NTSB Factual Report

On August 1, 2002, at 1420 eastern daylight time, N1177M, a Cessna 172K, was substantially damaged during a forced landing while on approach to Patuxent River Naval Air Station/Trapnell Field (NHK), Patuxent River, Maryland. The certificated commercial pilot received serious injuries and the passenger received minor injuries. Visual meteorological conditions prevailed, and a visual flight rules (VFR) flight plan was filed for the flight which originated at Myrtle Beach International Airport (MYR), Myrtle Beach, South Carolina at 1155. The personal flight was conducted under 14 CFR Part 91.

The pilot reported that he had flown from Patuxent River to Myrtle Beach 2 days prior to the accident for a short vacation before beginning Navy test pilot school. The pilot flew direct to Myrtle Beach, and upon landing the airplane's Hobbs meter indicated the flight duration had been 3.7 hours.

On the day of the accident, the pilot received a weather briefing from Anderson Flight Service Station (FSS) for the return flight from Myrtle Beach to Patuxent River, and filed a VFR flight plan. He then performed a pre-flight inspection and visually checked the fuel gauges inside the airplane. According to the pilot, the gauges indicated that the tanks were about 1/4 - 1/2 full, which he estimated to be about 8 gallons of fuel per tank. The pilot stated that he was unable to determine exactly how much fuel was in the tanks because he did not have a way to measure it.

The pilot added 20 gallons of fuel to the tanks, and estimated that he had a total of 36 gallons of fuel onboard, or 4 1/2 hours of flight time. He started the airplane around 1145, taxied to the runway, performed a runup check, and checked the fuel gauges again. They indicated about 3/4 tank each side, which he estimated to be 36 gallons of total fuel.

The pilot flew direct to Patuxent River at an altitude of 5,500 feet, and a power setting between 2,400-2,500 rpm. The carburetor heat was applied "occasionally" as the carb ice detector indicated "prudent" and the engine was leaned "periodically." The pilot performed several ground speed calculations during the flight, indicating a consistent groundspeed of 100-110 mph. The pilot did not perform any fuel burn calculations during the flight.

When the pilot was about 10 miles from the airport, he was instructed by the tower controller to expect a left base entry for a full-stop landing on runway 02. About 3 miles from the airport, the pilot was instructed to perform a 360-degree turn for spacing and to change to a straight-in approach for runway 06. As the pilot was leveling the airplane from the turn, the airplane's engine "stopped producing power." The pilot then checked the fuel gauges which indicated 1/8 full on the left side, and 1/4 full on the right side. He increased the throttle, which momentarily brought power back to the engine. The airplane then pitched up, and the engine lost power again. The pilot initiated a 90-degree turn and held a nose-high attitude to clear trees in the flight path. Once over the tree line, the pilot lowered the nose and performed a forced landing to a field.

According to a Federal Aviation Administration (FAA) inspector, the airplane impacted the ground approximately 1/2 mile short of runway 06, on an approximate heading of 150 degrees. Visual examination of the fuel tanks revealed that the left wing tank was "completely dry," and approximately 1/8 of an inch of fuel was observed in the right wing fuel tank. The fuel selector was observed between the "both" and "right" positions, and the mixture and throttle control levers were observed in the full forward position.

The engine was examined at a salvage facility in Clayton, Delaware, under the supervision of a Safety Board Investigator. The fuel lines from the wing roots to the gascolotors were absent of debris and obstructions, and the carburetor and gascolator fuel screens were also absent of debris. Less than 1 teaspoon of fuel was observed in the gascolator bowl. A test run of the engine was performed, on the airframe, by introducing fuel directly to the carburetor. The engine started without hesitation and ran continuously through a variety of power settings.

During the examination, it was noted that the Stewart Warner fuel level transmitters had been removed from the airplane and were unable to be tested with the fuel gauges at the salvage facility. The manager of the Patuxent River Navy Flying Club was questioned regarding the disposition of the transmitters. He stated that he had removed them from the airplane prior to the salvage company's arrival, and retained them for his own testing. He further stated that when he removed the transmitters, he was aware of Safety Board instructions specifying that the airplane had not been released.

The fuel level transmitters were then shipped to the Safety Board, and tested with the fuel gauges. No mechanical anomalies were noted.

According to flight logs kept by the Patuxent River Navy Flying Club, the accident airplane was checked out by the pilot on July 29, 2002 at a Hobbs time of 2214.5 and returned at a Hobbs time of 2215.9. An entry for 16.8 gallons of fuel was displayed on the same line, and an interview with a representative of the flying club revealed that aircraft are always refueled when they return from a flight. Another entry on the following line of the log indicated that the airplane was checked out again by the pilot on the day of the accident, at a Hobbs time of 2215.9. The Hobbs time at the accident site was 2222.8.

A Service Bulletin (SEB99-18) was issued by the Cessna Aircraft Company on November 1, 1999, which addressed inspections of the Stewart Warner fuel quantity indicating system. The purpose of the inspections was to verify that each fuel tank gauge indicated empty when the fuel tank contained only unusable fuel. The Service Bulletin stated that these inspections shall be accomplished within the next 100 hours of operation or 12 months, whichever came first. After the initial inspection, the inspection should be reaccomplished every 12 months thereafter.

Examination of the airplane and engine logbooks revealed no entries which addressed compliance with the Service Bulletin.

The pilot reported 815 hours of total flight experience, 124 of which were in fixed-wing aircraft, and 691 were in rotorcraft. In addition, the pilot had accumulated 9 hours in make and model.

The weather reported at Patuxent River, at 1355, included winds from 040 degrees at 9 knots, visibility 7 miles, few clouds at 3,000 feet, temperature 34 degrees, and dew point 19 degrees.

NTSB Probable Cause

The pilot's inadequate fuel calculations, which resulted in fuel exhaustion and a subsequent loss of engine power.