Individually Owned: 150,657
Corporate Owned: 137,281
Unalaska Airport
Aircraft Accident/Incident Report
Unalaska, Alaska 99685
Wednesday, April 9, 2008 16:30 AKD
NTSB Narrative Summary Released at Completion of Accident
The airline transport pilot was on an approach to land on Runway 30 at the conclusion of a visual flight rules (VFR)scheduled commuter flight. Through a series of radio microphone clicks, he activated threshold warning lights for vehicle traffic on a roadway that passes in front of the threshold of Runway 30. Gates that were supposed to work in concert with the lights and block the runway from vehicle traffic were not operative. On final approach, the pilot, who was aware that the gates were not working, noticed a large truck and trailer stopped adjacent to the landing threshold. As he neared the runway, he realized that the truck was moving in front of the threshold area. The pilot attempted to go around, but the airplane's belly struck the top of the trailer and the airplane descended out of control to the runway, sustaining structural damage. The truck driver reported that, as he approached the runway threshold, he saw the flashing red warning lights, but that the gates were not closed. He waited for about 45 seconds and looked for any landing traffic and, seeing none, drove onto the road in front of the threshold. As he did so, he felt the airplane impact the trailer, and saw it hit the runway. The accident truck's trailer is about 45 feet long and 13 feet tall. The Federal Aviation Administration (FAA) Facility Directory/Alaska Supplement recommends that pilots maintain a 25-foot minimum threshold crossing height. The NTSB's investigation revealed that the gate system had been out of service for more than a year due to budgetary constraints, and that there was no Notice to Airman (NOTAM) issued concerning the inoperative gate system. The FAA certificated airport is owned and operated by the State of Alaska. According to the Airport Certification Manual, the airport manager is responsible to inspect, maintain, and repair airport facilities to ensure safe operations. Additionally, the airport manager is responsible for publishing NOTAM's concerning hazardous conditions. A 10-year review of annual FAA certification and compliance inspection forms revealed no discrepancy listed for the inoperative gates until 16 days after the accident.
NTSB Probable Cause Narrative
The pilot's failure to maintain clearance from a truck while landing, and the vehicle operator's decision to ignore runway warning signals. Contributing to the accident was an inoperative vehicle gate system and the failure of airport management to adequately maintain the gate system and issue a NOTAM.
Event Information
| Type of Event | Accident |
| Event Date | 4/9/2008 |
| Event Day of the Week | Wednesday |
| Time of Event | 1630 |
| Event Time Zone | -- |
| Event City | Unalaska |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99685 |
| Event Date Year | 2008 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 535401N |
| Event Location Longitude | 1663200W |
| Event Location Airport | Unalaska Airport |
| Event Location Nearest Airport ID | PADU |
| 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 | 22 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1616 Atlantic Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | PADU |
| Elevation of weather observation facility | 22 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | ADT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 2200 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | -- |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | -1 |
| Dew Point at event time (in degress fahrenheit) | -6 |
| Wind Direction (degrees magnetic) | 300 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 9 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 15 |
| Altimeter Setting at event time (in. Hg) | 29.89 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Serious |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | 8 |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 9 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 25522 |
| NTSB Notification Source | FAA ROC, Anchorage, Alaska |
| NTSB Notification Date | Apr 9 2008 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jun 2 2009 2:17PM |
| User who most recently changed record | stam |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Anchorage FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N741 |
| NTSB Number | ANC08FA050 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 135: Air Taxi & Commuter |
| Type of Flight Plan filed | VFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | GRUMMAN |
| Aircraft Model | G-21A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | B-97 |
| Certified Max Gross Weight | 9200 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | 1 |
| Cabin Crew Seats | -- |
| Passenger Seats | 8 |
| Total number of seats on the aircraft | 10 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | AAIP |
| Date of Last Inspection | Mar 25 2008 12:00AM |
| Airframe hours since last inspection | 10 |
| Airframe Hours | 12228 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | C91 |
| Aircraft Owner Name | Peninsula Airways, Inc. |
| Aircraft Owner Street Address | 6100 Boeing Ave. |
| Aircraft Owner City | Anchorage |
| Aircraft Owner State | AK |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 99502 |
| Operator is an individual? | No |
| Operator Name | Peninsula Airways, Inc. |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | 6100 Boeing Ave. |
| Operator City | Anchorage |
| Operator State | AK |
| Operator Country | USA |
| Operator Zip code | 99502 |
| Operator Code | -- |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | PSNA044 |
| Indicates whether an air carrier operation was scheduled or not | Scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | KQA |
| Departure City | Akutan |
| Departure State | AK |
| Departure Country | USA |
| Departure Time | 1615 |
| Departure Time Zone | ADT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | DUT |
| Destination City | Unalaska |
| Destination State | AK |
| Destination Country | USA |
| Specific Phase of Flight | Approach |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jun 2 2009 2:17PM |
| User who most recently changed record | stam |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 30 |
| Runway Length | 3900 |
| Runway Width | 100 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |