Mosquito fuel tank order change

[moot]

A wish for the mossie's fuel tanks to fill the outer tanks last and burn them first.  Informed suggestions welcome on where the AUX tank ought to be in the fill/drain order.

[Scherf]

I use shift+F to cycle through the tanks moot.

As for the Aux tank, I really don't know how it affects CG - even at 50% full though, it doesn't last long.

[PFactorDave]

I wish that we could pre-program each aircraft with a fuel burn order, like we pre-program views.  Set an order, hit F10 and the system remembers it for our next flight.

There aren't many planes that I mess with the burn order, but I sure would like it if I didn't have to fiddle with it on the few airframes that I do mess with it.

[phatzo]

you have my vote on this, always forget and burn the left wing dry.

[moot]

I use shift+F to cycle through the tanks moot.

As for the Aux tank, I really don't know how it affects CG - even at 50% full though, it doesn't last long.

IIRC the AUX is further forward than the inners.  The outers arent a huge CG difference lengthwise, but they're definitely better off empty to help roll rate.

I'm asking because a while back Pyro said he was open to suggestions for another model that needed it (152), so this one seems reasonable enough.

[Scherf]

Heya:

Had a look at the CG table I posted to the AHwiki site ('doh!) and saw the arm for the centre tanks actually indicates it's further back than the wing tanks - about 4 ft arm as opposed to 2.5 feet or so for the wing tanks. The .303 ammo and the crew have negative arms, I assume as they are ahead of the CG.

So, if the AH Mossie is correct, draining the Aux tank will make the Mossie a touch less tail-heavy.

I confess, I don't know if being tail-heavy is good for dogfighting, though I guess in thinking about it, that it's a bad thing, m'kay.

[moot]

It depends on the plane.. I dont know the mossie well enough yet to tell.

[Krusty]

Somebody posted a nice diagram a while back with the exact positions of the fuel tanks shown. Don't suppose anybody saved it to their HD, or recalls which thread it was in?

[moot]

I had that diagram but lost it..  I know I posted in that thread, so maybe...

Oops.. I guess I'd already made this thread.
http://bbs.hitechcreations.com/smf/index.php/topic,213852.msg2557795.html
Milo should still have that diagram, but from what he says the ideal fuel distribution would be to have the inner tanks first, and then either the outer or aux tanks.  I do remember that there was no clear advantage to either aux/outer on paper, so practical results would be the only way to argue for this wish.

[Scherf]

Milo's conclusion is correct, however if he's referring to the cross-hatched diagram *I'm* thinking of, he's got the wrong version. Not all of the centre-section of the FB.VI wing is taken up with fuel tanks. If you look at the various FB.VI Pilot's Notes *.pdfs on the web, you'll see the centre tanks listed at 50 gallons, whereas on some other models it's 80 or even 136 gallons.

I asked a fellow from the de Havilland heritage centre (he helps restore three original Mossies on his weekends, ho hum), about why the FB.VIs centre tanks were so much smaller, and whether it was to do with the cannon feeds. His reply was:

"Yes, its to do with the cannon feeds. The centre section of the wing is split into four internally - the rear two compartments have the fuel tanks in. The rest allows room around the cannons."

So there are two small tanks, well back in the wing, so CG effect much further back than the wing tanks.

[mechanic]

It depends on the plane.. I dont know the mossie well enough yet to tell.

bored of the 152?

 

[moot]

incorrect.
You fly the mossie.  Add something on-topic to the thread.  The inners are definitely better for agility than the outers.  What fuel order would you suggest, and why?

Scherf, could you make a quick & dirty drawing of what you mean?  I'm not sure I'm picturing it right.

[mechanic]

Yes, I've flown the mosquito almost all the time for well over a year now. My wonderfully humourless and on topic snippet will follow: I use Shift F to manualy cycle fuel tanks in any planes I need to. Its what that fuction was designed for, i thought.

[Scherf]

Scherf, could you make a quick & dirty drawing of what you mean?  I'm not sure I'm picturing it right.

Sure thing, will stick something up tomorrow my time. Bed now, got to catch the wave of fatigue before it dissipates.

[Scherf]

OK

Milo's cross-hatched drawing may have looked something like this (from a German Magazine, Luftfahrt International IIRC, hence capacities shown in liters):



Note the two tanks in the centre of the wing/directly behind the cockpit - that size of tank applies to bomber variants

However, in the case of the FB.VI and the other armed Mossies, the cannon ammo boxes and feeds took up the front portion of the compartment, as can be seen in this drawing (from, again IIRC, the Kagero book - an excellent Japanese/Italian co-production if ever there was one). The centre tanks are located between the chutes for the spent shell casings (little black L-shaped things near the middle of the fuselage) and the rear spar (to which flaps are attached):



The ammo boxes are directly are in line with the chutes for the spent shell casings and links, but were quite tall, as can be seen in this drawing from the FB.VI manual:



When strung together, the whole system looked like this:



Note that there are therefore two centre tanks, AND (for long range use only - for example the intruders of 418 Squadron on their epic Baltic / Czech sorties before D-Day) an auxiliary tank, which could be fitted into the bomb-bay.

So, I don't know if AH has modelled the aux tank behind the cannon, OR simply combined the two smaller tanks into a single unit. Judging by the speed at which the fuel is used in-game though, one might guess the latter.

EDIT - On actually looking at the last diagram, I see the two 25-gal tanks are actually plumbed as a single unit, with one feeding into the other, so modelling it as one tank is correct.