NTSB Factual Report

HISTORY OF FLIGHT

On October 10, 2005, about 1435 Pacific daylight time, an American Champion Aircraft Corporation (ACAC) 8KCAB, N943D, impacted terrain seconds after taking off from the Oroville Municipal Airport, Oroville, California. The airplane crashed into an open field about 0.2 miles east of the departure end of runway 12. The airplane was destroyed during the impact sequence and by post impact ground fire. The certified flight instructor (CFI), who held an airline transport pilot certificate, and the second pilot, who held a private pilot certificate, were fatally injured. The CFI was providing dual flight instruction to the second pilot. Alpine Aviation, Inc., Grass Valley, California, operated the airplane. Visual meteorological conditions prevailed at the time of the local area instructional flight, and no flight plan had been filed. The flight was performed under the provisions of 14 CFR Part 91, and it originated from Grass Valley about 1400.

An eyewitness to the accident, who was located about 1.2 miles northwest of the accident site, reported observing the airplane on a close-in left base leg to runway 12. The airplane made a "sharp" left turn and landed on the runway. Seconds thereafter, the airplane took off and climbed to an estimated maximum altitude of 650 feet above the ground. Suddenly, the airplane banked "sharply" left and "fell out of the sky."

Another eyewitness, who was located between 0.25- and 0.5-mile southwest of the airport, reported observing the airplane on its takeoff roll from runway 12. After the airplane became airborne, it climbed at an estimated 45-degree nose up pitch attitude. The witness stated that the airplane climbed between 300 and 400 feet above the ground, whereupon it appeared to stall. Thereafter, it made a steep left bank and looked as though it was out of control. As the airplane descended in a nose down attitude it completely reversed its direction. The airplane burst into flames seconds after crashing into the ground.

The owner of Alpine Aviation indicated to the National Transportation Safety Board investigator that the CFI had flown with the student earlier in the day for 1.5 hours, as recorded in company records. The student was undertaking flying lessons in a curriculum that provided training involving stall-spin recovery, unusual attitude recovery, and critical in-flight situations. The records indicated, in part, that during their morning flight the CFI had likely continued instructing the student in unusual attitude maneuvers. The records specifically indicated that they had reviewed the following maneuvers: slips, rolls, unusual attitude recoveries and low altitude 180-degree approaches to landing. Additionally, the records indicated that the CFI had provided his student with practice regarding control loss in flight.

Alpine's owner reported that the CFI had outlined the day's lesson plan on the flight school classroom's whiteboard. Near the center of the whiteboard, and partially underlined, the following words were written by the CFI: "180 degree Pwr Off Lndg [and] Eng Fail after T/O & RTN."

Alpine's owner opined to the Safety Board investigator that this lesson plan indicated the CFI anticipated teaching the student a specific emergency procedure. The procedure involved simulating an engine failure after takeoff following which the airplane's course would be reversed with the intent of returning to the airport for a landing.

PERSONNEL INFORMATION

Pilot-in-Command (CFI).

The CFI held an airline transport pilot certificate, with an airplane multiengine land rating. He had commercial pilot privileges for airplane single engine land and sea. Additionally, he held a DC-9 type rating. The pilot also held a certified flight instructor certificate for airplane single engine, with an expiration date of January 2006.

On a pilot experience form dated July 20, 2005, the pilot informed his employer, Alpine Aviation, that he had 3,300 total logged civilian pilot flying hours. Also, he had 3,300 logged military flying hours. The pilot's total single engine fixed gear flying experience was 300 hours. The pilot's employer reported that the pilot's total flying experience in the accident model of airplane was about 200 hours.

Second Pilot.

The second pilot held a private pilot certificate with an airplane single engine land and an instrument rating. According to the owner of Alpine Aviation, the renter-pilot's total flying experience was about 924 hours. The pilot's total flying experience in the accident model of airplane was 10 hours.

AIRPLANE INFORMATION

The accident airplane, commonly referred to as a "Super Decathlon," was issued a Federal Aviation Administration (FAA) Standard airworthiness certificate in the normal and acrobatic category. The airplane was capable of inverted flight maneuvers.

The airplane's maximum certificated gross weight in the normal and acrobatic categories was 1,800 and 1950 pounds, respectively. Based on calculations provided by Alpine Aviation, at the time of the accident the airplane was being operated within the prescribed weight and balance limits. The estimated gross weight of the airplane was approximately 1,837 pounds, and the center of gravity was about 16.7 inches aft of datum. The aft limit was 18.5 inches aft of datum. (See Alpine's calculations in the docket for this report.)

The airplane was maintained on an annual and 100-hour inspection basis. The last annual inspection was performed on December 1, 2004, at a total airplane time of 142.4 hours. The last 100-hour inspection was performed on September 20, 2005, at a total airplane time of 301.3 hours. By the accident date, the airplane's total time was about 325 hours.

METEOROLOGICAL INFORMATION

The closest aviation weather observation station to the accident site was located at the Oroville Airport. In pertinent part, at 1453, the following weather conditions were reported by the airport's automated surface observing system (ASOS): sky clear; visibility 10 miles; wind from 160 degrees at 9 knots; and temperature/dew point 27 and 4 degrees, Celsius, respectively.

COMMUNICATION

The FAA reported that no communications or services were provided to the accident pilot/airplane during the accident flight.

AIRPORT AND GROUND FACILITIES

The Oroville Municipal Airport, elevation 192 feet mean sea level (msl), has runway 01-19, which is 6,020 feet long by 100 feet wide, and runway 12-30, which is 3,540 feet long by 100 feet wide. No obstructions are listed beyond the departure end of runway 12.

WRECKAGE AND IMPACT INFORMATION

Under the Safety Board investigator's direction, the FAA coordinator responded to the accident site and performed the on-scene wreckage examination. The FAA coordinator reported that the airplane impacted an open, near level dirt field, about 140 feet msl. The accident site was located about 0.2 miles east of the departure end of runway 12. The approximate coordinates of the location are 39 degrees 29.17 minutes north latitude by 121 degrees 36.42 minutes west longitude.

The initial point of ground impact (IPI) was identified by the presence of a ground swath, consistent with the width of the airplane's fuselage. The swath was cut into the native grass vegetation and was oriented along a northeasterly course nearly perpendicular to the runway. The ground swath led toward the main wreckage, which was an estimated 125 feet northeast of the IPI. The propeller assembly was found in the ground swath, about 1/3 the distance between the IPI and the main wreckage. In the same general area, oil was observed in the grass. The airplane came to rest in an upright attitude.

The airplane was consumed by fire except for the outboard portion of the left wing, the left horizontal stabilizer, and the left elevator assembly, which remained mostly intact. Both wing tips remained attached to the wings, and the wings' structure appeared predominately straight. Observable portions of the wings' leading edges were devoid of crush signatures in an aft direction. The longitudinal axis of the fuselage appeared aligned with the attached empennage, and the horizontal and vertical stabilizers appeared predominately straight. All of the flight control surfaces remained attached to the airplane.

MEDICAL AND PATHOLOGICAL INFORMATION

The CFI held a second-class aviation medical certificate that was issued in March 2005. The certificate bore the limitation that the pilot must wear corrective lenses for distant vision. The pilot's reported weight was 226 pounds.

The second pilot held a third-class aviation medical certificate that was issued in March 2004. The certificate bore the limitation that the pilot must have available classes for near vision. The second pilot's reported weight was 154 pounds.

Autopsies were performed on the pilots by the Butte County Sheriff-Coroner, 33 County Center Drive, Oroville.

Toxicology tests were performed on the pilots by the FAA's Civil Aeromedical Institute, Oklahoma City, Oklahoma. No evidence of carbon monoxide cyanide, ethanol, or screened drugs of abuse (barbiturates, marihuana, etc.) was detected in either pilot.

Diphenhydramine was detected in the CFI's urine, but not in his blood.

Quinine was detected in the student's urine and blood. Also, acetaminophen was detected in the student's urine, and omeprazole was detected in his blood.

TESTS AND RESEARCH

Maintenance Records.

The airplane's maintenance records were provided to the FAA for review and examination. According to the FAA, all required inspections had been complied with, and no outstanding maintenance discrepancies were found. Applicable airworthiness directives had been complied with, according to the records.

Airframe Structure and Cabin Examination.

After the airplane was recovered, a detailed examination of its structure and engine was performed at the facilities of Plain Parts, Pleasant Grove, California. In summary, the following was noted by the Safety Board investigator and the ACAC participant:

The majority of the airplane's fuselage was found subjected to a post impact ground fire. No evidence of soot streaking in an aft direction was noted on any of the unburned skin located on the outboard portion of the left wing or on the left side of the elevator assembly. The entire fuselage, inboard left wing, entire right wing, vertical stabilizer, rudder, and the right horizontal stabilizer had been subject to fire (see photographs).

The upper longerons in the fuselage, between the cabin and the empennage, appeared generally straight. The left wing's leading edge and its forward and rear spars appeared straight. The wingtip appeared undamaged.

The inboard half of the right wing's leading edge was totally destroyed by fire. The outboard portion of the wing was fire-damaged. The wing's leading edge did not appear crushed. The wing tip was also fire damaged, but it appeared intact, and no evidence of deformation or crush was noted.

The seats were found connected to their respective attachment points with the exception of the front seat's front right leg. This leg was located in an impacted and crushed area of its support structure. No evidence of seat back failure was found.

Flight Controls and Cable Examination.

The trim, rudder, elevator, and the aileron surfaces with their associated cable control attachments were examined. Except in locations where fire had destroyed connections, the continuity of the flight control system was verified. All of the flight control cables were examined, and all Nicopress swage fittings were inspected to ascertain compliance with Airworthiness Directive 2005-24-10. (This airworthiness directive became effective on January 17, 2006, about 3 months after the accident.) All of the cable turnbuckles and Nicopress fittings were found intact. No anomalies were noted. (See ACAC's examination report for additional details.)

Engine Information.

Under the direction and supervision of the Safety Board investigator, the Lycoming Engine participant performed a partial teardown examination of the fire-damaged engine. No evidence of a preimpact case rupture or cylinder separation was observed.

An examination of the top spark plugs revealed wear signatures consistent with normal operation, according to the Lycoming Engine participant. The participant rotated the crankshaft, and "thumb" compression was confirmed in all cylinders. The valves and the rocker assemblies moved in their respective order.

No evidence of foreign object damage or detonation was observed. The valves and pistons were intact. The crankshaft gear dowel bolt was secure and intact. The oil pump gears were intact and undamaged.

The fuel injector nozzles were removed and were found clear. The throttle and mixture cables were found secure at their respective control arms at the fuel servo unit.

The fuel flow divider was secure at the flange on top of the engine. The fuel lines were secure at each fitting of the flow divider and nozzle. The diaphragm was intact. No visible contaminants were observed. The fuel pump was secure at its mounting pad and was mostly consumed by the fire.

The magnetos were fire damaged. Their drive gears could not be rotated by hand.

The lubricating system was examined. The oil suction screen was clear. The oil filter was completely destroyed by fire. No element was observed. Engine oil was observed on several internal components and in the oil pan. No foreign objects or evidence of metallic objects were observed in the oil or in any of the engine's internal cavities. The propeller governor gasket screen was clean.

In summary, the Lycoming Engine participant opined that the mechanical continuity of the engine's internal rotating and reciprocating parts was verified. No evidence of any mechanical malfunction was noted.

Spinner and Propeller Information.

The propeller assembly was observed broken from the crankshaft a few inches aft of the propeller-mounting flange. The adjacent starter ring support was also observed broken. The break in the crankshaft was found consistent with a torsional overload, according to the Lycoming Engine and ACAC participants.

The spinner was found attached to the propeller hub. No evidence of scratches or accordion folding of the spinner was noted.

The propeller blades were found securely attached in the hub, and the blades were torsionally twisted and bent in an aft direction. The blades exhibited leading edge gouges and chordwise scratches.

ADDITIONAL INFORMATION

All of the recovered wreckage was released to the owner's assigned insurance adjuster on June 8, 2006. No parts or records were retained.

NTSB Probable Cause

The certified flight instructor and the private pilot's failure to maintain adequate airspeed while attempting a return to runway maneuver, which resulted in an inadvertent stall.