller Company on January 23, 1998. The dome and piston of the right propeller were
absent. The pitch control rod of the right propeller was broken approximately midway
between the piston and the yolk. The fracture was elliptical and an area of displaced
metal on the forward face of the hub conformed to the fracture shape of the rod. According
to a Hartzell representative, the position of the rod failure relative to the forward face
of the hub corresponds approximately to a low pitch blade position at the time the mark
was transferred. A mark transferred from the R2 blade root to the adjacent preload plate
corresponded to a 21-degree blade position at the time the mark was transferred, according
to the same Hartzell representative. The blade root pin of the R1 blade was bent
approximately 5 degrees toward the low pitch direction and the pin on the R2 blade was
bent a like amount in the high pitch direction.
The pitch control rod of the left propeller was broken in the threaded area on both
sides of the yolk assembly. The remaining portion of the rod aft of the yolk was bent at
mid-length. According to the Hartzell representative, if the bent rod was positioned so
that the bent portion was between the yolk and the last point of support for the rod on
the aft face of the hub cavity, the blade position corresponded to approximately the low
pitch position when the rod was bent. Transfer marks on the preload plate of the L2 blade
corresponded to blade angles of 40, 78, and 88 degrees, according to the Hartzell
representative. The pitch change pins on the root of both blades of the this propeller
were bent approximately 5 degrees toward the high pitch position.
Additional Information
An autopsy was performed on the pilot by the Washoe County Medical Examiner/Coroner and
a toxicology analysis was performed by the FAA Civil Aeromedical Institute.
The aircraft wreckage was released to Mr. Ernest Despain, insurance adjuster for Kern
and Wooley, LLP, on February 11, 1998.
Probable Cause
The failure of the pilot to maintain airspeed after being distracted by the nose
baggage door opening in-flight resulting in a stall/spin. Factors contributing to the
accident were the pilot's inadequate preflight inspection and lack of experience in the
type aircraft.