N1682G

On August 22, 2018, about 1615 Pacific daylight time, a Champion 7KCAB, N1682G, was substantially damaged when it was involved in an accident about 8 miles northwest of Descanso, California. The flight instructor (FI), and a pilot receiving instruction (PRI) were fatally injured. The airplane was operated by the FI as a Title 14 Code of Federal Regulations Part 91 instructional flight.

A review of radar data showed the airplane depart Gillespie Field Airport (SEE), San Diego/El Cajon, California and proceed in a northeasterly heading, climbing to about 3,200 ft above ground level (agl) across rising terrain. About 15 minutes into the flight, the radar data showed the airplane in a slight left turn at about 2,400 ft agl then enter a right 360o decreasing turn before dropping off radar. The last radar hit was about 1,500 ft above the accident site. (See Figure 1)

Figure 1-Radar flight track and accident site.

A pilot who flew with the instructor earlier on the day of the accident, said that the instructor told him that he had a flight in the afternoon and was not looking forward to the spin training that was planned.

PERSONNEL INFORMATION

Flight Instructor

The instructor's logbook was not recovered. On the application for his most recent medical certificate dated August 28, 2017, he did not report any flight experience. In his previous application for a medical certificate, dated June 19, 2013, he reported 7,120 total hours of flight experience.

Pilot Receiving Instruction

On the application for his most recent medical certificate dated August 26, 2014, he reported 0 hours of flight experience. During the investigation, a review of the pilot's logbook showed 269 total hours of flight experience.

AIRCRAFT INFORMATION

Following the accident, the weight and balance figures provided in the airplane's documentation were used to calculate weight and balance information. The maximum gross weight of the airplane was 1,650 lbs. According to the weight and balance calculations, the airplane weighed 1,723 lbs at takeoff, which was over the maximum gross weight by 73 lbs, and outside both the normal and acrobatic category flight envelope.

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest in a wooded ravine, which had an elevation of 2,585 ft msl and was situated within a mountainous area. The main wreckage was contained within a debris field about 120 ft in length and about 20 ft wide on a directional heading of 112° magnetic. The debris field was level compared to the surrounding terrain that was increasing in elevation to the north. (See figure 2)

Figure 2-Accident site.The first identified point of contact (FIPC) was an area of disturbed ground containing a small crater. A flat rubber seal was found near the FIPC and contained small fragments of green glass, consistent with the right-wing tip navigational light, which would be consistent with the right wing impacting the ground first. Small red wing access panels were also found near the FIPC. Further up through the debris field was an area of disturbed ground and brush about 70 ft in length and about 6 ft wide. The area contained a larger crater, about 4 ft in diameter and 6 in deep, about 30 ft from the FIPC. More red and blue wing panels were found in this area. The aircraft cabin door had impact damage and was found near the ravine in the bushes adjacent to the large crater. Broken Plexiglas was found surrounding this area. A broken red lens fragment was found near bushes on the left of the debris field about 70 ft from the FIPC. The main wreckage was found about 90 ft from the FIPC. The left wing had impact damage and was intact.

Hydraulic deformation was evident on both wing fuel tanks, which were breached. Residual fuel was noted within several engine fuel supply lines.

The right-wing had excessive impact damage and remained attached to the main wreckage. A landing gear strut and wheel assembly separated from the main wreckage and found near the main wreckage. The other main gear strut was the furthest piece of wreckage in the debris field and the wheel assembly had separated and was not found. The main wreckage was on a directional heading of about 180° magnetic.

The empennage remained intact and flight control continuity was established to the cockpit controls. The left rudder control cable exhibited overload signatures near the connection of the rudder pedal. Aileron and flap continuity could not be attained onsite. Both ailerons and flaps remained attached to the wings.

The cabin area showed crush damage and the engine, and its mounting assembly was broken from the airframe structure. The propeller and the crankshaft propeller flange separated from the engine. The propeller blades showed light chordwise scuffing on the cambered sides, the leading edges of the blades had nicks and striations, both were bent slightly aft with torsional twisting of the blades and trailing edge S-bending.

A follow-up examination of the engine and propeller revealed no evidence of preimpact anomalies.

MEDICAL AND PATHOLOGICAL INFORMATION

Flight Instructor

According to the autopsy performed by the San Diego County Medical Examiner's Department, the cause of death for the FI was blunt trauma and the manner of death was accident. In addition to the blunt trauma to the head, neck, torso, and extremities, moderate to severe atherosclerotic cardiovascular disease was noted. The heart was of normal size and shape. While the left main, left circumflex, and right coronary arteries had minimal atherosclerosis, there was 75% narrowing of the left anterior descending coronary artery. There was no evidence of an acute coronary event. Microscopic exam of the myocardium showed no inflammation or fibrosis. Moderate to severe atherosclerosis was noted in the aorta; there was no evidence of any aortic aneurisms. The arteries at the base of the brain had no atherosclerosis or aneurisms.

Toxicological testing performed by the FAA's Forensic Sciences Laboratory identified 0.014 grams per deciliter (gm/dL, 0.014%)) ethanol in cavity blood, no ethanol in brain tissue, or 0.011 gm/dL (0.011%) in muscle. While ethanol is primarily a social drug that acts as a central nervous system depressant, ethanol may also be produced in the body after death by microbial activity. No tested drugs or carboxyhemoglobin were detected in cavity blood. Toxicological testing by the San Diego coroner was negative for drugs of abuse and showed a chest blood alcohol concentration of 0.02% (weight per volume).

Pilot Receiving Instruction

According to the autopsy performed by the San Diego County Medical Examiner's Department, the cause of death in the PRI was blunt trauma and the manner of death was accident. No significant natural disease was identified.

Toxicological testing performed by the FAA's Forensic Sciences Laboratory identified 0.028 gm/dL. (0.028%) ethanol in cavity blood, no ethanol in brain tissue, and 0.019 gm/dL (0.019%) in muscle. No tested drugs or carboxyhemoglobin were detected in cavity blood. Toxicological testing by the San Diego coroner was negative for drugs of abuse and showed a central blood alcohol concentration of 0.04% (weight per volume).

ADDITIONAL INFORMATION

The FAA Airplane Flying Handbook (FAA-H-8083-3A), chapter 4, states the following concerning spin procedures:

Developed Phase

The developed phase occurs when the airplane's angular rotation rate, airspeed, and vertical speed are stabilized in a flightpath that is nearly vertical. In the developed phase, aerodynamic forces and inertial forces are in balance, and the airplane's attitude, angles, and self-sustaining motions about the vertical axis are constant or repetitive, or nearly so. The spin is in equilibrium. It is important to note that some training airplanes will not enter into the developed phase but could transition unexpectedly from the incipient phase into a spiral dive. In a spiral dive the airplane will not be in equilibrium but instead will be accelerating and G load can rapidly increase as a result.

Recovery Phase

The recovery phase occurs when rotation ceases and the AOA of the wings is decreased below the critical AOA. This phase may last for as little as a quarter turn or up to several turns depending upon the airplane and the type of spin.

To recover, the pilot applies control inputs to disrupt the spin equilibrium by stopping the rotation and unstalling the wing. To accomplish spin recovery, always follow the manufacturer's recommended procedures. In the absence of the manufacturer's recommended spin recovery procedures and techniques, use the spin recovery procedures below. If the flaps and/or retractable landing gear are extended prior to the spin, they should be retracted as soon as practicable after spin entry.

1. Reduce the Power (Throttle) to Idle

2. Position the Ailerons to Neutral

3. Apply Full Opposite Rudder against the Rotation

4. Apply Positive, Brisk, and Straight Forward Elevator (Forward of Neutral)

5. Neutralize the Rudder After Spin Rotation Stops

6. Apply Back Elevator Pressure to Return to Level Flight

The FAA Airplane Flying Handbook (FAA-H-8083-3A), chapter 4, also states the following concerning weight and balance requirements related to spins:

In airplanes that are approved for spins, compliance with weight and balance requirements is important for safe performance and recovery from the spin maneuver. Pilots must be aware that even minor weight or balance changes can affect the airplane's spin recovery characteristics. Such changes can either degrade or enhance the spin maneuver and/or recovery characteristics.

An airplane that may be difficult to spin intentionally in the utility category (restricted aft CG and reduced weight) could have less resistance to spin entry in the normal category (less restricted aft CG and increased weight). This situation arises from the airplane's abi...