N177FGCessna 177 · 1968

On May 31, 2013, at 0012 eastern daylight time, a Cessna 177B, N177FG, was substantially damaged when it impacted a residential structure during a forced landing near Herndon, Virginia. The commercial pilot, pilot-rated passenger, and one occupant of the structure incurred minor injuries. Visual meteorological conditions prevailed, and a visual flight rules flight plan was filed for the flight, which originated from Northeast Philadelphia Airport (PNE), Philadelphia, Pennsylvania, about 2140, and was destined for Manassas Regional Airport (HEF), Manassas, Virginia. The aerial observation flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. According to the pilot, the purpose of the flight was to perform aerial photography in the vicinity of Gaithersburg, Maryland; Frederick, Maryland; and Philadelphia, Pennsylvania. Prior to departing from the airplane's base at HEF, the pilot prepared the airplane by attaching the necessary photographic equipment and removing excess weight from the baggage compartment. He also noted that both of the airplane's fuel tanks were "topped off" with 48 gallons of useable fuel following the previous flight. The pilot and passenger departed from HEF about 1215, and during the takeoff the pilot noted that despite the engine being at full power, the resulting climb rate was only between 150 and 200 feet per minute. He attributed the performance to the airplane's gross weight, which was within the prescribed limits, and the high density altitude that prevailed. The pilot then decided that he would not top off the airplane's fuel tank during the next planned fuel stop at PNE.

After flying in the vicinity of Gaithersburg and Fredrick, the flight proceeded to Chester County Airport (MQS), Coatesville, Pennsylvania and landed. The pilot then repositioned to PNE, and landed about 1550. Prior to departing on the accident flight, the pilot visually checked the fuel utilizing a fuel quantity test stick. He then calculated how much fuel would be required for 3 additional hours of flight and determined that 15 additional gallons of fuel was necessary. According to a fuel receipt from PNE, 10 and 5 gallons of fuel were added to the left and right fuel tanks, respectively.

The pilot and passenger then departed PNE about 2140. After completing the photography portion of the flight, the flight began heading toward HEF, around 0000. About that time, the pilot and passenger began discussing the airplane's fuel situation, noting that the left fuel quantity gauge indicated just above empty while the right fuel quantity gauge indicated just above 1/4-tank. The pilot and passenger decided that adequate fuel remained and that they would continue to HEF. While enroute, the pilot contacted Potomac Approach Control and requested to transition through the class B airspace of Dulles International Airport (IAD), Herndon, Virginia at an altitude of 3,500 feet. The request was subsequently approved.

About 0007, the airplane's engine experienced a total loss of power, and the pilot requested an emergency landing at IAD. The passenger also operated the mixture and throttle controls in an effort to restore engine power, which was initially successful, but the engine again ceased producing power after about 15 seconds. According to archived air traffic control communications, when air traffic control queried the pilot regarding how much fuel the airplane had remaining, the pilot stated, "We're out of fuel, I think that's our problem."

The pilot eventually realized that the airplane would not be able to reach IAD, and prepared for an off-airport landing. Shortly thereafter, the airplane struck the residential structure.

A Federal Aviation Administration inspector examined the airplane at the accident site about 45 minutes after the accident. The inspector stated that the integrity of both the left and right wing fuel tanks appeared to have been compromised during the impact sequence. Despite the breach of the tanks, the inspector observed no evidence of a fuel leak and no odor of fuel at the scene.

A JP Instruments EDM-711 engine monitoring device was recovered from the airplane following the accident, and its data were extracted. The total elapsed time for the earlier flights between HEF and PNE was about 3 hours and 22 minutes, with a total calculated fuel consumption of 37.6 gallons. The total elapsed time recorded for the accident flight was 2 hours and 54 minutes, with a total calculated fuel consumption of 29.2 gallons.

According to the Federal Aviation Administration Type Certificate Datasheet for the Cessna 177B, the airplane had a total fuel capacity of 50 gallons of fuel (drawing from two 25 gallon fuel tanks), and a total usable fuel capacity of 49 gallons.