# NTSB FTW01TA194: Piper PA-18-150, N91187, Van Horn, TX, August 23, 2001 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Final report - Date: August 23, 2001, 18:00 local (23:00 UTC) - Place: Van Horn, TX - Coordinates: 30.688055, -104.927497 - Nearby events: https://openairdocs.org/map.md?lat=30.6881&lon=-104.9275&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report April 29, 2003 - Report: Approved by Office Director - Parties: Federal Aviation Adminsitration - NTSB case key (mKey): 53456 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW01TA194 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53456/pdf - Page: https://openairdocs.org/ntsb/FTW01TA194 ## Probable cause The pilot's failure to maintain adequate airspeed which resulted in an inadvertent stall. A factor contributing to the accident was the high density altitude. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - airspeed - not maintained, pilot in command (cause) - stall - inadvertent - weather condition - high density altitude (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis The border patrol pilot was performing routine patrol duties over rolling terrain at an estimated altitude of about 500 feet above ground level. While making a right turn and crossing a ridge, "the bottom fell out." The pilot applied full power and leveled the wings in order to recover; however, his actions were not sufficient to arrest the rate of descent and the airplane impacted the next ridge line. Examination of the airframe and engine after the accident did not reveal any anomalies that could have prevented normal flight operations. The calculated density altitude at the time of the accident was approximately 7,428 feet. ## Factual narrative On August 23, 2001, approximately 1800 central daylight time, a Piper PA-18-150 single-engine airplane, N91178, registered to and operated by the U.S. Border Patrol of Marfa, Texas, was destroyed upon impact with terrain following a loss of control while maneuvering near Van Horn, Texas. The instrument rated commercial pilot, sole occupant of the airplane, received minor injuries. Visual meteorological conditions prevailed and a company flight plan was filed for the 14 Code of Federal Regulations Part 91 Public Use flight. The aerial observation flight originated from Marfa, Texas, at 1530. In the enclosed NTSB From 6120.1/2, the 1,668-hour pilot reported that he was performing routine patrol duties over rolling terrain at an estimated altitude of about 500 feet above ground level. The pilot added that he "made a right turn and crossed a ridge when the bottom fell out." The pilot further stated that he applied full power and leveled the wings in order to recover; however, his actions were not sufficient to arrest the rate of descent and the airplane impacted the next ridge line. The FAA inspector, who traveled to the accident site, confirmed that the airplane was destroyed by impact forces. Examination of the 1981 model airplane, which at the time of the accident had accumulated a total of 8,889 hours, did not reveal any anomalies that could have prevented normal flight operations. Company records confirmed that the pilot had accumulated a total of 1,668 hours, of which 192 hours were in the same make and model of airplane. At the time of the accident, density altitude was calculated by the NTSB investigator-in-charge as 7,428 feet. ## Aircraft - Registration: [N91187](https://openairdocs.org/aircraft/N91187), registered now, S/N 18-8109079, built 1981 (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: 18-8109079 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Destroyed - Flight: Public aircraft, Part 91 - Registered owner: US Border Patrol Air Operations - Airworthiness certificate: Standard, Utility - Departed: MRF, Marfa, TX - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: minor; commercial; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 1, valid medical--no waivers/lim.; last flight review March 28, 2001; seat: front; flight hours: 1,668 total, 192 in this make and model, 119 as pilot in command, 104 in the last 90 days, 19 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 100 °F, dew point 37 °F - Altimeter: 30.18 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 20010823025919A](https://openairdocs.org/incident/20010823025919A), Aug 23, 2001: Piper PA18150, Vanhorn, TX, No damage. (-23) On August 23, 2001, at approximately 1730 central daylight time, a Piper PA-18 airplane, N91178, registered to and operated by the us border patrol of… 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.