Safety In Numbers

If there's a wild card in the accident rates, it's in the number of flight hours upon which the calculations are based. Flight hours for GA are estimated by the FAA. The FAA's estimate for 2003 was 25,705,000. For 2004, the estimate was 25,900,000 flight hours. Some pilots who observed that traffic at their home airports was lighter in 2004 than in the past might wonder how the FAA came up with an estimate of increased general aviation flight hours. One possible explanation is because of the increased business aircraft activity, which would have a positive effect on the accident rates, since flight crews of upscale business aircraft generally engage in recurrent training, hold advanced certificates and ratings, and may even be full-time professionals.

So as a category, GA has made good progress in the area of safety according to the statistics. But there's still more work to be done. Here are two examples of accidents from 2004, which might have been avoided through better preflight planning and in-air decision making as well as a better understanding of aircraft limitations.

Cessna 182G
On January 1, 2004, about 7 p.m., a Cessna 182G crashed in snow-covered terrain about 21 miles southwest of Glasgow, Mont. The airplane was owned by the pilot and was being operated as a VFR cross-country personal flight under Part 91. The private pilot and three passengers were fatally injured. Dark night conditions prevailed. The flight originated at Mobridge, S.D. The pilot's flight-planned destination was Cut Bank, Mont. The aircraft departed Mobridge approximately three hours prior to the accident. At 6:23, the pilot contacted the FAA's Automated Flight Service Station at Cedar City, Utah, and requested an in-flight "weather update from Glasgow to Cut Bank." The specialist reported, in part, that low ceilings and visibilities were forecast for Cut Bank and that VFR flights were not recommended along the intended route of flight due to an AIRMET for IFR conditions, icing conditions and areas of mountain obscuration. After receiving the forecast weather for the route as well as current weather observations for north central Montana, the pilot reported that he was diverting to Havre, Mont. At that time, the most current observation for Havre reported broken clouds at 5,500 feet and a visibility of 8 sm.

After midnight, the FAA issued an alert notice for the aircraft after it failed to arrive at the pilot's flight-planned destination. A search for the missing aircraft was initiated. On the afternoon of January 4, 2004, the aircraft wreckage was located approximately 21 miles southwest of Glasgow, southeast of the intended alternate. Bad weather, including blowing snow and below-zero temperatures, prevented investigators from reaching the site until January 7.

The pilot held a private-pilot certificate with an airplane single-engine land rating. The pilot didn't hold an instrument rating. The pilot's third-class medical certificate contained a limitation requiring the pilot to wear corrective lenses. On his medical application, the pilot reported that he had accumulated approximately 175 total flight hours, including approximately three hours in the six months preceding the application date. At 7:16, the hourly report for Havre was wind from 030 degrees at nine knots; visibility, 3 sm with light snow; sky conditions and clouds, 1,100 feet overcast; temperature, minus-13 degrees C; dew point, minus-16 degrees C; altimeter, 29.69.

The 6:56 hourly observation at Cut Bank was wind from 350 degrees at 13 knots; visibility, 3⁄4 mile in light snow and mist; vertical visibility at 600 feet; temperature, minus-16 degrees C; dew point, minus-17 degrees C.

Infrared weather satellite imagery showed areas of widespread cloud cover northwest of the accident location on the night of the accident. An examination of the engine, airframe and aircraft systems failed to find any problems.

The NTSB determined the probable cause of this accident was the loss of aircraft control, resulting in an in-flight collision with terrain. Factors included marginal weather and dark night conditions.

Cessna 172P
On August 9, 2004, at approximately 5:15 p.m., a Cessna 172P crashed into mountainous terrain while maneuvering near Monarch Pass in Colorado. A post-crash fire ensued. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under Part 91 without a flight plan. The two pilots sustained fatal injuries. The cross-country flight originated at Montrose, Colo., at 3:25 p.m., and was en route to McCook, Neb.

According to the operator, the pilots departed Allegheny County Airport in Pittsburgh, Pa., on August 4, 2004, and flew to Phoenix, Ariz., via Lexington, Ky. Flying three three-hour legs each day, they arrived in Phoenix on August 6. They picked up a passenger and flew to San Diego, Calif. They departed San Diego on August 8, and flew back to Phoenix, where the passenger disembarked. From there, they flew to Bryce Canyon, Utah, and spent the night.

The next morning, one of the pilots telephoned his wife and told her that they were en route home and that they would stop at West Bend, Wis. The two pilots departed Bryce Canyon and flew to Montrose. The pilot telephoned the aircraft's operator at approximately 2 p.m., and reported that the weather was fine and that the airplane was performing well.

FAA records indicate that the pilot telephoned the Denver Automated Flight Service Station and received a weather briefing for a flight from Montrose to McCook. He didn't file a flight plan. The airplane departed Montrose at approximately 3:30. After takeoff, the pilot told the Unicom operator that they were going to "circle the area for a while."

Two Virginian tourists hiking near the Continental Divide heard an airplane approaching. One of the tourists turned and saw an airplane "at eye level, maybe 100 yards away, coming toward me. Then the plane seemed stationary in flight, the engine skipped, [the airplane] took a hard right-hand turn as I faced the plane, then the tail went straight up over the wing and straight down. [It burst] instantly into flames."

The other tourist saw the airplane "come up [the] mountain [pass], tried to turn around and went straight down." One of the tourists hitched a ride to nearby Monarch Ski Resort to report the accident.

The left-seat pilot held a private-pilot certificate with airplane single-engine land and instrument ratings. He also held a first-class airman medical certificate. According to the airplane operator's records, the pilot had logged approximately 190 flight hours.

The right-seat pilot held a private-pilot certificate with airplane single-engine land and instrument ratings. He held a second-class airman medical certificate. According to the airplane operator's records, the pilot had logged approximately 234 flight hours.

When investigators examined the engine and airframe, they found no discrepancies. Using the weather information recorded by a remote AWOS weather observation facility located on Salida Mountain, about one mile east of the accident site, investigators computed the density altitude at about the time of the accident. It was computed to have been about 14,300 feet MSL. According to the 1984 Cessna 172P Skyhawk information manual, the airplane's service ceiling is 13,000 feet.

The NTSB determined that the probable cause of this accident was the pilot's failure to maintain airspeed, which resulted in a stall, and his decision to conduct flight beyond the performance capability of the aircraft. A contributing factor was the high-density altitude and an inadvertent stall.

Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, NY 10602-0831.