# NTSB MIA93LA022: Mason, Jack A. Velocity, N157JM, Crystal River, FL, November 25, 1992

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: November 25, 1992, 15:00 local (20:00 UTC)
- Place: Crystal River, FL
- Location: 28.8955° N, 82.6019° W: Placed by OpenAirDocs: center of Crystal River, FL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=28.8955&lon=-82.6019&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report June 21, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 33199
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA93LA022
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/33199/pdf
- Page: https://openairdocs.org/ntsb/MIA93LA022

## Probable cause

FAILURE OF AN UNKNOWN INDIVIDUAL TO DETERMINE THAT THE PROPELLER WAS PROPERLY SECURED AFTER REMOVAL OF THE PROPELLER SPINNER, RESULTING IN SEPARATION OF ONE OF THE PROPELLER BLADES DURING CRUISE FLIGHT. CONTRIBUTING TO THE ACCIDENT WAS UNSUITABLE TERRAIN ENCOUNTERED DURING THE FORCED LANDING.

## 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 - separation
  - maintenance - improper, unknown (cause)
- Forced landing, descent - emergency
- In flight collision with object, descent - emergency
  - object - tree(s)
  - unsuitable terrain or takeoff/landing/taxi area - encountered, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - water

## Analysis

DURING CRUISE FLT, APRX 17 INCHES OF ONE PROP BLADE SEPARATED.  DURING THE EMERGENCY DESCENT FOR A FORCED LANDING, THE ACFT COLLIDED WITH TREES THEN THE WATER.  EXAM OF THE PROP REVEALED THAT THE FWD HUB WHICH CONTACTS THE FWD MOUNTING FLANGE WAS BURNED.  A PROP SPINNER WAS NOT INSTALLED.  IT HAD BEEN REMOVED BEFORE THE PLT PURCHASED THE ACFT APRX 9 MONTHS EARLIER.  THE PROP SPINNER BACKING PLATE WHICH IS .125 INCH THICK ATTACHES BETWEEN THE FWD MOUNTING FLANGE AND THE FWD HUB OF THE PROP. THE CORRECT PROCEDURE TO DETERMINE IF THE ATTACH BOLTS ARE THE CORRECT LENGTH IS TO INSTALL THEM THROUGH THE AFT MOUNTING FLANGE & THE PROPELLER BACKING PLATE (IF INSTALLED), THEN SCREW THEM INTO THE FWD MOUNTING FLANGE UNTIL THE BOLTS BOTTOM OUT. THE WIDTH BETWEEN THE TWO FLANGES (IF A PROP SPINNER IS NOT INSTALLED) SHOULD BE MEASURED, THEN THE WIDTH OF THE PROP HUB SHOULD BE MEASURED. THE WIDTH OF THE PROP HUB SHOULD BE GREATER THAN THE WIDTH BETWEEN THE FLANGES TO ALLOW FOR COMPRESSION OF THE HUB WHEN THE BOLTS ARE PROPERLY TORQUED.

## Aircraft

- Registration: [N157JM](https://openairdocs.org/deregistered/N157JM-1995-06-07), registration cancelled 1995-06-07, S/N DM099 (OpenAirDocs)
- Reported make and model: MASON, JACK A. VELOCITY
- Registry model: [Mason Jack A VELOCITY](https://openairdocs.org/model/mason-jack-a-velocity) (registry code 05616BH) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: DM099
- Engines: LYCOMING IO-360 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Black, Charles K.
- Registered owner: Black, Charles K.
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, February 1, 1992, 100 hours before
- Departed: LOU, LOUISVILLE, KY
- Destination: SRQ, SARASOTA, FL
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 600 total, 100 in this make and model, 500 as pilot in command, 50 in the last 90 days, 20 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 8 knots
- Visibility: 7 statute miles
- Lowest ceiling: 25,000 ft broken
- Temperature: 82 °F, dew point 70 °F
- Altimeter: 30.00 inHg
- Observed at: GNV, 50 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 19921125047889A](https://openairdocs.org/incident/19921125047889A), Nov 25, 1992: Amtr VELOCITY, Cystal River, FL, Substantial damage. Severe vibration. Secured engine. Unable airport. Ditched in gulf. 17 inches prop separated. Bolts improper torqued

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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