On December 31, 1998, at 1151 hours Pacific standard time, an experimental Young Harmon Rocket II, N288M, was destroyed following an in-flight fire and hard landing at a private airstrip near Esparto, California. The commercial pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. He and one passenger departed approximately 10 minutes before the mishap. The pilot was in serious condition after suffering burns over 1/3 of his body and succumbed to his injuries over a month after the accident; the passenger sustained minor injuries. Visual meteorological conditions prevailed for the local personal flight and no flight plan had been filed.

The pilot completed one flight and was taking another passenger up for a short flight around the area. On the downwind leg witnesses reported everything looked and sounded normal, and then they heard several pops, which they attributed to the engine being throttled back. One witness asked the other if the airplane was on fire. The flames he thought he observed went away. They dismissed his observation as sun glare and turned away. When they looked at the airplane again on base leg, 2 to 3 feet of bright yellow/orange flame and a trace of black smoke emanated from the cowling. On touchdown the airplane bounced, hit again, then skewed 20 degrees to the left. The left main landing gear collapsed outboard and the right main collapsed underneath the airplane. They gathered fire extinguishers and did not see the airplane come to a stop.

The passenger stated he saw light gray smoke in the cockpit and notified the pilot. The pilot secured the master switch and turned onto the base leg. At this point the passenger did not observe flames or feel any heat. As the airplane turned wings level onto final, thick black smoke that smelled like burning fiberglass or plastic filled the cockpit. After the airplane came to rest, he observed flames around the pilot and felt high heat. He yelled to the pilot to open the canopy, but the pilot responded he could not get it to open. Momentarily, the canopy opened halfway.

As the rescuers arrived, flames were still coming from under the cowling. The front cockpit was so filled with smoke that they could not see if the pilot was still in the airplane. The rescuers helped the rear passenger out, and then noticed the pilot on the side of the runway.

A Safety Board investigator and a representative from the engine manufacturer, Textron Lycoming, inspected the wreckage in the owner's hangar on January 13, 1999. The engine was a Textron Lycoming IO-540-C4B5, serial number RL-6849-48.

The engine exhibited thermal damage in the left rear section. The fuel flow divider on top of the engine was sooty, but undamaged. The fuel injection unit on the bottom of the engine was undamaged. Components in the front right quadrant were not discolored or damaged. Discoloration and damage became evident and increased in severity moving toward the components in the left rear quadrant. The engine controls appeared secure at their respective mountings.

Components of the accessory section at the rear of the engine displayed damage. The engine driven fuel pump displayed more damage than the other accessories. The airframe in this area exhibited the most damage.

The aluminum housing of the engine driven fuel pump had melted and the center section of the pump was disintegrated. Fire consumed the pumping chamber, valves, and diaphragms. The top half of the pump remained securely attached to the engine. The bottom of the pump fell into the rubble. Molten metal remained on the lower portion of the pump piece that remained attached to the engine.

The attachment fittings for the inlet and output fuel lines for the fuel pump were detached and lying in the engine compartment. The inlet line had globules of molten metal on the threads and around the fitting. The output fitting did not have any residue on it; the threads and fitting were clean and undamaged. The fire sleeve surrounding the output line changed colors moving away from the fitting. Several inches of fire sleeve nearest the fitting were gray on the engine side and black on the part of the line that rested against the black engine mount. The fire sleeve then became orange, the same color as undamaged fire sleeve. The "B" nut on the output fitting was 1 1/4 turns loose. The remaining fuel line "B" nuts were secure. The Lycoming representative described the fitting as an industrial fitting rather than an aviation fitting, but he did not observe any evidence of mechanical failure.

Investigators removed the fire sleeve from the flexible fuel lines. They did not observe any damage or chaffing of the braided material. They did not find evidence of any ruptures or other hose failures.

A condition inspection (annual equivalent for amateur-built experimental aircraft) was completed on November 9, 1998, 10 hours prior to the accident.

The Safety Board investigator released the airframe wreckage to the owner's representative on January 13, 1999. Components retained for further study were returned to the owner's representative on March 23, 2001.

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