Piper PA-25-235 accident near Panama City, Florida, March 18, 2013
On March 18, 2013 at about 7:05 pm local time, a 1965 Piper PA-25-235, registered N86AB, was substantially damaged in an accident during enroute (cruise) near Panama City, Florida. It was a banner-towing flight under general aviation rules (Part 91). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A loss of preload to the crankshaft gear attachment bolt, resulting in rotation of the crankshaft gear and a subsequent total loss of engine power. The root cause for the loss of preload could not be determined during a postaccident examination of the components.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 18, 2013 · about 7:05 pm local time
- Place
- Panama City, Florida · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-25-235, built 1965 · all PA-25-235s on the register
- Registration
- N86AB · registry record · serial 25-3409
- Damage
- Substantial damage
- Flight
- Banner-towing flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot departed and picked up an aerial advertising banner for a local flight. About 6 minutes later, the airplane's engine suddenly lost all power. The pilot unsuccessfully attempted to troubleshoot the loss of engine power, jettisoned the banner at an altitude of about 500 feet, and performed a forced landing to a pine forest below, which resulted in substantial damage to the airplane. Postaccident examination of the engine revealed that the crankshaft gear alignment dowel had sheared and that the gear had rotated from its normal position. The gear's attaching hardware remained installed and undamaged. Detailed examination of the gear and alignment dowel showed that their hardness was consistent with that required by the design and that they were within or nearly within nominal dimensional tolerances described by the manufacturer. The counter-bored pilot hole at the aft of the crankshaft where the gear was seated was between 0.0008 and 0.0013-inch oversized. There were no discrepancies found with the retaining bolt, and it could be threaded into the crankshaft with minimal resistance. A definitive cause for the loss of preload to the crankshaft gear attaching bolt could not be determined during the engine examination. Review of maintenance records showed that the engine had been installed onto the accident airplane following an overhaul, which was originally precipitated by a propeller strike. The records provided that documented the overhaul and returned the airplane/engine to service lacked language specifying compliance with a manufacturer service bulletin that provided explicit instructions for the installation of the crankshaft gear to the crankshaft; however, the provided records did document part numbers and torque values consistent with those specified by the service bulletin.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of engine power (total) during enroute (cruise) defining event
- Off-field or emergency landing during emergency descent
- Controlled flight into terrain or object (CFIT) during emergency descent
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng rear section › Fatigue/wear/corrosion
- cause Not determined › Not determined › (general) › (general) › Unknown/Not determined
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine sea; instrument: airplane
- Flight time: 4,273 hours in all; 67 in this make and model; 73 in the last 90 days; 58 in the last 30 days; 4,181 as pilot in command
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: ctr
- Injury: minor injuries
The aircraft
- Airframe total time: 8,100 hours
- Last inspection: 100-hour inspection, February 22, 2013; 63 hours since
- Maximum gross weight: 4,800 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming O-540-B2C5 (piston); 4,803 hours total
- Operator: Aerial Banners INC
The flight
- Departed from: ECP Panama City FL at 6:00 pm
- Destination: ECP Panama City FL
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 130° at 16 knots, gusting 21
- Visibility: 10 statute miles
- Sky: broken clouds at 2,600 ft; scat at 1,500 ft
- Temperature: 73°F (23°C), dew point 64°F (18°C)
- Altimeter: 29.94 inHg
- Observation at 5:53 pm from KECP, 2 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
8 documents, released by the NTSB on August 14, 2014. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Engine Maintenance Logs (Excerpts) | PDF, 7 pages | View Download |
| 3 | Engine Overhaul Supporting Documents | PDF, 14 pages | View Download |
| 4 | Materials Laboratory Factual Report 14-005 | PDF, 7 pages | View Download |
| 5 | Lycoming Sb 475C - Crankshaft Gear Modification and Assembly Procedure | PDF, 7 pages | View Download |
| 6 | Release of Aircraft Wreckage, NTSB Form 6120.15 | PDF, 1 page | View Download |
| 7 | Photo 1 - Main Wreckage (Photo Courtesy of FAA) | PDF, 1 page | View Download |
| 8 | Photo 2 - Crankshaft Gear | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N86AB the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.