# NTSB BFO94LA128: Hankins/Dickerson Clipped Wings II, N4287R, Laurel, MD, August 9, 1994 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: August 9, 1994, 18:30 local (22:30 UTC) - Place: Laurel, MD - Coordinates: 39.100643, -76.880676 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.1006&lon=-76.8807&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report March 13, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 8952 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO94LA128 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8952/pdf - Page: https://openairdocs.org/ntsb/BFO94LA128 ## Probable cause THE FAILURE OF THE ENGINE IGNITION SYSTEM CAPACITOR DISCHARGE UNIT WHICH CAUSED LOSS OF TOTAL ENGINE POWER. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, approach - ignition system - failure,partial (cause) - Forced landing, descent - emergency - In flight collision with object, descent - emergency - object - residence ## Analysis THE PILOT WAS ON A FLIGHT TO TEST THE OPERATION EFFICIENCY OF THE PROPELLER WHICH HE PLANNED TO REPLACE. HE INTENDED TO REMAIN IN THE TRAFFIC PATTERN FOR THE FLIGHT. THE PILOT STATED THE FLIGHT FROM TAKEOFF THROUGH POSITIONING FOR FINAL LEG WAS WITHOUT INCIDENT. ACCORDING TO THE PILOT, 'ON FINAL APPROACH THE ENGINE SUDDENLY SPUTTERED TO A STOP. UPON NOTICING TH FALTERING (ENGINE) I IMMEDIATELY GAVE IT FULL CHOKE AND PULLED BACK THE THROTTLE BACK THE THROTTLE IN ORDER TO ENRICH THE FUEL FLOW. I DID THIS IN CASE I HAD A FUEL PROBLEM. THIS PROCEDURE HAD NO EFFECT, THE ENGINE COASTED TO A COMPLETE STOP. I THEN PUT THE THROTTLE IN A START POSITION AND CLOSED THE CHOKE TO INITIATE A NORMAL WARM ENGINE START. I PRESSED THE ELECTRIC STARTER BUTTON. THE ENGINE TURNED OVER BUT GAVE NO INDICATION OF STARTING.' THE PILOT WAS UNABLE TO GLIDE THE DISTANCE TO THE AIRPORT AND THE AIRPLANE STRUCK THE ROOF OF HOUSE. POST ACCIDENT EXAMINATION OF THE ENGINE REVEALED THE CAPACITOR DISCHARGE UNIT OF THE IGNITION SYSTEM HAD FAILED. ## Factual narrative On August 9, 1994, about 1830 eastern daylight time, a Clipped Wings Special II homebuilt experimental airplane, N4287R, lost total engine power on approach to runway 23 at the Suburban Airport located in Laurel, Maryland. During the emergency descent, the airplane collided into a house. The pilot was seriously injured. The house occupants were not injured. The airplane was substantially damaged. Visual meteorological conditions prevailed. The local personal flight was conducted under 14 CFR Part 91. According to the pilot, on final approach to the runway, the engine "...suddenly sputtered to a stop." He stated he tried to restart the engine to no avail. The pilot stated, "At this point I then concentrated more completely on stretching the glide slope in order to avoid hitting any occupied area and perhaps reaching the runway. My efforts succeeded in getting to a point past every occupied dwelling and area below, save the last house between me and a stretch of trees separating it from the airport. My last memory is just above the house." According to a Federal Aviation Administration Safety Inspector, witnesses stated that they heard the engine sputter and then stop. They stated they heard the engine restart and then stop again. They said they looked up to see the airplane and observed it descend straight down into the house. Post accident examination of the engine revealed its Capacitor Discharge Unit had failed. No other engine or airframe anomalies were noted. ## Aircraft - Registration: [N4287R](https://openairdocs.org/deregistered/N4287R-2013-10-29), registration cancelled 2013-10-29, S/N CH20190CW0611, built 1991 (OpenAirDocs) - Reported make and model: HANKINS/DICKERSON CLIPPED WINGS II (CLIPPED WI) - Registry model: [Hankins Gary W CHALLENGER SPEC](https://openairdocs.org/model/hankins-gary-w-challenger-spec) (registry code 05676RM) (OpenAirDocs) - Registry engine: [Hirth F20](https://openairdocs.org/engine/hirth-f20) (registry code 33720, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: CW0611 - Airframe hours: 111 - Engines: HIRTH 2703 55 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Hankins/Dickerson - Registered owner: Hankins/Dickerson - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Continuous airworthiness, August 9, 1994, 0 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; private; airplane ratings: single-engine land; medical: class 2, expired; seat: front; flight hours: 179 total, 108 in this make and model, 146 as pilot in command, 7 in the last 90 days, 6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 10 knots - Visibility: 12 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 72 °F - Altimeter: 30.00 inHg - Observed at: BWI, 8 nm away ## 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 19940809020969A](https://openairdocs.org/incident/19940809020969A), Aug 9, 1994: Amtrqc CHALLENGER2, Laurel, MD, Substantial damage. Engine quit on approach to airport. Crashed into house short of runway. Engine capactor discharge unit failed. 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.