Individually Owned: 150,657
Corporate Owned: 137,281
Marathon Airport
Aircraft Accident/Incident Report
Marathon, Florida 33050
Wednesday, July 3, 1996 20:15 EDT
NTSB Narrative Summary Released at Completion of Accident
During a previous flight, the helicopter was reported to have excessive vertical vibration and to require excessive collective forces during flight. Mechanics worked on the main rotor blades to correct the problem, then the helicopter was flown on a maintenance test flight. During the test flight, the pilot noted that the vertical vibration had 'gone away,' but before landing, the vertical vibration returned. Shortly thereafter, the pilot heard a loud 'pop'. As he flared for landing, the blue main rotor blade separated and the helicopter crashed. Examination of the separated blade showed the wood in the area of the blade grip had failed, allowing the blade to separate. Evidence of a previous repair was present in this area, which lacked adequate adhesive between some of the mating surfaces. Also, an unapproved sealant had been used over the repaired area, and oil had contaminated the wood in this area. There was no evidence of dry rot in the failed area. The logbook records did not show the previous blade repair.
NTSB Probable Cause Narrative
Improper repair of a previous crack in the blue main rotor blade by unknown persons; improper inspection of the main rotor blades by maintenance personnel, following a reported vibration problem; and subsequent failure of the main rotor blade, which resulted in an uncontrolled collision with the terrain.
Event Information
| Type of Event | Accident |
| Event Date | 7/3/1996 |
| Event Day of the Week | Wednesday |
| Time of Event | 2015 |
| Event Time Zone | Eastern Daylight Time |
| Event City | MARATHON |
| Event State | FLORIDA |
| Event Country | -- |
| Zipcode of the event site | 33050 |
| Event Date Year | 1996 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | MARATHON |
| Event Location Nearest Airport ID | MTH |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 1 |
| Degrees magnetic from airport | 70 |
| Airport Elevation | 77 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 2053 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 70 |
| Weather Observation Facility ID | EYW |
| Elevation of weather observation facility | 7 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Dusk |
| Lowest Ceiling Height | 7500 |
| Lowest Non-Ceiling Height | 5000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 7 |
| Air Temperature at event time (in degrees celsius) | 27 |
| Dew Point at event time (in degress fahrenheit) | 22 |
| Wind Direction (degrees magnetic) | 180 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 7 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | 1200 |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | 2 |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1032 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jul 3 1996 12:00AM |
| NTSB Notification Time | 2039 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 10:13AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N301CH |
| NTSB Number | MIA96LA176 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Hiller |
| Aircraft Model | OH-23C |
| Aircraft Series Identifier | OH-23C |
| Aircraft Serial Number | 56-2252 |
| Certified Max Gross Weight | 2500 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 3 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Jun 1 1996 12:00AM |
| Airframe hours since last inspection | 18 |
| Airframe Hours | 5222 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | JACK SHAHAN |
| Aircraft Owner Street Address | 12188 OVERSEAS HIGHWAY |
| Aircraft Owner City | MARATHON |
| Aircraft Owner State | FL |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 33050 |
| Operator is an individual? | -- |
| Operator Name | |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | |
| Operator City | |
| Operator State | |
| Operator Country | |
| Operator Zip code | |
| Operator Code | |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | MTH |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 2013 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Landing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:34AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 25 |
| Runway Length | 5008 |
| Runway Width | 100 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |