F-16 Fuel Quantities (was Power generation & "environmentalism")
-
If you are in your F16 with 2000 pounds of fuel and the next tanker is 30 minutes away when using 4000pph.
Wrong example
With 2000 lbs of fuel, you should be bingo and heading for home plate, not looking around for a tanker :mrgreen:But still, replace tanker by airbase and you have a point. Oh, and add 1000 lbs (give or take), since this is the minimum fuel value you are allowed to have at landing.
-
Wrong example
With 2000 lbs of fuel, you should be bingo and heading for home plate, not looking around for a tanker :mrgreen:But still, replace tanker by airbase and you have a point. Oh, and add 1000 lbs (give or take), since this is the minimum fuel value you are allowed to have at landing.
Can be higher. Kunsan F-16s need 2400 lbs fuel on landing - so that they can divert to Osan if needed, and hold there if needed. Emergency fuel at 1000 lbs, priority fuel at 1200 lbs. Add holding fuel to that, then add travel to divert field to that.
Once you do that, you stop questioning why RL pilots would carry wing bags all the timeā¦!
EDIT: numbers dont seem to back me up here. 1200 lbs normal recovery, 1000 minimum recovery, and 800 emergency is in the AFI11-F16v38FWSUPP. Trying to find the doc which had the higher numbersā¦
-
Once you do that, you stop questioning why RL pilots would carry wing bags all the timeā¦!
Definitely. Something to think of for the future : doing random flameouts when fuel is below the minimum. This way V-pilots would understand the need for fuel tanks
-
Can be higher. Kunsan F-16s need 2400 lbs fuel on landing - so that they can divert to Osan if needed, and hold there if needed. Emergency fuel at 1000 lbs, priority fuel at 1200 lbs. Add holding fuel to that, then add travel to divert field to that.
Once you do that, you stop questioning why RL pilots would carry wing bags all the timeā¦!
EDIT: numbers dont seem to back me up here. 1200 lbs normal recovery, 1000 minimum recovery, and 800 emergency is in the AFI11-F16v38FWSUPP. Trying to find the doc which had the higher numbersā¦
Peacetime manual limits historically havenāt meant jack in actual conflicts - even in 2003 there is an account of an F-16 hitting the tanker at 800 lbs. Historically there plenty of accounts of tankers flying into the combat zone to save jets - or jets diverting - or even an F-4 pushing another F-4 in mid air when it was low on fuel after a fuel leak
. Iām sure flying over ISIS manual limits can be observed flying the whole thing on Alt hold - but flying over a high threat environment like Nam hitting the tanker on fumes after dealing with unforseen events seemed more like the standard procedure. -
Definitely. Something to think of for the future : doing random flameouts when fuel is below the minimum. This way V-pilots would understand the need for fuel tanks
-
Peacetime manual limits historically havenāt meant jack in actual conflicts - even in 2003 there is an account of an F-16 hitting the tanker at 800 lbs. Historically there plenty of accounts of tankers flying into the combat zone to save jets - or jets diverting - or even an F-4 pushing another F-4 in mid air when it was low on fuel after a fuel leak
. Iām sure flying over ISIS manual limits can be observed flying the whole thing on Alt hold - but flying over a high threat environment like Nam hitting the tanker on fumes after dealing with unforseen events seemed more like the standard procedure.Peacetime limits are the result of the need to weigh the requirement for training against the requirement to keep aircrew safe.
In war, limits are broken. The consequences are often light if they are there at all, because the necessity may outweigh the reasoning that held true in peacetime conditions.
I see you are also a fan of Dos Gringoās tale of how they flew the whole mission on alt holdā¦! XD
DROPPINā JDAM!
-
The thing is, Migbuster, in your example of the F-16 hitting the tanker, at 800 lbs the guy was definitely at risk of flameout - so it was really close. In BMS, at the moment, with 800 lbs, I can do 50 NM or more and land without too much sweat
-
I see you are also a fan of Dos Gringoās tale of how they flew the whole mission on alt holdā¦! XD
DROPPINā JDAM!
One of the best lines - cracked me up!
-
The thing is, Migbuster, in your example of the F-16 hitting the tanker, at 800 lbs the guy was definitely at risk of flameout - so it was really close. In BMS, at the moment, with 800 lbs, I can do 50 NM or more and land without too much sweat
Me to - I throttle back to zero and glide all the way back
-
The thing is, Migbuster, in your example of the F-16 hitting the tanker, at 800 lbs the guy was definitely at risk of flameout - so it was really close. In BMS, at the moment, with 800 lbs, I can do 50 NM or more and land without too much sweat
800 lbs I would wager would still be okay. Under 700 and trying to do negative Gs I would expect a flameout. I kinda thought the -1 would cover how low you can get on fuel, but the only references to it were a line stating that usable fuel is equal to totalizer displayed fuel unless due to a fault, and another saying that the DED bingo page fuel should correlate to within 100 pounds of the totalizer fuel.
Which would support the position that you should be able to get to 100 on the totalizer without worrying under normal flight conditions.
-
DED data and totalizer are different mesures of the fuel state. IIRC, totalizer sums up values of each fuel gauges, while DED data is what in france is called ādetotaliseurā, ie : total fuel at ramp minus fuel consumed, fuel consumed being measured near the engine. The -1 just says both should be more or less equal within a margin - normal.
But you have fuel the feeding system cannot get to in the tanks, and this is why you can still have a flameout while fuel on board is still a few hundreds lbs. This is the whole purpose of emergency and minimum fuel.
As for the mention of useable fuelā¦ā¦ this would imply that everything in the tanks can be pumped to the engine. IMO, that is not the case.
-
DED data and totalizer are different mesures of the fuel state. IIRC, totalizer sums up values of each fuel gauges, while DED data is what in france is called ādetotaliseurā, ie : total fuel at ramp minus fuel consumed, fuel consumed being measured near the engine. The -1 just says both should be more or less equal within a margin - normal.
But you have fuel the feeding system cannot get to in the tanks, and this is why you can still have a flameout while fuel on board is still a few hundreds lbs. This is the whole purpose of emergency and minimum fuel.
As for the mention of useable fuelā¦ā¦ this would imply that everything in the tanks can be pumped to the engine. IMO, that is not the case.
The aircraft basic weight includes UNUSABLE fuel. There is aircraft fuel which is not counted in the totalizer and is unusable. The totaliser only counts usable fuel. Additional fuel is in the fuel lines at flameout, but cannot be used by the engine and is not included in the totalizer value.
-
The aircraft basic weight includes UNUSABLE fuel. There is aircraft fuel which is not counted in the totalizer and is unusable. The totaliser only counts usable fuel. Additional fuel is in the fuel lines at flameout, but cannot be used by the engine and is not included in the totalizer value.
This is what Iām reading too, fuels tanks are the same. So indeed, you might be right ! Need to check more what the risk are of going below minimum fuel.
-
From F-16 operation procedures :
3.22.4. Minimum/Emergency Fuel. Declare the following when it becomes apparent that an aircraft
will enter initial or start an instrument final approach at the base of intended landing or alternate, if
required, with:
3.22.4.1. Minimum Fuel:
3.22.4.1.1. All F-16 Blocks 10 through 32 - 800 pounds or less.
3.22.4.1.2. All F-16 Blocks 40 and higher - 1,000 pounds or less.
3.22.4.2. Emergency Fuel:
3.22.4.2.1. All F-16 Blocks 10 through 32 - 600 pounds or less.
3.22.4.2.2. All F-16 Blocks 40 and higher - 800 pounds or less.Definition of minimum fuel and emergency fuel :
http://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/info/all_infos/media/2008/info08004.pdfBasically :
emergency fuel : from where you are, you need to proceed directly to the airbase if you want to land with final reserve fuel.
minimum fuel : emergency + some margin : if any delay occurs, you will be in emergency fuel.From this we can deduce the final reserve fuel, under which we can safely assume there IS a risk of flameout.
So all thatās left to do is take a clean F-16 Block 40 or 50, for ex, run it dry up to 1000-1500 lbs more or less (so that you get more or less the total weight you would have in an emergency), go into a 15 NM final (noting precisely your fuel beginning your approach), land, see what is your fuel at touchdown so you can deduce fuel spent on the approach.
Substract fuel spent on approach to emergency fuel, and you have Final reserve fuel, fuel under which you do have risks of flameout. I need to make the test, but Iām pretty sure that will come to around 500-600 lbs for a Block 40 or up, and 300-400 for Block 32 or less. Not neglectableā¦
Oh, and BTW : :tjacked:
-
under positive Gās and with the fuel pumps working the dash reads a lot like you get a flameout from fuel starvation around 0 on the totalizer. Elsewise it is not usable fuel.
That said the fuel flow section does comment that with the fuel pumps off, and less than full reservoirs, any negative G maneuvering can cause air to get to the siphons that run the FFP which can cause fuel starvation to the engine even with usable fuel in the reservoirs.
RE the threadjacking - my demands are as follows: the thread returns to friendly discussion and no people saying they want to build power plants next to peoples homes!
If my demands are not met, then you will never see the thread (in its original condition) again!
-
under positive Gās and with the fuel pumps working the dash reads a lot like you get a flameout from fuel starvation around 0 on the totalizer. Elsewise it is not usable fuel.
That said the fuel flow section does comment that with the fuel pumps off, and less than full reservoirs, any negative G maneuvering can cause air to get to the siphons that run the FFP which can cause fuel starvation to the engine even with usable fuel in the reservoirs.
RE the threadjacking - my demands are as follows: the thread returns to friendly discussion and no people saying they want to build power plants next to peoples homes!
If my demands are not met, then you will never see the thread (in its original condition) again!
+1 for the threadjacking
I know for the pumps nad negative Gs, dont worry
But its not what Iām talking about.I actually just ran the test : on a circuit just like defined on the Dash-1 (so downwind, base, final) or on a long final, you burn 300 lbs. So with an emergency fuel at 800 on the beginning (like for a Block 40/50), you land with 500 lbs. So 500 lbs margin.
500 lbs is around 10 min of flight in economic cruiseā¦. so not a critical emergency to me
These minimum fuels in F-16 OPERATION PROCEDURE can only mean, for me, that you do run the risk of a flameout below 500 lbs.And that can be explained by a number of things besides unuseable fuel : gauge errors, vaporized fuel, fuel expanding with temperature, etcā¦
-
+1 for the threadjacking
I know for the pumps nad negative Gs, dont worry
But its not what Iām talking about.I actually just ran the test : on a circuit just like defined on the Dash-1 (so downwind, base, final) or on a long final, you burn 300 lbs. So with an emergency fuel at 800 on the beginning (like for a Block 40/50), you land with 500 lbs. So 500 lbs margin.
500 lbs is around 10 min of flight in economic cruiseā¦. so not a critical emergency to me
These minimum fuels in F-16 OPERATION PROCEDURE can only mean, for me, that you do run the risk of a flameout below 500 lbs.And that can be explained by a number of things besides unuseable fuel : gauge errors, vaporized fuel, fuel expanding with temperature, etcā¦
Or that they want you to land with a fixed reserve of 500 pounds. Lets face it, beaurocrats would never let it work like that. It would be called flameout fuel then, not emergency fuel.
-
The reservoir is 480lbs iirc. Following simple physics, random flameouts may occur when one of the fuel pumps feeding out of that tank runs dry. Would like to see that modelled, it would lead to more fuel discipline among the virtual pilots.
I get nervous everywhere around 1000lbs
-
Or that they want you to land with a fixed reserve of 500 pounds. Lets face it, beaurocrats would never let it work like that. It would be called flameout fuel then, not emergency fuel.
Emergency fuel has a fixed definition - I believe its FAA or something. Definition being : minimum fuel needed to get straight to the next runway and land with the Final Fuel Reserve.
In the F-16, I would make sense that the final fuel reserve is the reservoir feeding the tank indeed : the slightest G you get (in any direction), the fuel goes around everywhere and you risk to have a pump stall. Especially with negative Gs, as you said earlier Blu3wolf.
-
The reservoir is 480lbs iirc. Following simple physics, random flameouts may occur when one of the fuel pumps feeding out of that tank runs dry. Would like to see that modelled, it would lead to more fuel discipline among the virtual pilots.
I get nervous everywhere around 1000lbs
both reservoirs are 480 lbs +/-30.
Normally fuel pumps are not the primary supply method to the reservoirs, they are a supplement to the siphoning action from the reservoirs. This method does depend on the reservoirs being full though.
Fuel pumps feed equally from both reservoirs to the FFP and from there to the engine.
It does seem to suggest in the emergency section that you can get flameouts if the reservoirs are not full and you select high fuel flow rates over 6000pph.
