F18E External Tanks
F18E External Tanks
A few months ago there was an article in an Australian flying magasine about the delivery flights of the 1st group of Super Hornets for the RAAF.
They apparently used 3 x 1500lt external tanks, even though there is plumbing on all 5 stations. Centrline, inboard and outboard. The magazine stated that carrying 5 tanks was never used, refering it as a "party trick".
So can someone explain why this is so to a humble GA driver?
2nd question.
If you have 20,000 ltrs on board, 10,000 internal and 10,000 in external tanks. I gather the tanks are pressurised by engine bleed air to provide positive pressure to facilitate fuel transfer.
Does it start to transfer the moment the fuel is drawn from the main tanks.
Would you have any indication if fuel failed to transfer from say 1 drop tank.
They apparently used 3 x 1500lt external tanks, even though there is plumbing on all 5 stations. Centrline, inboard and outboard. The magazine stated that carrying 5 tanks was never used, refering it as a "party trick".
So can someone explain why this is so to a humble GA driver?
2nd question.
If you have 20,000 ltrs on board, 10,000 internal and 10,000 in external tanks. I gather the tanks are pressurised by engine bleed air to provide positive pressure to facilitate fuel transfer.
Does it start to transfer the moment the fuel is drawn from the main tanks.
Would you have any indication if fuel failed to transfer from say 1 drop tank.
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Don't know the answer but perhaps the extra two tanks increase the drag index to a point where you see negative returns when flying for range and unable to jettison the tank/s when empty.
Never flew an F18, but the type I flew had similar plumbing arrangements. Assymetric transfer was detected by increasing stick sideloads requiring aileron trim. First step was to shake the aircraft up a bit to release stuck valves. Second step was tank jettison.
Brian's comment on increased DIs and negative ROI for fuel investment is spot on.
Brian's comment on increased DIs and negative ROI for fuel investment is spot on.
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You actually get a similar ferry range with three tanks as you do with five, due to the extra weight and drag. The five tanks are commonly used by the USN for buddy refuelling, and this config has also been cleared on RAAF Rhinos.
RAAF doesn't have any F18E's only F/A-18F's
Speaking of fuel; a friend flew one of the last F-111 ops off the coast vs. the new Super Bugs. They bingoed three sets of Bugs before RTB with 1.5hrs of gas still in the tanks.
Speaking of fuel; a friend flew one of the last F-111 ops off the coast vs. the new Super Bugs. They bingoed three sets of Bugs before RTB with 1.5hrs of gas still in the tanks.
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Speaking of fuel; a friend flew one of the last F-111 ops off the coast vs. the new Super Bugs. They bingoed three sets of Bugs before RTB with 1.5hrs of gas still in the tanks.
Moot point now, BUT... If you got a Pig into a turning and burning fight, a well flown Hornet could engage and disengage virtually at will, and would bingo the Pig almost every time. To survive, the F-111 had to run away, but when it did it was uncatchable! But like I said, it's a moot point now...
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Originally Posted by Shaft109
Just curious to ask would Australia have been better off buying refurb'd F14's? Surely some of the later models must have had some life left in them?
OK... so you can have another orphan, obsolete aircraft fleet where you are the only ones in the world flying them, the only source of repair parts is a boneyard in the US, and the RAAF would have to pay for a number of current weapons to be integrated onto the aircraft (avionics etc system mods, clearance trials, etc)?
Just for a "special capability" that is irrelevant for the purposes for which the RAAF wants them? The big advantage for the F-14 was always its special missile... but the AIM-54 missile was getting obsolete itself, and the RAAF doesn't want a long-range anti-bomber aircraft, it wants a heavy strike aircraft!
Yes, the F-14D was far more capable as a tactical bomber than the F-14A, but its planned retirement meant that it wasn't kept up-to-date for new weapons even before its retirement 2 years ago... there are now a lot of weapons it can't use that the F/A-18F can.
The advantages for the F-14D are:
1. higher top speed (the speed advantage wasn't much, was used for sprint only anyway, neither normally went anywhere near their top speed in 95%+ of mission profiles the RAAF plans to use.)
2. longer un-refueled range
3. Aim-54 Missile (for long-range shoot-down of larger aircraft).
The disadvantages for the F-14D are:
1. integration of new weapons must be fully funded by RAAF.
2. parts not being manufactured (limited supply because the USN disposed of them over the last 2 years, after they run out getting them made will cost a ****e-load).
3. no engineering support (again), so the RAAF has to pay for defect analysis & solution work and all upgrade design & integration.
4. no EW capability.
5. mechanically-scanned radar... less capable and less upgradable
6. older aircraft subsystems (hydraulics, etc), materials tech, and airframe design require more maintenance per flight hour, thus higher cost.
7. limited self-diagnosis of faults, so they have to be tracked down the "old-fashioned" way, increasing maintenance time & cost.
The advantages of the F/A-18F are:
1. fully cleared for all modern weapons in the USN arsenal.
2. in production, thus parts are easy to get.
3. in service with the USN (and will be for a couple of decades more), thus engineering support and upgrades are a phone call away, and fully funded by someone other than the RAAF.
4. half the RAAF fleet are set up for EW escorts (EA-18G configuration), needing only purchase of the external pods & accessories... but are still fully functional as both tactical bomber and fighter.
5. fully-modern AESA radar... highly capable and upgradable.
6. modern aircraft sub-systems, materials tech, and airframe design mean fewer maintenance hours per flight hour, thus lower cost.
7. highly self-diagnosing, far quicker & easier to find what's wrong.
The disadvantages of the F/A-18F are:
1. somewhat slower speed (of limited usefulness, as carrying a significant weapons load put both aircraft sub-sonic or barely supersonic).
2. shorter un-refueled range (needs aerial re-fueling, available from the KC-30As, which takes care of the range issue).
3. no long-range anti-bomber missile (not required by the RAAF).
