# NTSB CHI90LA276: Mooney M20E, N7197U, Morrison, IL, September 27, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 27, 1990, 13:45 local (18:45 UTC)
- Place: Morrison, IL
- Coordinates: 41.800174, -89.960983 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.8002&lon=-89.9610&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report December 14, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 14785
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI90LA276
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14785/pdf
- Page: https://openairdocs.org/ntsb/CHI90LA276

## Probable cause

IMPROPER MAINTENANCE OF THE PROPELLER BLADE BY UNKNOWN PERSONS AND THE SUBSEQUENT FAILURE OF THE BLADE IN FATIGUE DURING CRUISE FLIGHT. A FACTOR WAS: UNSUITABLE TERRAIN.

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - propeller system/accessories,blade - fatigue (cause)
  - maintenance - improper, unknown (cause)
- Forced landing, descent - emergency
- Complete gear collapsed, landing - flare/touchdown
  - object - fence post
  - terrain condition - none suitable (contributing factor)

## Analysis

THE ACCIDENT AIRPLANE EXPERIENCED AN INFLIGHT FAILURE OF A PROPELLER BLADE DURING CRUISE FLIGHT. ACCORDING TO THE PILOT'S STATEMENT THE AIRPLANE STARTED A SEVERE VIBRATION AND REDUCING THE ENGINE POWER HAD NO EFFECT ON IT. THE VIBRATION STOPPED AFTER HE SHUT DOWN THE ENGINE AND RAISED THE NOSE IN ORDER TO STOP THE WINDMILLING PROPELLER. DURING THE FORCED LANDING THE LANDING GEAR COLLAPSED AND THE AIRPLANE SLID INTO A DIRT BANK. EXAMINATION OF THE REMAINING PORTION OF THE FAILED PROPELLER BLADE FRACTURE SURFACE SHOWED A FATIGUE CRACK EXTENDING FROM THE LEADING EDGE TO A POINT 3-1/4 INCHES MEASURED IN THE CHORDWISE DIRECTION. THE LEADING EDGE HAD BEEN REWORKED BY FILING OR GRINDING.

## Aircraft

- Registration: [N7197U](https://openairdocs.org/deregistered/N7197U-2013-08-20), registration cancelled 2013-08-20, S/N 415, built 1964 (OpenAirDocs)
- Reported make and model: MOONEY M20E
- Registry model: [Mooney M20E](https://openairdocs.org/model/mooney-m20e) (registry code 5870212) (OpenAirDocs)
- Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 415
- Airframe hours: 3050
- Engines: LYCOMING IO-360 A1A 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Lloyd Crandall
- Last inspection: Annual, June 22, 1990, 20 hours before
- Departed: CAD, CADILLAC, MI
- Destination: F91, WEATHERFORD, OK
- Airport: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; private; airplane ratings: single-engine land, single-engine sea; medical: class 3, valid medical--w/ waivers/lim; flight hours: 850 total, 150 in this make and model, 10 in the last 90 days, 5 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point -0 °F
- Observed at: SQ1, 20 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 19900927042559A](https://openairdocs.org/incident/19900927042559A), Sep 27, 1990: Mooney M20E, Morrison, IL, Substantial damage. Lost tip of prop en route. Struck fence on forced landing due to extreme vibration. Prop tip had prior nicks filed.

## Other investigations on N7197U (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 MIA68F0428](https://openairdocs.org/ntsb/MIA68F0428), Feb 24, 1968: Mooney M20E (N7197U), Gadsden, AL, 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.

---
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.