# NTSB MIA85IA203: Mitsubishi MU-2K, N7DD, San Juan, PR, June 24, 1985

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: June 24, 1985, 17:39 local (21:39 UTC)
- Place: San Juan, PR
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 31292
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA85IA203
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/31292/pdf
- Page: https://openairdocs.org/ntsb/MIA85IA203

## Sequence of events

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

- Airframe/component/system failure/malfunction, climb
  - landing gear,nose gear - binding(mechanical) (cause)
  - door,landing gear - movement restricted (cause)
  - landing gear,nose gear - movement restricted (cause)
  - landing gear,normal retraction/extension assembly - overload (cause)
- Nose gear collapsed, landing - roll
  - landing gear,nose gear - disconnected (cause)

## Analysis

AFTER DEPARTURE THE NOSE GEAR UNSAFE LIGHT REMAINED ILLUMINATED PETER GEAR RETRACTION. ATTEMPTS TO GET A SAFE LIGHT ON THE NOSE GEAR IN THE EXTENDED POSITION WAS UNSUCCESSFUL AND WHEN THE AIRCRAFT LANDED IT SETTLED ONTO A PARTIALLY RETRACTED NOSE GEAR. INSPECTION OF THE AIRCRAFT REVEALED THAT THE NOSE GEAR STRUT HAD NOT FULLY EXTENDED AND THAT WHEN THE GEAR WAS RETRACTED THE NOSE GEAR TIRES CAUGHT THE NOSE GEAR DOORS PREVENTING THEM FROM OPENING. THE GEAR RETRACTED AGAINST THE GEAR DOORS CAUSING FAILURE OFTHE RETRACT JACKSCREW. A MICROSWITCH WHICH CUTS THE GEAR MOTOR OFF WHEN THIS CONDITION OCCURRS WAS FOUND OUT OF ADJUSTMENT AND DID NOT OPERATE. ADDITIONALLY IT WAS FOUND THAT THE MECHANICS WHO DID THE LAST GEAR RETRACT TEST ON THE AIRCRAFT USED A MAINTENANCE MANUAL FOR AN EARLIER MODEL AIRCRAFT WHICH DID NOT HAVE THIS SAFETY SWITCH THUS FAILING TO CHECK IT FOR ADJUSTMENT. NO REASON AS TO WHY THE NOSE GEAR STRUT DID NOT FULLY EXTEND WAS FOUND.

## Aircraft

- Registration: [N7DD](https://openairdocs.org/aircraft/N7DD), registered now, S/N 297, built 1974 (OpenAirDocs)
- Reported make and model: MITSUBISHI MU-2K
- Registry model: [Mitsubishi MU-2B](https://openairdocs.org/model/mitsubishi-mu-2b) (registry code 5780404) (OpenAirDocs)
- Registry engine: [AiResearch TPE331-5&6SER](https://openairdocs.org/engine/airesearch-tpe331-5-6ser) (registry code 01515, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 297
- Airframe hours: 2170
- Engines: Airesearch TPE331-6-251M 724 horsepower turbo prop
- Damage: Minor damage
- Flight: Part 135
- Operator: Executive Airline & Charter
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, May 20, 1985, 50 hours before
- Departed: STT, ST.THOMAS
- Flight plan: VFR
- Airport: SJU, Puerto Rico International, runway 10, 8,000 × 150 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: valid medical--no waivers/lim.; seat: left; flight hours: 10,412 total, 337 in this make and model, 10,281 as pilot in command, 110 in the last 90 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 11 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Altimeter: 29.00 inHg
- Observed at: SJU

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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