The Human Factor: Minimizing an Aviation Fuel Emergency

This is especially true when pilots get into a low fuel situation. It doesn’t help that the regulations are not particularly clear on the meaning of minimum fuel vs. a fuel emergency. Neither the Airman’s Information Manual nor the FARs actually define what it means when a pilot declares a fuel emergency, but most pilots and controllers understand it to mean that the aircraft requires priority handling by ATC to proceed directly to the airport of intended landing due to low fuel. A declaration of “minimum fuel” is defined in the AIM and the AIM Pilot/Controller Glossary as an indication that “an aircraft’s fuel supply has reached a state where, upon reaching the destination, it can accept little or no delay. This is not an emergency situation but merely indicates an emergency situation is possible should any undue delay occur.”

There is more information available to controllers in the Air Traffic Control Handbook, which states that “a minimum fuel advisory does not imply a need for traffic priority. Common sense and good judgment will determine the extent of assistance to be given in minimum fuel situations. If at any time the remaining usable fuel supply suggests the need for traffic priority to ensure a safe landing, the pilot should declare an emergency and report fuel remaining in minutes.”

I would be willing to bet that a lot of pilots would be very surprised to learn that declaring “minimum fuel” to ATC does not imply a need for traffic priority. The controller could try to expedite the approach within the normal traffic flow, but the only way to indicate a need for priority handling is to declare an emergency. Even then, the controller would have to work within the restrictions of maintaining safe clearance from other aircraft and any limitations imposed by severe weather in the vicinity.

This misunderstanding is true even for Part 121 airline pilots and is becoming even more of an issue as airlines work to save fuel by minimizing reserves to reduce the weight of the airplane. Even with advanced navigation systems and sophisticated weather forecasting and reporting capabilities, it is still all too easy to get backed into a corner by a combination of weather and traffic when your reserves have been cut to the minimum amount possible.

Confusion Across Board
Reports to the Aviation Safety Reporting System bear witness to this confusion even on the part of airline pilots. One pilot reported that, due to a forecast for a chance of thunderstorms, the captain and crew decided to increase the fuel on board. However, this extra fuel was not enough, and after dealing with severe thunderstorms, wind shear and "holding and vectors all over the place," the airplane had less than the fuel they would need to accept any further delays, and they communicated this to the controller. The reporting pilot's lack of understanding of responsibility in that situation is evident in his shocked comment that "they had no plan!" It seemed that this pilot assumed that the controller would be aware of their fuel state and, while dealing with all the other aircraft under his control, would have a plan in his back pocket to deal with their situation.

The captain declared that they were “minimum fuel,” but because they were so hesitant to declare an emergency, they ended up going back and forth with the controller. First the controller cleared them direct to a VOR. They informed the controller that they could not go to that VOR and make it back to the airport. The controller tried to help them out by asking if they were declaring an emergency. They still did not declare an emergency but informed the controller that, if he insisted that they go to that VOR, they would declare an emergency. After the controller vectored them in a different direction, they broke out in the clear and were able to land with minimum fuel on board. The reporting pilot seems to have learned something from this since he stated that “next time we will declare an emergency.”

The controller working with a 737 crew was much more explicit about the options available to that crew. As they approached a holding fix, the controller was issuing EFC (expect further clearance) times of one hour, and there were quite a few aircraft in the holding pattern below them. They informed the controller that they were minimum fuel and could not hold for that long. The controller gave them three choices, “either hold, divert to your alternate or declare an emergency.” The crew determined they did not have enough fuel to divert, so after consulting with dispatch, they declared an emergency and “landed at the airport with no incident.”

Air traffic controllers can take matters into their own hands by declaring an emergency for an aircraft whose crew are hesitant to do so. In one example, an airplane approached the destination with minimum fuel reserves after considerable diverting due to weather. The weather at the destination was good, with ceilings of 12,000 overcast and nine miles’ visibility, so even though they would be landing only 100 pounds above their minimum landing fuel, they decided it was not necessary to declare minimum fuel. A few minutes from the initial approach fix, the controller asked if they could hold. In a vast understatement, the crew responded that their fuel situation “could become an issue.”

The controller apparently “read between the lines,” because when they reached the approach fix, they were told to contact Approach Control and that ATC was declaring a fuel emergency for them. The crew informed the controller that if they had to hold they would be in a minimum fuel situation, not an emergency situation. However, when they contacted the approach controller, he did not mention their fuel situation but allowed them to continue toward the airport without holding. When they parked at the gate, they had less than the minimum required fuel on board the aircraft.

Pilots need to realize that controllers’ options are restricted by the regulations and their operating orders. As stated above, a minimum fuel advisory does not imply a need for traffic priority. If you tell a controller you are minimum fuel, you are merely providing information without freeing the controller to take any action outside of normal operations to help you. It is obviously very frustrating to a controller to be dealing with a pilot who is saying he doesn’t have enough fuel to accept a vector or hold, but who doesn’t want to actually declare an emergency, which is what the controller needs to hear to be able to help the pilot. It is fortunate that controllers have the authority to declare an emergency for the pilot, and are willing to use that authority if it will benefit the pilot.

Don't Hesitate
Why are pilots so reluctant to declare an emergency? To a certain extent this hesitancy is probably based on our natural tendency not to want to ask for help, combined with a fear of the consequences of declaring an emergency. Many pilots feel that anyone who declares an emergency is required to submit extensive reports and will probably receive a violation. Reality is very different. FAR 91.3 states that, if a pilot uses his emergency authority to deviate from any rule, he may be asked to submit a written report to the FAA. In a similar manner, FAR 91.75 allows a pilot to deviate from an ATC clearance and states that ATC may ask for a detailed report if the pilot was given priority.

Notice that, in each case, the regulation does not actually require a written report, or any report at all. While the FAA does routinely investigate almost every declared emergency, experience shows that this seldom results in anything more than a phone conversation with the pilot. Legal action is very rare and reserved for the most extreme examples of unprofessional flying. Air traffic controllers want to help pilots stay alive and safe. They want us to feel free to declare an emergency without fear of punishment, and they need a declaration of an emergency to free them to provide the maximum amount of assistance available. They realize that weather, traffic and mechanical issues can cause problems that cannot be foreseen or planned for, and they are truly relieved when a pilot lands safely after declaring an emergency.

If you end up in a corner with few or no viable options, remember that controllers can help only to the extent that they understand the problem and have the authority to deal with it. It is better to declare an emergency and clearly communicate your lack of fuel to the controller than to drag out the minimum fuel charade as you continue to consume what is left in your tanks. Even if a phone call or written report is not requested after you land, it would be nice to contact the facility and thank the appropriate personnel for the excellent job they do helping to keep us safe and getting us out of the fixes we sometimes find ourselves in.