Warbird newbie drop tank puzzle..

[daytonite_andy]

Having just bought the excellent A2A P-51D Mustang (pre-weekend sale :icon_eek:) I'm a bit confused as to when I should release my drop tanks. There are fuel gauges for the centre and left and right tanks but no indication of fuel in the drop tanks.

In my first few flights I usually use the drop tank contents first and then drop them to reduce drag but I was just wondering how it was done back in WWII. Do I just wait for the engine to start spluttering and then change tank or should I guess (calculating estimated fuel burn x flight time) before switching?

I'm having 'pre-A2A P-51 accusim' nightmares about ruining my engine I think....:icon_lol:

[PRB]

I don’t think there were fuel quantity indicators of any sort for the drop tanks. During the Round The World Race, I set a timer and switched between the two tanks at 5 minute intervals until the engine quit, then I switched to the internals and dumped the tanks. I think I could get about 30 minutes out of them… Not sure what the real procedure was, or what dire and tragic consequences you will be forced to endure by accusim if you run the tanks dry!

[stansdds]

In real life, and in most sims, there is no fuel quantity gauge for a drop tank. The procedure is to start up, taxi, and take off using reserve or main fuel tanks. You cruise on the drop tanks, then when the engine sputters or you have calculated your fuel consumption and have been timing yourself, switch to your main tanks. During WW II, tanks were dropped when enemy action was encountered. Today, the FAA frowns upon objects such as drop tanks being dropped from aircraft.

[blazefox2]

hehe just dont forget to switch from external to internal fuel feed after you drop or else your engine goes ka-put (dont that a number of times with the p-47 :isadizzy:)

[peter12213]

the guage for drop tank fuel was behind the headrest and usless in flight a2a should have a guage in the shift menu tho!!

[stansdds]

I think that would be for the auxiliary tank and not the drop tanks.

[peter12213]

ahh sh*t sorry you are right my mistake sorry guys i'll keep my mouth shut in future!!:ernae:

[DaveQ]

I had the pilot's notes for the Mustang III (P-51B) and the A2A P-51D flies pretty much to the same kind of numbers in terms of fuel consumption. I've been trying to verify them but the book's disappeared. From memory then at 2,400rpm with 34 inches of boost and a lean mixture the A2A P-51 will cruise at something like 50-60 U.S. gallons per hour at around 20,000 feet. This gives you over 2 hours flying on the drop tanks. Again, as I recall, on a fully fuelled -D model with the fuselage tank full, the procedure was to use the fuselage tank first because it affected the handling quite badly. Again you can get over an hour's worth out of that so, unless you're going a long way, leave it empty or with enough fuel to get off the ground then use the drop tanks.

Enjoy the A2A Pony Daytonite_Andy; it's my favourite flightsim add-on by a country mile!!

DaveQ

[Bomber_12th]

An interesting tidbit that I learned while spending the last couple of years researching the Merlin-powered Mustangs, is that in some manuals it is recommended to leave 48-gallons of fuel in the fuselage tank for combat, as it was deemed the perfect balance of CG for dogfighting. The typical routine of fuel tank-operation was to switch from one tank to another every 15 minutes, for both the main wing tanks and the drop tanks. The manual recommends starting and taking off on the left main wing tank, as fumes were collected and put back into the engine with the left tank, and then focus should be switched to either the fuselage tank, right wing drop tank, or right main wing tank. Many WWII pilots however state that they started and took off on the fuselage tank, to burn as much as possible, and then went to their drop tanks once they had burned away enough fuel in the fuselage tank to feel comfortable. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
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It definitely is not a good thing to let one tank dry down completely before switching to another, and I'd imagine most decisions as to when to stop using the tanks and/or release them would be based on pre-calculations of endurance, if not to jump into combat.<o:p></o:p>

[Cag40Navy]

well, i know that when you are going into a hot-zone of combat or have a bogey:icon31:, you drop the drop tanks to start then return (unlees you got shotdown:icon31::rocket:) on what you have on the wing tanks. unless im doing a flight that needs them, i dont take'em. i always use center tank because this way at least ill have fuel to get back to base when i get done in the hot-zone.

[daytonite_andy]

Thanks to everyone who replied.


The A2A manual for the P-47 (yes I had to buy that one also!) has a bit of useful advice. "There are no gauges for the external tanks. Time your consumption and when you figure a tank is about to run dry, watch the fuel pressure gauge. Switch tanks the instant the indicator oscillates."


I'm not sure how well this is modelled in the P-51 I have but maybe that was the procedure in real life. I think I'll stick to timing my consumption though.



DaveQ - If you haven't found that manual there are a few excellent ones to be downloaded here (http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/mustang-manuals-9051.html)


peter12213 - Yep, no 2D panels on this model is a bit of nightmare, since I like to use the checklist to startup etc. Things get a little tough in the vc when you have to zoom in and out to flick switches. I may have a go at making some.


Again...thanks all.

Andrew