These quadcopters attach to the jet fighters, and raise them for takeoff, or land them wherever needed.

Prior art: [Voice]'s 2012 Airplane lifting hot air balloon and my ([Pashute]'s) 2004 Lighter Than Air Landing Gear idea.

Incentive: Jet planes flying around in fear of being caught off guard during tense times heard from my house, the thought of the cost of jet fuel, the waste of energy, while remembering images of the 6 day war with the IAF's knockout to the Syrian and Egyptian air forces.
-- pashute, Feb 22 2021

same, but for civilian light aircraft Robberfly_20Airport
[FlyingToaster, Feb 22 2021]

complimentary idea Airbase_20convoy
[Voice, Feb 22 2021]

Sort of... https://dronelife.c...s-the-best-of-both/
An RC plane with detachable quadcopter unit [neutrinos_shadow, Feb 22 2021]

Electric JATO Electric_20JATO
[bs0u0155, Feb 23 2021]

DF-21 Carrier Killer https://en.wikipedia.org/wiki/DF-21
[bs0u0155, Feb 23 2021]

Airplane lifting hot air balloon Airplane_20lifting_20hot_20air_20balloon
[Voice, Feb 24 2021]

Are you sure they're worried about the planes' ability to take off, as opposed to being attacked while on the ground?
-- Loris, Feb 22 2021


I'm sure I've read about this sort of thing somewhere before, but I can't find it (other than the linked model, which I hadn't seen before...); unless I came up with it independently myself (which is definitely a possibility).
-- neutrinos_shadow, Feb 22 2021


//take off, as opposed to being attacked while on the ground//

The two things are related; if the first attacking aircraft crater the runway, remaining defending aircraft are then stuck on the ground as sitting targets for subsequent attacks.
-- pertinax, Feb 22 2021


But if the attacking aircraft can blat the lumbering quadcopters as they desperately strive for altitude, they won't have to come back for the runway.
-- Loris, Feb 23 2021


True, but even a large and slow- moving quadcopter is a smaller and more agile target than a runway, and you can have many more of them at a given airstrip.
-- pertinax, Feb 23 2021


I dunno, but I suspect they're significantly easier to destroy, easy to target, and the survivability of any incident pretty low. How high do you think they have to get before the plane can launch?

You might be better off with an integrated VTOL like a harrier.
-- Loris, Feb 23 2021


I'd suggest that takeoff would be significantly easier than landing, but also much more important. If the landing site is destroyed, the craft can find somewhere else to land like a road. With that in mind, the quadcopters only need enough power to get the plane a few feet in the air. The plane can provide it's own acceleration and the quadcopters can break loose once the plane exceeds stall speed. Having a single use rocket powered version of this might also make sense except that the rockets would not be a stable as quadcopters. However if maybe 3/4 of the power was provided by rocket, and 1/4 by quadcopter, the quadcopters could be used to compensate for any variation in rocket power.
-- scad mientist, Feb 23 2021


[scad mientist]; that's deserving of it's own Idea: half the trouble with rockets is the stabilising/gimballing. A fixed rocket with a "quadrotor nosecone" for control might just work, and simplify (= cheaper) in the process.
-- neutrinos_shadow, Feb 23 2021


//You might be better off with an integrated VTOL like a harrier.//

The Harrier was exceptional as a piece of engineering, but the compromises needed to make it VTOL make it a sitting duck Vs any conventional fighter. In many ways it's better to think of a Harrier as a really fast, big payload attack helicopter. We'll have to see how the F35B performs in the real world. Expensively, probably.

In general, protecting aircraft on the ground is already a matter of doctrine, you go with distributed airfields, or SAM/AA/interceptor protected airfields, or some mix. That all falls a bit flat when you consider things like the DF-21, if it's a carrier killer, then it can also be a theater- airfield killer.

//[scad mientist]; that's deserving of it's own Idea://

almost what I did with my Electric JATO idea <link>.
-- bs0u0155, Feb 23 2021


//...the quadcopters only need enough power to get the plane a few feet in the air. The plane can provide it's own acceleration and the quadcopters can break loose once the plane exceeds stall speed. //

I don't think that's the case, actually. Once the plane is moving horizontally, the helicopter blades would lose lift on the backstroke, if they remain on a horizontal axis. You could have them swivel forward, and effectively become propellors - some VTOL are "tiltrotors" already. But if you then want the propellors to detach so the main body becomes a jet -well, that's starting to look a bit awkward.
So otherwise - the plane would need to detach, then get out of stall before it hits the deck. Seems risky.

//The Harrier was exceptional as a piece of engineering, but the compromises needed to make it VTOL make it a sitting duck Vs any conventional fighter.//

It didn't seem to do too badly against contemporary fighters - Mirage IIIs and Daggers - in the Falkands war, although there were other factors in its favour. I agree though that the parameters have changed over time.
-- Loris, Feb 23 2021


// I don't think that's the case, actually. Once the plane is moving horizontally, the helicopter blades would lose lift on the backstroke, if they remain on a horizontal axis. You could have them swivel forward, and effectively become propellors - some VTOL are "tiltrotors" already. But if you then want the propellers to detach so the main body becomes a jet -well, that's starting to look a bit awkward. So otherwise - the plane would need to detach, then get out of stall before it hits the deck. Seems risky. //

I didn't address this in my first anno because I didn't want to scare people away with the length, and while it may affect the design, those workarounds will not change the overall appearance of how the system works. The tip speed on your hobby quadcopters is pretty low, but for something that's going to lift a fighter jet, you might have props that look more like what you'd find on a small plane. Those can have a tip speed around mach 0.8 (533 knots). The stall speed of a jet is somewhere near 100 knots, so you'll probably want to slow those props down to by 100 knots. That means the retreating blade will still be going 333 knots. So, as you said, as the air speed increases, lift will decrease on the retreating blade. At the same time will increase on the advancing blade, but it likely won't compensate entirely. That loss of lift will be compensated for partially by lift from the wings of the airplane as the airspeed increases. If additional lift is needed, just crank up the power on the quadcopters. That of course means that initially, the quadcopters (with or without rockets) need to be designed to support the plane at something less than full power with blades moving less than 433 knots (in this handwaving example).

There is a possibility that the uneven lift on the retreating blade might cause excessive vibration of the blades. This could be solved by allowing the blades to flap like on a helicopter, but that increases complexity. Since the the blades are shorter and stiffer than a helicopter's, I'm hopping we can just strengthen the bearings and watch out for resonant frequencies.
-- scad mientist, Feb 24 2021


I'm not sure from the original idea, but was this envisioned as one large quadcopter per plane or multiple small ones? I think I'd vote for one large one mounted on top with a total length and width barely less than the the length and width of the plane. That unfortunately makes it heavier with the weight of the structure needed to hold the rotors. Several small quadcopters mounted near wingtips and nose might work, but I'd worry especially about the one by the nose hitting the tail after separation. A swarm of quadcopters with longish cables might be interesting for lifting initially, but I suspect would become highly unstable at the higher airspeeds.
-- scad mientist, Feb 24 2021


Just lift it high enough to recover from the stall.
-- Voice, Feb 24 2021


So have the base at 20,000ft.
-- not_morrison_rm, Feb 24 2021


I think the Indians and Chinese are trying that in the Himalayas.
-- pertinax, Feb 24 2021


// It didn't seem to do too badly against contemporary fighters - Mirage IIIs and Daggers - in the Falkands war, although there were other factors in its favour.//

Plenty of other factors. Tactics, training, experience, RADAR and missile quality & operational necessity. If you're in a delta-winged fighter, you want the fight at high altitude and high speed, then if things look bad, point the nose down trade height for speed and leave the Harriers trailing in your supersonic wake. Except the Harriers didn't engage up at altitude and at that altitude you're vulnerable to ship-borne missiles. Plus, you're attacking/covering attacks on shipping, so now your delta wing turbojet is at bingo fuel from all the flying down on the deck, even worse, you mix it with low-level experts over cloudy sheep country, which might as well be a Welsh training area. Only a couple of things had to change for the force to quickly start running out of Harriers, even if the Argie AAA could have avoided shooting down quite so many of their own aircraft, things could have been a lot trickier for us. Even so, the Harriers, and associated crew did an amazing job just staying serviceable.

Just think how much mission capability we could have had with a refreshed Sea Harrier, build on the AV8b, better and lighter avionics, more composite structure, composite fan & I'm sure RR could squeeze another 10% thrust. It's not going to fare well against F15's, but we don't fight those. Just use it as a quick helicopter that can lob 1000lb JDAMS.
-- bs0u0155, Feb 24 2021


^Right. Is this a valid use of recursion?
-- wjt, Feb 25 2021


Seems like a profligate use of fuel, to get quadcopters with relatively low lifting capacity to carry around heavy, fully-laden, manned fighter aircraft of dubious value.

Put together a fleet of unmanned drone / loyal wingman aircraft, which are much lighter and can therefore increase payload.

Add a very large lighter-than-air base dirigible platform aircraft with massive redundancy of flotation compartments, and guard it very well against attack (Air- air missiles and CIWS cannon)

Gigantic, airborne aircraft carriers with low crew numbers and high altitude launch capacity for the drones it carries. Once launched, they have a loiter time of around 36 hours, as I recall.
-- UnaBubba, Feb 26 2021


//^Right. Is this a valid use of recursion?//

Recursion, had to look that up briefly. I'm not sure I have my head around it fully, but it seems somewhere between evolution/natural selection, engineering iteration, and the simple behavior "software" of simple animals.

//Seems like a profligate use of fuel, to get quadcopters with relatively low lifting capacity to carry around heavy, fully-laden, manned fighter aircraft of dubious value.//

Maybe, but I'm not sure you're seeing the advantages. It's true that the quad/hexa/octacopters etc. have low lifting capacities when compared to conventional aircraft and even turbine powered helicopters, but, there is opportunity here. Military aircraft are often limited in terms of payload by what they can take off with in the space available, and for nearly all of them, the take off is a very inefficient part of the flight regime. Some sort of strap on multi copter could be made, they scale quite well and the mass production has advanced the flight electronics remarkably quickly. They don't need endurance, maybe 2 minutes of flight to hoist the aircraft up and forward to above stall speed and you effectively eliminate the take-off portion and increase payload. Then the copter can fly back for a re charge. It's injecting energy like a carrier's steam catapult, but potentially more energy less violently. The trick would be reliable attachment/detachment.
-- bs0u0155, Mar 01 2021



random, halfbakery