History of Flight
On September 19, 2011, at 1310 mountain daylight time, a Concannon Radial Rocket experimental amateur-built airplane, registration N91TX, sustained substantial damage when it impacted terrain while maneuvering near the Socorro Municipal Airport (ONM), Socorro, New Mexico. The commercial pilot and a pilot-rated passenger sustained fatal injuries. The airplane was owned and operated by the pilot. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight conducted under 14 Code of Federal Regulations Part 91. The flight departed Dallas Executive Airport (RBD), Dallas, Texas, at 0939 central daylight time.
According to the previous owner, the pilot and passenger arrived in Mississippi on September 17 to purchase the airplane. On September 18, the previous owner and pilot performed a 30-minute flight involving basic maneuvers; the previous owner noted the pilot was smooth and coordinated. The pilot-rated passenger then received a 10-minute ride. The group spent additional hours reviewing the airplane, during which the pilot expressed concerns about the complexity of the electronic flight information system (EFIS), autopilot, mixture control, switch placement, and boost pumps. The pilot had difficulty locating airspeed and altitude readouts on the EFIS display. The previous owner stated the pilot appeared attentive and demonstrated understanding of the discussions.
The pilot and passenger departed Mississippi en route to Dallas, Texas, where they spent the night. After arrival, the pilot had the airplane fueled with 16.5 gallons of aviation gasoline and requested tools to perform a repair on the left main landing gear.
On September 19, the airplane departed RBD. A passenger contacted flight service for winds aloft, describing the airplane as a Cessna 172. Data from a handheld GPS showed departure from RBD and descent toward ONM, with the track ending about 2 miles from the accident site.
A witness, a mechanic at ONM, heard a loud pop and observed the airplane heading east to west toward ONM. The airplane turned north, exhibiting wing rocking, then struggled to maintain altitude while wobbling. It turned west, lost lift, and nosed down. The witness heard popping noises from the engine but saw no smoke. Another witness near the accident site observed low-altitude maneuvering resembling crop-duster operations, a brief nose-up pitch, then impact.
Personnel Information
The commercial pilot, seated in the front, held single-engine land, multi-engine land, and glider ratings. He reported 4,000 total flight hours on his FAA first-class medical certificate dated November 15, 2010, with no medications reported. No personal flight records were found. His commercial certificate was suspended for 100 days from September 16, 2009, to December 24, 2009.
Aircraft Information
The Concannon Radial Rocket was a two-place composite airplane with fixed conventional landing gear, powered by a 400-horsepower supercharged M-14P nine-cylinder radial engine. It received an experimental amateur-built airworthiness certificate on November 10, 2006. The last conditional inspection was completed on June 4, 2011, at a tachometer time of 183.2 hours. The tachometer was destroyed in the accident, so total airframe and engine times could not be determined. Records were partially consumed by postimpact fire.
Recovered notes from the previous owner included reminders: "Boost must be on...", "Boost 2 must be on for takeoff and landing (5 minutes)", "Mixture must be full rich for takeoff, landing, rapid throttle movements", and "Failure to do #2 and #3 may result in engine stumble or brief shutdown."
Meteorological Information
At 1315, the ONM automated weather observing system reported wind from 140 degrees at 9 knots, clear sky, temperature 28°C, dew point 5°C, and an altimeter setting of 30.24 inches of mercury.
Wreckage and Impact Information
The accident site was on a rocky embankment adjacent to an interstate highway on/off ramp about 1 mile northeast of ONM. The airplane impacted the lower embankment and came to rest on the upper portion. The debris path was oriented on a 185-degree heading. A postimpact fire consumed the airplane.
Main wreckage included the fuselage, both wings, engine, and empennage. Portions of the main landing gear and underside were found between initial impact and main wreckage. The cockpit/cabin was destroyed by fire; the instrument panel was unreadable.
All flight control surfaces were located with the main wreckage, but continuity could not be established due to fire damage. Surfaces remained partially attached, and no preimpact anomalies were noted. The left flap actuator was extended; the right was consumed by fire.
The three-bladed wooden propeller hub remained attached. Two blades separated and splintered; the third had a separated outboard section. Leading edges showed gouges and dents.
The engine remained attached to its mount, which stayed on the firewall. Components displayed thermal damage; fuel lines were consumed. The fuel servo valve was found at full throttle and free to rotate. The fuel servo mixture valve was not free to move. The fuel pump drive shaft was intact.
Medical and Pathological Information
Autopsies by the University of New Mexico Office of the Medical Investigator listed cause of death for both occupants as multiple blunt force and thermal injuries. Toxicology testing by the FAA detected:
- Pilot: Ibuprofen (urine), Lorazepam (urine, 2.203 µg/mL; blood unsuitable), Tramadol (blood, 2.293 µg/mL; urine).
- Passenger: Lorazepam (urine).
No carbon monoxide, cyanide, or ethanol were detected in either occupant.
Additional Information
A 2012 NTSB safety study on "The Safety of Experimental Amateur-Built Aircraft" concluded that purchasers of used experimental amateur-built aircraft face challenges transitioning to unfamiliar aircraft, requiring learning of unique handling characteristics and systems without the builder's firsthand knowledge. The NTSB recommended that the FAA and Experimental Aircraft Association develop transition training resources and incentives for builders and purchasers.