Cessna 172P accident near Conroe, Texas, January 4, 2012
On January 4, 2012 at about 3:45 am local time, a Cessna 172P, registered N54872, was substantially damaged in an accident during landing near Conroe, Texas. It was a public-use flight (federal) under public-use (government) rules. No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
Failure of the rear crankshaft gear dowel pin due to improper installation, which resulted in a total loss of engine power.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 4, 2012 · about 3:45 am local time
- Place
- Conroe, Texas · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172P · all 172Ps on the register
- Registration
- N54872 · no longer on the register · serial 17275074
- Damage
- Substantial damage
- Flight
- Public-use flight (federal) · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
The airplane was at 1,600 feet mean sea level with the engine power set at 2,300 rpm. When the airplane was about 6 miles from the airport, the pilot heard a loud “boom” and the engine lost all power. The pilot did not have sufficient altitude to glide to the airport, so he landed the airplane on a street. When the airplane was on final approach to land, it collided with power lines. The pilot was able to land the airplane, but was forced to swerve to the right to avoid oncoming traffic. The right wing struck a utility pole, which resulted in substantial damage. A postaccident engine examination revealed that when the crankshaft was turned, there was no movement of the intake or exhaust valves or magneto gears. The rear crank gear bolt was loose and the gear dowel pin was sheared, which would cause the camshaft and rear accessory gears to stop turning. Metallurgical examination revealed beach markings at the aft end of the crankshaft approximately in plane with the aft face of the crankshaft where it mated to the crankshaft gear. There was fretting damage on the crankshaft gear, wear on the dowel pins, and wear on the lock washer, indicative of movement as a result of insufficient clamping force from the attachment bolt at the time of installation. The engine had accrued 752 hours since it was overhauled in August 2007.
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 (climb to cruise)
- Off-field or emergency landing during emergency descent
- Collision during takeoff/land during landing defining event
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng rear section › Failure
- cause Personnel issues › Action/decision › Action › Incomplete action › Maintenance personnel
- Environmental issues › Physical environment › Object/animal/substance › Wire › Contributed to outcome
- Environmental issues › Physical environment › Object/animal/substance › Pole › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 108 hours in all; 83 in this make and model; 39 in the last 90 days; 11 in the last 30 days; 66 as pilot in command
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 4,757 hours
- Last inspection: annual inspection, June 28, 2011; 89 hours since
- Maximum gross weight: 2,550 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-360-A4M (piston); 0 hours total
- Operator: Civil Air Patrol, INC.
The flight
- Departed from: KIWS Houston TX at 3:20 am
- Destination: KCXO Conroe TX
Weather at the time
- Light: night, dark
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 32°F (0°C), dew point 27°F (-3°C)
- Altimeter: 30.61 inHg
- Observation at 3:53 am from KCXO
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.