# NTSB SEA95LA159: Cessna 402B, N51816, Wenatchee, WA, July 29, 1995

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 28, 1995, 21:00 local (Jul 29, 1995, 04:00 UTC)
- Place: Wenatchee, WA
- Coordinates: 47.490337, -120.190612 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.4903&lon=-120.1906&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report February 14, 1996
- Report: Approved by Office Director
- NTSB case key (mKey): 42201
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA95LA159
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42201/pdf
- Page: https://openairdocs.org/ntsb/SEA95LA159

## Probable cause

IMPROPER INSTALLATION (FAILURE TO INSTALL COTTER KEY) BY COMPANY MAINTENANCE PERSONNEL.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, takeoff - initial climb
  - flt control syst,elevator trim/tab control - jammed (cause)
  - maintenance,installation - improper, company maintenance personnel (cause)
- In flight collision with terrain/water, emergency landing after takeoff
  - proper touchdown point - not possible, pilot in command

## Analysis

THE ELEVATOR TRIM JAMMED SHORTLY AFTER TAKEOFF. THE PILOT RETURNED TO THE DEPARTURE AIRPORT, WHILE HOLDING ABOUT 150 POUNDS OF BACK PRESSURE ON THE CONTROL WHEEL. WHEN HE MOVED ONE HAND TO THE THROTTLES TO REDUCE THE POWER, HE WAS UNABLE TO HOLD THE NOSE UP, AND THE AIRCRAFT IMPACTED TERRAIN ABOUT 300 FEET SHORT OF THE APPROACH END OF THE RUNWAY. INVESTIGATION REVEALED THAT COMPANY MAINTENANCE PERSONNEL HAD FAILED TO INSTALL A COTTER KEY, AND THE TRIM TAB PUSH ROD ATTACHMENT BOLT, NUT, AND COTTER KEY WERE MISSING.

## Factual narrative

On July 28, 1995, approximately 2100 Pacific daylight time, a Cessna 402B, N51816, impacted the terrain while attempting an emergency landing at Pangborn Memorial Airport, Wenatchee, Washington. The commercial pilot, who was the sole occupant, was not injured, but the aircraft sustained substantial damage. The Part 135 cargo flight, which had just departed Pangborn Airport for Boeing Field, Seattle, Washington, was being operated in visual meteorological conditions at the time of the accident. The pilot had filed an IFR flight plan, and there was no report of an ELT activation.

According to the operator, the elevator trim actuator rod failed during the takeoff sequence when the aircraft was about 100 feet above ground level. The rod then became jammed in a manner that resulted in a nose-down trim greater than the normal full nose-down position. The pilot therefore immediately attempted an emergency landing on the runway from which he had just departed.  During this attempted landing, the aircraft impacted the terrain about 300 feet short of the runway threshold.

The pilot stated that he estimated about 150 pounds down force on the yoke.  He let go of the yoke with one hand to retard the throttles, and was unable to keep the aircraft from impacting short of the runway threshold.

FAA investigators found that the elevator trim tab was in the extreme nose-down trim position, while the cockpit trim wheel was found in the extreme nose-up trim position.  The trim was tested with no effect.  Inspectors then noted that the attaching bolt, nut, and cotter key for the trim-tab push rod to the trim-tab actuator-assembly was missing.  The disconnected end of the trim- tab push rod was wedged behind the elevator spar, forcing the trim tab into its extreme nose-down trim position.  Maintenance logs showed that the right elevator had been replaced on July 15, 1995, 24.9 flight hours prior to the accident.  The mechanic performing the repair stated that he had used the old hardware to perform the installation, but he was certain he had installed the cotter key.

The operator provided an incomplete portion of the NTSB form 6120.1/2, which is attached.

## Aircraft

- Registration: [N51816](https://openairdocs.org/deregistered/N51816-1998-02-04), registration cancelled 1998-02-04, S/N 402B0816 (OpenAirDocs)
- Reported make and model: CESSNA 402B
- Registry model: [Cessna 402B](https://openairdocs.org/model/cessna-402b) (registry code 207590P) (OpenAirDocs)
- Category: Airplane
- Serial number: 402B0816
- Airframe hours: 7162
- Engines: CONTINENTAL IO-520-E 310 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Aeroflight Executive Ser.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, June 5, 1995, 110 hours before
- Departed: EAT
- Destination: BFI, SEATTLE, WA
- Flight plan: IFR
- Airport: EAT, Pangborn Memorial, runway 30, 5,500 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 4,000 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 13 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 46 °F
- Altimeter: 29.00 inHg
- Observed at: EAT

## 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 19950728046929A](https://openairdocs.org/incident/19950728046929A), Jul 28, 1995: Cessna 402B, Wenatchee, WA, Substantial damage. Elevator trim control rod disconnected on climbout. Jammed trim full down. Landed short. Recent work on trim.

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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