Individually Owned: 150,657
Corporate Owned: 137,281
Grand Canyon Airport
Aircraft Accident/Incident Report
Grand Canyon, Arizona 86023
Monday, April 20, 1998 16:15 MST
NTSB Narrative Summary Released at Completion of Accident
The instructor pilot and new company pilot were practicing autorotations, which were terminating in a power-recovery. The flight instructor demonstrated a straight-in autorotation and said that the governor lagged behind but stayed in the green range. The instructor stated that this was typical of this particular helicopter and that he didn't consider the governor lag unusual. The instructor then had the dual student set up for a 180-degree autorotation. During the maneuver he told the student that he was ready to roll on the throttle at 200 feet agl. He stated that at 50 feet and 50 to 55 knots, the pilot flared the helicopter and at 15 feet he had the pilot pull in more collective. At this point, the instructor pulled in some collective himself. He stated that the torque gauge did not move and that it sounded like the engine sound was dragging down and the rpm's in the dual tach decayed. The flight instructor proceeded to take the controls and level the aircraft. The aircraft landed hard and came to a complete stop. After the aircraft was shut down, the tail boom was found still attached but hanging to the ground. A Bell Operations Safety Notice advises that tail boom failure can occur in autorotations where touchdown occurs at 70 percent main rotor speed due to a resonance response of the structure to the main rotor. A postaccident test of the governor function was performed. Power checks were done to duplicate an autorotation and the tests revealed that the engine was slow to accelerate and the governor surged with continual fluctuation of Ng readings.
NTSB Probable Cause Narrative
The malfunction and erratic speed control of the engine's governor, and the flight instructor's delayed remedial action.
Event Information
| Type of Event | Accident |
| Event Date | 4/20/1998 |
| Event Day of the Week | Monday |
| Time of Event | 1615 |
| Event Time Zone | Mountain Standard Time |
| Event City | GRAND CANYON |
| Event State | ARIZONA |
| Event Country | -- |
| Zipcode of the event site | 86023 |
| Event Date Year | 1998 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | GRAND CANYON AIRPORT |
| Event Location Nearest Airport ID | KGCN |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | 6300 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1550 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | GCN |
| Elevation of weather observation facility | 6303 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | MST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Clear |
| 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) | 18 |
| Dew Point at event time (in degress fahrenheit) | -3 |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Variable |
| Wind Speed (knots) | 5 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1140 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Apr 20 1998 12:00AM |
| NTSB Notification Time | 1700 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 11 2000 11:08AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N8533F |
| NTSB Number | LAX98LA139 |
| 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 | Bell |
| Aircraft Model | 206B |
| Aircraft Series Identifier | 206B |
| Aircraft Serial Number | 254 |
| Certified Max Gross Weight | 3200 |
| 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 | 100 Hour |
| Date of Last Inspection | Mar 17 1998 12:00AM |
| Airframe hours since last inspection | 63 |
| Airframe Hours | 21392 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | GULF INC. |
| Aircraft Owner Street Address | 12515 WILLOWS ROAD N.E. #200 |
| Aircraft Owner City | KIRKLAND |
| Aircraft Owner State | WA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 98034 |
| Operator is an individual? | -- |
| Operator Name | PAPILLON AIRWAYS |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | P O BOX 455 |
| Operator City | GRAND CANYON |
| Operator State | AZ |
| Operator Country | |
| Operator Zip code | 86023 |
| Operator Code | PGCH |
| Owner has at least one certificate | Yes - certificate holder |
| 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) | Instructional |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | GCN |
| Departure City | |
| Departure State | AZ |
| Departure Country | |
| Departure Time | 1506 |
| Departure Time Zone | MST |
| 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 10:30AM |
| 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 | -- |