New RAF Transport

[ancientaviator62]

KenV,
I assume your A400M fuel figure is wing tanks alone. The 'K' had 'only 63000 lbs until we put in the Andover tanks. Then we had an extra 28000 lbs 'downstairs'.

[BEagle]

The A400M's nominal wing fuel load is around 50 tonne. It was always the intention to include provision for up to 2 additional cargo bay tanks of 7200 litre each, giving a total fuel load of 62.1 tonne (about 136868 lb).

However, I do not know whether the CBT option is currently being offered.

[KenV]

KenV, I assume your A400M fuel figure is wing tanks alone. The 'K' had 'only 63000 lbs until we put in the Andover tanks. Then we had an extra 28000 lbs 'downstairs'.

That is correct. The cited fuel capacity was for wing tanks only.
Perhaps a better solution would be to make the centerwing section "wet". My understanding is that the A400, like the C-17, was designed with a dry centerwing section (the wing section directly over the cargo bay.) From P71 on, C-17's centerwing tank is wet and can contain fuel. The center tanks are true ER (extended range) tanks that cannot feed the engines, but the fuel can be transferred outboard to the main tanks which in turn feed the engines. A centerwing tank would seem to be a much neater solution than putting fuel tanks in the cargo bay, but that's just my opinon.

BTW, the C-17 has hardpoints and plumbing in the wings to accommodate wing hose & drogue pods. So far no one has exercised that option. Douglas did a LOT of studies for also installing a boom, but any kind of fuselage mounted boom would severely degrade the C-17's cargo utility. So Douglas dusted off some earlier DC-8 based tanker designs which included wing mounted booms. Nothing came of those. The C-17 is a STOL aircraft that can go pretty slow, but the air behind the aircraft when in STOL mode is pretty dirty. So Douglas looked at putting a hose/drogue at the top of the T-tail for refueling helos and maybe UAVs.

[BEagle]

Excluding any additional CBTs, 23.4% of the A400M's fuel capacity is carried in the centre wing box tank.

[KenV]

23.4% of the A400M's fuel capacity is carried in the centre wing box tank.

Wow! That's fascinating! It was a HUGE effort and hassle to get permission from the certification authorities to make the centerwing section wet in the C-17. They were insistent in not permitting fuel above the passengers' heads, and ours was a military certified airplane. I would have thought that that would be even more difficult in a civilly certified airplane. We even used the example of the BAE-146 airliner which had a high wing and wet wing center section as an argument to allow it in the C-17.

Thanks for the update.

[sycamore]

Must be a load of ex-VC-10 tanks around....

[snippy]

Re VC10 tanks.


Yes there are loads about....in Boots the chemist under "Mens Shaving Products"......

[VinRouge]

No mention yet of deck angle in the cruise?

[biggins]

Originally Posted by VinRouge

No mention yet of deck angle in the cruise?

Why does that matter?

[Xercules]

A400 as tanker

BEagle is correct in that the RAF's Atlas aircraft will not be equipped as a tanker in that the RAF is not procuring any pods for the role. However, every aircraft comes with capability as a wing pod tanker in-built. The hard point for the pods, the fuel piping and the electrics etc in the wing are all included in the basic aircraft. If you want a centre-line hose, CCTV monitoring or CBTs they can be provided as extras but, for ease and lower cost, would be included in the original build.

Probably, as BEagle has said because of the AirTankers contract,the RAF has not bought pods and denies the need to exercise any of the tanker capability.

[cobalt42]

If you want a centre-line hose, CCTV monitoring or CBTs they can be provided as extras but, for ease and lower cost, would be included in the original build.

That's a real gem. The Centreline Hose Drum Unit (HDU) is Role Fit. Goes on the Rear Ramp on an Interface Frame. It's (going to be) a pig to do the re-role; the ramp has to be taken apart, the HDU and its fairings fitted followed by Pressurisation checks. It'll take hours! The re-role back to box-mover will be the same - a real pain for the maintainers.

Current customers for the HDU? single figure numbers for France and Germany. the Pods - WARP in current nomenclature - are going to France, Germany, Spain and Malaysia... and good luck to 'em.

[ancientaviator62]

KenV,
on the RAF 'K' tanker we could not feed the HDU direct from the fuselage tanks but had to pump the fuel up into the wing tanks first.

[dragartist]

C'mon guys someone must have an answer for Vin on the Deck Angle. I am interested too.


I did not mean to pi$$ Ken off re his double row of Unimogs honest. Apologies Ken.


Drag

[chevvron]

Last few evenings, I've heard a very heavy sounding turboprop heading east in the Woking area on odd nights. Could these be A400s? They sound totally different to Hercules.

[cessnapete]

Russian turbo props out of EMA, went over Reading at 7/8000 ft.

[chevvron]

Ah yes; probably contra rotating props causing the throbbing noise.

[Rhino power]

Originally Posted by chevvron

Ah yes; probably contra rotating props causing the throbbing noise.

No, just ordinary turboprops, it's An-12's that have been in and out of EMA recently...

-RP

[smujsmith]

Any truth in the rumour that since its arrival, the new aircraft has refused to start, with the computerised systems spewing out copious amounts of fault codes ? Despite being ex Herc, I'm looking forward to this beast showing up in the local area, and hopefully showing that it is not simply a C130 replacement. Bad news if the "technicalities" are creating hardware problems. The story is doing the rounds in the area, as many ex transport fleet people regularly meet and beat gums. Let's hope it's just a rumour, more appropriate to ARRSE than this forum. I apologise in advance if I've spoken out of turn, but I am curious, and you guys seem to be in the know.

Smudge

[KenV]

I did not mean to pi$$ Ken off re his double row of Unimogs honest. Apologies Ken.

And my apologies if I gave the impression I was "pi$$ed off". I was just trying to clarify my intent when I posed my questions regarding A400 design points.

[KenV]

I don't believe C17 would ever compete with A400M on soft field and turning circle.

I personally doubt that A400 and C-17 would ever actually "compete" any more than the C-130 and C-17 compete. They are different designs intended to accomplish different things for different services.

But you nevertheless make a good point about soft and/or narrow field capability. Using "assault" procedures C-17 routinely puts a max payload into an unpaved 90 ft x 3000 ft runway. The C-17 can turn around on that 90 ft wide runway with 5 feet of margin on either side (i.e. 80 ft effective turn width) and safely operate from 60 foot wide taxiways.
C-17 ground flotation is actually pretty good for such a large aircraft, with a CBR of 12 at assault landing weight. That's not that much higher than a C-130's CBR of 8/9. I have no idea what the A400's CBR and short field numbers are.