NTSB Identification: DEN99LA130.
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Accident occurred Tuesday, July 27, 1999 in CENTENNIAL, WY
Probable Cause Approval Date: 10/13/2000
Aircraft: American AA-1, registration: N5989L
Injuries: 2 Minor.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The pilot departed Rawlins, Wyoming, en route to North Platte, Nebraska. His final destination was Biddeford Maine. He said that after he entered the Medicine Bow Mountains at 9,500 feet mean sea level (MSL), he realized the airplane could not outclimb the rising terrain. He saw a clearing and decided to make a forced landing. Unexpected downdrafts caused him to land hard and short of his intended point of touchdown. The reported temperature and altimeter setting at Laramie, Wyoming, located 31 miles east of the accident site and situated at an elevation 7,278 feet MSL, was 24 degrees C. (75.2 degrees F.) and 30.33 inches of mercury, respectively. The computed pressure and density altitudes at Laramie were 6,868 feet MSL and 9,421 feet MSL, respectively. According to the AA-1 Pilot Operating Handbook, the normal and utility category service ceiling is 11,000 and 13,150 feet MSL, respectively. The Handbook also indicated that under standard atmospheric conditions, the maximum rate of climb at 8,500 feet MSL was 240 feet per minute.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot's failure to consult the airplane performance charts and allowing the airplane to exceed its climb performance. Factors were high density altitude conditions and a downdraft.

Full narrative available

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