# NTSB LAX95LA106: Burkhart Grob Twin Astir, N333BH, Fort Huachuca, AZ, February 11, 1995 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 11, 1995, 15:00 local (22:00 UTC) - Place: Fort Huachuca, AZ - Coordinates: 31.569263, -110.380401 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.5693&lon=-110.3804&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 31, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 29031 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX95LA106 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29031/pdf - Page: https://openairdocs.org/ntsb/LAX95LA106 ## Probable cause IMPROPER IN-FLIGHT PLANNING/DECISION BY THE PILOT, WHICH RESULTED IN HIS FAILURE TO REMAIN CLEAR OF TREE(S) DURING AN OFF-AIRPORT LANDING. FACTORS RELATED TO THE ACCIDENT WERE: LACK OF THERMAL LIFT, AND HIGH OBSTRUCTIONS IN THE OFF-AIRPORT LANDING AREA. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, approach - vfr pattern - final approach - in-flight planning/decision - improper, pilot in command (cause) - weather condition - no thermal lift (contributing factor) - terrain condition - high obstruction(s) (contributing factor) - object - tree(s) - clearance - not maintained, pilot in command (cause) - In flight collision with terrain/water, approach ## Analysis AFTER THE TOW RELEASE, THE GLIDER PILOT HAD DIFFICULTY LOCATING THERMALS FOR LIFT. HE SAW A FIELD AND PROCEEDED TO MANEUVER FOR AN OFF-AIRPORT LANDING. DURING THE APPROACH PHASE, HE SAW POWER LINES PERPENDICULAR TO THE INTENDED LANDING DIRECTION, SO HE MANEUVERED TO LAND PARALLEL TO THE POWER LINES. AS HE CONTINUED THE APPROACH, WHICH WAS OVER THE LEE SIDE OF SOME HILLS, THE GLIDER ENCOUNTERED AN INCREASE IN SINK RATE AND A DECREASE IN AIRSPEED. THE PILOT ATTEMPTED TO GAIN ENERGY AND TO CLEAR OBSTACLES; HOWEVER, THE LEFT WINGTIP COLLIDED WITH A TREE AND THE GLIDER CRASH LANDED. ## Factual narrative On February 11, 1995, at 1500 hours mountain standard time, a Grob Twin Astir glider, N333BH, operated by the Tucson Soaring Club, Inc., of Tucson, Arizona, collided with a tree with its left wing during a forced landing near Fort Huachuca, Arizona. The aircraft was substantially damaged. The pilot and his passenger were not injured. Visual meteorological conditions prevailed at the time of the local pleasure flight. According to the pilot's report, after the tow release at 2,000 feet above ground level, he had difficulty locating thermals for lift. Along the route, the pilot encountered a heavy sink rate and no lift. He saw a field and proceeded to set up for a forced landing. During the approach phase, the pilot noticed some power lines perpendicular to the intended landing direction. He decided to put the glider on a base leg for a landing to the northeast, parallel to the power lines. As the pilot began the final approach, there was a sudden, dramatic increase in the sink rate, coupled with a decrease in the airspeed. In an attempt to gain energy to clear the rapidly approaching obstacles, the pilot put the nose down and tried to level out. Moments later, the left wing tip struck the top of a tree. The pilot stated that there were no mechanical problems with the aircraft prior to the crash. ## Aircraft - Registration: [N333BH](https://openairdocs.org/deregistered/N333BH-1996-11-06), registration cancelled 1996-11-06, S/N 3218 (OpenAirDocs) - Reported make and model: Burkhart Grob TWIN ASTIR - Registry model: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g103-twin-astir) (registry code 1660202) (OpenAirDocs) - Category: Glider - Serial number: 3218 - Airframe hours: 1472 - Engines: unknown - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Tucson Soaring Club, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 25, 1994, 325 hours before - Departed: FHU, AZ ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; private; seat: rear; flight hours: 204 total, 41 in this make and model, 114 as pilot in command, 3 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 5 knots, gusting 10 - Visibility: 45 statute miles - Lowest ceiling: none - Temperature: 64 °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 19950211001599A](https://openairdocs.org/incident/19950211001599A), Feb 11, 1995: Grob G103TWNASTIR, Fort Huachuca, AZ, Substantial damage. Unable find thermals after tow release and high sink rate wing. Struck a tree on attempt to land in a field. 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.