# NTSB FTW92LA110: Piper PA-23-250, N6460Y, Denver, CO, April 3, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 3, 1992, 10:05 local (17:05 UTC)
- Place: Denver, CO
- Coordinates: 39.890956, -105.109527 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.8910&lon=-105.1095&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report July 23, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18475
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW92LA110
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18475/pdf
- Page: https://openairdocs.org/ntsb/FTW92LA110

## Probable cause

THE LOSS OF HYDRAULIC FLUID DUE TO A RUPTURED HYDRAULIC LINE IN THE LANDING GEAR SYSTEM.

## Sequence of events

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

- Airframe/component/system failure/malfunction, missed approach (ifr)
  - hydraulic system,line - ruptured (cause)
  - fluid,hydraulic - loss,total (cause)
  - gear extension - attempted, pilot in command(cfi)
  - emergency procedure - not possible, pilot in command(cfi)
- Gear collapsed, landing - flare/touchdown

## Analysis

A CFI WAS INSTRUCTING AN INSTRUMENT RATED COMMERCIAL PILOT. DURING A PRACTICE MISSED APPROACH, THE LANDING GEAR FAILED TO RETRACT. THE CREW ATTEMPTED TO LOWER THE LANDING GEAR USING ALL AVAILABLE EMERGENCY PROCEDURES. A FLY-BY THE TOWER REVEALED THAT THE MAIN GEARS WERE DOWN WHILE THE NOSE LANDING GEAR WAS IN TRANSIT. DURING LANDING ROLLOUT, THE NOSE GEAR COLLAPSED AS SOON AS IT MADE CONTACT WITH THE RUNWAY. THE GEAR MALFUNCTION WAS THE RESULT OF A RUPTURED HYDRAULIC FLUID LINE. THE DEPLETION OF THE HYDRAULIC FLUID RENDERED THE LANDING GEAR SYSTEM INOPERABLE.

## Aircraft

- Registration: [N6460Y](https://openairdocs.org/aircraft/N6460Y), registered now, S/N 27-3754, built 1967 (OpenAirDocs)
- Reported make and model: PIPER PA-23-250
- Registry model: [Piper PA-23-250](https://openairdocs.org/model/piper-pa-23-250) (registry code 7102308) (OpenAirDocs)
- Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 3754
- Airframe hours: 5894
- Engines: LYCOMING IO-540-J4A5 250 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Richard D. Sunderland
- Registered owner: Richard D. Sunderland
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 1, 1991, 94 hours before
- Departed: 2V2, LONGMONT, CO
- Airport: BJC, Jeffco, runway 11, 9,000 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; flight instructor, airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 5,950 total, 500 in this make and model, 5,050 as pilot in command, 50 in the last 90 days, 20 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 6 knots
- Visibility: 80 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 28 °F
- Altimeter: 29.00 inHg
- Observed at: BJC, 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 19920403042499A](https://openairdocs.org/incident/19920403042499A), Apr 3, 1992: Piper PA23250, Denver, CO, Substantial damage. Nose gear failed to lock down collapsed landing. Hydraulic line ruptured. Allowed fluid to drain from system.

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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