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N11ZQ accident description

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Tail numberN11ZQ
Accident dateMay 24, 2001
Aircraft typeSchempp-Hirth Nimbus-3DM
LocationAlamogordo, NM
Near 32.759722 N, -105.807778 W
Additional details: None

NTSB description


On May 24, 2001, at 1216 mountain daylight time, a Schempp-Hirth Nimbus-3DM motorglider, N11ZQ, was destroyed when it impacted terrain while maneuvering near Alamogordo, New Mexico. The two private pilots were fatally injured. SAJ, LLC, of Powell, Wyoming, was operating the motorglider under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local long-duration flight that originated at approximately 1155. No flight plan had been filed.

The two pilots had arrived from Europe 3 days before the accident to take part in a 2 week long world record soaring attempt. They had traveled to Albuquerque, New Mexico, on May 22, 2001, to convert their European flight credentials to American private pilot certificates. They flew their first flight together from Alamogordo on May 23, 2001. They had flown north to the vicinity of Santa Fe Ski Basin (Lake Peak), New Mexico, a distance of 660 kilometers (365 nautical miles [nm]), and were airborne for approximately 6 hours.

On the morning of the accident, the two pilots had breakfast, and proceeded to the airport to preflight their motorglider. Edy Naef was sitting in the back seat and was the designated pilot-in-command (PIC) for the flight. His English was better and he had flown at Alamogordo the year before. Gilbert Gerbaud performed the takeoff on runway 21 (it is normal procedure for the front seat occupant to do the takeoff) and Edy Naef waved at the people on the ground as they lifted off. A friend of the two pilots and fellow motorglider pilot said that the motor is usually stowed at 1,000 meters, or 3,281 feet above ground level (agl). He said that the full stowing procedure takes between 2 to 3 minutes. He also said that the aircraft is at its maximum drag scenario during the stopping of the engine, centering the propeller, and stowing the engine. If for any reason the engine were to be extended during flight, it is recommended that the procedure be performed no lower than 1,500 feet agl. Normally, he said, the engine is used only for self-launching, and after that the aircraft is flown strictly as a glider.

Radar data from Holloman Air Force Base (White Sands Missile Range; elevation 4,093 feet; 290 degrees and 18 nm from the accident site) indicated the glider headed east-southeast after takeoff. The last radar return was recorded at 1215 (N32 degrees, 51.36'; W105 degrees, 49.47'), and the downed glider was located approximately 1 mile east of that location. No altitude data could be obtained from the raw radar data; the glider was not equipped with a mode C transponder.

Witnesses said that no radio transmissions were ever received from the glider. Search and rescue teams located the downed aircraft on May 27, 2001.


The pilot-in-command, Edwin Naef, had an estimated 3,249 hours of glider flight experience. It was his second visit to Alamogordo to fly motorgliders, and his second flight this visit. He was sitting in the rear seat.

The second pilot, Gilbert Gerbaud, was from France, and he had been the world glider champion. He had an estimated 6,370 hours of flight experience, with 5,430 hours in gliders. A fellow pilot said that Gilbert Gerbaud had flown all over the world in a wide variety of environments.


The motorglider was a single engine, propeller-driven, two seat aircraft, which was manufactured by Schempp-Hirth (Germany), in 1992. It was an experimental certificated aircraft which had a maximum gross takeoff weight of 1,808 pounds. The glider was powered by a retractable Bombardier Rotax 535c, two cylinder, two cycle, reciprocating, belt drive, carbureted, engine which had a maximum takeoff rating of 59 horsepower (7,200 RPM) at sea level. The motorglider had an 81 foot wing span, and the engine was used for takeoff and initial climb to approximately 3,000 feet agl. The engine was then shut down, the propeller was centered, and the engine was stowed into the fuselage (which took from 2 to 3 minutes). At the time of the accident, maintenance records indicated that the airframe had accumulated approximately 211 hours of flight time.

The glider was equipped with a permanent internal oxygen system for the crew members, which had the capacity to support two individuals for approximately 40 flight hours. The aircraft had three fuel tanks, an 18.3 liter bladder in each wing and an aluminum 14.3 liter tank in the fuselage; the total usable fuel available was 13.21 gallons. Five rechargeable batteries met all the electrical needs of the aircraft. A GPS (Global Positioning System) provided navigation information and flight data logging (for post flight review) for the pilots, The recorded data, from the accident flight, was lost during the impact sequence.

The POH (Pilot's Operating Handbook) for the motorglider stated that the aircraft had a maximum glide ratio of 57:1 L/D (lift over drag). The owner of the aircraft said that it took 12 to 14 seconds to extend the engine, but the L/D was reduced to approximately 18:1 with it extended. The motorglider's POH states: "normally the loss of height from extending the engine to the moment when it runs is about 30 to 40 meters (98 to 131 feet)."


At 1211, the weather conditions at the Alamogordo-White Sands Regional Airport (elevation 4,197 feet), 290 degrees 9 nautical miles (nm) from the accident site, were as follows: wind 010 degrees at 6 knots; visibility 10 statute miles (sm); clear of clouds; temperature 88 degrees Fahrenheit; dew point 52 degrees Fahrenheit; altimeter setting 30.03 inches. At 1216:38, the Apache Point Observatory, owned and operated by a private Astrophysical Research Consortium (elevation 9,155 feet), 320 degrees 1.4 nm from the accident site, recorded the wind at 310 degrees at 7 knots gusting to 17 knots; the temperature was 65 degrees Fahrenheit. The airplane's impact location had a calculated density altitude, at the time of the accident, of 11,731 feet.


The motorglider was found on a heavily forested irregular mesa (N32 degrees, 45.58 minutes; W105 degrees, 48.47 minutes; elevation 9,100 feet). The trees were up to 18 inches in diameter and 60 to 80 feet in height. Numerous separated branches and tree tops were found at the main wreckage site. One of the aircraft's batteries was found approximately 120 feet from the main wreckage on a 235 degree orientation. The temperature on the mesa was approximately 25 degrees cooler than the departure runway.

All of the motorglider's major components were accounted for at the accident site. Two of six right wing sections were found approximately 35 to 55 feet from the main wreckage, and separated from each other. The leading edge between outboard sections two and three exhibited significant impact damage. The inboard end of the remaining right wing was elevated above the ground and wedged between two trees. The left wing's outer 2/3 exhibited minimal impact damage. The left wing's inboard 1/3 was laying near the crushed and deformed fuselage. The T-tail empennage was separated from the fuselage, and remained attached by rudder control cables. No flight control continuity could be established due to impact damage. The single main landing gear was found retracted. The main motor switch was found in the off position, and the engine's retractable mount electrical spindle drive indicated that it was in the stowed position. The propeller was found centered in the proper stowing position. There was no leading edge impact damage or cordwise scratches on either propeller blade.

No preimpact engine or airframe anomalies, which might have affected the motorglider's performance, were identified. There was no evidence of fire.


The University of New Mexico's School of Medicine's Office of the Medical Investigator, Albuquerque, New Mexico, performed an autopsy on both pilots on May 28, 2001. The medical investigator said that Gilbert Gerbaud had fractures of the wrists, hands, and feet, which were consistent with a pilot who was at the aircraft controls at the time of impact. Edy Naef, the PIC, did not have fractures of either hand or feet bones.

The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on both pilots. According to CAMI's report (#200100139001), the PIC's liver sample was tested for drugs with negative results; carbon monoxide and cyanide tests were not performed. The following volatiles were found in muscle, heart, kidney, and brain samples: ethanol, acetaldehyde, and N-propanol. CAMI personnel reported that because the body was not recovered for 3 days, the presence of alcohol and its metabolites were most likely attributed to decomposition processes.

CAMI's report on the second pilot (#200100139002), tests for carbon monoxide and cyanide were not performed. The following volatiles were found in samples of heart, kidney, brain, and lung: ethanol, acetaldehyde, and N-propanol. CAMI personnel reported that these positive results were most likely attributed to decomposition processes. The liver and kidney did prove positive for the drug Phenobarbital, which is a prescription barbiturate, typically used for sedation, but also used to treat various medical conditions. The FAA does not approve this medication for pilots, while they are on flight status.


The glider, including all components and logbooks, was released to the owner's insurance company on June 21, 2001.

(c) 2009-2011 Lee C. Baker. For informational purposes only.