# NTSB CHI00LA215: Lutke Rotoway Exec 90, N1183M, Kalamazoo, MI, July 22, 2000

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 22, 2000, 15:35 local (19:35 UTC)
- Place: Kalamazoo, MI
- Coordinates: 42.299148, -85.700691 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.2991&lon=-85.7007&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report September 26, 2001
- Report: Approved by Office Director
- NTSB case key (mKey): 49819
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI00LA215
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/49819/pdf
- Page: https://openairdocs.org/ntsb/CHI00LA215

## Probable cause

the loss of main rotor rpm due to the failure of the top engine mount and the subsequent loss of the main rotor drive belt tension.  A factor was the confined area landing zone.

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise
  - engine installation,mounting bolt - failure (cause)
  - rotor drive system,main rotor drive belt - loose (cause)
  - rotor system,main rotor - disengaged (cause)
  - autorotation - initiated, pilot in command
- Hard landing, emergency landing
  - terrain condition - congested/confined area (contributing factor)

## Analysis

The pilot reported he was flying his experimental helicopter about 700 feet above ground level in cruise flight when the top motor mount made of cast aluminum broke.  He reported that the belt tension to the main rotor was lost and he was unable to maintain rotor rpm.  He executed an autorotation to a small back yard surrounded by trees.  The helicopter landed hard and the main rotor blades flexed down and chopped off the tailboom.

## Factual narrative

On July 22, 2000, at 1535 eastern daylight time, an amateur built Lutke Rotoway Exec 90 helicopter, N1183M, piloted by a private pilot, was substantially damaged during a malfunction of the rotor system and the subsequent loss of power and hard landing in Kalamazoo, Michigan.  The flight was operating under the provisions of 14 CFR Part 91, and was not operating on a flight plan.  Visual meteorological conditions prevailed at the time of the accident.  The pilot and his passenger reported no injuries.  The flight had departed from Newman Airport (4NO), Kalamazoo, Michigan, at about 1500.

The pilot reported he was flying his experimental helicopter about 700 feet above ground level in cruise flight when the top motor mount made of cast aluminum broke.  He reported that the belt tension to the main rotor was lost and he was unable to maintain rotor rpm.  He executed an autorotation to a small back yard that was surrounded by trees.  The helicopter landed hard and the main rotor blades flexed down and chopped off the tailboom.

## Aircraft

- Registration: [N1183M](https://openairdocs.org/deregistered/N1183M-2003-03-24), registration cancelled 2003-03-24, S/N J123151, built 1993 (OpenAirDocs)
- Reported make and model: Lutke ROTOWAY EXEC 90 (ROTOWAY EX)
- Registry model: [Lutke Michael T ROTOWAY EXEC 90](https://openairdocs.org/model/lutke-michael-t-rotoway-exec-90) (registry code 0560348) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Helicopter, amateur-built
- Serial number: J123151
- Airframe hours: 175
- Engines: Rotorway EXEC 150 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Michael T Lutke
- Airworthiness certificate: Special, Experimental (Special)
- Departed: 4NO, MI

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; private; medical: class 3, valid medical--no waivers/lim.; seat: right; flight hours: 158 total, 158 in this make and model, 68 as pilot in command, 21 in the last 90 days, 5 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 330° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: 8,000 ft broken
- Temperature: 154 °F, dew point 127 °F
- Altimeter: 30.00 inHg
- Observed at: AZO, 10 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 20000722036649A](https://openairdocs.org/incident/20000722036649A), Jul 22, 2000: Amtr EXEC90, Kalamazoo, MI, No damage. (-23) During cruise flight pilot expereienced an engine problem and made an emergency landing after touch down the rotor hit the ground and spun the helicopter…

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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