# NTSB MIA99LA204: Rockwell S-2R, N8482V, Isola, MS, July 28, 1999 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: July 28, 1999, 06:50 local (11:50 UTC) - Place: Isola, MS - Coordinates: 33.259288, -90.590255 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.2593&lon=-90.5903&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report June 21, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46951 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA99LA204 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46951/pdf - Page: https://openairdocs.org/ntsb/MIA99LA204 ## Probable cause Failure of the No. 4 cylinder due to a leaking intake valve resulting in loss of engine power and collision with a ditch while making a forced landing on unsuitable terrain. Contributing to the accident was improper maintenance adjustment of the engine valves and spark plugs. ## 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, maneuvering - engine assembly,rocker arm/tappet - other - maintenance,adjustment - improper, company maintenance personnel (cause) - ignition system,spark plug - other - maintenance,adjustment - improper, company maintenance personnel (cause) - engine assembly,valve,intake - leak (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, landing - roll - terrain condition - none suitable - terrain condition - ditch ## Analysis While performing aerial application the pilot stated the engine backfired twice, lost oil pressure, backfired again, and then shutdown. While making a forced landing, the aircraft collided with a ditch and a post crash fired erupted. Postcrash examination of the engine under FAA supervision showed the No. 4 cylinder had compression of 35 over 80 psi and was leaking through the intake valve. Also, 7 of 18 valves were not adjusted within manufacturer's limits and all spark plug gaps were above manufacturer's limits. ## Factual narrative On July 28, 1999, about 0650 central daylight time, a Rockwell S-2R, N8482V, registered to and operated by Gary Flying Service, Inc., crashed while attempting a forced landing following loss of engine power near Isola, Mississippi, while on a Title 14 CFR Part 137 aerial application flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was destroyed and the commercial-rated pilot was seriously injured. The flight originated from Belzoni, Mississippi, the same day, about 0630. The pilot stated that while performing aerial application, the engine backfired twice, lost oil pressure, backfired again, and then shut down. While making a forced landing, the aircraft collided with a ditch, which separated the landing gear. The aircraft then spun around 180 degrees and came to rest. A postcrash fire erupted in the left wing area of the aircraft and destroyed the aircraft. Postcrash examination of the engine was conducted at an engine overhaul facility under the supervision of an FAA inspector. The No. 4 cylinder compression was 35 over 80 psi., with leakage through the intake valve. Compression limits for the engine are 60 over 80 psi or above. Seven out of 18 valves were not adjusted within normal limits. All spark plug gaps were set above normal limits. See the FAA inspector's statements and mechanic's statement attached to this report. ## Aircraft - Registration: [N8482V](https://openairdocs.org/deregistered/N8482V-2012-08-02), registration cancelled 2012-08-02, S/N 2242R (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: 2242R - Airframe hours: 4579 - Engines: P&W R-1340-AN1 600 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Aerial application, Part 137 - Registered owner: Gary Flying Service, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, March 2, 1999, 144 hours before - Departed: BELZONI, MS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 12,888 total, 11,476 in this make and model, 12,788 as pilot in command, 148 in the last 90 days, 68 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dawn - Wind: calm - Visibility: 6 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 75 °F - Altimeter: 30.00 inHg - Observed at: GLH, 16 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 19990728010079A](https://openairdocs.org/incident/19990728010079A), Jul 28, 1999: Ayres S2R, Isola, MS, Destroyed. Acft was involved in aerial application when it lost engine oil pressure, the engine failed, and the acft struck trees while attempting to land, other… 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.