N10EZ

HISTORY OF FLIGHTOn September 05, 2022, about 0948 Pacific daylight time, a Rutan Varieze, N10EZ, was substantially damaged when it was involved in an accident near Columbia, California. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot had been performing maintenance on the accident airplane and upgrading various systems. The weeks before the accident, he installed an Electroair electronic ignition system. The accident flight was the first flight out of maintenance.

The radar and ADS-B data indicated that the airplane departed runway 17 about 0845. The airplane continued southeast about 8 nautical miles (nm) and then retuned back to the airport, landing on the same runway about 0858.

The recorded data then shows that around 0903 the airplane departed and continued southeast in a climb for about 35 nm. After about 18 minutes, the airplane made a 180° left turn while passing through 13,500 ft mean seal level (msl). The airplane climbed to a peak altitude of 16,475 msl and then began a descent, maneuvering into a left traffic pattern for runway 35. The airplane made a high-speed pass over runway 35 and then continued north-northeast for about 5 nm.

The airplane returned back to the airport; around 0945, it passed over the center of the airport at an altitude of 2,850 ft (see Figure 1 below). The airplane turned right and joined the right traffic pattern for runway 17. At 0946:56, the airplane turned onto the base leg and the airspeed decreased.

Figure 1: Recorded ADS-B Data from the end of the flight

A comparison of the first flight and the accident flight revealed that the speeds were similar during the landing approach. The first flight passed near the location of the last recorded ADS-B return about 75 ft higher (see Figure 2 below).

Figure 2: Comparison of first flight and accident flight AIRCRAFT INFORMATIONThe amateur-built airplane was powered by a rear-mounted Continental O-200 reciprocating engine rated at 100 horsepower, and drove a fix-pitched, two-bladed propeller. A review of Federal Aviation Administration (FAA) records revealed that several individuals had owned the airplane and the accident pilot had purchased the airplane in May 2021.

The Hobbs meter at the accident displayed 668.1 hours, equating to 11.4 hours before the last recorded maintenance; the reason for the discrepancy of hours is unknown. The last annual inspection was recorded as being completed on October 6, 2021, at a total airframe time of 676.4 hours and 701.4 hours of engine time since the last major overhaul. During that inspection the mechanic noted that both magnetos needed to be replaced and were overdue for a 500-hour inspection; additionally, the carburetor had reached the maximum time-between-overhauls (in excess of 10 years).

According to VariEze Owner’s Manual, during an engine-out emergency landing, the landing gear should be down, and the pilot should turn off the electrical power and magnetos to minimize any potential fire hazard. AIRPORT INFORMATIONThe amateur-built airplane was powered by a rear-mounted Continental O-200 reciprocating engine rated at 100 horsepower, and drove a fix-pitched, two-bladed propeller. A review of Federal Aviation Administration (FAA) records revealed that several individuals had owned the airplane and the accident pilot had purchased the airplane in May 2021.

The Hobbs meter at the accident displayed 668.1 hours, equating to 11.4 hours before the last recorded maintenance; the reason for the discrepancy of hours is unknown. The last annual inspection was recorded as being completed on October 6, 2021, at a total airframe time of 676.4 hours and 701.4 hours of engine time since the last major overhaul. During that inspection the mechanic noted that both magnetos needed to be replaced and were overdue for a 500-hour inspection; additionally, the carburetor had reached the maximum time-between-overhauls (in excess of 10 years).

According to VariEze Owner’s Manual, during an engine-out emergency landing, the landing gear should be down, and the pilot should turn off the electrical power and magnetos to minimize any potential fire hazard. WRECKAGE AND IMPACT INFORMATIONThe accident site was located in a sparsely populated residential neighborhood in uneven terrain made up of large boulders, loose rocks, and numerous trees and brush. The main wreckage, consisting of a majority of the airframe and engine, was about 0.5 nm north of the runway threshold (see Figure 3 below). There was a northwest-southeast oriented main-road located 375 ft east of the accident site and numerous other streets in the immediate area.

Figure 3: Main wreckage in reference to the runway

The first identified point of impact was a 50-ft maple tree that had several severed limbs. Adjacent to the tree was a small portion of the outboard right-wing cuff. The second point of impact was a large 80-ft tall fir tree that had severed branches about 35 ft up the tree. The airplane fuselage came to rest inverted, and the wings remained attached. The wreckage was consistent with the nose gear being in the down position.

Complete control continuity could not be verified due to the extensive impact-related damage. The airplane sustained major crush damage to the front cockpit.

The fuel tanks were all intact and there was no evidence of a breach. There was no fuel found in the left tank, about 2 gallons found in the right tank, and about 6 ounces in the header tank. The fuel found was free of water and debris. There was evidence of seepage out of the vented cap in the header tank (blue staining). The same liquid was found when activating the accelerator pump in the carburetor, but the bowl was dry. The impact and position that the airplane came to rest made it impossible to determine the total fuel quantity at the time of impact.

A Safety Board investigator performed a complete disassembly of the Continental O-200 engine. Investigators established continuity of the valve and gear train by rotating the crankshaft via the crankshaft flange (exerting force on the propeller); compression was detected in all cylinders. Normal lift action was observed at each rocker assembly. Clean, uncontaminated oil was observed at all four rocker-box areas. There was no evidence of valve-to-piston face contact observed. The pistons and their respective rings were intact. The valves were intact and undamaged. The back of the intake valves and the intake pipes were sooty down through the intake manifold to the area above the butterfly valve of the carburetor.

The two-bladed fixed pitch propeller remained intact and attached to the engine with no visible chordwise scratches or leading-edge damage. One blade was cracked at the tip as a result of coming to rest on a rock.

Ignition System

The airplane was equipped with a dual ignition system that the pilot had configured in the month before the accident; there was one electronic ignition and one magneto installed at the time of the accident.

The ignition system was configured with the Electroair routed to the top spark plugs and the left magneto to the bottom spark plugs. Investigators confirmed that they were both timed correctly. The magneto was operated by a keyed ignition and the electric ignition was operated by a single-pole single-throw (SPST) switch. The airplane’s wiring in the front of the airplane was found hanging over a boulder and it is unknown how much damage was due to impact. The key was not in the magneto ignition, and the switch was in the “off” position. The master switch was the sole toggle switch in the “on” position. The position of the electronic ignition could not be confirmed, and it was not attached in the airframe.

The magneto had two P-leads connected. Both wires were routed to the keyed ignition switch: one attached to the “right” and one to the “left” position. This would result in the magneto not being operable in the OFF, RIGHT, and LEFT positions, with only the BOTH position producing an operational magneto. This would have made it impossible for the pilot to verify that both ignition systems were operable during the runup.

The Electroair unit was removed from the airplane. The wire from the coil pack to the bus (Bundle #3; 10 amp) was separated at the butt splice and had not been properly crimped on one side (the barrel not depressed on one side); the wire was also chaffed where it had been routed along the fuel lines. The wire strand had wires that were deformed on one side and then bent back under adjacent wires, consistent with the wires being pulled out of a crimped connection and reinserted at an unknown time. Although there was evidence of a prior loose connection, the wire strand was consistent with having a sufficiently tight connection before separation. There was scraping damage on one side of the insulator with elements commonly associated with rock and soil transferred to the damaged areas of the insulator and the adjacent wires next to the insulator. This was consistent with sliding contact with the terrain sufficient to damage the insulator with at least some connection to the wires.

The wire from the controller to the bus (Bundle #4; 3 amp) connection had a tighter crimp and had sliding contact marks through the crimp barrel that was consistent with it making contact, despite the crimp not being secured on both sides. Two wires in the strand had been cut, and several others had substantial scraping damage next to the insulator cut.

The electronic ignition switch had a tang bent and one wire was not connected; the switch was broken internally; however, the investigation was not able to determine if the damage occurred before or during impact.

Figure 4: Electronic system showing wire separation

Disassembly of the magneto revealed a fine carbon dust in the housing and the distributor brush was worn, both consistent with extensive wear.