# NTSB NYC93LA168: Piper PA-25-225, N9556P, Chesapeake, VA, August 26, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 26, 1993, 09:15 local (13:15 UTC) - Place: Chesapeake, VA - Coordinates: 36.619098, -76.229064 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.6191&lon=-76.2291&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 13, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 38642 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC93LA168 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/38642/pdf - Page: https://openairdocs.org/ntsb/NYC93LA168 ## Probable cause The loosening of the crankshaft geardrive as a resulted of a sheared bolt and guide pin which resulted in the loss of engine power. A factor was a forced landing on a crop field. ## 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 - aerial application - accessory drive assy - loose (cause) - Forced landing, descent - emergency - In flight collision with terrain/water, landing - terrain condition - crop - Nose over, landing ## Analysis THE PILOT WAS CONDUCTING A CROP SPRAYING FLIGHT, WHEN THE ENGINE SUDDENLY LOST POWER. HE WAS TOO LOW TO ATTEMPT A RESTART, AND HE INITIATED A FORCED LANDING ONTO A FIELD WITH TALL CROPS. THE AIRPLANE NOSED OVER DURING LANDING. EXAMINATION OF THE ENGINE REVEALED 'THE CRANKSHAFT GEAR TO BE LOOSE AND THE ALIGNMENT PIN AND ATTACHMENT BOLT WERE SHEARED. THE CRANKSHAFT GEAR AND MAGNETO DRIVE GEAR HAD TEN TEETH BROKEN OFF.' ## Factual narrative On Thursday, August 26, 1993, at 0915 eastern daylight time, a Piper PA-25-235, N9556P, registered to Spraying Specialists, Inc., and piloted by Peter A. Cummings, sustained substantial damage during a forced landing in Chesapeake, Virginia. the pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight was being conducted under 14 CFR 137. The pilot was conducting a spraying flight. In his report, the pilot stated: Engine failure occurred while making final alignment for normal aerial application swath. An emergency landing was conducted in the field being sprayed. the airplane flipped over...because of the dense foliage of the crop. Mr. Fred E. Teator, Air Safety Inspector (Airworthiness) for the Federal Aviation Administration, conducted an examination of the engine. In his report, Mr. Teator stated: Prop was virtually undamaged...The engine was removed from the aircraft, after it was determined that the engine was difficult to rotate, indicating an internal problem...External appearance of the engine showed nothing unusual. Accessories were removed with nothing to note. When the crankcase pan was removed there were four broken teeth found. The gear case cover when removed showed the crankshaft gear to be loose and the alignment pin and attachment bolt were sheared. Crankshaft gear and magneto drive gear had 10 teeth broken off. There was no indication that maintenance (or lack of) caused the engine stoppage. Consensus of opinion is that the engine stopped after the crankshaft gear bolt and guidepin sheared. There was no other obvious internal engine damage and the engine rotated freely when the damaged gear was removed. The cause of the bolt and pin shearing cannot be determined. ## Aircraft - Registration: [N9556P](https://openairdocs.org/deregistered/N9556P-2013-05-23), registration cancelled 2013-05-23, S/N 25-7405670, built 1974 (OpenAirDocs) - Reported make and model: PIPER PA-25-225 - Registry model: [Piper PA-25-235](https://openairdocs.org/model/piper-pa-25-235) (registry code 7102504) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 25-7405670 - Airframe hours: 1552 - Engines: LYCOMING O-540-B2C5 235 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Spraying Specialists, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, December 15, 1992, 300 hours before - Departed: NONE, PUNGO, VA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; flight hours: 5,900 total, 3,000 in this make and model, 150 in the last 90 days, 75 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 70 °F ## 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 19930826031449A](https://openairdocs.org/incident/19930826031449A), Aug 26, 1993: Piper PA25235, Chesapeake, VA, Substantial damage. Lost power on spray run. Landed in tall crop. Nosed over. Crankshaft gear alighnment pin and attach bolt 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.