# NTSB CHI88DEX11: Continental Copters MK-5, N25561, Redkey, IN, August 10, 1988

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: August 10, 1988, 12:15 local (17:15 UTC)
- Place: Redkey, IN
- Coordinates: 40.429878, -84.979629 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.4299&lon=-84.9796&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report October 16, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 13919
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI88DEX11
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13919/pdf
- Page: https://openairdocs.org/ntsb/CHI88DEX11

## Probable cause

PHYSICAL IMPAIRMENT OF THE PILOT DUE TO DRUGS WHICH RESULTED IN A MISJUDGED APPROACH AND SUBSEQUENT CONTACT WITH TREES DURING THE APPROACH TO AN AERIAL APPLICATION SWATH RUN.

## Sequence of events

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

- In flight collision with object, maneuvering - aerial application
  - object - tree(s) (contributing factor)
  - planned approach - misjudged, pilot in command (cause)
  - impairment(drugs), pilot in command (cause)
  - clearance - not maintained, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - crop

## Analysis

THE ACCIDENT OCCURRED DURING AN AREIAL APPLICATION FLT. AFTER A REVERSAL TURN TO MAKE A SWATH RUN, THE TAIL ROTOR STRUCK A TREE AT THE EDGE OF THE FIELD. THE HELICOPTER ENTERED AN UNCONTROLLED DESCENT AND CRASHED IN FIELD. TOXICOLOGY REVEALED HIGH CONCENTRATION OF THE SEDATIVE ANTIHISTAMINE DIPHENHYDRAMINE IN BOTH THE PILOT'S BLOOD & URINE. INTERPRETIVE COMMENTS ACCOMPANYING THE TOXICOLOGY REPORT STATED THAT HE BLOOD CONCENTRATION PRESENT WOULD MOST PROBABLY BE ASSOCIATED WITH SIGNIFICANT DROWSINESS.

## Aircraft

- Registration: [N25561](https://openairdocs.org/aircraft/N25561), registered now, S/N TC-TWH-1, built 1975 (OpenAirDocs)
- Reported make and model: Continental Copters MK-5
- Registry model: [Continental Copters-Transworld TOM CAT MARK 5A](https://openairdocs.org/model/continental-copters-transworld-tom-cat-mark-5a) (registry code 2390301) (OpenAirDocs)
- Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: TC-TWH-1
- Engines: LYCOMING O-435 200 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Aerial application, Part 137
- Registered owner: John W. Hinshaw
- Airworthiness certificate: Special, Restricted (Special)

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; toxicology performed; flight hours: 3,074 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 210° at 2 knots
- Visibility: 4 statute miles
- Temperature: 90 °F
- Altimeter: 30.00 inHg

## 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 19880810033729A](https://openairdocs.org/incident/19880810033729A), Aug 10, 1988: Bell OH13HMK5A, Redkey, IN, Destroyed, 1 fatal. On a spray turn around, crashed after striking a tree. High level of medical drugs in pilot.

## Other investigations on N25561 (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 NYC01LA130](https://openairdocs.org/ntsb/NYC01LA130), May 29, 2001: Continental Copters Tom Cat Mark 5A (N25561), Benton, PA, substantial damage. Probable cause: The pilot's inadequate preflight inspection, which resulted in a takeoff with a hose still attached and a subsequent dynamic rollover.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.