N958RVVans Aircraft RV-8A · 2015

On January 2, 2016, about 1530 Pacific standard time, an experimental amateur-built Kai Engstad RV-8A airplane, N958RV, was substantially damaged following a loss of engine power and subsequent forced landing at McNary Field (SLE), Salem, Oregon. The pilot, who was also the builder/owner of the airplane, was not injured. Visual meteorological conditions prevailed for the local flight, which was operated in accordance with 14 Code of Federal Regulations (CFR) Part 91, and a flight plan was not filed. The flight had departed SLE about 1500.In a report submitted to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that the flight was in conjunction with Phase 1 of the test period for the experimental airplane, with the goals of the flight focused on breaking in the engine and an evaluation of the systems/flight characteristics. The pilot stated that subsequent to the preflight being performed, a short ground run was accomplished, with no issues noted. In flight, the pilot reported that there was an issue with an elevated cylinder head temperature, which he controlled with airspeed, altitude, mixture, and power settings. The pilot opined that upon his return to the departure airport, and with clearance by air traffic control to enter a right base leg for runway 34, he requested a left 360 degree turn from the controller, due to conflicting traffic. The controller then advised the pilot to extend his right downwind leg, and that he would call his base leg. The pilot reported that upon his return to the airport the engine began to run rough and power was lost. An attempt to restart the engine was successful, however, a short time later he again experienced a loss of power. The pilot subsequently landed in a field short of the runway, which resulted in substantial damage to the airplane.

On January 14, 2016, the initial phase of the postaccident examination of the airframe and engine was overseen by a Federal Aviation Administration aviation safety inspector at the pilot/owner's hangar, located at SLE. As a result of his examination, the inspector reported that he observed bends in the firewall that affected the alignment of the engine mount. The nose landing gear was bent aft but remained connected to the forward fuselage area. Both propeller blades were impact damaged. Additionally, fuel (100LL) recovered from both the left and right fuel tanks was clear, with no contaminants observed. The fuel selector was in the left tank position. The fuel bust pump was observed to operate normally, with proper fuel pressure noted. The electric boost pump operated normally, and an inspection of the fuel vent lines revealed no obstructions. After a fuel line was disconnected from the engine, a check of the fuel again revealed no contaminants. All remaining fuel lines were left connected in place. All linkages to the throttle body were intact, with no anomalies observed. The inspector's examination of the fuel system revealed no anomalies that would have precluded normal operation. The inspector further reported that both magnetos were of the electronic ignition type. Photographs provided by the inspector to the NTSB IIC of the airframe revealed no damage, with the exception of the damage previously reported. The inspector subsequently supervised the removal and shipment of the engine to Aero Sport Power, Kamloops, British Columbia, Canada.

On April 14, 2016, under the supervision of the NTSB IIC, the airplane's engine was examined at the facilities of Aero Sport Power, Kamloops, British Columbia, Canada. Aero Sport Power provided three aircraft technicians to perform the examination, which culminated with the following findings:

The engine was removed from the as arrived crate and secured onto a test stand. Some slight scrape marks were observed on the #2 and #4 valve covers, a small dent on one of the pushrod tubes, and one cross threaded valve cover screw. The starter also has some clearance modifications. The engine crankshaft was rotated and turned freely without interruption. A static timing check on the "P" mags was performed, with timing confirmed set at zero degrees, which was correct for this engine model. The engine was then installed on the test stand, accompanied by a test propeller being installed. The original 6 ½ quarts of engine oil was retained in the engine for the engine run. The original oil filter was removed from the engine and cut open. No foreign material was observed in the paper filtration cartridge. A new oil filter was then installed on the engine. The original oil temperature probe was removed due to incompatible wiring for the Aero Sport Power test stand; a substitute test probe was installed. A "cold" leak down test was performed on the cylinders prior to the initial startup, with leak downs recorded as good - #1 75.6/80; #2 76/80; #3 75/80; #4 75/80. The top spark plugs were removed, followed by the engine oil system being prelubed by rotating the engine with the starter motor until oil pressure was observed on the oil pressure gauges installed in the test stand. The top spark plugs were then reinstalled as per the "P" mag directions; as two plugs lead were missing, two substitute test leads were used, and wired with the test wiring harness. The test stand was then repositioned to an on-airport test area where the engine was started without interruption. The engine was then run for about 30 minutes at various rpm ranges, with no interruptions notes. The engine was examined for oil leak subsequent to the test run having been completed, with no oil leaks observed. A "hot" leak down test was performed and recorded as good - #1 77/80; #2 78/80; #3 78/80; #4 78/80. The oil filter was removed and cut open, with no foreign material observed. The engine run revealed that the engine ran as designed and was in good operating condition, with no anomalies noted that would preclude normal operation. (Refer to the Aero Sport Power Engine Inspection Report, Section 6, which is appended to the docket for this report.)

Subsequent to the examination of the engine at the facilities of Aero Sport Power, the propeller governor was removed from the engine and retained by the NTSB IIC. On July 19, 2016, the governor was shipped to the facilities of MT-Propeller, located in DeLand, Florida, for examination. On August 4, 2016, under the supervision of an FAA aviation safety inspector, the governor was inspected by an MT-Propeller technician. The technician reported that the governor was not damaged, that the drive shaft could be rotated freely by hand, and that the control arm was observed to move freely from high rpm to low rpm stops. The technician further reported that after flushing the governor with parts cleaner, it was installed on a test bench. After reaching operating temperature, a bench check was performed. All parameters were found to be within manufacturer's specifications. No anomalies with the governor were revealed that would have precluded normal operation. (Refer to the MT-Propeller governor examination report, which is appended to the docket for this report.)

The examination of the airplane's engine and associated components failed to reveal what precipitated the reported loss of engine power.