NTSB Factual Report

HISTORY OF FLIGHT

On August 21, 2011, about 1800 eastern daylight time, an Aero Commander Callair A-9B airplane, N7638V, was substantially damaged when it impacted terrain following a glider tow operation at Brooks Field Airport (RMY), Marshall, Michigan. The pilot was airlifted from the scene in critical condition and died about 7 hours later of injuries sustained in the accident. The airplane was registered to and operated by the Marshall Soaring Club. The flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The local flight originated from RMY about 1758.

The pilot of the glider being towed by the airplane (towplane) reported that the aerotow takeoff was normal with the exception of some gusty winds. Beginning about 15 seconds into the flight, the glider's airspeed began to repeatedly increase and decrease, with the airspeed oscillations increasing in amplitude as they progressed. During the third or fourth airspeed cycle, he encountered a high intensity thermal. He lost sight of the towplane briefly, relocating it below and slightly to the right of the glider. Tension on the tow rope was high and he elected to release from the tow. At that time the towplane wings were level and it appeared to be stable. He subsequently returned for a landing.

A witness stated that the takeoff appeared to be normal, but the towplane and glider encountered some turbulence near the end of the runway. He commented that the glider pilot appeared to be having some difficulty staying in position behind the towplane. At one point, the glider was subjected to a tugging motion, which appeared to be due slack being taken out of the tow rope. The glider subsequently separated from the tow. The towplane turned right, while the glider continued straight ahead briefly. The towplane was approximately 350 feet above ground level when the right wing dropped and it entered a 60 to 70-degree nose down attitude. The towplane completed about one-half of a rotation before the witness lost sight of it behind trees.

The airplane impacted an open field about 1/2 mile west of the departure end of the runway. The airplane sustained substantial damage to the wings and fuselage.

PERSONNEL INFORMATION

The airplane pilot, age 59, held an airline transport pilot certificate with single and multi-engine land airplane ratings. His pilot certificate also included single-engine sea airplane, helicopter, and glider ratings, which were limited to commercial pilot privileges. The certificate also included Boeing 737 and Cessna 500 type ratings. He held a flight instructor certificate with single-engine, multi-engine, and instrument airplane ratings. His pilot certificate was issued in October 2010, with the addition of the glider rating. His flight instructor certificate was renewed in March 2010.

The pilot was issued a first class airman medical certificate on January 19, 2011, with a limitation for near and intermediate vision corrective lenses. The pilot's subsequent application for a first class airman medical certificate, dated August 3, 2011, was deferred by the aviation medical examiner pending further evaluation by the FAA. A decision regarding the pilot's medical certificate application was still pending at the time of the accident.

On his most recent medical certificate application, the pilot indicated a total flight of 31,000 hours, with 325 hours in the preceding 6 months. He noted that he was employed as an airline pilot. The pilot's personal flight time (non-airline) logbook included four entries related to 2011. Three of the entries noted the accident airplane and totaled 2.0 hours. One additional entry was dated the day of the accident and noted the accident airplane. There was no flight duration listed with this entry.

According to records provided by the glider club, the accident pilot applied for membership in September 2009. He had accumulated about 30 hours in Aero Commander A-9B airplanes (same make/model) and 35 hours in gliders.

AIRCRAFT INFORMATION

The accident airplane was a 1968 Aero Commander Callair A-9B, serial number 1366. The single-place, single-engine airplane was configured with a tailwheel landing gear configuration. It was being operated on restricted category special airworthiness certificate for agriculture/glider towing purposes. The airplane was powered by a 300-horsepower Lycoming IO-540-K1A5 engine, serial number RL-14096-48A.

According to the airplane maintenance records, the most recent annual inspection was completed on June 26, 2011, at 6,833.3 hours total airframe time. The engine had accumulated 444.7 hours since rebuild at the time of the inspection. At the time of the accident, the airplane had accumulated 27.1 hours since the inspection. Airplane records did not contain any record of unresolved maintenance issues.

METEOROLOGICAL CONDITIONS

At 1800, the RMY Automated Weather Observing System (AWOS) recorded conditions as: wind from 280 degrees at 14 knots, gusting to 19 knots; 10 miles visibility; scattered clouds at 5,500 feet agl; temperature 23 degrees Celsius; dew point 12 degrees Celsius; and altimeter 29.94 inches of mercury.

AIRPORT INFORMATION

Brooks Field Airport (RMY) was served by a single east-west oriented, asphalt runway. Runway 10-28 was 3,501 feet long by 75 feet wide. Glider operations were conducted from the grass area south of the asphalt runway.

WRECKAGE AND IMPACT INFORMATION

The accident site was located approximately 1/2 mile west of the departure end of the runway. The airplane came to rest upright, oriented on a north bearing. The forward fuselage was damaged, with deformation of the skin and airframe substructure. The engine remained attached to the engine mount and firewall. Both wings were partially separated from the airframe, and each exhibited crushing and buckling damage. The flight controls remained with the airplane; although, the ailerons and flaps were partially separated. One exception was the left aileron, which remained completely attached to the left wing.

A postaccident examination did not reveal any anomalies consistent with a preimpact failure or malfunction. Elevator and rudder control continuity was confirmed. Damage to the aileron control system appeared consistent with overload failures resulting from impact forces. Engine examination confirmed internal continuity via crankshaft rotation. Compression was obtained on all cylinders, and both magnetos exhibited spark when rotated. Fluid consistent with fuel in appearance and odor was observed in the gascolator and flow divider. The fuel filter appeared free of contamination. The fuel pump operated when provided electrical power. Engine throttle and mixture control continuity was confirmed. The two-bladed propeller assembly remained attached to the engine. One blade was intact and appeared undeformed. The second blade was bent approximately 90 degrees at the root. The airspeed indicator was tested and determined to indicate within 2 mph throughout the operating range.

The tow rope was recovered about 400 feet east of the accident site. The 200-foot long tow rope was separated approximately 166 feet from one end. The corresponding tow ring remained attached. The remaining portion of the rope was not recovered.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy of the pilot was performed on August 23, 2011. The pilot's death was attributed to multiple injuries received in the accident.

The FAA Civil Aerospace Medical Institute (CAMI) toxicology report stated:

No Ethanol detected in Vitreous;

Atropine detected in Liver;

Atropine detected in Blood (Periph.);

Atropine not detected in Heart;

Etomidate detected in Liver;

Etomidate detected in Blood;

Lidocaine detected in Heart;

Lidocaine detected Blood (Periph.);

Midazolam not detected in Blood (Periph);

Midazolam detected in Liver;

Ondansetron detected in Liver;

Ondansetron detected in Blood.

ADDITIONAL INFORMATION

The pilot of the glider being towed held a private pilot certificate with a single-engine land airplane rating. He was not glider rated. He was issued a third class airman medical certificate on July 20, 2011, with a restriction for near vision corrective lenses. On the medical certificate application, he reported a total flight time of 472 hours, with 4 hours flown within the previous 6 months. According to records provided by the glider club, the glider pilot applied for membership in June 2011. Since that time, he had completed a total of 36 glider flights, totaling 9.2 hours. Of that total, he had accumulated approximately 3.8 hours of solo glider flight time. His initial glider solo flight was on July 17, 2011.

The glider pilot was fatally injured in an unrelated airplane accident on October 6, 2011, in Holland, Michigan.

The FAA Glider Flying Handbook (FAA-H-8083-13) provides information and guidance related to glider operations. Regarding launch procedures, the handbook notes that once airborne and climbing, the glider can fly one of two tow positions. High tow is aerotow flight with the glider positioned above the wake of the towplane and is preferred for climbing out. However, the handbook cautions that "one of the most dangerous occurrences during the aerotow is allowing the glider to rise high above and losing sight of the towplane." The tension on the tow rope by the glider may ultimately limit the towplane elevator authority. Additionally, the towplane pilot may not be able to release the tow rope." This situation can be critical if it occurs at altitudes below 500 fee agl. Upon losing sight of the towplane, the glider pilot must release immediately."

NTSB Probable Cause

The towplane pilot's loss of control during an aerotow operation due to the glider pilot's inability to maintain a proper position behind the towplane while encountering turbulence on initial climb.