Aviation Accident Summaries

Aviation Accident Summary CHI00FA170

LAKEVILLE, MN, USA

Aircraft #1

N81681

Aeronca 7AC

Analysis

The airplane impacted terrain following an in-flight loss of control while on approach to runway 12. The front seat pilot was fatally injured and the pilot rated rear seat occupant was seriously injured. A witness stated, "On several of these approaches, I noticed that the nose would rise to above level flight slightly during or after the turn, and it appeared that the application of right rudder was used to force the nose to align with the runway causing a skid during a portion of the turn. ... I commented to my wife that the technique used would likely be disastrous some day for whoever was flying the plane. ... It was apparent that the same techniques were being used on this approach, and suddenly the right wing started down, rotation began and the aircraft contacted the ground nearly straight down, maybe a block from the end of the runway facing west/northwest. The close in base leg with relatively flat turn (bank angle) and skid from right rudder application were visible before the roll started. The engine was audible, sounding as though normal full throttle had been applied, in an attempt to recover from the obvious spin that had begun. The aircraft spun to the right and hit the ground." Another witness stated, " I do not believe he was belted in - when I looked into the cockpit to check on pilot (female front seat) the rear seat belt on left side appeared to be somewhat neatly tucked in next to the seat. The right side belt was hanging out of the aircraft, which was the side he came out of." The pilot rated rear seat occupant stated that the aircraft did not have a nose up attitude before it nosed over. He stated that he and the front seat pilot were alternating flying the takeoffs and landings. He said the front pilot was flying the accident approach to land. The pilot did not describe a typical pattern when asked. He stated there was no binding in the aircraft controls and the engine was performing normally. The airplane's operator endorsed both pilots' applications for their instructor ratings. Leading edge nicks and chordwise abrasion were found on both propeller blades. Flight control continuity was established to all control surfaces. The engine exhibited a thumb compression at all cylinders. The magnetos produced a spark when rotated by hand. Control continuity to the engine was established. An aluminum colored seat belt end from the rear seat was found detached from the fastener that secured it. That fitting's hole was found deformed and a section was torn in the radius area about that hole.

Factual Information

HISTORY OF FLIGHT On June 23, 2000, about 2030 central daylight time, an Aeronca 7AC, N81681, sustained substantial damage on impact with terrain west of the approach end of runway 12 (4,098 feet by 75 feet, dry asphalt) at Airlake Airport (LVN), near Lakeville, Minnesota. The commercial rated front seat pilot was fatally injured and the commercial rated rear seat occupant was seriously injured. The 14 CFR Part 91 personal flight was not on a flight plan. Visual meteorological conditions prevailed at the time of the accident. The local flight originated from LVN about 2015 and was performing an approach to runway 12 at the time of the accident. A witness stated, "... I observed the involved aircraft flying several approaches to what I assume were touch and go landings. I could not see the runway, so the touch and gos are an assumption. The approaches were made to the southeast runway at Airlake from a right traffic pattern. I don't know the runway heading, but would guess that it is about 110-120 degrees. The wind was fairly strong, blowing from what appeared to be nearly straight south. It seemed to me that the downwind leg was being flown quite close to the runway, and that the downwind altitude seemed possibly lower than normal. As the aircraft turned to a base leg, the groundspeed increased, making the wings level portion of the base leg to be of short duration, with a turn to the runway started quickly. I estimate that the bank did not exceed 30-35 degrees during most turns to final. On several of these approaches, I noticed that the nose would rise to above level flight slightly during or after the turn, and it appeared that the application of right rudder was used to force the nose to align with the runway causing a skid during a portion of the turn. Very little or no increase in bank angle was noticed during the skidding portion of these turns. I commented to my wife that the technique used would likely be disastrous some day for whoever was flying the plane. When my son and his family arrived, the aircraft was again visible in the pattern, and I pointed out my observation to them. We were discussing our jobs, etc., when the aircraft returned again, flying the pattern that the accident occurred on. I said to them, 'Let's see if he does the same thing.' It was apparent that the same techniques were being used on this approach, and suddenly the right wing started down, rotation began and the aircraft contacted the ground nearly straight down, maybe a block from the end of the runway facing west/northwest. The close in base leg with relatively flat turn (bank angle) and skid from right rudder application were visible before the roll started. The engine was audible, sounding as though normal full throttle had been applied, in an attempt to recover from the obvious spin that had begun. The aircraft spun to the right and hit the ground. We lost visual contact with the aircraft before it contacted the ground, but the sound of the crash left no doubt what had occurred. My son left immediately in his car to see if he could assist at the scene." The witness further said, "Once the stall was apparent to the pilot, I believe he did everything possible to correctly initiate a recovery, but the low altitude did not make recovery possible." Another witness stated, " I watched the aircraft make 4 or 5 approaches toward the southwest end of runway. Each approach appeared to be poorly executed (not smooth, very choppy manuevers)[.] On the last approach, it appeared as the pilot was very low 100 ft or less and made a very tight, flat turn to the right almost skidding through the air nose high. The right wing dipped very hard - pilot attempted to recover by adding full throttle[.] It then spiraled straight down with power on. Heard it hit the ground. I was the second person on the scene[.] The rear occupant was partially out of the aircraft and rolled onto the ground. He was still conscious but badly hurt. I do not believe he was belted in - when I looked into the cockpit to check on pilot (female front seat) the rear seat belt on left side appeared to be somewhat neatly tucked in next to the seat. The right side belt was hanging out of the aircraft, which was the side he came out of." The pilot rated rear seat occupant was interviewed by Federal Aviation Administration (FAA) inspectors and was asked the following questions: " 1. Q. Can you tell me if the aircraft had a nose up attitude before it nosed over. A. No a normal turn. 2. Q. Who was flying the aircraft. A. She [the front seat pilot] was. This was her third landing. I did two. Q. So you did alternate the take offs and landings. A. Yes. 3. Q. Describe a typical touch and go landing. A. I don't what you mean. A. typical pattern. 4. Q. Any binding before take off seat belts / aircraft controls. A. Controls free and seat belts free. Q. Any binding of the seat belts. A. No they worked fine. 5. Q. Were either pilot given any flight instruction if so, who, what kind of instruction and why. A. No instruction. 6. Q. Weather conditions at the time of the accident. A. Clear, wind out of the S. SE. wind 5 to 10 knots 5 to 10 miles visualiby. 7. Q. Taking off in what direction. A. Heading southeast runway 12. 8. Q. What was the phase of flight just before the accident. A. Base to final. 9. Q. Was the aircraft equipped with a stall warning horn. A. No, no stall warning system. 10. Q. What was the airspeed before the aircraft nosed over. A. Could not see. 11. Q. How was the engine performing during the operation of this flight. A. Normal. 12. Q. How much fuel was aboard the aircraft before the accident flight. A. 1/2 tank. 13. Q. How long was the aircraft flying before the accident. A. 15 to 20 minutes. 14. Q. Did you have a communication device aboard the aircraft. A. None. 15. Q. Before the aircraft lost altitude did it shudder indicating a stall. A. No it just broke right wing down. 16. Q. Was there any thing unusual about the flight. A. No. 17. Q. Were the two of you switching back and forth in piloting the aircraft. A. Yes. 18. Q. Who was flying this leg. A. She [the front seat pilot] was. 19. Q. Estimate how high the aircraft was while in the pattern, down wind, base and final. A. Could not see the instruments. 20. Q. Did you receive a weather data, by whom. A. AWOS. 21. Q. Did you file a flight plan. A. No. 22. Q. Any thing else you can reflect on. A. No. I asked [the pilot rated rear seat occupant] if he could not see the instruments / gauges how could he fly the aircraft. Answered, she [the front seat pilot] would move over and kind of bend down." PERSONNEL INFORMATION The front seat pilot held a commercial pilot certificate and held an instrument, single, and multiengine land airplane ratings. She held a flight instructor certificate issued on May 8, 2000. On the application for that flight instructor rating, she listed 400 hours of total time in airplanes, 233.9 hours of pilot in command time in airplanes, and a "1st Class" medical certificate dated March 31, 2000. The airplane's operator endorsed that application for her flight instructor rating and conducted her tailwheel checkout in the accident airplane. The operator stated that she had between 40 to 50 hours of flight time in the accident airplane. The pilot rated rear seat occupant held a commercial pilot certificate and held an instrument, single, and multiengine land airplane ratings. He held a flight instructor certificate. The airplane's operator listed his total flight time in all aircraft as 3,300 hours, 50 hours in this make and model, and 15 hours of instructor time in this make and model. The operator listed his last medical as a first class medical dated November 23, 1999. The operator endorsed the rear seat occupant's application for his flight instructor rating. AIRCRAFT INFORMATION An attached data plate indicated the airplane was an Aeronca 7AC, serial number 7AC-300, type certificate 759, and was manufactured December 11, 1945. The standard airworthiness certificate was issued February 9, 1957. The airplane's logbook entries for July 12, 1999 showed the airplane's last annual inspection was performed that date, listed a tachometer reading of 602.0 hours, and showed that the airplane accumulated 3,016 hours of total time. At the scene, the tachometer was found damaged. The tachometer's hundreds digit read 7, its tens digit was damaged, and its ones digit read 7. METEOROLOGICAL INFORMATION At 2035, the LVN weather was: Wind 190 degrees at 6 knots; visibility 10 statute miles; sky condition clear; temperature 26 degrees C; dew point 20 degrees C; altimeter 29.77 inches of mercury. WRECKAGE AND IMPACT INFORMATION The airplane came to rest in a grass-covered field on its nose and right wing approximately 200 yards west of the approach end of runway 12 at LVN. The right wing's leading edge exhibited a rearward crush and wrinkling of its skin from about mid-wing outward to the wing's tip. The left wing's leading edge exhibited a rearward crush from abeam the mid-span of the aileron to the wing's tip. The left aileron bell crank's rod end was found detached from its push rod. The lower engine cowling was found crushed upward and rearward with a crush angle of about 30 degrees from the airplane's longitudinal axis. Leading edge nicks and chordwise abrasion were found on both propeller blades. The throttle was found in the open position. A smell of fuel was found in the cockpit. The fuel tank exhibited ruptures. Flight control continuity was established to all control surfaces. The engine exhibited a thumb compression at all cylinders. The magnetos produced a spark when rotated by hand. The carburetor bowl exhibited moisture on its internal bottom surface and exhibited a fuel smell. Control continuity to the engine was established. The removed spark plugs exhibited a brown to dark brown coloration. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot by the Minnesota Regional Coroner's Office on June 24, 2000. The FAA Civil Aeromedical Institute prepared a Final Forensic Toxicology Accident Report. The report indicated 8.446 (ug/ml, ug/g) Acetaminophen detected in blood. SURVIVAL ASPECTS An aluminum colored seat belt end from the rear seat was found detached from the fastener that secured it. That fitting's hole was found deformed and a section was torn in the radius area about that hole. See appended photo and specification diagram. ADDITIONAL INFORMATION A party to the investigation was the FAA. The aircraft wreckage and retained parts were released to the airplane's operator.

Probable Cause and Findings

the pilot not maintaining aircraft control and the stall/spin she encountered during the approach on base to final. A factor was the pilot passenger not detecting the remedial action needed to correct the aircraft's nose up attitude during the approach.

 

Source: NTSB Aviation Accident Database

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