# NTSB BFO86LA040: Cessna 172L, N3933Q, Aberdeen, MD, July 16, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 16, 1986, 01:30 local (05:30 UTC)
- Place: Aberdeen, MD
- Coordinates: 39.489009, -76.139762 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.4890&lon=-76.1398&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 11253
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO86LA040
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/11253/pdf
- Page: https://openairdocs.org/ntsb/BFO86LA040

## 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, cruise - normal
  - engine assembly,push rod - bent (cause)
  - engine assembly,valve,intake - failure,total (cause)
- Forced landing, descent - emergency
- In flight collision with object, maneuvering - turn to landing area (emergency)
  - light condition - dark night (contributing factor)
  - airport/facilities - not operating
  - object - tree(s) (contributing factor)

## Analysis

THE PLT STATED THAT THE ENG BEGAN TO RUN ROUGH DURING FLT, THEN ALL AT ONCE, IT STARTED VIBRATING EXCESSIVELY. HE ATTEMPTED TO LAND AT THE PHILLIPS AAF, BUT THE ARPT WAS CLOSED & THE RWY LIGHTS WERE NOT ILLUMINATED. BY THE TIME HE SAW THE RWY, THE ACFT WAS NOT IN A POSITION TO LAND, SO HE TRIED MANEUVERING TOWARD AN OPEN AREA ON THE ARPT. HOWEVER, THE ACFT COLLIDED WITH TREES & CRASHED. AN EXAM OF THE ENG REVEALED THAT THE #3 EXHAUST VALVE PUSHROD WAS BENT & THE #1 INTAKE VALVE WAS BROKEN. AFTER THIS ACCIDENT, THE OWNER/OPERATOR (CAP) STOPPED USING PHILLIPS XC2 ENG OIL DUE TO POSSIBLE PROBLEMS ASSOCIATED WITH ITS USE WHICH INCLUDED STICKING VALVES.

## Aircraft

- Registration: N3933Q (not matched to a registry record)
- Reported make and model: CESSNA 172L
- Category: Airplane
- Serial number: 60033
- Airframe hours: 3464
- Engines: LYCOMING O-360-A1A 180 horsepower reciprocating
- Damage: Destroyed
- Flight: Public aircraft, Part 91
- Operator: Civil Air Patrol-Maryland Wing
- Registered owner: Civil Air Patrol
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, November 15, 1985, 151 hours before
- Departed: FME, FT MEADE, MD
- Flight plan: VFR
- Airport: APG, Phillips Aaf, runway 22, 8,000 × 200 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 95 in this make and model, 129 in the last 90 days

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 250° at 5 knots
- Visibility: 12 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 66 °F
- Altimeter: 30.00 inHg
- Observed at: BAL, 29 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 19860716085839A](https://openairdocs.org/incident/19860716085839A), Jul 16, 1986: Cessna 172L, Aberdeen, MD, Destroyed. The engine failed during a cap search flight and the aircraft hit trees. Intake valve broken. Phillips XC2 oil used

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.

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