# NTSB FTW99LA247: Rockwell S-2R, N4919X, Lookeba, OK, September 6, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 6, 1999, 07:00 local (12:00 UTC) - Place: Lookeba, OK - Coordinates: 35.359481, -98.35913 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.3595&lon=-98.3591&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 30, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 47281 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW99LA247 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47281/pdf - Page: https://openairdocs.org/ntsb/FTW99LA247 ## Probable cause The loss of engine power resulting from a cylinder that failed for an undetermined reason. ## 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 - roll/run - engine assembly,cylinder - failure (cause) - reason for occurrence undetermined (cause) - On ground/water encounter with terrain/water, takeoff - aborted ## Analysis The airplane's engine lost power during the takeoff roll. According to the pilot, during the 'run-up before takeoff the engine spit, backfired, and then cleared up.' He initiated the takeoff roll and 'everything was fine for a few seconds,' and then 'about half way down the runway the engine coughed, spit, and backfired again.' Smoke was coming from the engine compartment and entering the cockpit, and subsequently, he aborted the takeoff. The airplane overran the runway and came to rest in a ditch. The pilot/operator removed and examined the engine oil sump from the Pratt and Whitney R-1340-AN1 engine. He observed 'numerous pieces and shavings' of ferrous metal. He stated that the pieces resembled cylinder parts. No further examination of the engine was conducted. ## Factual narrative On September 6, 1999, at 0700 central daylight time, a Rockwell International S-2R agricultural airplane, N4919X, was destroyed during an aborted takeoff following a loss of engine power near Lookeba, Oklahoma. The airplane was registered to and operated by the pilot. The airline transport rated pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 137 aerial application flight, and no flight plan was filed. The local flight was originating from a private grass airstrip at the time of the accident. According to the pilot, during the engine start, "the engine was a little harder to crank than normal." He reported that "on the run-up before takeoff the engine spit, backfired, and then cleared up." He initiated the takeoff roll and "everything was fine for a few seconds," and then "about half way down the runway the engine coughed, spit, and backfired again." He stated that smoke was coming from the engine compartment and then smoke entered the cockpit. The pilot aborted the takeoff, and subsequently, the airplane departed the end of the runway and rolled into a ditch. The pilot exited the airplane and observed "flames emitting from the front section of the engine, near the carburetor." Subsequently, the airplane was consumed by a fire. The pilot/operator removed and examined the engine oil sump from the Pratt and Whitney R-1340-AN1 engine. He observed "numerous pieces and shavings" of ferrous metal. He added in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that the pieces resembled cylinder parts. No further examination was conducted. ## Aircraft - Registration: [N4919X](https://openairdocs.org/deregistered/N4919X-2000-09-15), registration cancelled 2000-09-15, S/N 2113R (OpenAirDocs) - Reported make and model: Rockwell S-2R - Registry model: [Rockwell International S-2R](https://openairdocs.org/model/rockwell-international-s-2r) (registry code 7630202) (OpenAirDocs) - Category: Airplane - Serial number: 2113R - Airframe hours: 5759 - Engines: P&W R-1340-AN1 600 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Aerial application, Part 137 - Registered owner: Robert S. Guest - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, August 11, 1999, 150 hours before - Departed: NONE - Airport: NONE, Sickles, runway 36, 1,800 × 100 ft, dirt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 21,000 total, 5,000 in this make and model, 20,580 as pilot in command, 200 in the last 90 days, 50 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 1.5 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 64 °F - Altimeter: 30.00 inHg - Observed at: OKC, 40 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 19990906024709A](https://openairdocs.org/incident/19990906024709A), Sep 6, 1999: Ayres S2R, Lookeba, OK, Destroyed. (.19) On September 6, 1999, at 0700 central daylight time, a rockwell international S-2R agricultural airplane, N4919X, was destroyed by a postaccident fire… 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.