#6 of my series Behind the Cockpit Door
If you’re a pilot, you’ve probably heard the term “Bingo Fuel” but may not know how much it’s “always on my mind.” The term refers to what concerns all pilots, especially those of us who are rationed or carry other than full tanks of fuel. Many passengers don’t realize that airlines almost NEVER fill their fuel tanks…they take what they need plus reserves and contingency fuel to get them to their destination. That way, there’s more weight allowed for passengers and cargo.
Bingo fuel is a number, and a sacred one, that I’d write in the margin of my flight plans to indicate how low the fuel could go before I HAD to land or proceed to the alternate airport. I always had in mind my personal minimum fuel that needed to be on board as the wheels touched down at (hopefully) the destination. Adding to that how much I needed to get to that touchdown spot from the holding pattern gave me that “bingo fuel” number which was carved in stone during the trip planning stage, when the heat of the battle was nowhere to be seen. The difference between the FOD or fuel over destination, calculated by the dispatcher as he prepared our computerized flight plan, and the bingo number I wrote down was how long we could “hang around” or delay until I felt we HAD to leave holding and head for our landing site.
One afternoon as we departed LAX for IAH (Houston Intercontinental Airport), a trip of some 1275 nm or approximately 3 hours flying time, that difference really got my attention. We were scheduled to arrive in the IAH area with 18.0 (18,000) lbs of fuel. My bingo fuel was 9.0 (9,000) and so there was a lots to spare… Usually we need to add fuel, so having extra meant that something was going on which required a call to the dispatcher. “What’s up” I inquired as I was glad to have the extra fuel, but wondered what was so bad as to cause him to give us almost an hour and a half of holding time? “Unforecast thunderstorms in the area, moving slowing ENE,” he told me. Ah, the dreaded afternoon thunder bumpers that were the mainstay of Texas spring and summer weather.
With that information in hand, I’d still kept my Bingo Fuel at 9.0 (6.0 @ touchdown + 3.0 to get there from holding) and looked carefully at the two alternate airports I’d had in my pocket as escape plans: Austin and San Antonio. Our flight into IAH would pass directly between them, so I had some options for landing spots if the bad weather persisted (as it was known to do) and hung around, possibly closing IAH as a destination.
We entered the holding pattern at 32,000 feet, waiting for the airport to reopen. As we moved down in the stack of airplanes awaiting clearance to proceed to IAH, the chatter became less and less as more airplanes reached their bingo fuel number and left for their alternate airport. We kept a close eye on the fuel gauges, watching our fuel on board decrease from 18.0 pounds down to 17, 16, 15, now 14. I began to be less certain that we had enough to wait it out. We’d be down to 9.0 shortly and would have to leave the holding pattern and go to our alternate. Finally, like a cliffhanger mystery, just as we’re about to yell “Uncle!” the controller said “You’re cleared to the IAH airport, descent and maintain 10,000 feet, you’re number 1 for the approach.” What had seemed like an excessive fuel load back in LAX 4 hours earlier had now saved us from an expensive diversion allowing us to be the first in line to land when the airport reopened.