Author Topic: 190-A5 Fuel Burn Order  (Read 870 times)

Offline Slade

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190-A5 Fuel Burn Order
« on: January 14, 2014, 02:05:10 PM »
Guys I was hoping the separate fact from fiction with your help.

Some contest that a FW190-A5 is significantly more maneuverable if you burn the FWD fuel 1st.  Others feel it makes the 190-A5 more unstable if you do this.  I am still unsure.

Which is it?


Thanks,

Slade  :salute
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Offline colmbo

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Re: 190-A5 Fuel Burn Order
« Reply #1 on: January 14, 2014, 02:07:52 PM »
I bet you really can't tell the difference other then it "feels" different...but no real numbers showing a performance difference.

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Offline BnZs

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Re: 190-A5 Fuel Burn Order
« Reply #2 on: January 14, 2014, 02:18:16 PM »
As far as I can tell, all this theorizing about the advantages/disadvantages of fuel burn order come from the example of the P-51, which had an 85 gallon tank placed far enough aft that it could move the COG of the aircraft deleteriously far back. That is why that tank was burned even before the drop tanks on long escort missions, and sometimes left empty (AHII's 75% is nearly equivalent to this) for missions that didn't tax the Mustang on range.

 I don't think it matters much with other aircraft.
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Offline SmokinLoon

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Re: 190-A5 Fuel Burn Order
« Reply #3 on: January 15, 2014, 11:27:23 AM »
Stop drinking the kool-aid.  Let the plane burn it for you.

Only in a certain few planes do I burn tanks based on probably damage.  Otherwise, I only burn the F4U-1A left wing tank first because it indeed does help with the stall.  FACT.  There is an actual pilot instruction video on youtube that explains it all.
Proud grandson of the late Lt. Col. Darrell M. "Bud" Gray, USAF (ret.), B24D pilot, 5th BG/72nd BS. 28 combat missions within the "slot", PTO.

Offline bacon8tr

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Re: 190-A5 Fuel Burn Order
« Reply #4 on: January 15, 2014, 06:49:24 PM »
I don't know the preferences for other A5 drivers.  My standard sortie is 50% and the DT.  I burn the DT to target or until engaged and kick it.  I use the forward tank and save what's left in the Aft tank for the trip home.  I like my A5 light, so rarely do I go higher than 50% on the internals.  Just a personal preference for me.

Offline Tank-Ace

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Re: 190-A5 Fuel Burn Order
« Reply #5 on: January 15, 2014, 08:22:59 PM »
I burn foreward to 50%, and use that as my emergency reserve if the other tanks get holed, or I just forget to watch my time.
You started this thread and it was obviously about your want and desire in spite of your use of 'we' and Google.

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Offline Debrody

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Re: 190-A5 Fuel Burn Order
« Reply #6 on: January 15, 2014, 11:40:18 PM »
I liked to leave it on auto.
Burning the forward tank first makes this plane unsteady in the stallfight. The nose will bounce all over, just like in a 152 - still not as bad though, but the feeling will be simmilar.
Emptying the aft tank first results a nose-heavy aircraft. Nice and steady, but feels sluggish in any close encounter.
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Offline MiloMorai

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Re: 190-A5 Fuel Burn Order
« Reply #7 on: January 16, 2014, 05:23:45 AM »
front tank:
182kg
arm/m > 1.34
massxarm > 243.88

rear tank:
228kg
arm/m > 2.24
massxarm > 510.72

mass > 4271.6kg
CoG > 0.666

Anyone familiar with doing load plans should be able to calculate the CoG shift for each tank being empty.

A more rearward CoG will make an a/c more unstable. As mentioned, the P-51 with a full fuselage tank and the same for the Spitfire when so fitted.

When a full drop tank is fitted the CoG is 0.673 (4592.96kg).

Offline BnZs

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Re: 190-A5 Fuel Burn Order
« Reply #8 on: January 16, 2014, 02:45:30 PM »
front tank:
182kg
arm/m > 1.34
massxarm > 243.88

rear tank:
228kg
arm/m > 2.24
massxarm > 510.72

mass > 4271.6kg
CoG > 0.666

Anyone familiar with doing load plans should be able to calculate the CoG shift for each tank being empty.

A more rearward CoG will make an a/c more unstable. As mentioned, the P-51 with a full fuselage tank and the same for the Spitfire when so fitted.

When a full drop tank is fitted the CoG is 0.673 (4592.96kg).

In theory, wouldn't a rear COG make the elevator deflection required to point your nose less? But you can already jerk the 190 into a stall instantly any time you like...so I don't see what this would help.
"Crikey, sir. I'm looking forward to today. Up diddly up, down diddly down, whoops, poop, twiddly dee - decent scrap with the fiendish Red Baron - bit of a jolly old crash landing behind enemy lines - capture, torture, escape, and then back home in time for tea and medals."

Offline hitech

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Re: 190-A5 Fuel Burn Order
« Reply #9 on: January 17, 2014, 10:54:40 AM »
In theory the most aft CG that still allows the plane to fly would turn faster then the most forward CG.

The reason is that the tail force required to hold the AOA is pushing opposite (or pushing less then level flight) toward the out side of the turn.

So the wing lift is creating the turn pushing to the center of the circle. The tail is pushing to the out side of the turn creating less total force to turn with. Same reason a forward CG has a higher stall speed.

Now the reason I said theoretical is because the aft CG will probably make it harder to stay on the pre stall edge.  And bumping the stall looses lots of turn quickly.

HiTech

Offline mthrockmor

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Re: 190-A5 Fuel Burn Order
« Reply #10 on: January 17, 2014, 11:15:44 AM »
If I am flying a long distance for a fight I burn forward down to 50%, go to drop tank and go to work. If it is a shorter fight I burn it down to 25%, go back to drop tank and fight.

I always burn the forward down, seems to give me a more stable platform for gunnery.

boo
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Offline Slade

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Re: 190-A5 Fuel Burn Order
« Reply #11 on: January 17, 2014, 05:06:32 PM »
HiTech,

Thanks for answering that so clearly.

Slade  :salute
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