Friday, January 22, 2016

Piper PA-31 Navajo, N997DN: Accident occurred January 22, 2016 near Denton Enterprise Airport (KDTO), Denton County, Texas

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Fort Worth, Texas AFW FSDO-19
Piper Aircraft; Florida 

Aviation Accident Final Report -  National Transportation Safety Board: https://app.ntsb.gov/pdf

Docket And Docket Items - National Transportation Safety Board:   https://dms.ntsb.gov/pubdms

Aviation Accident Data Summary - National Transportation Safety Board:  https://app.ntsb.gov/pdf

http://registry.faa.gov/N997DN

NTSB Identification: CEN16LA102
14 CFR Part 91: General Aviation
Accident occurred Friday, January 22, 2016 in Denton, TX
Probable Cause Approval Date: 02/13/2017
Aircraft: PIPER PA31, registration: N997DN
Injuries: 1 Minor.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The commercial pilot reported that, during the postmaintenance test flight, the right engine surged and then behaved consistent with a fuel flow issue. The right engine subsequently lost power, and the pilot prepared to return to the airport. However, before the pilot could secure the right engine, the left engine started to surge and then lost power. The pilot conducted a forced landing to a field, during which both wings and the engine nacelles sustained substantial damage. 

Although a fuel smell was present on scene, there was no visual evidence of fuel in the fuel tanks or in the field. Only a quart of fuel was recovered from the left fuel tank. Further examination of the airframe and fuel system revealed that the fuel tanks were not compromised, and no mechanical anomalies with the airframe, engine, or the fuel system were found that would have precluded normal operation. 

The pilot reported that there should have been about 120 gallons of fuel on board at the time of departure. Additionally, a fuel receipt confirmed that 99.36 gallons of fuel had been added to the fuel tanks before a 36-minute maintenance engine test run conducted 3 days before the accident flight. No other flights were conducted between the test run and the accident flight, which the engine data monitor indicated was about 30 minutes long. 

Based upon calibrations set by the operator, the engine data showed that the engines consumed about 5.6 gallons of fuel during the test run and 19.2 gallons of fuel during the accident flight. Performance information from the manufacturer indicated that the engines should have burned between 10 and 18 gallons of fuel during the test run and between 27 and 50 gallons of fuel during the accident flight. Although it is possible the discrepancy between the recorded fuel consumption and the fuel consumption calculations was due to the operator setting the engine data monitor’s calibrations incorrectly, it could not be determined when or by whom the calibrations were set. The absence of fuel on-scene and the loss of engine power are consistent with fuel exhaustion; however, the investigation was unable to determine why there was no fuel on board at the time of the accident.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The total loss of engine power due to fuel exhaustion for reasons that could not be determined because postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.

On January 22, 2016, about 1530 central standard time, a Piper PA-31 airplane, N997DN, was substantially damaged during a forced landing near Denton, Texas. The commercial rated pilot received minor injuries. The personal flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. Visual meteorological conditions prevailed at the time of the accident. The local flight departed Denton Enterprise Airport (KDTO), Denton, Texas, about 1500.

According to the pilot, the accident flight was a routine maintenance flight following maintenance and a 2-year period where the airplane had not flown regularly.

Several days prior to the accident flight, the pilot conducted an extensive preflight of the airplane and supervised the fueling of the airplane. He stated that the inboard tanks were filled to 56 gallons and the outboard tanks had 10 gallons of fuel added . The nacelle tanks were empty. 

Before conducting a flight in the airplane, the pilot performed a maintenance test run of the engines. He stated that he started and shut down the engines on the inboard tanks and conducted the taxi and engine run-ups on the outboard tanks. He estimated that he ran the engines for about 30 minutes. Aside from issues with the fuel boost pumps and the left and right fuel flow indicators, he noted no anomalies with the airframe, engines, or related systems during the taxi and engine run-up.

The airplane sat for three days between the maintenance test run and the accident flight. During the preflight inspection he noted a fuel spot on the floor under the right main fuel tank sump. Further examination revealed that the plug was not seated correctly. He estimated that less than a cup of fuel was lost during that time. For the accident flight the pilot estimated the fuel on board at takeoff was 120 gallons – no additional fuel was added prior to the flight, nor did he visually verify the fuel quantity as no one had flown the airplane or ran the engines since his last engine run three days prior.

The run-up of both engines prior to the flight revealed no anomalies. The pilot departed with the fuel selected to the inboard tanks and then once at altitude switched to the outboard tanks. The fuel flow meters were now working and when he noted the right engine flow start to drop he switched back to the inboard tanks. He climbed to 1,000 feet, checked multiple systems and then conducted a low approach to Bishop Field. He climbed back up to 2,000 feet and was conducting the cruise checklist when the right engine surged. The pilot noted the sound and behavior consistent with no fuel/fuel flow. The pilot checked the fuel selector valves and trouble shot the engine surge without resolve.

The pilot obtained clearance to enter a downwind for runway 36 at DTO at which time the right engine lost power. Before the pilot could declare an emergency and secure the right engine the left engine surged and lost power. During the forced landing to the field both wings and engine nacelles were substantially damaged.

According to the Federal Aviation Administration (FAA) inspectors who responded to the scene, they could smell fuel on scene but found no evidence of fuel. There was no fuel in the fuel tanks and there was no pooling of fuel outside of the airplane in the debris field or where the airplane came to rest. Only a quart of fuel was recovered from the left fuel tank by the airplane recovery team.

An examination of the airframe, wings, and fuel system was conducted under the auspices of the National Transportation Safety Board investigator-in-charge, inspectors from the FAA, and an investigator from Piper Aircraft. The examination revealed that the fuel tanks and fuel system had not been compromised during the accident. No mechanical anomalies were noted with the engine, airframe, or airframe fuel system that would have precluded normal operation.

The airplane was equipped with a J.P. Instruments EDM-790 that had the capability to monitor and record exhaust gas temperature, cylinder head temperature, oil pressure and temperature, manifold pressure, outside air temperature, turbine inlet temperature, engine rpm, compressor discharge temperature, fuel flow, and battery voltage. The unit contained non-volatile memory for data storage of the recorded parameters.

The recorder was in good condition and data were extracted normally. The EDM contained 2.7 hours of data and 15 power cycles. Both the engine run and the accident flight were captured on the EDM. The engine run captured 36 minutes of engine data. The accident flight captured 30 minutes of data. Based upon the calibrations set by the operator, in the EDM, total fuel consumption for the engine run was 5.6 gallons and total fuel consumption for the accident flight was 19.2 gallons.

Performance data from the airplane flight manual indicate that fuel consumption (at high cruise) to be 54 gallons per hour (gph) for both engines, and 28 gph at maximum endurance. Using data from the pilot's operating manual and airplane flight manual, investigators estimated the fuel burn for the maintenance test run, 3 days prior to the accident flight, to be between 10 and 18 gallons. Further, investigators estimated fuel burn for the accident flight to be between 27 and 50 gallons. Fuel receipts confirmed the addition of 99.36 gallons of fuel, prior to the engine maintenance test run, on January 18, 2016.

NTSB Identification: CEN16LA102 
14 CFR Part 91: General Aviation
Accident occurred Friday, January 22, 2016 in Denton, TX
Aircraft: PIPER PA31, registration: N997DN
Injuries: 1 Minor.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

On January 22, 2016, about 1530 central standard time, a Piper PA-31 airplane, N997DN, was substantially damaged during a forced landing near Denton, Texas. The pilot received minor injuries. The personal flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. Visual meteorological conditions prevailed at the time of the accident. The local flight departed Denton Enterprise Airport (KDTO), Denton, Texas, about 1500.

According to the Federal Aviation Administration inspectors who responded to the scene, the airplane had not flown for some time and the pilot was taking it on a routine flight following maintenance. During the flight the right engine surged several times before losing power. Shortly after the right engine lost power, the left engine surged and lost power. The wings, engine nacelles, and landing gear were substantially damaged during the forced landing to a field.  




An Aubrey pilot walked away from an emergency landing with only bumps and bruises Friday afternoon.

After experiencing engine trouble in the Piper PA-31 Navajo airplane he was flying, David Kinney landed the plane in a field next to George Owens Road on the south side of U.S. Highway 380, west of Denton. 

Kinney was making a routine maintenance flight and had taken off from Denton Enterprise Airport prior to the emergency.

Skid marks could be seen in the grass. The landing gear was not visible.

Department of Public Safety troopers, Denton County sheriff’s deputies and Krum emergency officials responded to the scene.

Kinney sustained minor injuries and was not transported to a hospital, according to DPS spokesman Lonny Haschel. He said because there was no one seriously hurt, no property damage and no fire, it was not a big incident to DPS, but added that the Federal Aviation Administration will be investigating.

FAA officials could not be reached for comment Friday evening.

Story and photo gallery:  http://www.dentonrc.com

After taking off from Denton Enterprise Airport and experiencing engine trouble, a pilot landed a Piper Navajo just yards away from U.S. Highway 380 west of Denton.


A small plane is down in west Denton County, according to sheriff's officials. 

Denton County Sheriff's Office Spokesperson Sandi Brackeen said the aircraft went down off U.S. Highway 380 near the town of Krum at about 3:30 p.m. Friday.


The pilot was experiencing engine trouble and was forced to land, officials said.


The Krum Fire Department said the pilot landed in a field on the south side of 380, then bounced over the highway, while staying low enough to avoid hit power lines. The plane then came to a stop near the intersection of George Owens Road and 380.


The Federal Aviation Administration is investigating.


Story and photo: http://www.nbcdfw.com

1 comment:

  1. To clarify...the aircraft did not bounce over Hwy 380 as the story says.

    The pilot landed the plane in the field just east of the the Mormon church, on the north side of 380 just beyond the service road. The plane was heading east on impact.

    The aircraft slide about 200 feet across the field, through a fence, bounced across the blacktop lane, slide through the fence on the other side of the lane, then came to rest about 100 feet in the field on the east side of the lane under the power lines.

    ReplyDelete