Aviation Accident Summaries

Aviation Accident Summary IAD04LA023

Old Town, ME, USA

Aircraft #1

N7793E

Cessna 150

Analysis

The pilot stated that during the takeoff roll, when the airplane reached about 1/3 the runway's length (about 1,060 feet), he thought it should have been airborne. At 2/3 the runway's length (about 2,120 feet), the pilot knew he had a problem, but "rotated" the airplane at 40 knots and became airborne. After rotation, he felt that the engine was not developing full power, and was "sluggish and lacking horsepower." The pilot briefly employed carburetor heat, then attempted to adjust the engine's mixture control; however, neither adjustment improved the airplane's performance. After bouncing once in a field, the pilot was able to land the airplane on an interstate median, where it nosed over in muddy terrain. There was no evidence of mechanical malfunction. Computation of weight and balance information provided by the pilot revealed that the airplane was 184 pounds over maximum gross weight at takeoff. Performance data revealed that an airplane at maximum gross weight should have been airborne in less than 600 feet of runway distance.

Factual Information

On May 17, 2004, at 1810 eastern daylight time, a Cessna 150, N7793E, was substantially damaged during a forced landing, shortly after taking off from Dewitt Field/Old Town Municipal Airport (OLD), Old Town, Maine. The certificated private pilot and the passenger were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the local personal flight, conducted under 14 CFR Part 91. According to the pilot, he conducted a full preflight inspection, engine run-up, and magneto check. At the beginning of the takeoff roll from runway 22, the tachometer indicated 2,500 rpm, and all engine indications "looked normal." The pilot stated that when the airplane reached about 1/3 the runway's length, he thought it should have been airborne. At 2/3 the runway's length, the pilot knew he had a problem. The pilot "rotated" the airplane at 40 knots and became airborne. After rotation, he felt that the engine was not developing full power, and was "sluggish and lacking horsepower." The pilot briefly employed carburetor heat, then attempted to adjust the engine's mixture control. Neither adjustment improved the airplane's performance. The pilot then looked for a possible landing site, and ahead was a field with a gully running through it. The pilot bounced the airplane over the gully, and when he did so, the airplane experienced a momentary performance gain. The pilot described the performance gain as the engine possibly developing full power, or lift increasing due to the "weightless" state of the airplane. The airplane climbed to 50 feet, and the pilot was able to make a 90-degree turn and land on the median of Interstate 95. The airplane then rolled about 450 feet, the nose wheel became stuck in the mud, and the airplane nosed over. A Federal Aviation Administration (FAA) inspector stated that he could find no evidence of mechanical malfunction. He also noted that he was not able to run the engine due to damage from the ground impact. An examination of the "Weight and Balance Report" submitted by the pilot revealed that the empty weight of the airplane was 1,081 pounds and the maximum gross weight was 1,400 pounds. When asked about the fuel load of the airplane, the pilot stated that it was about 18 gallons, and that he measured the fuel level with a "dip stick." The pilot estimated that his weight at the time of the accident was 205 pounds and his passenger's weight was about 190 pounds. The pilot also stated that he had previously flown the accident airplane with other, heavier passengers, without a problem. The calculated gross weight of the airplane at takeoff was 1,584 pounds. Runway 22 was 3,199 feet long and 75 feet wide. According to the 1959 Cessna Owner's Manual performance data, the takeoff run of a Cessna 150 at 1,500 pounds, temperature 59 degrees F, and no wind, would have been 680 feet. Takeoff distance would have been reduced by 10 percent for every 4 knots of headwind, and increased by 10 percent for each temperature rise of 35 degrees. Weather, reported at an airport about 10 nautical miles to the southwest, 13 minutes before the accident, included winds from 190 degrees at 13 knots, 10 statute miles visibility, clear skies, temperature 64 degrees F, dew point 48 degrees F, and a barometric pressure of 30.32 inches of mercury.

Probable Cause and Findings

The pilot's failure to abort the takeoff. Factors were the pilot's incorrect assessment of the airplane's weight and the muddy terrain.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports