Often as ATC, I receive Emergency Fuel declarations from pilots, and there’s nearly one universal trait shared by all:
They are all extremely high for their location and still flying at max cruising speed.
This is precisely what not to do if you’re running low on fuel and want to be moved to the front of the line.
First off, Fuel Time Remaining is calculated based on your instantaneous burn and volume remaining. Flying full throttle will obviously only increase your instantaneous fuel burn. If you’re flying at FL200 at M0.86, I promise you’ll have more than half an hour of fuel left if you react differently than simply expecting the airspace be cleared on your account.
Slowing down and descending will instantly lower your fuel burn and, ta-da, more fuel time remaining. Not to mention, if you’re closer to intercept altitude, we might actually be able to slot you in.
If you’re still at FL240 an 476 knots GS, there’s really nothing we can do for you. If you’re running low on fuel, it would be advisable to stop burning through it as fast as you can. Fuel Time Remaining isn’t a concrete number. It’s based on your current fuel burn. Lower that number by slowing and descending responsibly, and your fuel burn can only go down. Bonus, we can actually slot you in for landing.
(Side note: Please don’t announce you have a half an hour of fuel left if you’re cleared number one for landing and on a 5 mile finals. There is quite literally nothing that can make your situation any better at that point, since we cannot, as of yet, slide the field underneath your plane. I know everyone loves hitting the button because they don’t always get the chance, but, really, you’re number one and on short final. What am I supposed to do for you?)
Pre-emptive response: I’m not talking about situations where you’ve been in a hold at FNF for a half hour. I’m speaking of Tower only scenarios where it’s left to the pilot to descend responsibly and they don’t, even though there’s not a high volume of other inbounds to worry about. If you’re worried about fuel, it would be advisable to descend from the stratosphere and slow down. Remember, that “time” remaining isn’t set in stone. It’s based on what you’re burning through at that moment. You can’t ‘outrun’ it, so-to-speak. Slowing down will slow the burn and give you more time.