NTSB Factual Report

HISTORY OF THE FLIGHT

On May 2, 1994, about 1030 mountain daylight time (mdt), a Maule M7-235, N525GS, piloted by the private pilot/registered owner, was destroyed when it impacted an earth bank and came to rest in a stock pond near McIntosh, South Dakota. The non-instrument rated private pilot and the one passenger on board the airplane received fatal injuries. Instrument meteorological conditions (IMC) prevailed for the flight, no flight plan was filed. The flight operated under 14 CFR Part 91, and originated from Aberdeen, South Dakota, approximately 0900. The intended destination was Miles City, Montana.

According to Air Traffic Control (ATC) records and family testimony, the pilot and the one passenger were en route from their home base airport in Green Bay, Wisconsin to Kamiah, Idaho, on a hunting/camping vacation. ATC records revealed the pilot planned to depart the Green Bay area about 0400, refuel at Aberdeen, South Dakota, and stop at Miles City, Montana on the way to their destination.

Records indicate the pilot obtained two preflight weather briefings from Green Bay Automated Flight Service Station (AFSS) before departure. Green Bay AFSS personnel advised the pilot that, although there was a possibility of light rain showers in Montana, visual flight rules (VFR) conditions were forecast along the planned route of flight throughout the day. The briefer reminded the pilot that Flight Watch would be available for weather updates and pilot reports.

While en route, the pilot contacted Princeton AFSS twice (at 0531 and 0621) for updated weather information. He contacted Huron AFSS at 0707, reported he was inbound to Aberdeen, and requested Aberdeen weather. All transmission were reported to be routine. Excerpts from the ATC package are appended.

According to airport personnel, the pilot landed at the Aberdeen Municipal Airport approximately 0800 in VFR weather conditions. At the pilot's request, the airplane was refueled with 52.2 US gallons of 100LL fuel. Airport personnel reported their dealings with pilot and airplane were routine, and the pilot departed Aberdeen between 0830 and 0900. There was no further known communication with the accident airplane.

Residents south and southwest of McIntosh, South Dakota reported they saw a cream colored airplane flying very low overhead on the morning of May 2, 1994. The accident airplane was cream colored with blue trim. The witnesses stated the weather was bad and the airplane was only visible for a short time, through breaks in the low clouds and fog. The witnesses stated the airplane appeared to be operating normally, except for the low altitude and weather conditions. One witness estimated the airplane was about "...two telephone poles high..." when it flew overhead. The witnesses indicated they were concerned because the airplane was travelling in a westerly direction, towards rising terrain. One witness stated "...I figured if he made it past Hump Butte he'd be ok." There were no further known sightings of the accident airplane. Witness statements are appended.

A search for the missing airplane was initiated. No Emergency Locator Transmitter (ELT) signal was detected, and there was no radar track data available. Search and rescue personnel flew grid patterns between Aberdeen and Miles City. The airplane wreckage was discovered by airborne Civil Air Patrol (CAP) personnel on May 12, 1994, approximately 1030. The wreckage was located on a ranch approximately 6 1/2 miles southwest of the town of McIntosh.

CREW INFORMATION

The pilot held a private pilot certificate, with airplane single engine land privileges, issued June 3, 1989. Records indicated the pilot had a total flight time of 1,303 hours, including 95 hours in the accident make and model airplane. The pilot had flown 47 hours in the accident airplane within the 90 days preceding the accident. The pilot's flight logbook indicated 3 hours of simulated instrument flight, with no actual instrument flight time listed. The pilot also held a Third Class Medical Certificate, with no limitations, dated September 17, 1992.

AIRCRAFT INFORMATION

Maintenance records indicate the airplane underwent production flight tests on October 6, 1993, and received its original airworthiness certificate on October 7, 1993. The aircraft registration certificate was issued to the pilot on November 15, 1993. A notebook located in the airplane indicated the tachometer reading recorded at Aberdeen was 81.8 hours. The total time on the airplane tachometer at the time of the crash was 82.9 hours. The pilot's notebook indicated an oil and filter change occurred on March 28, 1994, at a tachometer time of 52.8 hours. There were no entries in the maintenance logbooks.

METEOROLOGICAL INFORMATION

Transcripts of the preflight weather briefings obtained by the pilot indicated VFR conditions were expected along the planned route of flight. Local residents described the weather the morning of the accident as cloudy and foggy, with occasional visibilities of less than 1/4 mile. One witness stated: "The weather was crappy...looked up and saw the airplane. He was real low. I couldn't see more than 100 yards...foggy...low clouds."

A review of the weather in the vicinity of the crash site at the time of the accident was accomplished by an NTSB meteorologist. His factual report states: "...widespread instrument flight rules (IFR) conditions and marginal visual flight rules (MVFR) with patchy light rain, drizzle, and fog [extending] from Texas into the Western Dakotas." The AIRMET which addressed these conditions was issued at 0745, approximately 38 minutes after the pilot's last contact with AFSS.

The metallurgist's report also indicated the area was subject to a moist, southerly flow over upsloping terrain. (Aberdeen Municipal Airport, field elevation 1,300 feet, is located about 130 nautical miles (nm) from the accident site. Mobridge, South Dakota, elevation 1,696 feet, is located approximately 48 nm east of the accident site. The accident site elevation is estimated to be 2,275 feet.) A copy of the meteorologist's factual report is appended.

WRECKAGE/IMPACT INFORMATION

The airplane impacted rising terrain and water on a southerly heading. It was located partially submerged in approximately 4 feet of water at the edge of a pond. The tail section and right wing were visible above water. The fuselage was split and twisted forward of the horizontal stabilizer. The left wing and cabin roof were located on the bank at the east edge of the pond, separated from the fuselage except for flight control cables. There was wreckage debris scattered on rising terrain to the south and east of the main wreckage, to a distance of 200 feet. The left muffler and exhaust pipe were located about 40 yards east of the main wreckage.

The engine and cabin compartments were totally submerged in water when the airplane was discovered. When the airplane was pulled from the pond, the engine had separated except for cables. The propeller blades were twisted and bent aft, with evidence of chordwise scratches.

Both wings were buckled and twisted along their length. The leading edges of the wings were crushed aft, with the most extensive crush evident on the left wing. The right wing flap was bent and buckled, and separated from the wing except at the root. Wing flaps were in the retracted position. Both main landing gear were separated from the fuselage. The tail wheel remained attached.

Postaccident investigation revealed no evidence of preimpact malfunction. Flight control continuity was established, and engine continuity was verified. The ELT was located lodged in mud under water, with the impact actuator forward (activated). Photographs of the wreckage are appended.

MEDICAL/PATHOLOGICAL INFORMATION

An autopsy examination of the pilot (report number 94-46M) was conducted on May 13, 1994, by Donald M. Habbe, MD, Forensic Pathologist, at Clinical Laboratory of the Black Hills, P.O. Box 238, Rapid City, South Dakota, 57709, (605) 343-2267. The autopsy report revealed no evidence of preimpact anomaly.

A toxicological examination of specimens received from the pilot revealed the presence of ethanol, acetaldehyde and methanol. FAA Medical personnel stated the concentration levels present "...are certainly insignificant, and could be the result of postmortem factors." A copy of the toxicological report is appended.

ADDITIONAL INFORMATION

The airplane wreckage was released to the operator's representative upon completion of the onscene portion of the investigation. A copy of the NTSB Form 6120/15, Wreckage Release, is appended.

NTSB Probable Cause

VFR FLIGHT BY THE NON-INSTRUMENT RATED PILOT INTO INSTRUMENT METEOROLOGICAL CONDITIONS (IMC), AND HIS FAILURE TO MAINTAIN SUFFICIENT ALTITUDE (OR CLEARANCE) FROM RISING TERRAIN. FACTORS RELATED TO THE ACCIDENT WERE: FAILURE OF THE PILOT TO UPDATE HIS WEATHER INFORMATION AT THE EN ROUTE STOP, THE ADVERSE WEATHER CONDITIONS, RISING TERRAIN, AND THE PILOT'S LACK OF INSTRUMENT EXPERIENCE.