# NTSB DEN88DTE06: Helfrich-Leonard BD-5B, N250TH, Englewood, CO, July 1, 1988

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: July 1, 1988, 12:35 local (18:35 UTC)
- Place: Englewood, CO
- Coordinates: 39.580581, -104.859794 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.5806&lon=-104.8598&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 July 10, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 17330
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN88DTE06
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17330/pdf
- Page: https://openairdocs.org/ntsb/DEN88DTE06

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, takeoff - initial climb
  - powerplant - overtemperature (cause)
  - engine assembly,piston - burned (cause)
  - acft/equip,inadequate design, manufacturer (cause)
- Forced landing, descent - emergency
- Main gear collapsed, landing - flare/touchdown
  - terrain condition - rough/uneven (contributing factor)
  - landing gear,nose gear - overload
  - landing gear,nose gear - collapsed

## Analysis

THIS EXPERIMENTAL ACFT IS POWERED BY A MODIFIED HONDA 1250 CC, WATERCOOLED ENG. THE PLT REPORTED THAT AFTER TAKEOFF THE ENG TEMP REACHED THE REDLINE AND THE ENG LOST POWER. DURING THE FORCED LANDING THE MAIN LANDING GEAR COLLAPSED. EXAMINATION OF THE ENG AFTER THE ACDT REVEALED THAT A HOLE WAS BURNED IN THE #4 PISTON AND A PORTION OF THE HEAD GASKET BETWEEN THE #3 AND #4 CYL WAS MISSING. THE OWNER AND TECHNICIANS FAMILIAR WITH THE ENG SUGGEST A LARGER RADIATOR, RETIMING OF THE IGNITION, AND/OR A RICHER MIXTURE MAY PRECLUDE RECURRENCE OF THE PROBLEM.

## Aircraft

- Registration: [N250TH](https://openairdocs.org/deregistered/N250TH-2012-08-21), registration cancelled 2012-08-21, S/N 1032, built 1978 (OpenAirDocs)
- Reported make and model: HELFRICH-LEONARD BD-5B
- Registry model: [Helfrich-Leonard BEDE BD-5B](https://openairdocs.org/model/helfrich-leonard-bede-bd-5b) (registry code 11307B3) (OpenAirDocs)
- Registry engine: [Honda CIVIC](https://openairdocs.org/engine/honda-civic) (registry code 33802, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 1032
- Airframe hours: 311
- Engines: HONDA 1250 70 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Foster Mark E.
- Registered owner: Mark E. Foster
- Airworthiness certificate: Special, Experimental (Special)
- Departed: APA
- Destination: APA
- Airport: APA, Centennial

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; commercial; airplane ratings: single-engine land; medical: class 1, valid medical--no waivers/lim.; seat: center; flight hours: 1,272 total, 20 in this make and model, 1,145 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 20° at 5 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 79 °F
- Altimeter: 30.00 inHg
- Observed at: APA

## 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 19880701035799A](https://openairdocs.org/incident/19880701035799A), Jul 1, 1988: Amtrbd BEDEBD5B, Denver, CO, Substantial damage. Engine overheated and quit on climb out due to a lean mixture and inadequate cooling system. Crashed off airport.

## Other investigations on N250TH (1)

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.

- [NTSB DEN78FTE78](https://openairdocs.org/ntsb/DEN78FTE78), Jul 22, 1978: Bede 5-B (N250TH), Longmont, CO, substantial damage

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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