16 Apr 2012: PRENDERGAST JOHN/VANS RV-7A — John Prendergast

16 Apr 2012: PRENDERGAST JOHN/VANS RV-7A (N5025G) — John Prendergast

No fatalities • Gerrardstown, WV, United States

Probable cause

The pilot/builder's misjudgment of the required spacer width needed after engine housing lap grinding, which resulted in bearing oil hole misalignment and insufficient internal engine lubrication.

— NTSB Determination

Accident narrative

On April 16, 2012, about 1500 eastern daylight time, an experimental amateur-built Van's Aircraft RV-7A, N5025G, was substantially damaged during a forced landing to an agricultural field in Gerrardstown, West Virginia. The commercial pilot was not injured. Visual meteorological conditions prevailed. No flight plan had been filed for the local flight, which originated at Eastern West Virginia Regional Airport/Shepherd Field (MRB), Martinsburg, West Virginia. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.

According to the pilot, the airplane departed MRB about 1230, and during the flight, while maneuvering about 3,000 feet, the Mazda 13B rotary engine's coolant temperature rose. The pilot turned the airplane back toward the airport, and the engine seized and would not turn over during an attempted restart. The pilot advised MRB control tower personnel that he would have to land in a field, which included recently-planted apple trees. The pilot was able to land on a flat portion of the field; however, during the landing rollout, the airplane encountered a ditch that caught the nose wheel and bent the nose strut back, and the airplane nosed over.

After the airplane was recovered from the field, the pilot, who was also the builder, disassembled the engine, which he stated had 4 hours of operation since it was rebuilt. The pilot first noted that the water pump, which was newly installed prior to the accident flight, had rust-colored water at the outlet hole from the pump bearing. The pilot also noted that a lot of metal had passed through the engine and the reduction drive, and that the stationary gear/bearing was frozen to the eccentric shaft.

The pilot/builder further noted that during the recent rebuild, he had attempted to fine tune the engine by having the side and intermediate housings undergo lap grinding. The pilot/builder knew the grinding would require wider spacers, which he used, but those used may have been insufficient in width. The insufficient width resulted in bearing oil hole misalignment on the eccentric shaft which blocked oil from reaching rotating engine and reduction drive shaft parts.

Contributing factors

  • Related maintenance info
  • Related maintenance info
  • cause Owner/builder

Conditions

Weather
VMC, wind 170/11kt, vis 10sm

Loading the flight search…

What you can do on Flight Finder

  • Search flights between any two airports with live fares.
  • By aircraft — pick a plane model (e.g. Boeing 787, Airbus A350) and see every route it flies from your origin.
  • Route map — click any airport worldwide to explore its destinations, or draw a radius to find nearby airports.
  • Global aviation safety — aviation accident database, 5,200+ records since 1980, with map and rankings by aircraft and operator.
  • NTSB safety feed — recent U.S. aviation accidents and incidents from the official NTSB CAROL database, updated daily.

Frequently asked questions

How do I search flights by aircraft type on FlightFinder?

Pick an aircraft model — Boeing 737, Airbus A320, A380, Boeing 787 Dreamliner and more — enter your origin airport, and FlightFinder shows every route that plane flies from there with live fares.

Which aircraft types can I filter by?

We support Boeing 737/747/757/767/777/787, the full Airbus A220/A319/A320/A321/A330/A340/A350/A380 family, Embraer E170/E175/E190/E195, Bombardier CRJ and Dash 8, and the ATR 42/72 turboprops.

Is FlightFinder free to use?

Search and schedules are free. Pro ($4.99/month, $39/year, or $99 one-time lifetime) unlocks the enriched flight card — on-time stats, CO₂ per passenger, amenities, live gate & weather — plus My Trips with push alerts.

Where does the route data come from?

Live schedules come from Amadeus, AeroDataBox and Travelpayouts. Observed routes (which aircraft actually flew a given city pair) are crowdsourced from adsb.lol ADS-B data under the Open Database License.