St. Croix, VI Civil Air Patrol Pilot and 2 Cadets Die in a CAP Cessna 172P Crash, Oct 1996
The purpose of the flight was to take CAP cadets on an orientation flight around the local area, and return to the airport. Witnesses observed the airplane taxi to runway 9, proceed onto the runway without performing a run-up, and take off. The captain of a regional airline, which departed after the Cessna, said the Cessna climbed to an altitude of about 900 feet then turned sharply to the left, followed by a sharp turn to the right. The captain said the airplane went into a 'steep' right spiral, and impacted the ground with no forward movement. In addition, the captain said that the wind was down the runway, it was a clear day, and it was not unusually turbulent. Most of the witnesses that saw the accident gave similar accounts.
Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
the pilot's failure to maintain airspeed.
HISTORY OF FLIGHT
On October 26, 1996, about 0959 eastern daylight time, a Cessna 172P, N9818L, registered to the Civil Air Patrol (CAP), operating as a Title 14 CFR Part 91, local orientation flight, crashed in the vicinity of St. Croix, United States Virgin Islands. Visual meteorological conditions prevailed, and no flight plan was filed. The airplane was destroyed. The commercial pilot and two passengers were fatally injured.
The flight had originated in San Juan, earlier that day, flew to St. Thomas, dropped off a passenger, and arrived at St. Croix about 0945. The purpose of the flight was to take CAP cadets on an orientation flight around the local area, and return to the St. Croix Airport. This segment of the flight was originating at the time.
Witnesses observed the airplane taxi to runway 9, proceed onto the runway without performing a run-up, and takeoff. The crew of an American Eagle flight, which departed 2-3 minutes after the Cessna, witnessed the accident, and according to the first officer (FO), "...he [the Cessna] had started a turn to the left, then came...around to the right." The Cessna "started this maneuver at about 700 feet, and the pitch attitude of the aircraft was 15 degrees pitch up until about 90 degrees into his turn to the right. At that point, the nose of the aircraft abruptly pitched down 40-60 degrees until impact with the ground. From the start of the turn to the right until impact the aircraft made about one full revolution." The captain said, when he was checking the traffic during initial climb he realized that the Cessna "had reversed his course." The Cessna had "turned northeast" after takeoff and now it seemed that he made a "very rapid course reversal (high rate of bank) as if trying to come back to the runway." The captain further stated that, "it was at this time that the nose dropped and the airplane seemed to go into a high speed steep spiral, and struck the ground" with no forward movement. In addition, the captain had told the NTSB that the wind was down the runway, it was a clear day, and it was not unusually turbulent. Most of the witnesses that saw the accident gave similar accounts. Most of the ground witnesses reported hearing the sound of the engine until the airplane impacted the ground.
The accident occurred during the hours of daylight about 17 degrees, 42 minutes north, and 064 degrees, 47 minutes west.
Information on the pilot is contained in this report on page 3, under First Pilot Information.
Visual meteorological conditions prevailed at the time of the accident. Meteorological information is contained in this report on page 3, under Weather Information.
MEDICAL AND PATHOLOGICAL INFORMATION
An autopsy was performed on the pilot, on October 29, 1996, at the Medical Examiner's Office, St. Croix, Virgin Islands, by Dr. Francisco Landron.
Toxicological tests were conducted at the Federal Aviation Administration, Research Laboratory, Oklahoma City, Oklahoma, and revealed, "...no drugs or alcohol."
WRECKAGE AND IMPACT INFORMATION
The airplane impacted in rising terrain about 1/2 mile from the departure end of runway 9, and about 1/4 mile to the left of the extended runway centerline.
There were no ground scars observed in the vicinity of the crash site. The left wing was found rotated forward of the wreckage about 90 degrees from its original mounted position. Control continuity was verified to the rudder, elevator and ailerons.
The left aileron cable, and the left aileron interconnect cables were observed to have separated. The cable ends were "broomed" in appearance, and were pulled in the direction of the left wing. The aileron cable displayed some corrosion. The flaps were found in the "up" position. The elevator trim was found forward of neutral position.
Both fuel tanks were not breached. About 5 to 7 gallons of fuel was observed in the left tank. The fuel was tested with water finding paste, and no water was observed. The right tank was about 1/2 full. No water tests were performed on the right tank, because the tank was not accessible.
Examination of the airplane's engine, at the crash site, revealed that the cowling, and the engine were still partially attached to the airframe. Both magnetos and the carburetor were partially dislodged from their mounts. The propeller had remained attached to the engine. One propeller blade was bent rearward about 1/4 of the distance from the hub to the tip. In addition, the blade was twisted, and chordwise scratches were observed on the forward face of the blade. The blade displayed dents and gouges on the leading edge, at the tip. The other blade had no discernible scratches or damage along the leading edge. The blade was bent forward. The engine and propeller were removed from the crash site and taken to the Port Authority Fire Department at the St. Croix Airport, for further examination.
TEST AND RESEARCH
On October 28, 1996, the engine was examined under the supervision of the NTSB IIC, at the Airport Fire Department's facilities.
After the cooling baffles and propeller were removed, it was observed that the propeller flange bushings were broken and had pulled through the crankshaft flange. The crankshaft was bent and the starter ring gear was deformed. The exhaust pipes were crushed inward and the muffler was crushed against the oil sump.
The crankshaft was rotated by hand. The engine turned freely and continuity was confirmed. Thumb compression was obtained from all four cylinders.
The left magneto was found broken open, the distributor and its drive gear were dislodged. The impulse coupling functioned and the shaft rotated freely by hand. No spark was produced from the left magneto. The right magneto rotated freely by hand, and spark was produced through the ignition leads.
The carburetor throttle body had broken off just below the mounting flange. The throttle shaft and valve remained with the mounting flange on the oil sump. The throttle valve was found in the idle position. The linkage between the throttle shaft and the accelerator pump was found broken. The carburetor airbox had remained attached to the carburetor, and the heat valve was in the cold position. The fuel inlet fitting boss was broken. The inlet fitting and screen were not found. Fuel was drained out of the carburetor, and no discrepancies were found in the carburetor. The mixture control could not be moved, due to impact damage, the shaft was found in an intermediate position.
The top spark plugs were removed. Examination of the spark plugs revealed no discrepancies with the color or wear. Inspection of the engine, and engine accessories, did not reveal any discrepancies.
The aircraft wreckage was released to Mr. Gary Woodsmall, Chief of Safety, Civil Air Patrol, on October 28, 1996.