'Aerial Carriers'...

[deathjester]

Madoc: it depends on the relative speeds of the carrier and the planes though. An airship carrier's unlikely to make three-figure speeds, which is fine for prop-fighters upto the end of WWII, but heavy fast jets don't fly that slow (particularly at altitude) without serious compromises being made to their design. So if we've got an airship doing 90 knots, and a jet fighter with a stall speed of 130 knots, then the latter still needs to scrub off 40 knots after "touchdown". That's much more benign than the real carrier condition, but it still needs to be accomodated.

How about the X-31 post stall demonstrator?  It is designed to be controllable after the stall, so it shouldn't have a problem matching speed with an airship.  Also, does anyone know the stall speed of the Typhoon, as I am sure I saw one flying in formation with a spitfire....

[Weaver]

Madoc: it depends on the relative speeds of the carrier and the planes though. An airship carrier's unlikely to make three-figure speeds, which is fine for prop-fighters upto the end of WWII, but heavy fast jets don't fly that slow (particularly at altitude) without serious compromises being made to their design. So if we've got an airship doing 90 knots, and a jet fighter with a stall speed of 130 knots, then the latter still needs to scrub off 40 knots after "touchdown". That's much more benign than the real carrier condition, but it still needs to be accomodated.

How about the X-31 post stall demonstrator?  It is designed to be controllable after the stall, so it shouldn't have a problem matching speed with an airship.  

Indeed - I wasn't saying it couldn't be done, just that it requires design compromise (big wing, big flaps, vectored thrust, etc...) on the part of the fighter. You could give an F-18 a 50-knot landing speed on a sea-carrier if you really wanted to: you just have to decide to accept the compromises: big, heavy, draggy wing or the complication of vectored thrust, etc....

Something that occurs to me about the X-31: how controllable is "controllable"? The pilot might be able to point the nose enough to retain "control" in the normal flying sense of the word post-stall, but can he put a probe/hook onto a trapeze, or touch down gently on a deck?

Also, does anyone know the stall speed of the Typhoon, as I am sure I saw one flying in formation with a spitfire....

Well the Spit could have been going at anything upto 400ish knots, so that's not neccessarily much help.

Another general point is altitude: upto what height can these slow-flying jet fighters still do the trick? If your airship carrier has to come down into the envelope of relatively simple AA weapons (remember it's a big, slow target) in order to launch/recover aircraft then that's a tactical compromise worthy of some serious pondering......

[deathjester]

Think you are right on all counts there old chap!!
  In that case we'll have to look at the Yak-141 Freestyle / F35 / Harrier variant, with the Skyhook system fitted.

[Weaver]

Think you are right on all counts there old chap!!
  In that case we'll have to look at the Yak-141 Freestyle / F35 / Harrier variant, with the Skyhook system fitted.

Now that's got definite possibilites: Harrier have an altitude limit for out-of-ground-effect-hover (don't know what it is, unfortunately), but of course, this would be 90-knot "flying" with vectored-thrust assist. There's probably a limit on that too, but I'm not sure how you'd find it out.

You could probably use this technique with some of the less VTOL-compromised jet proposals that have been made, but rejected due to poor hover-safety and/or surface erosion in ground landings. For instance, if you had all your engines in swivelling tip pods and you lost one while docking with an airship at altitude, you'd just fall away, with (relatively) plenty of time to recover or eject. You also wouldn't need pure VTOL capability, just enough deflected thrust (in the sense of the deflected thrust Meteor) to get the minimum controllable speed under 90 knots (or whatever the carrier can manage).

[deathjester]

I think this is a good excuse to wheel out the P1154, or the P1173 once again!
  Just a thought:  If the carrier and it's fighter are up in the jetstream, would that take care of the stall on aproach problem?  Or would the relative speeds stil be the same?
  Also, if the carrier is dropping fighters out of it's hangars, it could drop other stuff too, like cruise missiles, or vehicles / paratroops. 

[Weaver]

I think this is a good excuse to wheel out the P1154, or the P1173 once again!
 Just a thought:  If the carrier and it's fighter are up in the jetstream, would that take care of the stall on aproach problem?  Or would the relative speeds stil be the same?
 Also, if the carrier is dropping fighters out of it's hangars, it could drop other stuff too, like cruise missiles, or vehicles / paratroops.  

The "wind-over-hook", so to speak, is a function of how fast the carrier's engines can push it into the prevailing headwind, so it's really a function of how powerful those engines are. More headwind is good of course, upto the point where the carrier can't maintain speed. At that point, you're into diminishing returns because the carrier is now effectively going backwards relative to a fighter in the same jetstream.

Regarding troops, one factor in favour of a flight-deck style design is the ability to operate helicopters, which are notoriously difficult to use with skyhooks....

[deathjester]

I don't know what you mean.....!
Gives me a good idea though on the troop carrying/deploying role though - the ducted fan Bell X-22A would be ideal for that sort of thing.

[deathjester]

Just checked the X-31 entry in my concept aircraft book, and it says that the plane can fly at 28 mph (45 knots ias)!!

[PR19_Kit]

The simplest solution from a weight savings perspective would be to have some sort of aerial trapeze docking mechanism used to launch and recover the smaller planes.  This, much like the USN came up with for the Akron and Macon as well as the USAF came up with in its FICON.  The launch and retrieval mechanism for the FICON in particular would be applicable here as it was designed from the outset for jet fighters to utilize and it involved a minimal amount of dedicated equipment aboard the fighter plane.  In fact, I believe it just required a hook mechanism mounted forward of the cockpit and that the plane's horizontal stabs be reconfigured with anhederal.

Being pedandtic (now that in itself is a laugh on here of all places! ) the RF-84K Thunderflashes used for the in service FICON system had a retractable hook forward  of the cockpit and two latches, one on each side, just aft of the cockpit. The pilot flew the hook onto the forward rail of the trapeze which then swing down until its two rear latches mated with the Thunderflashes rear latches and the whole shabang was then hoisted into the GRB-36s bomb bay.

I'd have LOVED to have seen that, but I don't think any of the combos ever came to Europe, anyone know different?

[JMN mode off]

[Madoc]

Folks,

Okay, I think we must needs define some criteria here.

Are we speaking of a zeppelin aerial carrier here or are we bespeaking some type of flying machine that depends not upon enormous volumes of helium-filled gasbags for its lifting force?

Is this aerial carrier we're speculating upon one which is made using current tech?  Future tech?  1930's tech?  Do tell!

An uber-Macon was well within the limits of 1930's tech and several such craft were planned.  They all used the hook / trapeze recovery method and that's also what the FICON built off of - albeit in a much more streamlined form that operated at much higher speed.

One thing to bear in mind about lighter than air craft is their relatively small payload fraction.  The things had to be gi-normous to contain sufficient helium in order to lift itself, its structure, and its equipment.  Even the uber-Macons the USN was planning for in the mid to late-30's only carried a handful of aircraft yet they cost almost as much as a full-on fleet carrier to construct and operate.  Not a good deal capability wise.

There are envisioned applications of a modern zeppelin type aerial carrier which deploys only UAVs.  Those things would be small enough that a useful number could be deployed with the aerial carrier.  Somehow though, I think this isn't quite what you guys have had in mind.

While I remain fond of zeppelins I also acknowledge their drastic operational limitations.  The things are to slow and to vulnerable to inclement weather.  Winds which barely jostle heavier than air craft are winds which put enormous stresses upon the hull and structures of a zeppelin.  This, if for no other reason than the vastly greater surface area the zepp has and its corresponding need for extreme lightness of that structure.

Now, by the 1950's and into the 60's there were several proposals for aerial carriers that used "conventional" layout in their structure.  These heavier than air craft were truly gigantic when compared to other wing-borne machines but were all much smaller in terms of total volume than your average zeppelin type machine.  It helped that these designs were usually nuclear powered as well.  Thus, they had not the need to loft their own fuel up into their air with them.  Or at least not the thousands and thousands of gallons it would otherwise take of the stuff to run the jets that they'd need to loft them.

Whether these designs used props or direct nuclear powered jets for their motive thrust was one thing.  They were intended to operate smaller aircraft as a matter of routine and they all had those aircraft make their connection to the carrier using the well understood hook and trapeze method.

Back in the 70's I remember seeing an aerial carrier proposal that made use of a C-5 Galaxy as the mothercraft that deployed A-37 "Tweets" as their air group.  This proposal was highlighted in an issue of AW&ST and it depicted that quite a number of such small planes could be deployed from the Galaxy and that with aerial refueling, the whole shebang could be kept on station and operational for quite a while.

I know that in the 80's there were proposals for a F-16 sized machine for a similar aerially deployed fighter / attack craft.

As I envision things, the aerial carrier would be some sort of absolutely huge flying wing that plods along as some several hundred miles an hour due to its several nuclear reactors powering its several sets of gi-normous props.  The thing would have the interior volume and payload capacity to carry one or two squadrons of F-15 sized aircraft.  There would also be some very specialized service and support aircraft designed to operate with this carrier.  They'd fulfill the COD role that the C-2 Greyhound fulfills for ocean based carriers today.  Thus this carrier could remain in the air and on station for as long as its engineers could keep the nukes running and the props turning.  The resupply aircraft would shuttle up to it and replenish its weapons magazines, its parts inventories, its crews, and its consumables (everything from food to toilet paper!).  Conventional aerial tanker craft would fulfill the need of providing the go-juice for the fighters and attack planes the aerial carrier deploys.

Back in the 80's or 90's there was a proposal for "span-loader" type flying wing designs that were to essentially remain airborne forever.  The things were large but not impossibly so and their larger interior volume allowed for cargo to be shifted around within their structure whilst in flight.  So to would any large replacement parts like entier engines, for instance.  The idea being here that the aircraft would be optimized for high altitude high speed flight and that the efficiencies gained through operating them continuously at that altitude and speed were worth having their cargoes brought up to them and down from them by local, short-ranged aircraft.  Those "lighters"  would dock with the big wing and tranship their goods.  Cargo transfer done, they'd uncouple and return to their home airfield whilst the big wing continued aloft to its other destinations.  I thought this woulda been hellacool.  But, as with many other such things, nothing ever came of it.

Madoc

[deathjester]

If this is a truly modern airship, I would envision the structure being made from composites, and possibly being a hybrid air vehicle, so it is a lifting body as well as a lighter -than -air craft.  This should allow it to lift significant loads, in the manner of the skycat craft.
  Also, good idea on the UAV's - why not put them in too, with the cruise missiles, troops, tanks, and planes!!  Perfect for CAP/AEW work.

[Talos]

Funny that you bring up the X-31, deathjester...

I threw this together a couple years back on that exact subject. Not as good as my current works, but it should be good for inspiration and discussion, at least. 

[dy031101]

I know the hook can generate turbulance that might have some funny effect on any vertical tailfin, but I've found a finless X-31 asthetically hard to get used to. 

Nice idea though. 

[Talos]

I figured they were going to take the tail off anyway, so I removed it more for clearance issues then for turbulence. Makes hooking-up a lot easier, or at least a lot less nerve-wracking in my mind. 

[deathjester]

It would save weight and space too, because the hangar wouldn't have to be as high with tailess fighters!