# NTSB DFW08LA052: Althouse RAF 2000 GTX, N136DG, Crowley, TX, December 29, 2007 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: December 29, 2007, 11:40 local (17:40 UTC) - Place: Crowley, TX - Coordinates: 32.55722, -97.485557 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.5572&lon=-97.4856&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report December 3, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 67314 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW08LA052 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/67314/pdf - Page: https://openairdocs.org/ntsb/DFW08LA052 ## Probable cause The pilot's failure to maintain rotor rpm while maneuvering, which resulted in a loss of rotor blade rigidity. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - rotor rpm - not maintained, pilot in command (cause) - rotor system,main rotor - buckled - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis The amateur built gyrocopter was destroyed following a loss of rotor rpm and subsequent collision with terrain while maneuvering. A witness initially heard a "loud pop" and then observed the gyrocopter, approximately 50-feet above the ground, descending at a nose down angle of approximately 60-degrees. The gyrocopter impacted the ground approximately 100-feet from where the witness was located. The witness further reported that before the impact, the rotor blades appeared to be spinning "slowly." Inspection of the wreckage revealed that the rotor blades had struck the rudder twice. In addition, the rotor hub and rotor blades exhibited evidence of upward coning, consistent with the rotor blades having lost rigidity due to low rpm. Inspection of the wreckage did not reveal any mechanical failure/malfunction which would have resulted in the loss of control. ## Factual narrative HISTORY OF FLIGHT On December 29, 2007, about 1140 central standard time, a single-engine Althouse RAF 2000 GTX gyrocopter, N136DG, was destroyed following a loss of rotor rpm and subsequent collision with terrain while maneuvering near Crowley, Texas. The sport pilot and passenger sustained fatal injuries. The gyrocopter was registered to and operated by the pilot. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The local flight had originated from the Fort Worth Spinks Airport (FWS), near Fort Worth, Texas. The gyrocopter departed on a local flight for the purpose of giving the nine year old passenger a ride. When the pilot and passenger failed to return to the airport the passenger's family notified local authorities. The wreckage was located a short time later. There was one reported eyewitness to the accident. According to the witness, he was driving his truck on a ranch when he heard a 'loud pop' which sounded like an "engine backfire." As he looked towards the noise he observed the gyrocopter, approximately 50-feet above the ground, descending at a nose down angle of approximately 60-degrees. The gyrocopter impacted the ground approximately 100-feet from where the witness was located. The witness further reported that before the impact, the rotor blades appeared to be spinning "slowly." PERSONNEL INFORMATION The pilot held a commercial pilot certificate with ratings for airplane single-engine land, multi-engine land, and instrument airplane. In addition, the pilot held a sport pilot certificate. His last Federal Aviation Administration (FAA) second-class medical was issued on July 9, 2007, with the limitation of "must wear lenses for distant – possess glasses for near vision." No personal flight records were located for the pilot and the aeronautical experience listed in this report was obtained from a review of the airmen FAA records on file in the Airman and Medical Records Center located in Oklahoma City. These records indicated that at his last medical examination, the pilot had reported a total of 8,000 flying hours with 100 hours logged in the last 6 months. The pilot's flying time in gyrocopters could not be determined. AIRCRAFT INFORMATION The 2005-model RAF 2000 GTX gyrocopter, serial number H2-03-14-563, was equipped with a single pusher engine, teetering blade rotor system with rotor stabilizer, and was configured for two occupants. The gyrocopter was powered by a four cylinder Subaru EJ22 engine rated at 130 horsepower, and was driving a three-bladed Warpdrive composite propeller. The gyrocopter's airframe and engine maintenance records were not located during the course of the investigation. METEOROLOGICAL INFORMATION At 1147, the automated weather observing system at the Fort Worth Spinks Airport (FWS), located about 10 nautical miles east from the site of the accident, reported wind from 150 degrees at 6 knots, 10 statute miles visibility, clear sky, temperature 46 degrees, dew point 19 degrees, and a barometric pressure setting of 30.15 inches of Mercury. WRECKAGE AND IMPACT INFORMATION An inspector from the Federal Aviation Administration (FAA) responded to the accident site. The inspector reported that the gyrocopter had impacted a flat open field and had come to rest on its side. There was no evidence of a post crash fire. The inspector further reported that the rotor hub and rotor blades exhibited evidence of upward coning, consistent with the rotor blades having lost rigidity due to low rpm. The gyrocopter was then recovered for further examination. The NTSB investigator-in-charge (IIC) examined the wreckage once it was recovered. All major components were accounted for. Control continuity was established to all flight and engine controls. Engine crankshaft continuity was established via rotation of the propeller. The rudder exhibited two black transfer marks consistent with material from the leading edge of the rotor blades. Inspection of the wreckage did not reveal any mechanical failure/malfunction which would have resulted in the loss of control. MEDICAL AND PATHOLOGICAL INFORMATION The Office of Chief Medical Examiner of Tarrant County, located in Fort Worth, Texas, performed an autopsy on the pilot on December 30, 2007. The cause of death was listed as, "Multiple Blunt Trauma due to Helicopter-Terrain Impact." ## Aircraft - Registration: [N136DG](https://openairdocs.org/deregistered/N136DG-2013-10-18), registration cancelled 2013-10-18, S/N H2-03-14-563, built 2005 (OpenAirDocs) - Reported make and model: ALTHOUSE RAF 2000 GTX - Registry model: [Althouse Gerald D RAF 2000 GTX](https://openairdocs.org/model/althouse-gerald-d-raf-2000-gtx) (registry code 05615L4) (OpenAirDocs) - Registry engine: [Subaru ALL MDLS A/B](https://openairdocs.org/engine/subaru-all-mdls-a-b) (registry code 59050, 4 cycle) (OpenAirDocs) - Category: Gyroplane, amateur-built - Serial number: H2-03-14-563 - Engines: Subaru EJ22 130 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Operator: Dase Daniel A - Registered owner: Dase Daniel A - Airworthiness certificate: Special, Experimental (Special) - Departed: FWS, FORT WORTH, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; injuries: fatal; commercial, sport pilot, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; seat: left; flight hours: 8,000 total ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 46 °F, dew point 19 °F - Altimeter: 30.14 inHg - Observed at: FWS, 10 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 20071229829239A](https://openairdocs.org/incident/20071229829239A), Dec 29, 2007: Amtr RAF2000GTX, Crowley, TX, Destroyed, 2 fatal. (-23) Investigation indicated aircraft impacted with terrain due to loss of control. Witness indicated that the aircraft descended at an approximately 60… 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.