Air to Air Refueling

[Fonsini]

A2A refueling has always had its mysteries for me so I'm hoping that some knowledgable soul will help fill in a few blanks for me.

First and foremost can combat aircraft top up their underwing or drop tanks - or is this ability limited to certain types and not available on others.

Also, the average combat aircraft contains a number of tanks and simply filing each one in sequence could cause a dangerous shift in CoG - so is the pilot responsible for shuffling fuel around via a fuel panel (with resultant workload issues all while formation flying) or are the aircraft's internal systems capable of handling the redistribution requirements ?

Any info appreciated.

[3engnever]

So,

1. Yes, external fuel tanks can be filled.

2. Depends on the aircraft and technology. Most modern aircraft sort it out themselves. Older generations do require a bit of fuel management.

Hope this helps with the mysteries of AAR

[Bob Viking]

Fonsini

I can speak about my only front line type (Jaguar) which will follow similar principles to most other FJs.
To allow fuel in you have to de-pressurise the tanks just as you would on the ground. Obviously as the tanks fill you need somewhere for the air to escape to as the fluid goes in. This will mean the aircraft is transferring fuel via gravity feed. This is fine since you will almost certainly be in 1G flight. Once the tanks are full the engine will then provide bleed air to pressurise the tanks to force fuel through in all flight regimes.
The tanks in the Jaguar would kind of fill up in reverse order to how they emptied. Most FJs aren't as sensitive to CofG as you might think. If they are they tend to have a clever system to automate the process.
I hope that answers your question. I'm sure some people cleverer than me will be along shortly to elucidate further.
BV

[Easy Street]

When refuelling in a Tornado there is little need to move fuel panel switches whilst in contact, but even on those rare occasions, it's not a big deal to look in momentarily to find the correct switch. The formation flying required once in contact is pretty forgiving (with the notable exception of the boom-drogue adapter, which can be a pig). A much less exciting but more challenging proposition is moving switches or tuning navaids during a formation instrument approach in poor weather!

[27mm]

And now to to technique in the mystical art of basket dancing:

1. Flying f#ck at a rolling doughnut (Victor wing hose in turbulence)

2. Pushing wet spaghetti up a cat's arse (KC-135FR)

[Bob Viking]

27mm

Number two made me laugh out loud. Never heard that before but so apt. On occasion.
I've said it many times but tanking is probably the main thing I miss about front line flying. I loved the challenge. It's what we love to refer to as pure 'Pilot sh1t'. No one or no thing (at least not on the Jaguar) can help you. It's just you versus the basket!
BV

[Fox3WheresMyBanana]

AAR
Refueling in the Tornado is auto-sequenced, but monitoring is important (only indicators are in the front cockpit) in case a tank fails to fill - though on the two occasions I had this it's obvious from the control feel.
Altitude/load is a bigger problem - trying to stay in contact using both burners is:
a) not allowed in the Aircrew Manual
b) f#cking difficult, for those of us who forgot that bit of the Aircrew Manual - mea culpa, those test pilots aren't wrong.

The hardest thing about AAR is when there are another 3 guys short on gas waiting their turn on your drogue, at night (or 8 guys in daytime; no pressure!!)

p.s. AAR is easier than guns tracking in ACT - that's "stuffing wet spaghetti up a wildcat's arse"

[Fonsini]

Thanks guys - for some strange reason fuel capacity and refueling procedures have fascinated me ever since I laid eyes on an FGR2s drop tanks during a tour of Coningsby back in the late 70s. I never did find out where that missile I fired in the simulator went, and we were royally told off for sneaking into an EW Canberra that was undergoing repair after a wheels up landing - presumably on grass as the damage didn't seem too bad.

The RAF were gracious and generous hosts but we were served the most god awful fish and chips I have ever had.

Now if someone can tell me why high density fuel never caught on......

[Fox3WheresMyBanana]

Wheels up on grass? Oh, no.

One of my early instructors did that in a Meteor around 1947. The wheels stuck up and he was told to put it down on the grass not the concrete, as that had always been standard on the piston aircraft. By the time he stopped, he was sitting in his seat, upright, with half the nosecone in front of him and the entire rest of the jet distributed across the airfield like confetti behind him.
After that, it was always "put in down on the concrete; it's smoother"

[OK465]

...there is little need to move fuel panel switches whilst in contact, but even on those rare occasions, it's not a big deal to look in momentarily to find the correct switch.

The Phantom had a rarely used switch on the front seat right console, a little toward the aft, that allowed for refueling 'internal only', no external tank fuel. Rarely used because in most cases rarely did you ever have enough fuel as it was. Amazingly, it was located right next to a switch whose purpose was controlled jettison of wing fuel tanks only. What wonderful ergonomic engineering.

Filling AAR squares one night, during the tanker rendezvous (not even in contact yet) on a track close to home anyway, I instructed my flight to "refuel internal only".

The next thing I heard was from #4....

"There they go, three."

In fairness this did allow #3 to refuel 'internal only'.

[ex-fast-jets]

Having learnt flying probe and drogue with the RAF from my early days, I spent three years on exchange with the USN, and found the same probe and drogue so much easier off little donors than the big jet donors I was used to with the RAF.

I then spent some time on exchange with the USAF.

My first AAR - at night - in an F-16 using boom refuelling - I arrived under the tanker and got myself into what I thought was about the right position, and was peering for the positioning lights when I was stabbed by the boom operator. Effortless!! So much easier than probe and drogue, and much less tense.

It has its limitations, but it also has its advantages.

[Tankertrashnav]

In the older generation of tankers, tanker/tanker refuelling was frequently necessary, as max takeoff fuel was far lower than the sort of figures achieved by more modern tankers.

In the case of the Victor, it was the co-pilot's job to shuffle the fuel around using a splendid fuel tray which was situated between the two pilots. Doing a 25,000 lb transfer, for example, could obviously involve large shifts in C of G in both tanker and receiver, which the co-pilot was responsible for taking care of.

Sorry I can't work out a link direct to the appropriate photo, but scroll down to see a nice pic of a Victor K2 fuel tray, which stows away neatly when not required

#twitterVforce Forum ? View topic - Victor XL231 work diary

[Alister101]

Sorry I can't work out a link direct to the appropriate photo, but scroll down to see a nice pic of a Victor K2 fuel tray, which stows away neatly when not required

#twitterVforce Forum ? View topic - Victor XL231 work diary

This should help the search:

http://i819.photobucket.com/albums/z...ps4b4e7ea8.jpg

http://i819.photobucket.com/albums/z...psab91f7d0.jpg

http://i819.photobucket.com/albums/z...ps04bd1d81.jpg

[Fonsini]

Filling AAR squares one night, during the tanker rendezvous (not even in contact yet) on a track close to home anyway, I instructed my flight to "refuel internal only".

Out of interest exactly how much trouble does one get into for punching off 2 rather expensive drop tanks by accident ?

[Bob Viking]

It depends where they land!
BV:o

[galaxy flyer]

At F-100 RTU in AZ, one of the flights joined up with the tanker, boomer lowered and extended the boom. Whatever bolt holds the telescoping part was apparently missing because it went falling into the Willcox Playa salt pan.

GF

[just another jocky]

In my cold war/Tornado GR1 days, I was qualified low-level buddy-buddy refuelling against the Buccaneer. That was a lot easier to plug and stay stabilised behind than a Tristar at FL200.

Mind you, the RV's were little trickier.

[OK465]

Out of interest exactly how much trouble does one get into for punching off 2 rather expensive drop tanks by accident ?

In fact the unfortunate guy put more pressure on himself that evening, worrying about where they hit. Didn't even show up for the obligatory post night air refueling beer. Said he'd had trouble sleeping.

It was done over southern Kansas which is pretty wide open, however when they were located the next day they were 'close enough' to a barn that I imagine the farmer was well paid for his 'trouble'.

Pilot felt relieved and no harm, no foul.

(Actually, though the two switches were cover guarded with different color guards (one black and one red), it was found that most of our red guarded wing tank jettison switch covers were not safety wired like they were supposed to be.)

[Fonsini]

(Actually, though the two switches were cover guarded with different color guards (one black and one red), it was found that most of our red guarded wing tank jettison switch covers were not safety wired like they were supposed to be.)

Good to hear no one got hurt and that the pilot didn't find himself sitting in front of 3 officers with discipline on their minds.

[Mr C Hinecap]

Now if someone can tell me why high density fuel never caught on

Given how close to diesel it is, Kero is one of the most energy dense transport fuels. If you are referring to anything manufactured that is above that, you start getting into very expensive territory for manufacturing, storing, transporting and engineering around.