# NTSB DFW05LA140: Debus/Mountain/Bowes Debus-Casst-Snoshoo, N102MB, Oklahoma City, OK, May 29, 2005 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: May 29, 2005, 12:15 local (17:15 UTC) - Place: Oklahoma City, OK - Coordinates: 35.488056, -97.823333 - Nearby events: https://openairdocs.org/map.md?lat=35.4881&lon=-97.8233&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report October 27, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 61588 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW05LA140 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61588/pdf - Page: https://openairdocs.org/ntsb/DFW05LA140 ## Probable cause The pilot's failure to maintain airspeed which resulted in an inadvertent stall. A contributing factor was the loss of engine power as result of the fracture of the number two piston to crankshaft connecting rod. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, maneuvering - engine assembly,connecting rod - fractured (contributing factor) - Forced landing, emergency descent/landing - Loss of control - in flight, descent - airspeed - not maintained, pilot in command (cause) - stall - inadvertent, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis On the third lap of an International Formula One Air Race the pilot aborted the race and turned south toward the center of the airport after experiencing a complete loss of engine power. The private pilot performed an emergency descent with an intended landing on runway 35R (a 3,502-foot-long and 75-foot wide asphalt/concrete runway). Near the approach end of runway 35R and approximately 50 feet above ground level (agl), the airplane stalled and started to spin to the left. Subsequently, the airplane impacted the edge of runway 35R in a near vertical nose-down attitude before coming to rest in an inverted position. An examination of the modified four-cylinder engine revealed the loss of engine power was due to a fracture of the number two piston to crankshaft connecting rod. ## Factual narrative On May 29, 2005, approximately 1215 central daylight time, a single-engine Debus/Mountain/Bowes Debus-Casst-Snoshoo experimental airplane, N102MB, was substantially damaged during a forced landing following a total loss of engine power while maneuvering at the Clarence E. Page Municipal Airport (F29), near Oklahoma City, Oklahoma. The private pilot, sole occupant of the airplane, sustained serious injuries. The airplane was registered to and operated by three individuals, one of whom was the pilot. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 air race flight. The local flight originated from F29 approximately five minutes prior to the accident. A witness, who was located about mid-field, reported the airplane completing its third lap of an International Formula One Air Race when it aborted the race and turned south toward the center of the airport. The airplane then turned north and began a gliding descent for an approach to runway 35L (a 6,013-foot long and 100-foot wide concrete runway). At an altitude of approximately 200 feet above ground level (agl), the airplane was observed turning to the east, side stepping to runway 35R (a 3,502-foot-long and 75-foot wide asphalt/concrete runway). Approximately 50 feet agl, the nose of the airplane was observed to have pitched upward "slightly" and entered into a left spin. Subsequently, the airplane impacted the edge of runway 35R in a near vertical nose-down attitude. A Federal Aviation Administration (FAA) inspector, who responded to the accident site, reported the airplane came to rest inverted, approximately 70 feet from the initial point of impact. The fuselage and empennage remained intact from the roll bar aft. The fuselage, forward from the pilot seat, was destroyed. Both wings were separated from the fuselage and fragmented. The engine was separated from its mounts and both composite propeller blades were destroyed. One of the owners/builders examined the modified four-cylinder engine and reported that the loss of engine power was due to a fracture of the number two piston to crankshaft connecting rod. The pilot held a FAA private pilot certificate with a rating for single-engine land airplane. At the time of his last second-class FAA medical certificate, issued on February 3, 2005, the pilot reported his total flight time as 702 hours, with 50 hours in the preceding six months. Due do the seriousness of the pilot's injuries; a completed Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) was not obtained. At 1153, the automated surface observation station at the Wiley Post Airport, near Oklahoma City, Oklahoma, located 9 miles east of the accident site reported wind from 110 degrees at 9 knots, visibility 10 statute miles, broken cloud layer at 2,200 feet, broken cloud layer at 3,200 feet, temperature 23 degrees Celsius, dew point 18 degrees Celsius, and an altimeter setting of 29.87 inches of Mercury. ## Aircraft - Registration: [N102MB](https://openairdocs.org/deregistered/N102MB-2016-08-26), registration cancelled 2016-08-26, S/N DMB-001 (OpenAirDocs) - Reported make and model: Debus/Mountain/Bowes Debus-Casst-Snoshoo - Registry model: [Debus J/Mountain S/Bowes E DEBUS-CASST-SNOSHOO](https://openairdocs.org/model/debus-j-mountain-s-bowes-e-debus-casst-snoshoo) (registry code 05614PC) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: DMB-001 - Airframe hours: 95 - Engines: Teledyne Continental O-200 reciprocating - Damage: Substantial damage - Flight: Air race/show, Part 91 - Operator: Steven L Mountain - Registered owner: James W Debus - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, July 1, 2004 - Departed: F29, OKLAHOMA CITY, OK - Destination: Oklahoma City, OK - Airport: F29, Clarence E Page Muni, runway 35R, 3,502 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; injuries: serious; private; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; seat: single; flight hours: 700 total, 15 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: 2,200 ft broken - Temperature: 73 °F, dew point 64 °F - Altimeter: 29.87 inHg - Observed at: PWA ## 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 20050529008919A](https://openairdocs.org/incident/20050529008919A), May 29, 2005: Amtr SNOSHOO, Oklahoma City, OK, Destroyed. (-23) Pilot was racing during formula one international air race. During race, pilot aborted race and climbed rapidly toward the center of the airport on a… ## Other investigations on N102MB (1) 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. - [NTSB SEA08FA196](https://openairdocs.org/ntsb/SEA08FA196), Sep 6, 2008: Debus J / Mountain S / Bowes E DEBUS-CASST-SNOSHOO (N102MB), Reno, NV, substantial damage, 1 fatal. Probable cause: The movement of the airplane’s modified horizontal stabilizer trim system during an intentional high speed aerobatic maneuver that resulted in exceedence of the design stress limits of the airplane… 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.