# NTSB MKC87FA138: Aero Commander 500-B, N9391R, Mason City, IA, July 14, 1987

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Field investigation · Final report
- Date: July 13, 1987, 20:17 local (Jul 14, 1987, 01:17 UTC)
- Place: Mason City, IA
- Coordinates: 43.150005, -93.190132 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.1500&lon=-93.1901&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report January 11, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 34296
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC87FA138
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34296/pdf
- Page: https://openairdocs.org/ntsb/MKC87FA138

## Sequence of events

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

- Loss of control - in flight, takeoff - initial climb
  - fuselage,seat - unlocked (cause)
  - checklist - not followed, pilot in command (cause)
  - pull-up - inadvertent, pilot in command (contributing factor)
  - stall - inadvertent, pilot in command (contributing factor)
- In flight collision with terrain/water, takeoff - initial climb

## Analysis

THE AIRPLANE WAS IN A NORMAL APPEARING CLIMB AFTER TAKEOFF WHEN IT PITCHED UP TO A 70 TO 80 DEGREE ATTITUDE, STALLED, DROPPED THE RIGHT WING, THEN LEVELED THE WINGS AND HIT THE GROUND IN A NEAR-FLAT ATTITUDE. THE WEIGHT AND CG WERE WITHIN LIMITS. NO PREIMPACT PROBLEMS WERE FOUND THAT COULD CAUSE AN INADVERTENT PITCHUP. PILOT'S ONLY MEMORY IS THAT HE COULDN'T GET THE CONTROL COLUMN FAR ENOUGH FORWARD TO STOP THE PITCHUP. THE PILOT'S SEAT WAS FOUND IN THE FULL FORWARD POSITION WITH THE RIGHT LOCKING PIN IN THE LOCKING HOLE AND THE LEFT PIN 1/4TH OF AN INCH FORWARD OF THE FRONT LOCKING HOLE. THERE WERE NO VISIBLE MARKS ON EITHER OF THE LOCKING PINS. DEEP SCRATCHES WERE FOUND ON THE SIDES OF THE RAIL WHERE THE SEAT ATTACHMENTS NORMALLY SLIDE BACK AND FORTH WHEN THE SEAT IS ADJUSTED. EXAM OF THE OUTBOARD SIDE RECESSED SURFACE NEAR THE AFT END DISCLOSED WHAT APPEARED TO BE A FRESH SCRATCH.

## Aircraft

- Registration: [N9391R](https://openairdocs.org/deregistered/N9391R-1991-03-25), registration cancelled 1991-03-25, S/N 500A90615 (OpenAirDocs)
- Reported make and model: AERO COMMANDER 500-B
- Registry model: [Aero Commander 500-B](https://openairdocs.org/model/aero-commander-500-b) (registry code 0141106) (OpenAirDocs)
- Category: Airplane
- Serial number: 500A-906-15
- Airframe hours: 8390
- Engines: LYCOMING IO-540 290 horsepower reciprocating
- Damage: Destroyed
- Flight: Part 135
- Operator: Miller Flying Servic,Inc.
- Registered owner: John D. Towner
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, February 25, 1987, 90 hours before
- Destination: DSM, DES MOINES, IA
- Flight plan: IFR
- Airport: MCW, Mason City Municipal, runway 30, 5,500 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; commercial; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 81 in this make and model, 1,561 as pilot in command, 81 in the last 90 days

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: 300° at 5 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 63 °F, dew point 55 °F
- Altimeter: 30.00 inHg
- Observed at: MCW, 1 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 19870713042009A](https://openairdocs.org/incident/19870713042009A), Jul 13, 1987: Gulstm 500B, Mason City, IA, Destroyed. Evidence indicates pilots seat not locked slid rearward o n takeoff. Pilot unable to control. Stalled and crashed

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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