The most simple explanation of when to declare emergency fuel vs minimum fuel and how to calculate BINGO fuel

Have you ever heard of Avianca 52? A scheduled flight from Medellin to New York, that crashed onto a hillside due to fuel starvation. The B-707 left Medellin with enough fuel to complete a safe landing at JFK. While en route, Avianca 52 was placed in a holding pattern. Due to poor communication between the crew and air traffic controllers and the pilots’ inadequate fuel load management, the flight became critically low on gas. This dire situation was not recognized as an emergency by the ATC because the pilots failed to use the word “emergency.”

The flight attempted to make a landing at JFK, but due to bad weather, poor CRM, and inadequate aircraft management, it was forced to go-around. The Captain told the FO to declare an emergency, but the FO used the incorrect terminology and just accepted a long vector to attempt another approach. The flight ran out of fuel before it was able to make a second landing attempt. The airplane crashed approximately 20 miles from JFK.

The NTSB determined that the crash occurred due to: 

  1. Failure of declaring fuel emergency correctly
  2. Failure to use an airline operational control dispatch system
  3. Inadequate fuel load management (Calculate Bingo)
  4. Lack of standardized terminology (Minimum Fuel vs. Emergency Fuel)
  5. Inadequate traffic flow management by Air Traffic Controller

In this article, we will cover minimum fuel, BINGO fuel, and emergency fuel. Since the FAA is vague on when a pilot should advise ATC about minimum fuel, we will first explain what minimum fuel is and when a pilot should announce it. Secondly, we will talk about fuel load management. It’s critical for a safe operation that a pilot identifies when he/she should continue to the destination after being held for some time or when to proceed to the alternate. In other words, how to calculate bingo fuel. Last but not least, when to declare emergency fuel. Although not defined in the AIM or FAA regulations, we will use ATB 2012-1 to explain what emergency fuel is and when you should declare it. 

Let’s start with minimum fuel. According to AIM 5-5-15;

“Use of the term “minimum fuel” indicates recognition by a pilot that the fuel supply has reached a state where, upon reaching the destination, the pilot cannot accept any undue delay.”

minimum fuel vs emergency fuel
Examples of undue delay: an extended downwind, delay vectors, or a holding pattern.

Minimum fuel is merely an ADVISORY to ATC, NOT an emergency. Pilots have to monitor fuel burn continuously and act accordingly. 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 should report the remaining fuel in minutes. Since the FAA is vague on when a pilot should advise ATC about minimum fuel, we will use the most common rule used by the 121 world (airlines) to explain when to ADVISE it. Yes, I am talking about “BINGO FUEL.” 

What is BINGO fuel? “BINGO Fuel” is a military slang that airlines use to identify the minimum fuel you must have on board to complete a flight from A to B, then fly to the farthest alternate plus the reserve fuel. When the crew becomes aware of this number, they can know how long a delay can be accepted before continuing to the alternate without attempting a landing at the destination. In other words, BINGO fuel is considered the point when a crew has reached minimum fuel. 

How do we calculate it.?  


The formula has three variables; I know it doesn’t look very easy, but I promise you it’s a breeze walk. Let’s start with the first part. Reserve fuel will always be the same, depending on the operation being conducted and the airplane being used. For example, if the flight is being operated under IFR rules, as states on §91.167, 45 mins of fuel must be on board at all times and this fuel can only be used in case of an emergency.

“No person may operate a civil aircraft in IFR conditions unless it carries enough fuel (considering weather reports and forecasts and weather conditions) to”: 

1. Complete the flight to the first airport of intended landing; 
2. Fly from that airport to the alternate airport [if one is required]; and
3. Fly after that for 45 minutes at normal cruising speed or”

14 CFR § 91.167

The second part, the farthest alternate. The farthest alternate means that if you have more than one alternate, use the farthest one. Depending on the weather and the type of operation, a flight can have two destination alternates.

At last, the fuel to the destination. This is the only part of the equation that is continuously changing. It depends on your current fuel burn and the actual distance to the destination. It sounds complicated, right? Don’t worry; it’s straightforward. Nowadays, we have electronic gauges that provide us with fuel burn and a GPS that helps us with the time and distance. 

Let see a real-life scenario. 

On a flight from CWA to ORD, ATC told the crew to hold over LYNNI as published, EFC 25 min. What will be the BINGO FUEL over LYNNI.? How long can the crew hold over the fix?

Onboard fuel5,100 lbs
Reserve fuel1,506 lbs
Fuel burn1,000 lbs per hour
1st alternate CWA1,962 lbs
2nd alternate LAN1,542 lbs
Required fuel to complete the flight to the destination from LYNNI890 lbs

BINGO = Reserve fuel + The furthest alternate + Fuel to the destination
BINGO = 1,506 + 1,962 + 890 
BINGO = 4,358 lbs

Extra fuel = 5,100 – 4,358
Extra fuel = 742 lbs

Max holding time = 742/1,000
Max holding time = 0.742 * 0.6 = 0.4452 = 45 minutes

Having calculated this, we can determine that the crew can accept the holding without a problem. Their BINGO fuel is 4,358 lbs. When the crew gets close to reaching BINGO, and the clearance has not been received yet, they could advise ATC about the minimum fuel situation or request a diversion to the alternate. Suppose the crew determined that the remaining usable fuel supply is not enough and there is a need for priority to ensure a safe landing. In that case, the crew should declare an emergency due to low fuel and report fuel remaining in minutes.  Declare emergency fuel? What is emergency fuel and when to declare it?

According to ATB 2012-1:

“Declare a fuel emergency at the point at which, in your judgment, it is necessary for you to proceed directly to the airport at which you intend to land. Declaration of a fuel emergency is an explicit statement that priority handling by ATC is necessary and expected.”

FAA is also vague on when a pilot should declare emergency fuel. It’s more of a judgment call. Anytime the lives of the people aboard are threatened, and the aircraft needs to land immediately, declare an emergency. But, if you want a specific number, declare an emergency anytime you are flying with your reserve fuel. Or, if you’re going to use IATA standards, you may declare an emergency anytime the flight has less than 30 minutes of fuel remaining on board. 

When can this scenario happen?

On my last recurrent training, I got the following scenario.

DCA to LGA, sky clear, winds calm in both destination and departure airports. No alternate was required for this flight. As we got closer to LGA, visibility dropped to 1 1/2 SM due to rain and fog over the field, and the only available approach was the LDA-A. We attempted an approach but could not see the runway at minimums; consequently, we went around and requested another attempt. On this attempt, we talked as a crew and decided that this was the last one, and if we were unable to land, we had to declare an emergency and proceed to the closest airport with an ILS. Indeed, that’s what happened; we went around, immediately, we declared an emergency because we had 30 minutes of remaining fuel. After that, we had priority over everyone, and ATC gave us short vectors for the ILS 22L at JFK. We landed safely at JFK.

In conclusion, minimum fuel is an ADVISORY to ATC that your fuel supply has reached a state where you cannot accept any undue delay. The safest way to calculate when you should advise ATC about this problem is by calculating BINGO fuel. Continuous fuel monitoring is fundamental to increase situational awareness and prevent further issues. If, at any time, the remaining usable fuel supply suggests the need for traffic priority to ensure a safe landing declare an emergency and report the remaining fuel in minutes. Do not hesitate to declare an emergency; remember that all the people on board are counting on you to land the aircraft safely.

Safe Flying!

Don’t stop here, let’s keep learning!