Sunday, November 03, 2019

Fuel Exhaustion: Cessna T337D Turbo Super Skymaster, N337J; accident occurred July 07, 2017 near Greenwood County Airport (KGRD), South Carolina

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

Additional Participating Entities:

Federal Aviation Administration / Flight Standards District Office; Charlotte, South Carolina
Continental Motors; Mobile, Alabama
Textron; Kansas City, Kansas

Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board:

Location: Greenwood, SC
Accident Number: ERA17LA235
Date & Time: 07/07/2017, 0735 EDT
Registration: N337J
Aircraft: CESSNA T337
Aircraft Damage:Substantial 
Defining Event: Fuel exhaustion
Injuries: 2 Minor
Flight Conducted Under: Part 91: General Aviation - Instructional 

On July 7, 2017, about 0735 eastern daylight time, a Cessna T337D, N337J, was substantially damaged during a forced landing near Greenwood County Airport (GRD), Greenwood, South Carolina. The flight instructor and a private pilot sustained minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the local instructional flight. The airplane was operated under the provisions of 14 Code of Federal Regulations Part 91.

The flight instructor stated that the purpose of the flight was for the single-engine rated private pilot (student) to become familiar with the accident airplane as he worked toward an instrument rating. The private pilot performed the preflight inspection with no anomalies noted. The flight instructor stated that their inspection of the fuel tanks revealed that they were ¾ full, which they verified on the airplane's fuel gauges. The student stated that during the preflight inspection they did not visually check the fuel tanks but noted that the fuel gages read between ½ and ¾ full. The engine run-up was normal and they departed from runway 27.

After departure, they practiced maneuvers uneventfully for about 30 minutes and then performed one aerodynamic stall. After practicing the stall, the front engine started to surge from high power to low power and then lost all power. The flight instructor told the pilot to turn back to the airport and fly to the runway while he looked in the emergency checklist for the engine-out procedure. The rear engine was still operating normally at the time. The flight instructor turned the fuel boost pump on, switched the fuel tank from main to auxiliary, and then back to main in an attempt to restore power to the front engine, to no avail. He recalled that sometime during the flight back to the airport, the rear engine also experienced a total loss of power. The airplane was too low to reach the runway, and the pilot transferred control to the flight instructor, who performed a forced landing into trees.

Examination of the wreckage by a Federal Aviation Administration (FAA) inspector revealed that the airplane came to rest on its right side. The right wing separated from the fuselage and was found inverted on the fuselage. The left wing and strut were still attached to the fuselage. A fuel sample was taken from the left wing auxiliary sump and found to be blue in color and absent of visible debris. The right-wing fuel tanks were not accessible. The salvage crew that removed the airplane from the accident site, stated to the FAA inspector that they removed 6 gallons of fuel in the left wing and no fuel was in the right wing. The FAA inspector further stated there was no smell of fuel at the accident site. Both wings had impact marks consistent with hitting trees. The front and rear engine propellers did not exhibit rotational scoring. The landing gear were extended.

Examination of both engines revealed evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation. The four-main fuel tank fuel quantity sender units were removed and tested with an ohm meter. In the empty position, the left outboard fuel sender had a resistance valve equal to an approximately half-full reading. The left and right inboard fuel senders had a resistance valve equal to an approximately full tank reading. The right outboard fuel sender unit displayed inconsistent resistance readings throughout its range of travel.

The airplane was equipped with a main fuel tank in each wing and an auxiliary fuel tank in each wing, which combined held a total of 131 gallons of fuel, with 128 gallons of useable fuel, and 3 gallons of unusable fuel. Each main fuel tank was comprised of two metal tanks, one outboard of the other, connected with hoses. Fuel automatically flowed from the outboard tank to the inboard tank through the hoses via gravity.

Each main fuel tank was equipped with two float-type fuel level sender units, one in the outboard tank and one in the inboard tank. The two sender units were connected electrically in parallel to a fuel quantity gage in the cockpit.

On November 29, 1999, the airframe manufacturer released mandatory Service Bulletin MEB99-21, which was applicable several models of airplane including the accident airplane . The purpose of the service bulletin was, "To inspect the Stewart Warner manufactured fuel quantity indicating system for verification that each fuel tank quantity gauge indicates empty when the fuel tank contains only unusable fuel and indicates full when the fuel tank is full." The service bulletin dictated that an initial inspection be completed within 100 hours of operation or 12 months, whichever occurred first, and should subsequent reoccur every 12 months.

The airplane's most recent annual inspection was completed on February 24, 2017 at 2,591 total airframe flight hours. Review of the airplane's maintenance logbooks revealed no evidence that MEB99-21 had been complied with.

Flight Instructor Information

Certificate: Airline Transport; Flight Instructor
Age: 42, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land
Seat Occupied: Right
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): Airplane
Second Pilot Present: Yes
Instructor Rating(s): Instrument Airplane
Toxicology Performed: No
Medical Certification: Class 1 Without Waivers/Limitations
Last FAA Medical Exam: 05/25/2017
Occupational Pilot: Yes
Last Flight Review or Equivalent: 06/21/2017
Flight Time: (Estimated) 9472 hours (Total, all aircraft), 8.4 hours (Total, this make and model), 7932 hours (Pilot In Command, all aircraft), 34 hours (Last 90 days, all aircraft), 18 hours (Last 30 days, all aircraft)

Pilot Information

Age: 22, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): None
Second Pilot Present: Yes
Instructor Rating(s):None 
Toxicology Performed: No
Medical Certification: Class 1 Without Waivers/Limitations
Last FAA Medical Exam: 04/24/2014
Occupational Pilot: No
Last Flight Review or Equivalent: 08/06/2016
Flight Time:   (Estimated) 61.9 hours (Total, all aircraft), 0 hours (Total, this make and model), 31.9 hours (Pilot In Command, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: CESSNA
Registration: N337J
Model/Series: T337 D
Aircraft Category: Airplane
Year of Manufacture: 1968
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 337-1017
Landing Gear Type: Retractable - Tricycle
Seats: 6
Date/Type of Last Inspection: 02/24/2017, Annual
Certified Max Gross Wt.: 4400 lbs
Time Since Last Inspection:
Engines: 2 Reciprocating
Airframe Total Time: 2591.2 Hours as of last inspection
Engine Manufacturer: Continental
ELT: C91 installed, not activated
Engine Model/Series: IO-360
Registered Owner: On file
Rated Power: 300 hp
Operator: On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KGRD, 631 ft msl
Distance from Accident Site: 1 Nautical Miles
Observation Time: 0735 EDT
Direction from Accident Site: 266°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 6 knots /
Turbulence Type Forecast/Actual: 
Wind Direction: 250°
Turbulence Severity Forecast/Actual:
Altimeter Setting: 30.06 inches Hg
Temperature/Dew Point: 23°C / 20°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Greenwood, SC (GRD)
Type of Flight Plan Filed: None
Destination: Greenwood, SC (GRD)
Type of Clearance: None
Departure Time: 0700 EDT
Type of Airspace: Class E

Airport Information

Runway Surface Type: Asphalt
Airport Elevation: 631 ft
Runway Surface Condition: Dry
Runway Used: 27
IFR Approach: None
Runway Length/Width: 5001 ft / 100 ft
VFR Approach/Landing: Forced Landing

Wreckage and Impact Information

Crew Injuries: 2 Minor
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 Minor
Latitude, Longitude: 34.250000, -82.143611 (est)


  1. "The flight instructor stated that their inspection of the fuel tanks revealed that they were ¾ full, which they verified on the airplane's fuel gauges."

    That is not clear. So did they do a visual inspection in the wing tanks or just verify fuel looking at gauges? Also, did the owner get a maintenance work order to address the service bulletin related to needing to verify fuel quantity at both unusable empty and full?

    That said, a quick check shows that fuel starvation related crashes comprise 15% of all 337 accidents, a rate nearly twice as high as all other light twins on average. These are great birds and they are being lost at an alarming rate. They aren't the fastest nor most efficient of the light twins, but they are unarguably safer with centerline thrust.

    Finally, based on where they went in in that densely tree populated forest area, they are lucky to have survived this.

  2. And by visual inspection I mean do the dipstick check and not just take a peek looking at liquid being in there and not having a clue as what the actual level is. It's easy to tell a tank is full or near full when your finger can touch it.

  3. Been awhile since I rented an acft, yet I knew the procedure as an acft was fully refueled before going back on line; that does not negate the pre flight visual fuel check by the PIC.