# NTSB SEA97LA163: Piper PA-18-150, N4249Z, Big Creek, ID, July 5, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 5, 1997, 11:00 local (17:00 UTC) - Place: Big Creek, ID - Coordinates: 45.069641, -115.970703 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.0696&lon=-115.9707&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 28, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 42652 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA97LA163 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42652/pdf - Page: https://openairdocs.org/ntsb/SEA97LA163 ## Probable cause The pilot-in-command's inadequate terrain clearance and failure to maintain directional control. Also, the overload of the aircraft's left main landing gear strut assembly. Factors contributing to the accident were high density altitude conditions, downdrafts (associated with the lee side of mountain flying), and crosswinds. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, maneuvering - weather condition - downdraft (contributing factor) - altitude/clearance - inadequate, pilot in command (cause) - weather condition - high density altitude (contributing factor) - Loss of control - on ground/water, takeoff - roll/run - weather condition - crosswind (contributing factor) - directional control - not maintained, pilot in command (cause) - Gear collapsed, takeoff - roll/run - landing gear,main gear strut - overload (cause) ## Analysis While circling the Mile Hi United States Forest Service emergency airstrip to look at another aircraft accident, the pilot encountered lee side winds (downdraft), lost altitude and 'wound up having to flare to land.' The pilot intended to coast upslope and southbound over the ridge on which the north/south strip is situated, and take off on the upwind side. When the aircraft reached the top of the ridge the aircraft encountered an upslope wind which yawed the aircraft right. The aircraft then became airborne, crossing the top of the ridge and impacting the left main landing gear which then collapsed. The pilot estimated the winds at the accident site as 130-140 degrees at 5 to 10 knots, and the temperature at 80 degrees Fahrenheit. The approximate density altitude based on that temperature and elevation was 8,700 feet. ## Factual narrative On July 5, 1997, approximately 1100 mountain daylight time, a Piper PA-18-150, N4249Z, registered to and being flown by a private pilot, was substantially damaged during an inflight collision with terrain while maneuvering in the vicinity of Mile High airstrip, Big Creek, Idaho. The pilot was uninjured. According to the pilot, visual meteorological conditions prevailed, and no flight plan had been filed. The flight, which was personal, was to have been operated under 14CFR91, and originated from Johnson Creek airstrip, Yellow Pine, Idaho, approximately 1000. The pilot reported that he "circled Milt Hi (airstrip) with the intent to look at a super cub wreckage (N27296) on top of the ridge" and that while circling, and on the north (lee) side of the airstrip/ridge he "lost altitude and wound up having to flare to 'land." The pilot stated that "at that point my intent was to coast over the ridge and take off on the upwind slope." The pilot further stated that as the aircraft reached to the top of the ridge "it abruptly turned to the right '(probably due to the wing coming up the slope)' and yawed right." He indicated that subsequently crossed the top of the ridge airborne, descended and struck the ground collapsing the left main landing gear at an estimated airspeed of 20-25 miles per hour (refer to photograph 1). The Mile Hi airstrip is considered a US Forest Service Emergency strip. It has no identifier and is situated at an elevation of 5,831 feet above sea level (refer to ATTACHMENT I). The strip is unidirectional with landings towards 190 degrees magnetic and takeoffs in the reverse direction. The landing direction provides a 15-22 percent uphill grade of approximately 560 feet length followed by an approximate 45 degree dogleg "run-out" to the right. The pilot estimated the winds at the accident site as 130-140 degrees at 5 to 10 knots, and the temperature at 80 degrees Fahrenheit. The approximate density altitude based on that temperature, elevation and a standard pressure setting of 29.92 inches of mercury was 8,700 feet. ## Aircraft - Registration: [N4249Z](https://openairdocs.org/aircraft/N4249Z), registered now, S/N 18-8478, built 1966 (OpenAirDocs) - Reported make and model: Piper PA-18-150 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-8478 - Airframe hours: 6990 - Engines: Lycoming O-320A2B 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Blomquist, Frank, O. - Airworthiness certificate: Standard, Utility - Last inspection: Annual, February 7, 1997, 30 hours before - Departed: 3U2, YELLOW PINE, ID - Airport: runway 19, 560 × 30 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: front; flight hours: 942 total, 424 in this make and model, 942 as pilot in command, 21 in the last 90 days, 15 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 10 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 81 °F ## 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 19970705047259A](https://openairdocs.org/incident/19970705047259A), Jul 5, 1997: Piper PA18150, Bigcreek, ID, Substantial damage. (-16) While he was circling an earlier aircraft wreckage, the pilot reported he was unable to maintain altitude and consequently impacted the rising terrain.… ## Other investigations on N4249Z (1) 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. - [NTSB WPR13CA339](https://openairdocs.org/ntsb/WPR13CA339), Jul 25, 2013: Piper PA-18 (N4249Z), Challis, ID, substantial damage. Probable cause: The pilot's failure to maintain directional control during the takeoff roll. 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.