Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Webster, Florida 33597
Friday, June 28, 1996 13:10 EDT
NTSB Narrative Summary Released at Completion of Accident
The helicopter (N598F) was flying at about 750 to 1,000 ft, when witnesses heard a loud noise, then saw N598F descending & spinning to the right. N598F impacted the ground upright at the edge of a pond. Postcrash exam showed that a tail rotor blade had separated in flight, followed by the other tail rotor blade, hub, & gearbox. Metallurgical exam showed the tail rotor blade had separated due to fatigue fractures in 9 of 11 plates in the tail rotor blade torsion tension (TT) bar. Fatigue originated at machining discontinuities on the inner surfaces of eye holes at the bushing ends, which had been punched in the plates during the manufacturing process. In 1977, Airworthiness Directive (AD) 77-07-08 & Fairchild Hiller Service Bulletin (SB) FH1100-55-2A were issued to inspect for this problem. Records of N598F showed the AD & SB had been complied with on 3/9/77, but the tail rotor assembly had been removed & replaced with another assembly on 3/17/83. Records did not show if the AD & SB had been complied with on the replacement tail rotor assembly. Overhaul procedures did not allow disassembly of the TT bar to examine the holes. Weight & balance calculations showed that after tail rotor separated, the center of gravity moved about 2.1 inches forward of the forward limit. FH-1100 emergency procedure for tail rotor failure required that the pilot immediately reduce engine power to zero torque & perform an autorotative landing. Throttle was found in full power range. Helicopter was not equipped with shoulder harnesses.
NTSB Probable Cause Narrative
inadequate compliance with AD 77-07-08 (and SB FH1100-55-2A) by other maintenance personnel, and subsequent fatigue failure of plates in the tail rotor torsion tension bar. Factors related to the accident were: manufacturing discontinuities (scoring/indentations) in holes of plates of the tail rotor torsion tension bars, and failure of the pilot to follow emergency procedures (reduce power to attempt an autorotative landing, following loss of the tail rotor assembly).
Event Information
| Type of Event | Accident |
| Event Date | 6/28/1996 |
| Event Day of the Week | Friday |
| Time of Event | 1310 |
| Event Time Zone | Eastern Daylight Time |
| Event City | WEBSTER |
| Event State | FLORIDA |
| Event Country | -- |
| Zipcode of the event site | 33597 |
| Event Date Year | 1996 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | |
| Event Location Nearest Airport ID | |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1252 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 100 |
| Weather Observation Facility ID | MCO |
| Elevation of weather observation facility | 96 |
| Distance of event from weather observation facility (units?) | 40 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 4000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 30 |
| Dew Point at event time (in degress fahrenheit) | 21 |
| Wind Direction (degrees magnetic) | 50 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 17 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | 1300 |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | 2 |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 897 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Jun 28 1996 12:00AM |
| NTSB Notification Time | 1400 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 8 2000 10:05AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N598F |
| NTSB Number | MIA96FA168 |
| 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 | FH-1100 |
| Aircraft Series Identifier | FH-1100 |
| Aircraft Serial Number | 174 |
| Certified Max Gross Weight | 2750 |
| 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 | 5 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | May 9 1996 12:00AM |
| Airframe hours since last inspection | 10 |
| Airframe Hours | 3856 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | TBH, INC. |
| Aircraft Owner Street Address | 201 EAST KENNEDY BLVD. |
| Aircraft Owner City | TAMPA |
| Aircraft Owner State | FL |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 33601 |
| Operator is an individual? | -- |
| Operator Name | CLEARWATER HELICOPTERS, INC. |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 1700 NORTH HERCULES #4 |
| Operator City | CLEARWATER |
| Operator State | FL |
| Operator Country | |
| Operator Zip code | 34625 |
| 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) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | X41 |
| Departure City | ODESSA |
| Departure State | FL |
| Departure Country | |
| Departure Time | 1230 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | SFB |
| Destination City | SANFORD |
| Destination State | FL |
| Destination Country | |
| Specific Phase of Flight | Descent - uncontrolled |
| 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 | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |