Individually Owned: 150,657
Corporate Owned: 137,281
Grand Canyon Nat'l Park Airport
Aircraft Accident/Incident Report
Grand Canyon, Arizona 86023
Thursday, April 1, 1999 11:36 MST
NTSB Narrative Summary Released at Completion of Accident
Shortly after takeoff and transition to forward flight, the helicopter's engine stopped. During the ensuing autorotative landing glide, a main rotor blade struck a tree about 30 feet above ground level and the helicopter fell to the ground. This was the first flight of the day and the helicopter had been stored outside overnight in conditions of cold temperatures and light snowfall without engine air inlet covers installed. Prior to the flight the engine was difficult to start. There were five aborted starts before the engine was successfully started. During the first three start attempts, fuel was introduced, ignition occurred, the engine acceleration hung at 30 percent, and the starts were aborted. After the third start attempt a mechanic noted that the engine inlets were approximately half blocked by snow and cleared the snow from the inlets using a towel. He did not check the plenum chamber aft of the particle separator and forward of the engine inlet for snow. In the wreckage, the plenum chamber inspection window was found to be opaque. After the accident, another company mechanic who had dealt with the same starting difficulty on another helicopter of the same type parked under the same circumstances without inlet covers, reported finding the plenum chamber of that helicopter contained several cups of snow. The engine manufacturer reported that tests of the engine had shown that ingestion of as little as 6 ounces of snow/slush could flame out the engine. The operator's procedure requiring that the last flight crew at the end of the day install the inlet covers on aircraft stored outside had not been followed.
NTSB Probable Cause Narrative
The failure of the flight crew to properly preflight the helicopter and to detect and remove accumulated snow from the engine inlets and plenum chamber. Factors in the accident were the clouded plenum chamber inspection window and the failure of preceding flight crew to install the engine inlet covers in accordance with the operator's procedure.
Event Information
| Type of Event | Accident |
| Event Date | 4/1/1999 |
| Event Day of the Week | Thursday |
| Time of Event | 1136 |
| Event Time Zone | Mountain Standard Time |
| Event City | GRAND CANYON |
| Event State | ARIZONA |
| Event Country | -- |
| Zipcode of the event site | 86023 |
| Event Date Year | 1999 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | GRAND CANYON NAT'L PARK |
| Event Location Nearest Airport ID | GCN |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 1 |
| Degrees magnetic from airport | 35 |
| Airport Elevation | 6606 |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1141 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | 215 |
| Weather Observation Facility ID | GCN |
| Elevation of weather observation facility | 6606 |
| Distance of event from weather observation facility (units?) | 1 |
| Time Zone of the weather observation | MST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 2500 |
| Lowest Non-Ceiling Height | 800 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | Broken |
| 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) | -1 |
| Dew Point at event time (in degress fahrenheit) | -9 |
| Wind Direction (degrees magnetic) | 230 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 6 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | 6500 |
| 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 | 1 |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1221 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Apr 1 1999 12:00AM |
| NTSB Notification Time | 1110 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Jan 10 2001 10:03AM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N992UC |
| NTSB Number | LAX99FA136 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | -- |
| Damage | Destroyed |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Bell |
| Aircraft Model | 206B |
| Aircraft Series Identifier | 206B |
| Aircraft Serial Number | 421 |
| 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 | Annual |
| Date of Last Inspection | Feb 10 1999 12:00AM |
| Airframe hours since last inspection | 28 |
| Airframe Hours | 15860 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | MONARCH ENTERPRISES, INC. |
| Aircraft Owner Street Address | 12515 WILLOWS RD. NE, STE 200 |
| Aircraft Owner City | KIRKLAND |
| Aircraft Owner State | WA |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 98035 |
| Operator is an individual? | -- |
| Operator Name | PAPILLON GRAND CANYON HELICOPT |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | PO BOX 455/HWY 64 |
| 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 | External Load |
| 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 | |
| Departure Country | |
| Departure Time | 1132 |
| 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 | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 10 2001 12:26PM |
| 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 | -- |