# NTSB DEN99LA130: American AA-1, N5989L, Centennial, WY, July 27, 1999 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 27, 1999, 07:30 local (13:30 UTC) - Place: Centennial, WY - Coordinates: 41.300739, -106.109863 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.3007&lon=-106.1099&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report October 13, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46920 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN99LA130 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46920/pdf - Page: https://openairdocs.org/ntsb/DEN99LA130 ## Probable cause 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. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, maneuvering - aircraft performance,climb capability - exceeded (cause) - performance data - not obtained, pilot in command (cause) - weather condition - high density altitude (contributing factor) - weather condition - downdraft (contributing factor) ## Analysis 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. ## Factual narrative On July 27, 1999, approximately 0730 mountain daylight time, an American AA-1, N5989L, was substantially damaged when it collided with terrain near Centennial, Wyoming. The private pilot and his passenger received minor injuries. Visual meteorological conditions prevailed for the personal cross-country flight being conducted under Title 14 CFR Part 91, and no flight plan had been filed. The flight originated at Rawlins, Wyoming, at 0630. In his accident report, the pilot said he was en route to North Platte, Nebraska, and his final destination was Biddeford Maine. After departing Rawlins and flying for approximately one hour, he entered the Medicine Bow Mountains at 9,500 feet msl (mean sea level) and was "unable to negotiate 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. In a telephone conversation with the pilot after he had returned home, he explained that the airplane could not outclimb the rising terrain. He tried turning left and started losing altitude. When he tried to turn right, he lost airspeed. After the accident, he was able to contact the pilot of an overflying United Airlines flight, who in turn relayed the information to search and rescue officials. The pilot and his passenger were rescued later that morning and airlifted to a Laramie hospital. 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 indicates that under standard atmospheric conditions, the maximum rate of climb at 8,500 feet msl is 240 feet per minute. The accident took place in the Medicine Bow Mountains at a location of 41 degrees, 25.15 minutes north latitude, and 106 degrees, 10.80 minutes west longitude. ## Aircraft - Registration: [N5989L](https://openairdocs.org/deregistered/N5989L-2000-02-01), registration cancelled 2000-02-01, S/N AA1-0289 (OpenAirDocs) - Reported make and model: American AA-1 - Registry model: [American AA-1](https://openairdocs.org/model/american-aa-1) (registry code 0630610) (OpenAirDocs) - Category: Airplane - Serial number: AA1-0289 - Engines: Lycoming O-235-C2C 108 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Roland P.V. Furman - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 23, 1999 - Departed: RWL, RAWLINS, WY - Destination: LBF, NORTH PLATTE, NE ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 900 total, 250 in this make and model, 30 in the last 90 days, 15 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 3 knots - Visibility: 55 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 45 °F - Altimeter: 30.00 inHg - Observed at: LAR, 31 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19990727009979A](https://openairdocs.org/incident/19990727009979A), Jul 27, 1999: Amrgen AA1, Laramie, WY. Acft crashed under unknown circumstances at the 9,500 foot level near Laramie, WY. (-23) pilot failed to negotiate terrain. Pilot lost partial control of a/c… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.