# NTSB CHI82DA341: Aero Commander 681, N10TN, Pontiac, MI, September 6, 1982

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: September 6, 1982, 17:39 local (21:39 UTC)
- Place: Pontiac, MI
- Location: 42.6656° N, 83.4205° W: Placed by OpenAirDocs at OAKLAND COUNTY INTL (PTK), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.6656&lon=-83.4205&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report September 6, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 72280
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI82DA341
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/72280/pdf
- Page: https://openairdocs.org/ntsb/CHI82DA341

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - hydraulic system,line - cracked (cause)
  - hydraulic system,line - fatigue (cause)
  - emergency procedure - performed, pilot in command (contributing factor)
- Gear collapsed, landing - roll
  - gear extension - not possible, pilot in command (cause)
  - landing gear,main gear - unlocked (contributing factor)
  - landing gear,main gear - buckled (contributing factor)

## Analysis

DURING CRUISE FLIGHT THE PILOT OBSERVED THE HYDRAULIC SYSTEM PRESSURE FLUCTUATING. THE PILOT IMMEDIATELY WENT INTO A HOLD PATTERN AND ATTEMPTED TO ASCERTAIN THE PROBLEM. AFTER REPEATED ATTEMPTS THE PILOT WAS ABLE TO LOWER THE NOSE GEAR AND THE RIGHT MAIN GEAR. DURING FINAL APPROACH FOR THE EMERGENCY LANDING THE PILOT FEATHERED THE LEFT ENGINE AND ON TOUCHDOWN THE RIGHT ENGINE WAS FEATHERED. TOUCHDOWN WAS MADE ON THE RIGHT GEAR WITH FULL RIGHT AILERON. THE PILOT LOST AILERON LIFT AND THE AIRCRAFT SETTLED ONTO THE LEFT GEAR AND THE GEAR COLLAPSED. INVESTIGATION REVEALED THAT THE LEFT, MAIN GEAR HYDRAULIC SYSTEM PLUMBING HAD A FATIGUE HAIRLINE CRACK IN THE PRESSURE LINE LEADING FROM THE PUMP TO THE CYLINDER. THE FRACTURE WAS IN THE 90 DEGREE BEND OF THE LINE.

## Aircraft

- Registration: N10TN (not matched to a registry record)
- Reported make and model: AERO COMMANDER 681
- Category: Airplane
- Serial number: 6037
- Airframe hours: 2232
- Engines: AIRESEARCH TPE-331-43BL 575 horsepower turbo prop
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Trans Industries
- Registered owner: Trans Industries
- Departed: DTW, DETROIT, MI
- Flight plan: IFR
- Airport: PTK, Oakland-Pontiac, runway 9, 6,200 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; flight hours: 13,510 total, 2,130 in this make and model, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 5 knots
- Visibility: 7 statute miles
- Lowest ceiling: 1,100 ft overcast
- Altimeter: 30.00 inHg
- Observed at: PTK

## 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 19820906043769A](https://openairdocs.org/incident/19820906043769A), Sep 6, 1982: Gulstm 681, Pontiac, MI, Substantial damage. Pilot observed hydraulic pressure fluctuating. Left gear collapsed during landing. Fatigue crack in pressure line.

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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