DFW08LA052

NTSB accident investigation · Althouse RAF 2000 GTX · Crowley, TX · December 29, 2007

Accident · FatalLimited investigationFinal report
Date
December 29, 2007, 11:40 local (17:40 UTC)
Place
Crowley, TX
Injuries
2 fatal
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N136DGAlthouse RAF 2000 GTX
Weather
Visual (VMC) · Day
Status
Completed · report December 3, 2008
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20071229829239A
Case key
67314

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's failure to maintain rotor rpm while maneuvering, which resulted in a loss of rotor blade rigidity.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of control - in flightManeuvering
Rotor rpm - not maintainedPilot in commandCause
Rotor system,main rotor - buckled
In flight collision with terrain/waterDescent - 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
Reported as
Althouse RAF 2000 GTX
Category
Gyroplane, amateur-built
Serial number
H2-03-14-563
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
52
Injuries
Fatal
Certificates
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.