NTSB Factual Report

On September 17, 2016, about 1125 Pacific daylight time, an experimental amateur built Ogg Glasair I, N70GG, experienced an in-flight fire during a closed course air race flight at the Reno-Stead Airport (RTS), Reno, Nevada. The airplane was registered to a private individual, and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91. The airline transport pilot, the sole occupant of the airplane, was not injured; the airplane sustained substantial damage. Visual meteorological conditions prevailed, and no flight plan had been filed for the air race flight, which originated from RTS about 10 minutes prior to the accident.

The pilot reported that at takeoff, she put the throttle into the full open position, and the engine ran normally. During the climb, she turned on the nitrous switch for a few seconds to test the system which was working correctly. A normal increase in power was felt, and all engine parameters were in the green. She turned off the nitrous system and reduced throttle appropriately to join the race formation.

At the start of the race, all airplanes are aligned abreast of each other. The pilot reported that in race formation the wingman's eye is on the airplane to the left to keep arranged distance for safety. Wingman do not have much time to spend reading each engine parameter. She glanced at the instrument panel prior to the race, and all engine parameters were in the green.

At the start of the race, the airplanes begin a descent toward the first pylon. The pilot reported that she smoothly opened the throttle to full and turned the nitrous system on. She felt acceleration, the airplane flew normally, and the engine sounds were normal. While passing pylon number 5, the engine suddenly stopped producing power. The pilot stated that she pulled up and declared a mayday with the intent to land on runway 18, but then heard that the fire trucks were positioning for runway 14. The pilot pulled the propeller lever, but the propeller pitch did not change. Smoke began to fill the cockpit and flames were seen on both sides of the engine cowling and in the cockpit under the instrument panel. The propeller stopped turning; the pilot placed the mixture in the idle cutoff position and the fuel selector valve to the OFF position. She landed on runway 14, exited the airplane, and emergency response personnel extinguished the fire.

Examination of the airplane revealed that the forward part of the fuselage and inboard portion of the left wing sustained fire and structural damage.

The owner reported that the engine had backfired prior to the loss of power. The backfire caused an explosion in the induction system, breaking the induction elbow. The throttle body and nitrous injector dropped into the bottom of the cowling spraying flammable fluid into the engine compartment, which resulted in the fire and loss of power.

NTSB Probable Cause

The failure of an induction elbow following an engine backfire, which resulted in an in-flight fire and loss of engine power.