# NTSB DEN99LA092: Hughes 269A, N7052L, Parkman, WY, June 1, 1999 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 1, 1999, 11:00 local (17:00 UTC) - Place: Parkman, WY - Coordinates: 44.960178, -107.310691 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9602&lon=-107.3107&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report March 31, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46417 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN99LA092 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46417/pdf - Page: https://openairdocs.org/ntsb/DEN99LA092 ## Probable cause The pilot's inadequate in-flight planning by exceeding the helicopter's performance climb capability. Factors were the downdraft encountered during initial climb following takeoff, and the high density altitude. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, takeoff - initial climb - in-flight planning/decision - inadequate, pilot in command (cause) - aircraft performance,climb capability - exceeded (cause) - weather condition - downdraft (contributing factor) - weather condition - high density altitude (contributing factor) - terrain condition - mountainous/hilly ## Analysis An hour after landing in an open field (6,200 feet msl) near Parkman, Wyoming, in the Bighorn National Forest, the pilot performed a practice takeoff without his passenger to test the aircraft's performance. The helicopter hovered normally after effective translational lift was achieved, and he climbed out at 40 knots. Shortly after clearing a 75-foot ridge 100 to 150 yards from the takeoff field just after coming out of ground effect, the aircraft experienced a downdraft and subsequently began to lose altitude. The power required for the helicopter to climb was greater than the power available. The aircraft impacted the ground through 60 to 80 feet of trees, and came to rest in an inverted position. According to the pilot, there were no mechanical problems and the engine was running on impact. Density altitude at the time of the accident was calculated to be 7,578 feet. According to calculated weight and performance data, the gross weight of the aircraft at the time of departure was approximately 1,232 lbs. At an indicated airspeed of 35 knots, the maximum obstacle clearance height was calculated to be 75 feet, with a maximum distance of 800 feet. ## Factual narrative On June 1, 1999, approximately 1100 mountain daylight time, a Hughes 269A helicopter, N7052L, owned and operated by the pilot, was substantially damaged after colliding with terrain during initial climb following takeoff from a field near Parkman, Wyoming. The airline transport rated pilot, the sole occupant aboard, sustained minor injuries. The aircraft was being operated under Title 14 CFR Part 91, and no flight plan had been filed for the flight to Laurel, Montana. Visual meteorological conditions prevailed. According to the pilot, he departed Laurel at 0900 to check out a camp in the Bighorn National Forest. He stated that he was concerned with the aircraft's performance, but had flown at similar altitudes with cooler temperatures. With his passenger aboard, he performed an out of ground effect hover at 60 feet above ground level (agl). The field's elevation was 7,200 mean sea level (msl). He stated that the aircraft hovered with maximum available power at 2,900 rpm. He entered forward flight and attempted to land in a open field at an elevation of 6,200 feet msl. He aborted his first landing due to downdrafts, and his second attempt was successful. During departure from the field, he elected to perform a practice takeoff without his passenger to test the aircraft's performance. The helicopter flew normally after effective translational lift (ETL) was achieved, and he climbed out at Vy (40 knots), the aircraft's best rate of climb speed. Shortly after clearing a 75-foot ridge 100 to 150 yards from the takeoff field just after coming out of ground effect, the aircraft encountered a downdraft and subsequently began to lose altitude. The power required for the helicopter to climb was greater than the power available. The pilot banked the aircraft to the right to avoid two tall trees. The helicopter impacted the ground through 60 to 80 feet of trees, and came to rest in an inverted position. The pilot stated that there were no mechanical problems, and that the engine was running on impact. The pilot performed an upwind takeoff, and the wind was from 045 degrees at 5 knots, gusting to 15 knots. Density altitude at the time of the accident was calculated to be 7,578 feet. According to calculated weight and performance data, the gross weight of the aircraft at the time of departure was approximately 1,232 lbs. With a maximum takeoff of 2,900 rpm, the maximum available horsepower was 132, and a maximum manifold pressure of 22.2 inches Hg. At an indicated airspeed of 35 knots, the maximum obstacle clearance height was calculated to be 75 feet, with a maximum distance of 800 feet. ## Aircraft - Registration: [N7052L](https://openairdocs.org/deregistered/N7052L-2015-05-21), registration cancelled 2015-05-21, S/N 980962 (OpenAirDocs) - Reported make and model: Hughes 269A - Registry model: [Hughes 269A](https://openairdocs.org/model/hughes-269a) (registry code 4470402) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 980962 - Engines: Lycoming HIO-360-B1A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Kent W. Potter - Airworthiness certificate: Standard, Normal - Departed: NONE - Destination: 6S8, LAUREL, MT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; flight instructor, airline transport, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 12,600 total, 200 in this make and model, 11,750 as pilot in command, 100 in the last 90 days, 50 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 45° at 5 knots, gusting 15 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F - Altimeter: 29.00 inHg ## 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 19990601047029A](https://openairdocs.org/incident/19990601047029A), Jun 1, 1999: Hughes 269A, Parkman, WY, Substantial damage. (.4)An hour after landing in an open field (6,200 feet MSL) near Parkman, Wyoming, in the bighorn national forest, the pilot performed a practice takeoff… 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.