Neglected Pit Stops

Fuel exhaustion comes in many forms, but usually boils down to the pilot not paying attention


Among the most avoidable mishaps are those caused by fuel exhaustion. Most of them seem inexcusable, yet virtually every pilot has flirted with this danger at one time or another.

You may pass up refueling at a major metropolitan airport because of the price. Or youre in a hurry and rationalize that you can make it with good leaning or tail winds – especially if youve made the same trip before. If the winds are not as forecast or your leaning is a bit off, you could be in for trouble. Ditto if you fail to recheck the weather en route and arrive to find it below minimums.

According to the AOPA Air Safety Foundations Nall Report there were 95 accidents due to fuel exhaustion in 1998. Seven of them were fatal, resulting in 13 deaths. In 1999 there were 51 mishaps, four of which were fatal resulting in seven deaths.

NTSB preliminary reports for two sample months for the year 2001 – January and May – turned up four accidents in each month that appeared due to fuel exhaustion.

Four were twins (two of these were turbo prop Twin Otters) and one was a helicopter. Six were VFR, two of which were at night. One twin ditched in Massachusetts Bay by moonlight. The other landed one mile short of his Florida destination.

These accidents bring to mind some basic decision-making principles. When you flew as a student pilot in Cessna 152s or Piper Warriors, your instructor probably told you to always fly with full fuel tanks. In the real world, however, its more complicated than that.

In most twins and singles, the allowable fuel load is limited by both gross weight and center of gravity considerations. This means you must physically measure (stick) the fuel tanks, because light airplane fuel gauges are notoriously unreliable. Most pilots dont bother sticking the tanks, however. They merely eyeball partial tanks and mutter, That ought to be enough.

Even if you accurately measure the fuel, your calculations to determine flying time available may not pass muster. You may not lean aggressively enough, substantially reducing the endurance quoted in the POH. ATC may keep you lower than you planned, increasing fuel burn. You also cant anticipate a fuel cap that siphons or a leaky sump drain or loose fuel line B nut that increases fuel consumption to a dangerous degree. Thus you must be constantly watching for signs of abnormal fuel consumption – a rapidly developing fuel imbalance or excessive fuel usage as shown on the fuel gauges.

Despite the half-hour VFR fuel reserve required by FAR 91.151 (45 minutes at night) or the 45-minute IFR reserve (FAR 91.167), make it a policy to always plan on a full hour of reserve fuel. This is just to handle complications like improper leaning, stronger-than-forecast headwinds or deteriorating weather. In addition, follow the instructions in the POH for fuel tank usage.

For example, the pilot of a Cessna P337H Skymaster was shooting multiple approaches and landings. During the last approach both engines lost power, causing the aircraft to hit the outer marker beacon and collide with a chain link fence. Then it skidded across a road and hit a car before finally coming to rest against yet another chain link fence.

Examination of the cockpit and fuel tanks showed the left tank completely dry and the right tank with only 4.5 gallons of gas. The POH states, The fuel selector valve handles must be turned to LEFT for the front engine and RIGHT for the rear engine for takeoff and landing, and all normal operations. If single-tank operation is being used when fuel levels are low, the fuel quantity in the tank in use should not be allowed to drop below 50 pounds prior to re-establishing normal single-engine per tank operation; this will avoid the possibility of dual engine stoppage due to fuel starvation.

Another case involved a Cessna 172F that ran out of gas three miles from its intended destination. The fuel tanks were found empty and an external check disclosed no leaks. The pilot had purchased 10 gallons of fuel at Key West and knew the airplane burned 8 gallons per hour. Unfortunately the nearly three-hour flight used more fuel than anticipated.

In yet another mishap, a Bell 206-L3 was on a non-scheduled air taxi flight to an oil rig. The pilot reported 0.9 hours of fuel remaining as he approached the destination rig and advised that he would be critical on fuel. He then requested that the refueling pad remain open.

Unfortunately, he missed the platform by flying a few miles to the east and had to find it again. The engine quit as he approached the platform for landing, whereupon he deployed the skid-mounted float system and auto-rotated to a successful water landing.

About five minutes after landing the helicopter rolled inverted and had to be lifted onto a boat. The FAA found about 1.2 gallons of fuel in the tanks. One could ask why the aircraft was not equipped with a GPS or Loran to provide precise navigation over the featureless expanse of the Gulf. This would have prevented the mishap. But the pilot took a chance in an effort to be on time – and lost the bet.

Another avoidable mishap occurred when a Cessna 210 ran out of fuel at night after an 11-hour flight. The aircraft had flown from Wisconsin to Pensacola, Fla., on an IFR flight plan. After missing two ILS approaches into Pensacola, the pilot canceled IFR and was heading VFR to Gulf Shores, Ala., when he casually told ATC he was out of gas. The pilot and three passengers survived with only minor injuries.

Distress And Urgency Procedures
A review of several fuel starvation mishaps showed that the pilot knew he (there were no shes involved, guys) was about to run out of fuel. But because of ego or fear of a violation, he failed to ask for help. Part of this could be the way the Aviation Information Manual hides the definition of Minimum Fuel in the glossary section. Thus some pilots dont realize they are supposed to advise ATC the moment they recognize a fuel problem. Minimum Fuel is a condition wherein the airplanes fuel supply is such that an emergency situation is possible should any undue delay occur.

Definition of an Emergency Fuel state is no longer found in the AIM, but using the term establishes a valid emergency in which the pilot must get on the ground quickly, as engine failure is imminent. Waiting until engine failure is imminent to suddenly announce your dangerously low fuel state shows very poor judgment and precludes help from anyone.

Consider the case of a turboprop King Air E90 that was operating as a Part 135 air taxi. The flight, with a pilot and three passengers, was on an IFR flight plan from OHare Field to Michigan City, Ind.

The report states Following a routine departure from runway 36 at OHare and a routine climb, (the aircraft) established radio contact with South Bend, Ind., approach control. The pilot was given weather as indefinite ceiling two hundred (feet), sky obscured, visibility 0.7 nm in fog: Wind calm, altimeter 30.10.

The King Air flew as cleared direct to Michigan City NDB, whereupon South Bend Approach established positive radar contact. The pilot was then instructed to turn left to heading 070 degrees and told that vectors would be given for the approach into Michigan City. The pilot acknowledged each transmission normally and was finally told to descend and maintain 2,500 feet. Once again the pilot responded normally. The vectors continued until suddenly radar contact was lost over Lake Michigan, about 6 nm north east of Michigan City.

All aboard survived the ditching and exited the airplane through the emergency escape hatch. About four hours after the aircraft disappeared from radar, the local Michigan City U.S. Coast Guard unit received reports from shore observers of flashing lights in the water. Unfortunately South Bend tower personnel had failed to follow established emergency procedures when radar contact was lost and all four occupants died of hypothermia. Only two of the bodies were recovered.

The King Air pilot departed OHare knowing the weather was below NDB minimums and that he had a marginal fuel supply, yet he failed to declare minimum fuel or emergency fuel. Then he continued in a business as usual manner until both engines flamed out. And in the descent to the water he still failed to call Mayday – which would have initiated rescue efforts.

Another instance involved a Cessna P210N on a late January VFR ferry flight from Goose Bay, Labrador to Narsarsuaq, Greenland. The filed alternate was Nuuk, Greenland. On board were the pilot and one non-pilot passenger. The weather briefer described the pilot as anxious to go.

Weather at Narsarsuaq – a VFR-only destination – was reported as 1,000 feet scattered, 3,500 feet overcast and visibility greater than 10 kilometers. Temporary conditions forecast for the time of arrival were an indefinite ceiling of 800 feet, with visibility 1,500 meters in rain and snow. VFR minima for the airports single runway 8/26 are 1,500 foot ceiling and visibility 8 km.

The visual approach chart has the following caution: Unless the ceiling is at least 4,000 feet and flight visibility at least 5 statute miles (8 Km) pilots without a good knowledge of the local topographical and meteorological conditions are advised not to make any attempt to approach Narsarsuaq through the fiords. Records showed the pilot had flown the route previously, which probably boosted his confidence.

Forecast for the alternate was 600 feet overcast and freezing rain, with a visibility of 5 km. Temporary conditions at ETA were given as 400 feet overcast, with visibility 800 meters in rain and snow. Both airports were below the VFR approach minima.

The POH for the P210N shows that even with deice boots, a hot prop and heated windshield strip, the Centurion is not certificated for flight in known icing conditions. Yet despite all the negative indicators the pilot chose to depart.

Odds Stacked Against Him
The VFR flight plan was filed, with a cruise altitude at or below 5,500 feet. His estimated time enroute was five hours, with seven hours of fuel on board. His endurance figure was optimistic, as the aircrafts Range Profile and Endurance Profile charts both show.

Approximately two hours into the flight the pilot was told the weather at the destination had deteriorated, as predicted. Surface winds were from 100 degrees at 27 knots, gusting to 38 – a 20-degree crosswind. The Cessna 210 has a published demonstrated crosswind capability of 21 knots. And while this is not strictly speaking a limitation, its the manufacturers way of saying yall be careful, because with anything greater youre on your own.

Although the airport is VFR only, it does have three NDB approaches. The minima are quite high, with a caution that the approach should not be attempted if winds exceed 30 knots.

The news from his alternate wasnt much better. In addition to a 600-foot ceiling, Nuuk was now reporting freezing rain and snow. At this point the pilot still could have reversed course and returned to Goose Bay.

At 14:33, two hours and 47 minutes into the flight, the pilot advised Sondrestrom that he would divert to Reykjavik, Iceland. He estimated Reykjavik at 17:17 and fuel exhaustion at 18:46.

At 16:58 the pilot radioed a revised ETA at Reykjavik as 18:28 and reported being 150 miles west. At 17:12 he was spotted on radar at 188 miles west on the 272 radial of Keflavik VOR. Winds at 5,500 feet were reported from 360 degrees at 25 to 30 knots. After receiving a forecast of winds from 360 degrees at 10 to 15 knots above 10,000 feet, at 17:21 he climbed to 15,000 feet.

Although the pilot had not declared an emergency, the Icelandic Directorate of Civil Aviation initiated search and rescue operations at 17:23. U.S.A.F aircraft and Icelandic ships were directed to the scene to launch search and rescue operations, if necessary.

Surface winds near the predicted ditching point were from 33 degrees at 28 gusting to 35 knots. Ocean swells were recorded as five to seven meters. The overcast was 900 feet with 25 miles visibility.

Around 17:51 the airplane began a descent from 15,000 feet Since it was dark twilight an Air Force C 130 dispensed flares to light up the sea. Some 6.4 hours after departure his fuel was exhausted, and at 18:26 the airplane ditched in the Atlantic Ocean on the 268 degree radial and approximately 36 miles west of Keflavik VOR.

An Air Force helicopter arrived about three minutes after the ditching, with the aircraft still visible. But there was no sign of the two occupants. At around 18:34 the aircraft had disappeared. The ELT continued operating for the next 15 minutes.

The U.S. considered the flight illegal because an export certificate of airworthiness had not been obtained. The seller in Iowa reported the pilot was in a big hurry to depart and was unwilling to await the FAA inspector from Des Moines who would issue the export ferry permit. We know there was survival equipment aboard, since Transport Canada officials refused authorization for the trans-Atlantic flight until the pilot obtained the minimum required necessities.

Why the two occupants failed to exit the airplane is only speculation, but may have been due to lack of underwater egress training. Once down, water pressure on the doors can hold them firmly closed until the cabin is flooded, at which point some of the external pressure is relieved. This means the occupants must hold their breath and wait until the pressure equalizes. Unfortunately in cold water – 50 degrees or colder – Coast Guard tests show that even the best can hold their breath for only 15 seconds. And with the water temperature near freezing, the immersed human body shuts down quickly.

This pilot was in such a hurry that it took the Canadian Government to force him to acquire the required survival equipment. At the least it shows a total disregard for the life of his passenger. Then his obsession to depart led him to over-estimate the Cessna P210Ns range. As they say in poker, he paid to learn.

The survivability of ditching in cold open water at night would be a moot point had the pilot correctly determined the airplanes fuel status and the weather at his destination. Pushing an airplanes range to its limits is difficult enough to justify when there are airports nearby and terra firma underneath. But flying over the frigid waters off Greenland certainly merits an even more conservative decision process.

Also With This Article
Click here to view “Cessna P210N Endurance Profile.”

-by John Lowery

John Lowery is an aviation researcher, and former Air Force and corporate pilot.


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