History of Flight
On January 11, 2012, at 1000 eastern standard time, a Cessna 150G, N4041J, operated by TENLE Aviation, was substantially damaged when it impacted terrain after experiencing a loss of engine power during initial climb near Fitchburg Municipal Airport (FIT), Fitchburg, Massachusetts. The certificated flight instructor sustained minor injuries, and the student pilot sustained serious injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight conducted under 14 CFR Part 91.
According to the flight instructor, he and the student met that morning at Minute Man Air Field (6B6), Stow, Massachusetts. During preflight, the student noticed that the power cord for the engine preheat was in the oil service door but was not plugged in; the outside air temperature was -01°C and the engine was cold. The student plugged in the preheater and cleaned frost from the windows. The wings and horizontal stabilizer had been covered and were free of frost. After about 30 minutes, they disconnected the preheater and attempted to start the engine. It required 4 or 5 attempts with increasing primer operation before starting. They taxied to runway 3, performed pretakeoff checks including magneto and carburetor heat checks, which were normal. They then departed for FIT.
At FIT, the student performed a touch-and-go landing and re-entered the traffic pattern. During the downwind leg, the engine began to run rough, and the student applied carburetor heat. During the climb after a second touch-and-go, the engine again ran rough. The flight instructor took control, lowered the angle of attack, and applied carburetor heat by pulling the knob. The engine immediately ran rougher, so he pushed the knob in, and the engine ran less rough but still rough. He observed minimal runway remaining and a tractor off the end, decided landing was not possible, and continued straight ahead. He maintained flight for about 15–20 seconds but then banked right to avoid a warehouse, and the airplane settled and struck trees.
The student pilot reported similar details, noting that cold weather starting procedures were used. He observed a brief engine hesitation on the downwind leg and applied carburetor heat. After the second touch-and-go, RPM dropped slowly and the engine ran rough. The flight instructor took control and applied carburetor heat, which worsened the roughness, then turned it off and pumped the throttle. The student looked for a landing spot and pointed out a dirt parking lot, but they banked to avoid a warehouse and landed in trees.
Witnesses observed the airplane at low altitude with the engine sputtering and quieter than normal. One witness saw a smooth right bank before the airplane disappeared from view; another heard sputtering and popping, saw a nose-high attitude with swaying, and then heard impact.
Personnel Information
The flight instructor held a commercial pilot certificate with single-engine, multi-engine, and instrument ratings, along with a flight instructor certificate. His most recent second-class medical was issued November 22, 2011. He reported 1,391 total flight hours, with 131 in the accident airplane make and model. The student pilot had about 20 total hours in the accident airplane and held a third-class medical issued June 17, 2010.
Aircraft Information
The accident airplane was a two-place, strut-braced, high-wing airplane of conventional metal construction, with tricycle landing gear. It was powered by an air-cooled, 100-horsepower Continental O-200-A engine driving a fixed-pitch propeller. The flight instructor reported maintenance issues since his purchase in August 2011, including navigation, communication, vacuum system, and starter problems, as well as recent carburetor heat sticking. The engine had been overhauled shortly before purchase. The student noted water in fuel sump samples early in his training, which was resolved by replacing overwing fuel cap seals. He also reported a missing radio, unresponsive attitude indicator, low vacuum indications, and inaccurate fuel quantity gauges. The airplane was manufactured in 1966. Its most recent annual inspection was completed August 11, 2011, at which time the engine had 105 hours since major overhaul and the airframe had 4,725.3 total hours. On November 4, 2011, the carburetor airbox, valve shaft, and bearings were replaced, along with a new carburetor heat cable.
Meteorological Information
Recorded weather at FIT at 0952, about 8 minutes before the accident, included calm winds, 10 miles visibility, overcast clouds at 10,000 feet, temperature 0°C, dew point -4°C, altimeter 30.12 inHg, and relative humidity 72%.
Airport Information
Fitchburg Municipal Airport was uncontrolled with two runways: 2/20 and 14/32. Runway 32 was asphalt, 4,510 feet long and 100 feet wide, with non-precision markings. Obstructions existed off the departure end: 50-foot trees 600 feet from the runway, 125 feet right of centerline, requiring an 8:1 slope to clear.
Flight Recorders
The airplane was not equipped with a flight recorder. The student had a Contour Nflightcam that recorded GPS data but no video or audio until after impact. GPS data showed a touchdown at 09:57:51, then liftoff, acceleration to 500 feet and 56 knots groundspeed, followed by deceleration and descent to 40 knots at 09:59:51. Impact occurred at 10:00:03, 2,379 feet off the departure end of Runway 32.
Wreckage and Impact Information
The airplane came to rest upright in a dirt parking lot, partially entangled in a hedgerow and trees. It impacted approximately 20-foot trees beginning about 50 feet south of the final resting point. No propeller strikes on trees were found. Examination revealed no preimpact failures or malfunctions. Wings remained attached; the empennage was torn from the fuselage aft of the rear bulkhead. Control cables had continuity. The left wing had extensive damage to the outboard 4–5 feet; the right wing had leading edge damage. Fuel samples from both tanks were clear blue 100LL with no contaminants. The fuel selector was in the OFF position (moved by the flight instructor at the request of a firefighter). Cockpit controls: ignition OFF, master OFF, throttle 7/8 open, mixture full rich, carburetor heat OFF, navigation and beacon lights ON, flaps toggle in neutral, elevator trim on takeoff bug (neutral). Control yoke continuity to elevator was confirmed; aileron cables had failed in tensile overload but continuity was visually established from ailerons to breaks and from breaks to control wheels. Rudder continuity was confirmed.
Propeller and engine examination showed no preimpact anomalies. Both magnetos produced spark. Engine compression was present on all cylinders. Spark plugs had light deposits and normal wear. Carburetor and intake manifold showed impact damage but no preexisting issues. The carburetor heat control cable was intact but its arm was bent. The carburetor heat system and procedures for detecting and removing carburetor ice were described in the report, as well as guidance from Continental Motors and FAA regarding carburetor ice avoidance.
Survival Factors
The ELT did not activate and was found in the ARMED position with no damage. Both cabin doors opened after impact, allowing egress. The student pilot sustained a cut on his head, pelvic injuries, and a broken knee. Lap belts from 1972 were installed; no shoulder harnesses were present. The report cited FAA literature that shoulder belts reduce major injuries by 88% and fatalities by 20%.