What In The World Were They Thinking?

Aeronca 7AC
An Aeronca 7AC crashed and burned just after takeoff from the Taunton Municipal Airport (TAN), Taunton, Mass., on August 25, 2013. The time of the accident was about 6:15 in the morning. The owner and a passenger were on board. Both held private pilot certificates, and both died in the accident. Neither held a current FAA medical certificate. The airplane did qualify to be operated in the light-sport category, so the pilot in command didn't need a medical certificate. LSA aircraft can only be operated under VFR conditions. The weather wasn't very good, with visibility two miles in mist and an overcast ceiling at 500 feet. The wind was from 100 degrees at 11 knots.

The airplane was based at TAN. The airport manager told investigators that the passenger also owned an Aeronca 7AC that was based at the airport. The manager also reported that the airport's security system showed that the passenger opened the gate to get into the airport at about 5:37 a.m. on the morning of the accident.

A witness reported seeing the airplane taking off from runway 30---a 3,500-foot-long by 75-foot-wide paved runway. The airplane accelerated and climbed normally until it was between 50 and 100 feet above the ground. It then entered a slow right turn and began to descend. The witness said that when it impacted the ground, it immediately became engulfed in fire. The witness added that he didn't hear anything that sounded like an engine problem. The wreckage was located in a ditch about 1,100 feet from the beginning and 250 feet to the right of runway 30.

The two-seater was manufactured in 1946. The fabric-covered wings contained a wood spar with aluminum alloy ribs. Both the front and rear occupants had flight and engine controls. Examination of the engine after the accident didn't reveal any pre-impact malfunctions. In addition, the flight control cables were found to be connected to the various flight control surfaces.

When investigators examined the wreck­age, they discovered that a rudder control gust lock was still in place over the rudder and vertical stabilizer. The control lock was about 48 inches long and constructed with a piece of PVC-type tubing covered in a foam wrap. The control lock was similar to a rudder control gust lock that was observed installed on another Aeronca 7CCM that was parked at TAN and was reported to be the one owned by the passenger.

Review of a Pilot Operating Handbook for the same make and model as the accident airplane revealed that it called for the preflight walkaround inspection to include a check of the rudder surfaces and a pre-takeoff check of the flight controls. Had the pilot in command or the pilot-rated passenger performed an adequate walkaround inspection, it would have been difficult not to notice that the gust lock was installed. Also, had the pilot in command performed a pretakeoff check of control operation, the inability to move the rudder would have been obvious.

The NTSB determined that the probable cause of this accident was the pilot/owner's inadequate preflight inspection and inadequate pretakeoff check of the flight controls, which resulted in a takeoff with the rudder gust lock installed. Contributing to the accident was the pilot-rated passenger's failure to detect that the gust lock was installed.

RV-6
On November 16, 2012, a Van's RV-6 crashed after its right wing came off about five miles south of Scio, Ore. Both people on board were killed. The private pilot, who was the registered owner, was in the left seat. The right-seat passenger held a commercial pilot certificate. Visual meteorological conditions prevailed. The personal flight had taken off from the Lebanon State Airport, Lebanon, Ore.

A witness reported seeing the airplane at 1,000 feet AGL. When the airplane was halfway through a turn, the witness saw one of the wings fold up. The airplane then rapidly descended to the ground. The airplane's right wing was found more than 1,000 feet from the main wreckage.

The owner of the FBO at the airport told investigators that the pilot and passenger were acquaintances. The pilot arrived earlier that day at the airport and met up with his passenger. The passenger had a set of portable video cameras that he was going to mount onto the foot step on the airplane to record the flight. Additionally, the pilot-rated passenger intended to show the pilot how to perform rolls.

The experimental amateur-built, two- seat, low-wing airplane was partially built by one owner. A second party bought the partially constructed airplane and finished the construction. The airplane was purchased by the pilot on May 29, 2012. The FAA's letter defining the airplane's Experimental Operating Limitations stated, in part, "This aircraft is prohibited from acrobatic flight, unless such flight were satisfactorily accomplished and recorded in the aircraft logbook during the flight test period." Examination of the airplane's maintenance logbooks didn't include any such entry that would satisfy the requirement and, thus, qualify it for aerobatics to be performed.

The airplane exhibited numerous differences from the kit design that Van's Aircraft produces. The wingspan of the accident airplane, as measured after the accident, was 22 feet. In contrast, the Van's RV-3 wingspan is 20 feet and the Van's RV-6 is 23 feet. There were additional differences in the wing spar construction. The wing spar construction of the accident airplane utilized the same materials and general design as the Van's RV-3 series of designs, and the wing appeared to be a modified and extended version of the RV-3 wing. However, the spar caps were different from what's found in standard Van's designs.

The right-wing spar was sectioned out of the wing, and the wing carry-through spar was sent to the NTSB's Materials Laboratory. The right wing separated approximately one foot from the centerline of the center section. The left wing remained attached to the center section. Microscope examination of the fracture faces on the forward and aft spar sections of the wing structure and those on the center section showed features consistent with overstress separation with no evidence of fatigue cracking.

The NTSB determined that the probable cause of this accident was the pilot's decision to perform aerobatics in an airplane that was prohibited from aerobatics as stated in its operating limitations document, which resulted in the failure of the right-wing spar.

CJ-6A
When a two-place Nanchang CJ-6A military trainer crashed just offshore from Ocean City, Md., on June 30, 2013, investigators had a lot of information to help them figure out what happened. The pilot had been performing aerobatics, including spins. It appeared that the pilot was thinking so much about the maneuvers he was performing that he neglected to initiate spin recovery. The phenomenon is called target fixation, and a U.S. military manual on aeromedical training warns that pilots can become so fixated on achieving a goal that they forget to think about basics like flying the airplane. The pilot and a passenger were killed in the accident.

A witness who had previously seen the airplane doing aerobatics over the beaches at Ocean City watched it on the day of the accident. He observed a loop and a barrel roll some distance from shore. He said the airplane flew out of sight, and he next saw it in a spiraling descent. He said he had never seen the airplane that low or close to the shore, and it finally pancaked into the water.

There were two video cameras on the airplane, both of which provided good information for investigators. Video from the first camera revealed that after takeoff, the airplane climbed to 5,000 feet and performed a series of aerobatic maneuvers. The second camera showed that later on, the airplane pitched up through 70 degrees, rolled through 120 degrees of bank, went inverted and then entered a nose-down spin. It maintained a 600-feet-per-minute descent. The video showed that the pilot's head was upright and faced forward. The control stick was held full aft by the pilot, and the rudder pedals moved slightly, but remained generally neutral. The airplane went through 22 complete revolutions before hitting the water, with the pilot holding the control stick full aft the entire time. An instructor told investigators that if the control stick is released, the airplane will recover from a spin in one turn.

The NTSB determined that the probable cause of this accident was the pilot's failure to terminate the intentional aerobatic spin at an altitude adequate to prevent impacting the water. Contributing to the accident was the pilot's loss of situational awareness due to target fixation during the prolonged aerobatic maneuver.

Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, N.Y. 10602-0831.