Emergency fuel profile

[Russ]

For the fighter/attack guys or those of you very fuel limited
I recently went from A to B only to find both runways at B were closed due to an incident, had to go to C (no alt fuel as wx was good)
My question is to do with min/emergency fuel profiles. It was a short flight to C, but it made me wonder what profile would have been best if I had less contingency gas. For turbofan/turbojet aircraft on a bingo/emergency profile, how does it differ from a normal one? Is it better to climb quickly to altitude and power back, or keep the forward speed up at the cost of climb rate? Any insight is appreciated

 

[Bustamove]

Can't speak for the Air Force, but Navy tactical jets have Bingo profiles for various ranges in Pocket Check Lists (single pub that contains normal procedures, emergency procedures, etc. in a g-suit pocket sized package). Our rule of thumb was 2000# plus 10#/nm, and that was usually pretty close for fuel required. That gave us 2000# at, I believe, 1500ft overhead the alternate, which was good for an approach and a couple of passes. Don't know how those numbers would translate to a commercial jet.

The profile depends on the range. Generally speaking, it's a mil climb to altitude followed by a max range cruise and idle descent to overhead. Altitude depends entirely on range, but it gets up into the high teens and 20's pretty quickly.

 

[Rush Limbaugh]

The F-16 has a great mode for emergency diverts. It figures the fuel you'll arrive with and the optimum altitude enroute.

As far as the climb, every jet I have flown has a tech order climb schedule you'd use to get to altitude that will burn the least amount of fuel. It is usually an airspeed in knots until you get to a mach number and then continue at that mach number. For example, if it was 300 knots and .85 mach, you'd climb at 300 knots in mil power until .85 and then allow the CAS to decrease while holding .85. The tendency in the Viper was to climb at a faster CAS to altitude simply because holding a low speed CAS like 300 in mil power puts the nose so high that if you have throttle-stick interconnect problems like I often do it is hard to get the nose at the perfect pitch to hold the airspeed. You are climbing so fast that by the time you get it right, everything changes because now you're holding a mach number, and by the time you get that right, you are leveling off.

Those were the days....

 

[H82BL8T]

Joker / Bingo

Concur with Rush. For the world's best Air Superiority fighter it is tech order climb (350KCAS to .85M) to an altitude equal to divert range divided by 3 (ie 100nm/3 = 33K) then cruise at max range AOA until idle descent starting at a range equal to altitude to lose multiplied by 2 (ie 33k x 2 = 66 nm). This technique has many small refinements to include reducing drag by jettisoning external stores if need be. If you still can't make it, then any 4-6K piece of concrete will do (finding a tanker may help too). Plan ahead & stay way ahead is always the best COA.

 

[Russ]

Thanks gents. Just found a company directive that has us climb at 250 all the way to altitude in a min fuel situation, well below a normal profile speed. Any heavy guys have anything that addresses this?

 

[Yahtzee]

Re: Joker / Bingo

If you still can't make it, then any 4-K piece of concrete will do (finding a tanker may help too).

You gotta luv an Eagle guy looking for a tanker.

H82BL8T...just giving you a little grief. It's always nice to have a pair of Eagles nearby when Mig 25s start popping up.

 

[H82BL8T]

Top Off Please

No Fuel - No Duel!
Got to have the go juice. Thanks, many times over.
The MIG-25 I've got.
Keeping you all back from the 'bottle rockets' is another story.

 

[Yahtzee]

H82BL8T,

Thanks for your service and your sacrifices.

Fighter guys are much appreciated by the tanker guys, especially when shots get fired.

Godspeed to you and your family as you retire!

Yahtz