# NTSB BFO93LA162: Sterner Super CAT, N531SC, Cherryville, PA, September 6, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 6, 1993, 19:00 local (23:00 UTC) - Place: Cherryville, PA - Coordinates: 40.750419, -75.540313 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.7504&lon=-75.5403&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report July 25, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 8810 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO93LA162 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8810/pdf - Page: https://openairdocs.org/ntsb/BFO93LA162 ## Probable cause THE MOVEMENT OF A THUMBSCREW ON THE FUEL FILTER SYSTEM WHICH RESULTED IN FUEL FLOW BLOCKAGE AND SUBSEQUENT PARTIAL POWER LOSS. A FACTOR IN THIS ACCIDENT WAS THE LACK OF SUITABLE TERRAIN FOR THE EMERGENCY LANDING. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, takeoff - fuel system,filter - blocked(partial) (cause) - fluid,fuel - starvation - Forced landing, descent - emergency - In flight collision with object, descent - emergency - terrain condition - none suitable (contributing factor) - object - tree(s) ## Analysis DURING TAKE-OFF CLIMB, AT ABOUT 150 FEET ABOVE THE GROUND, THE AIRPLANE'S ENGINE LOST PARTIAL POWER. THE AIRPLANE DID NOT HAVE ENOUGH AIRSPEED OR ALTITUDE TO LAND AT THE DEPARTED AIR FIELD, AND THERE WAS NOT ENOUGH POWER TO SUSTAIN FLIGHT. DURING THE DESCENT, THE AIRPLANE COLLIDED WITH TREES. POST ACCIDENT EXAMINATION OF THE ENGINE REVEALED THAT AN EXTERNALLY MOUNTED IN-LINE FUEL FILTER, MANUFACTURED BY PUROLATOR, PART NUMBER PRO-804, WAS RESTRICTING FUEL FLOW. FURTHER EXAMINATION OF THE FUEL FILTER REVEALED THAT THE FUEL FILTER'S ELEMENT RETENTION THUMBSCREW HAD LOOSENED AND ROTATED DOWN COVERING ABOUT 80 PERCENT OF THE FUEL INLET OPENINGS. ## Factual narrative On Monday, September 6, 1993, at about 1900 eastern daylight time, a homebuilt Super Cat, N531SC, owned, operated, and piloted by Kerry John Sterner of Bath, Pennsylvania, lost partial engine power during take-off climb from a private air field in Cherryville, Pennsylvania. The pilot executed an off-field landing and during the descent, the airplane impacted trees. The pilot was not injured. The airplane was substantially damaged. Visual meteorological conditions prevailed at the time of the accident. The local personal flight was conducted under 14 CFR Part 91. The pilot stated on his accident report form, "As I crossed over the end of the 1800 ft. runway, at an altitude of about 150' AGL, I heard the RPM drop, but all temps were normal. The engine RPMs continued to drop...." The pilot stated that the airplane did not have enough airspeed and altitude to make it back to the air field so he executed an off-field landing. He stated that there was no suitable terrain to land. The pilot stated, "...I headed for the area which had the smallest trees and executed a normal approach and landing...." The post-accident examination of the airframe and engine was accomplished by a Federal Aviation Administration safety inspector. The examination of the airframe did not reveal any anomalies. The engine was inspected and an externally mounted in-line fuel filter, manufactured by Purolator, part number PRO-804, was found to be restricting fuel flow. Further examination of the fuel filter revealed that the fuel filter's element retention thumbscrew had loosened and rotated down covering about 80 percent of the fuel inlet openings. ## Aircraft - Registration: N531SC (not matched to a registry record) - Reported make and model: STERNER SUPER CAT - Category: Airplane, amateur-built - Serial number: AH131651SC - Airframe hours: 1 - Engines: ROTAX 503 DCDI 52 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Kerry John Sterner - Registered owner: Kerry J. Sterner - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, July 28, 1993, 1 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: center; flight hours: 77 total, 1 in this make and model, 6 as pilot in command, 1 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Dusk - Wind: 240° at 5 knots - Visibility: 12 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 70 °F - Altimeter: 30.00 inHg - Observed at: ABE ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19930906032959A](https://openairdocs.org/incident/19930906032959A), Sep 6, 1993: Pinair SUPERV, Cherryville, PA, Substantial damage. Lost partial power on climbout. Landed in trees. External fuel line filter restricted fuel flow. Screw loosened. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.