Survey Aircraft Fatal Accident: Fatigue, Fuel Mismanagement and Prior Concerns

Survey Aircraft Fatal Accident: Fatigue, Fuel Mismanagement and Prior Concerns (C337A N5382S)

On 17 May 2008 Cessna 337A Super Skymaster, N5382S on a marine mammal survey flight, was destroyed when it impacted trees near Eagles Nest Airport, West Creek, New Jersey, during a fuel related diversion.  The pilot and one of the three passengers onboard were killed.

Wreckage of Survey Cessna C337 N5382S (Credit FAA via NTSB)

Wreckage of Survey Cessna C337 N5382S (Credit FAA via NTSB)

The US National Transportation Safety Board (NTSB) determined the probable cause to be:

The pilot’s departure with insufficient fuel for the planned flight, and his improper in-flight fuel management, which resulted in a total loss of power in both engines due to fuel starvation.

Contributing to the accident was the pilot’s fatigue, which was precipitated by his work activities during the days just prior to the accident flight.

Concerns had been raised about the pilot and the operation just days before.

This fatal accident highlights the importance of doing a proper due diligence and having independent aviation expertise available when contracting for special mission support.   A law suit brought by one survivor was settled out of court.

Background and Previous Concerns

According to the NTSB safety investigation report, the aircraft was operated by Ambroult Aviation, wholly owned by the accident pilot.  The aircraft “was one of several owned and operated by the pilot, who flew many of the missions, and conducted most of the maintenance.  Most missions were various types of survey flights”.

The accident pilot was according to a colleague “very intelligent but disorganized, and not a good businessman”, “struggling to stay financially afloat”, “very paranoid” of FAA inspectors and “reticent to make any distress calls”.  A local mechanic reported that the pilot/mechanic’s “maintenance record keeping was poor”.  Investigators were unable to located the full set or aircraft technical records.  The most recent annual inspection recorded was dated 25  June 2002.  The battery for the emergency locator transmitter bore a “replace by” date that was four years prior to the accident.

The pilot’s most recent flight review was successfully conducted on 24 February 2008.  As he didn’t have his log book with him the certificated flight instructor completed the endorsement on the back of a business card.  The pilot’s log books were never found.

For this contract:

The three passengers were employees of an environmental services company [Geo-Marine] that was contracted [by the State of New Jersey] to conduct aerial surveys of marine mammals [in areas intended for offshore windfarm development].

…the survey area extended approximately 80 miles north-south along the New Jersey shoreline, and extended approximately 20 miles east over the Atlantic Ocean. Each monthly survey consisted of flying 30 numbered course lines, called transects, to cover the entire survey area.

The contract between the environmental services company and the State of New Jersey required that the FAA be contacted “to determine flight restrictions in the area” of the survey, and that the survey flights were to be conducted at an altitude of 500 feet. While 14 CFR Part 91.119 permitted operation at altitudes less than 500 feet over open water, a waiver was required for the operator to fly less than 500 feet from any person, vessel, vehicle, or structure. No records of the operator contacting the FAA for flight restrictions were located, and the operator did not contact the FAA for any waivers. Consequently, this reduced the likelihood that the operator’s aircraft, records or personal qualifications would be inspected or reviewed by the FAA.

Each month, the pilot re-positioned the airplane from his base in Massachusetts to New Jersey to conduct the survey flights.

The previous month, the survey personnel documented concerns with the pilot’s performance and the condition of the airplane.

N5382S c337 survey apr 2008 note

Attempts to reconstruct the pilot’s schedule and activities in the days prior to the accident were only partly successful. According to a mechanic who assisted him, on either Monday or Tuesday, May 12 or May 13 respectively, the pilot replaced the alternator on the front engine of the accident airplane, and the replacement precipitated additional maintenance activity due to interference problems with a fuel line. After the maintenance was completed, the airplane experienced electrical and intercom problems. It was not determined whether the pilot either attempted or succeeded in rectifying these two issues, but he did not fly the airplane to MIV on May 14 as he was scheduled to do.

According to personnel and records from the Millville Jet Center at MIV [Millville Executive Airport], the airplane arrived about noon on May 15, and the pilot requested that the “mains be topped off.” The airplane was serviced with 55 gallons of 100LL avgas about 1210. No records of any subsequent fuel servicing could be located.

According to information obtained from passenger interviews, passenger survey notes, and a handheld global positioning system (GPS) unit recovered from the wreckage, the May 15 survey flight began when it departed from MIV at 1244. Due to the lateness of the day and the passengers’ concern about the pilot being tired, only half the survey grid was completed. The airplane returned to MIV, and the engines were shut down at 1721.

A member of the survey team documented concerns about the pilot’s performance and fatigue:

N5382S c337 survey may 2008 note

Charley horse (or charlie horse) is a colloquial term in North America for painful involuntary spasms or cramps in the leg muscles.

The customer’s project manager sensibly decided to cancel the rest of the flying programme based on the 15 May 2008 report (above).  However, this decision was overridden by the Vice President Environmental Resources at the survey company “who decided that the company would use the operator to complete the May survey, but then seek another operator for subsequent survey flights”.

The Accident Flight

The NTSB go on:

The pilot did not fly on May 16, but he spoke several times by telephone that evening to a pilot/employee about the airplane problem the preceding day. On Saturday May 17, after a weather-related delay, about 1104 the pilot and passengers departed from MIV on the accident flight.

About 90 minutes into the accident flight, the pilot informed the passengers that he “was having some fuel problems,” terminated the survey, and diverted [to Eagle’s Nest Airport (31E) in West Creek, NJ] for a precautionary landing.

N5382S c337 survey ground track 1

One passenger saw the front propeller stop and begin rotation more than once.

The airplane impacted trees and terrain approximately 400 feet to the side of the runway threshold.

N5382S c337 survey ground track 2

Several witnesses saw the airplane descend, heard it crash, and notified authorities, but the unsuccessful search efforts were terminated about 2 hours after the accident.

One witness reported he had been threatened with arrest for demanding a search be under taken.

A surviving passenger used his mobile phone to call for assistance, and the wreckage was located about 2 hours after that, which was about 4 hours after the accident.

N5382S c337 survey accident site

The pilot and a passenger were killed, and two passengers survived.

Autopsy results indicated that the pilot incurred a transected aorta, which is a non-survivable injury.

The fatally-injured passenger incurred a cervical fracture and a transverse basilar skull fracture. Though such injuries are commonly fatal, it is possible that appropriate and more immediate medical treatment would have increased the chances of the passenger’s survival.

Wreckage of Survey Cessna C337 N5382S (Credit FAA via NTSB)

Wreckage of Survey Cessna C337 N5382S (Credit FAA via NTSB)


Neither propeller exhibited evidence of rotation during impact.

The C337 fuel system consists of three metal tanks in each wing.

Two interconnected tanks in the outboard section of each wing comprised each main tank. Each main tank had a total capacity of 46.5 gallons, of which 46 were usable. One auxiliary tank was located in the inboard section of each wing, each with a total capacity of 19 gallons, 18 usable. Total airplane fuel capacity was 131 gallons, of which 128 were usable. Either main tank could provide fuel to either engine, but the left auxiliary tank could only provide fuel to the front engine, and the right auxiliary tank could only provide fuel to the rear engine.

While all fuel tanks were intact, the main tanks were empty, one auxiliary tank contained 11 gallons, and the other one contained 2 gallons. Records indicated that the airplane was not refueled between the previous flight and the accident flight.

According to the Cessna 337 Owner’s Manual (OM), for airplanes equipped with auxiliary fuel tanks, the electric pumps are not plumbed to the auxiliary fuel tanks, and therefore the engines can only be primed from the main tanks. This necessitates that the fuel selector valves be set to the main tanks for engine start and takeoff. For the same reason, the “Engine-Out During Flight” checklist in the OM specified that the fuel selector valve should be set to the main tank for an engine restart attempt. Finally, the OM specified that the main tanks should be used for 60 minutes prior to switching to the auxiliary tanks, and this information also appeared as a placard on the fuel selector panel.

Both engines were successfully test-run after the accident.

Our Comments

This aircraft was operated with very little regulatory oversight.  In other countries, relatively low utilisation aerial work aircraft also receive light touch regulatory oversight too.

If a rigorous due diligence process had occurred before the aircraft was contracted, either by the environmental service company or their end customer, a government agency, it is unlikely that this aviation company would have been contracted. Its critically important to only contract competent and capable air operators.

Periodic audits or operational safety reviews are likely to highlighted multiple concerns about this organisation, the pilot, the maintenance and flight following / emergency response arrangements.

When abnormalities are reported during an operation, there is considerable value in having independent, competent aviation advisory support on call to help triage reports, investigate, risk assess and, when necessary, provide the expert support to decisions to vary, pause or suspend operations.

This is an extreme case with big holes in every layer of cheese.  However, fatal accidents can still occur in far less extreme cases,with better organised operators, hence the value of competent aviation advisory support able to give independent assurance.

Aerossurance supports a wide range of blue chip and government customers who contract aviation service providers, including offshore helicopters, SAR and HEMS helicopters, survey aircraft and other special mission aircraft.

Safety Resources

NTSB Accident Report Highlights Charter Ops Audit Questions: the NTSB discuss how certain rating schemes that do not use audits can be misleading after an HS125 accident in Akron in 2015.

UPDATE 20 May 2019: Regulatory oversight of New Zealand helicopter operators was challenged after a 2015 accident.

Aerossurance‘s Andy Evans will be running two training sessions at European Rotors in November 2021.  One will be on safety leadership and the other on how to procure and assure aviation services.  He discussed these in a recent European Rotors Digital Series interview:

Aerossurance has extensive air safety, flight operations, aerial survey, airworthiness, human factors, aviation regulation and safety analysis experience.  For practical aviation advice you can trust, contact us at: