Chico Municipal Airport
Aircraft Accident/Incident Report

Chico, California 95926
Wednesday, April 20, 2005 18:50 PDT

NTSB Narrative Summary Released at Completion of Accident

Prior to the accident flight, the air tanker airplane had flown 9 times on the day of the accident, for a total flight time of 5 hours and 46 minutes. The purpose of the flights was to provide recurrent training for pilots scheduled to conduct fire-fighting operations for the United States Department of Agriculture Forest Service (USFS) during the upcoming fire season. Pilots aboard the airplane during the earlier flights reported no mechanical problems with the airplane. As was the mission for other flights that day, the accident flight, the tenth flight, was a training flight to conduct practice drops of water over an area of rugged mountainous terrain located north of the airport. Aboard the flight were the captain, the copilot, and the company's Chief Pilot, who was providing flight instruction. The Chief Pilot had been on board all the flights that day. Radar data indicated that the flight departed the airport and proceeded about 10.5 nautical miles to the north where it began maneuvering in a manner consistent with the conduct of practice water drops. The data showed the airplane entering and then following a right-hand racetrack pattern oriented northeast-southwest, during which it appeared that practice drops were being made on the southwest leg. During the last minute of the flight, the airplane was on the northeast leg of the racetrack pattern, flying up a valley that was oriented northeast-southwest with uphill being to the northeast. The airplane's flight path was initially near the middle of the valley. During the last 36 seconds of the flight, the airplane's flight path began to deviate towards the rising terrain on the eastern side of the valley. The last two radar hits show the airplane at an altitude of less than 100 feet above ground level. The airplane had completed approximately 1.75 circuits of the racetrack when the data ended with the airplane at 2,900 feet msl, heading northeast. The initial impact point was located about 2,150 feet northwest of the last radar data point at an elevation of about 2,450 feet msl, indicating the airplane entered a left descending turn and completed about 90 degrees of turn between the last radar hit and the impact. No distress calls were received from the airplane. According to local authorities, witnesses observed a "fire ball" at the time of the accident. Examination of the wreckage site revealed that the airplane impacted on about a 304 degree magnetic heading in a 40 degree left bank with the left wingtip striking the ground first. The airplane was severely fragmented and a severe post crash fire burned most of the structure and surrounding vegetation. Remnants of the entire airplane were accounted for at the wreckage site. There was no evidence of pre-existing structural failures or impact with foreign objects in any of the wreckage. All four of the engines and propellers were found at the wreckage site. The engines did not have any indications of an uncontainment, case rupture, or pre-impact in-flight fire. All four engines had damage to the compressor and/or turbine rotors that was consistent with engine operation. The cockpit engine instrumentation gages indicate that all four engines were running at about 2,200 shaft horsepower at impact. Review of the airplane's maintenance records did not reveal any chronic issues with the airplane nor any system/component anomalies that would have contributed to the accident. The airplane was equipped with neither a cockpit voice recorder (CVR) nor a flight data recorder (FDR) and Federal Aviation Regulations did not require the airplane to be so equipped. The reason for the in-flight collision with terrain could not be determined.

NTSB Probable Cause Narrative

Terrain clearance was not maintained while maneuvering for undetermined reasons. Mountainous terrain was a factor.

Event Information

Type of Event Accident
Event Date 4/20/2005
Event Day of the Week Wednesday
Time of Event 1850
Event Time Zone Pacific Daylight Time
Event City Chico
Event State CALIFORNIA
Event Country --
Zipcode of the event site 95926
Event Date Year 2005
Event Date Month 4
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 395914N
Event Location Longitude 1214712W
Event Location Airport Chico Municipal
Event Location Nearest Airport ID CIC
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 12
Degrees magnetic from airport --
Airport Elevation 238
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1854 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 315
Weather Observation Facility ID RBL
Elevation of weather observation facility 349
Distance of event from weather observation facility (units?) 25
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 11000
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions --
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 19
Dew Point at event time (in degress fahrenheit) 7
Wind Direction (degrees magnetic) 170
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 4
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.03
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 3
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 20243
NTSB Notification Source FAA
NTSB Notification Date Apr 20 2005 12:00AM
NTSB Notification Time 2200
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Aug 29 2006 3:49PM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office FAA Office AAI-100

Aircraft Involved

Aircraft #1

Aircraft Registration Number N926AU
NTSB Number SEA05MA085
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed Company VFR
Flight plan Was Activated? No
Damage Destroyed
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Lockheed
Aircraft Model P-3B
Aircraft Series Identifier --
Aircraft Serial Number 152731
Certified Max Gross Weight 105000
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 5
Number of Engines 4
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection AAIP
Date of Last Inspection Apr 1 2005 12:00AM
Airframe hours since last inspection 31
Airframe Hours 15614
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Aero Union Corporation
Aircraft Owner Street Address 100 Lockheed Avenue
Aircraft Owner City Chico
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 95973
Operator is an individual? No
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 AUCG
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation Agriculture
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 CIC
Departure City Chico
Departure State CA
Departure Country USA
Departure Time 1838
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code CIC
Destination City --
Destination State --
Destination Country --
Specific Phase of Flight Maneuvering
Report sent to ICAO? No
Evacuation occurred --
Date of most recent change to record Jun 12 2006 3:39PM
User who most recently changed record STAM
Since inspection or accident Time of Accident
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --