Accident Details
On July 24, 2010, at 1600 eastern daylight time, a Cessna 172N, registration N3480E, operated by Apollo Aviation Inc as a personal flight under 14 CFR Part 91, collided with a fence during takeoff from Eagles Nest Airport (W13) in Waynesboro, Virginia. Visual meteorological conditions prevailed and no flight plan was filed. The airplane sustained substantial damage. The certificated private pilot and two passengers reported no injuries. The flight was originating at the time of the accident.
Pilot's Account
The pilot reported that before departure, he checked the weather and calculated a density altitude of 4,000 feet using a temperature of 32 to 33 degrees Celsius (99 degrees Fahrenheit). He used 40 degrees Celsius in the pilot operating handbook and determined that the ground roll would be 1,500 feet at an airport elevation of 1,437 feet. He also calculated weight and balance and determined the airplane was below maximum gross weight.
The pilot and two passengers entered the airplane and started the engine. The pilot taxied to the threshold of runway 24, a 2,009-foot-long asphalt runway in poor condition. He then taxied back onto the grass overrun area to obtain an additional 500 feet for takeoff. After a normal engine run-up, he extended flaps to 10 degrees for a short field takeoff. He lined up on the runway, set the brakes, increased throttle to full power, and leaned the mixture for elevations above 3,000 feet, observing 2,400 rpm on the tachometer. Upon releasing the brakes, the takeoff roll began. Initial acceleration through the grass was slow, but acceleration became normal on the paved runway. The airplane lifted off at 60 knots and remained in ground effect, failing to climb. The pilot turned left to avoid trees, flew under power lines, and then made a forced landing to a field. The airplane collided with a fence, rolled out in the field, struck another fence, and came to a stop.
Witness Observations
The airport manager at W13, a certified flight instructor, stated the temperature at the time of departure was 98 degrees Fahrenheit and the density altitude at Shenandoah Valley Airport, 11 nautical miles northeast of W13, was 4,000 feet. He observed the pilot back taxi down the over-run area, perform an engine run-up, line up, and start the takeoff roll. He noted that the pilot did not appear to throttle to full power and assumed he wanted to avoid damaging the propeller on grass. When the airplane reached the runway threshold, the rpm remained unchanged. About two-thirds down the runway, the pilot forced the airplane into the air; it wallowed left to right, barely flying, and never exited ground effect. As trees at the runway end approached, the nose came up, then the airplane began to settle. After clearing a second set of trees, the airplane settled out of sight.
Aircraft Examination
Examination of the airplane revealed structural damage to the empennage, fuselage, and right elevator. Examination of the engine assembly and accessories revealed no anomalies.
Performance Data Review
The pilot operating handbook for the Cessna 172N, Section 4, states: "Normal and short field takeoffs are performed with flaps up. Flaps greater than 10 degrees are not approved for takeoff. Use of 10 degree flaps is reserved for takeoff from soft or rough fields. Use of 10 degrees flaps allows safe use of approximately 5 KIAS lower takeoff speeds than with flaps up. The lower speeds result in shortening takeoff distances up to approximately 10 percent. However, this advantage is lost if flaps up speeds are used, or in high altitude takeoffs at maximum weight where climb performance would be marginal with 10 degree flaps. Therefore, use of 10 degree flaps is not recommended for takeoff over an obstacle at high altitude in hot weather."
The FAA Accident Prevention Program for Density Altitude states: "Even at lower elevations, aircraft performance can become marginal and it may be necessary to reduce aircraft gross weight for safe operations. Therefore, it is advisable, when performance is in question, to schedule operations during the cool hours of the day, early morning or late afternoon, when forecast temperatures are expected to rise above normal. Early morning and late evening are sometimes more ideal for both departure and arrival."
The pilot indicated in a statement that the empty weight of the airplane was 1,485 pounds, the combined weight of the pilot and two passengers was 590 pounds, 28 gallons of fuel weighed 168 pounds, and baggage weighed 44 pounds. After subtracting 7 pounds for engine start, taxi, and run-up, the computed takeoff weight was 2,280 pounds. The maximum gross weight for the Cessna 172N is 2,300 pounds. The pilot and passengers were from Holland and returned home; the provided weights could not be verified.
The performance data in Section 5 for short field takeoff at maximum weight of 2,300 lbs notes: "For operation on a dry grass runway, increase distances by 15 percent of the ground roll figure." At a gross weight of 2,300 pounds and pressure altitude of 1,000 feet, ground roll at 40 degrees Celsius is 1,500 feet and distance to clear a 50-foot obstacle is 1,865 feet. At 2,000 feet pressure altitude, ground roll is 1,155 feet and obstacle distance is 2,055 feet.