[WWII] Manta Squadron Airplane

[Phaelen Bleux]

My plan is to design the submersible plane flown by Manta Squadron in "Sky Captain and the Worlds of Tomorrow." So, how to design the plane to handle high-speed impact with water and survive. Large frontal DR?? Super streamlining?? Extra-heavy frame?? (And this doesn't even consider the fact that the pilot's spleen would probably come out through his belly-button.)

Any creative thoughts?? (Mind you, I realize that its is probably impossible without deflector shields or super-science. . .and since they are not featured in the movie, I'm more inclined to ignore the viciousness of impact with a nod towards accounting for it a little.)

[Kale]

Originally Posted by Phaelen Bleux

Any creative thoughts?? (Mind you, I realize that its is probably impossible without deflector shields or super-science. . .and since they are not featured in the movie, I'm more inclined to ignore the viciousness of impact with a nod towards accounting for it a little.)

<Handwave>High-pressure air jets blown from nozzles on the leading edge of the wing as it hits the water. The cushion of compressible air will minimize the impact forces.</Handwave> @:-)

[Cernig]

Actually, that's not too bad a handwave. It's certainly "cinematic tech" at the very least but you could say that thousands of small pores along the airframe leak air at the moment of impact, creating a cavitation effect that effectively softens the water enough to reduce impact to a manageable level. The same cavitation effect would make the craft unusually fast (and quiet, since the bubble layer would interfere with sound) once in the water too, for added cine-tech fun.

[Kalzazz]

Check out the GURPS falling rules in campaigns, if you make a successful dive into water then you dont take damage

So, thus, entering the water safely should require a successful Swimming Plane Piloting check

[copeab]

Originally Posted by Phaelen Bleux

My plan is to design the submersible plane flown by Manta Squadron in "Sky Captain and the Worlds of Tomorrow." So, how to design the plane to handle high-speed impact with water and survive. Large frontal DR?? Super streamlining?? Extra-heavy frame?? (And this doesn't even consider the fact that the pilot's spleen would probably come out through his belly-button.)

Remember the Sky Captain's P-40 could also enter the water at high speed. I would suggest increased DR on the body and wing fronts. While the Mantas were better steamlined than the P-40, I wouldn't consider this an absolute requirement because of that. Increased frame strength makes sense.

There was a Russian project in WWII to create a submersible seaplane (although it landed on the water on pontoons, then submerged). IIRC, it was then to attack ships with torpedoes, but I can' remember if they were carried externally or in a bay.

EDIT: Looking at the collision rules, even at a mere 100 mph entry you'll need DR 150 to the front (I'm assuming the OP is using 3e rules here)

[Kale]

Originally Posted by Cernig

Actually, that's not too bad a handwave. It's certainly "cinematic tech" at the very least but you could say that thousands of small pores along the airframe leak air at the moment of impact, creating a cavitation effect that effectively softens the water enough to reduce impact to a manageable level. The same cavitation effect would make the craft unusually fast (and quiet, since the bubble layer would interfere with sound) once in the water too, for added cine-tech fun.

I got the idea from a Russian torpedo design. It's basically an underwater missile. The torpedo creates a bubble of compressed air at its nose that pushes the water out of the way. It could manage something like 180mph under water. I figured it would also help an object safely ENTER the water as well.

Originally Posted by copeab

EDIT: Looking at the collision rules, even at a mere 100 mph entry you'll need DR 150 to the front (I'm assuming the OP is using 3e rules here)

That is a lot of DR, a bit much for a plane. That's why I suggested the air jet thing. As part of the handwave you can say it reduces the collision damage by a large factor, but only for colliding with water. Or you could go the other way and say it provides extra DR but only for colliding with water. Or you could wave your hands wildly and say it just lets you ignore the entire issue of impact damage with water.

[copeab]

Originally Posted by Kale

That is a lot of DR, a bit much for a plane. That's why I suggested the air jet thing. As part of the handwave you can say it reduces the collision damage by a large factor, but only for colliding with water. Or you could go the other way and say it provides extra DR but only for colliding with water. Or you could wave your hands wildly and say it just lets you ignore the entire issue of impact damage with water.

I'm glad you mentioned a torpedo, because under the collision rules an airdropped torpedo should be destroyed when it impacts the water. I'd be comfortable saying that a certain level of streamlining divides effective water collision speed by a certain factor in a controlled entry. If the streamlining of Mantas divided effective crash speed by, oh, 10, that would drop DR to around 15 for 100 mph or 30 for 200 mph. Still a little high, but not outrageous.

[Kale]

Originally Posted by copeab

I'm glad you mentioned a torpedo, because under the collision rules an airdropped torpedo should be destroyed when it impacts the water. I'd be comfortable saying that a certain level of streamlining divides effective water collision speed by a certain factor in a controlled entry. If the streamlining of Mantas divided effective crash speed by, oh, 10, that would drop DR to around 15 for 100 mph or 30 for 200 mph. Still a little high, but not outrageous.

That makes a lot of sense. Throwing a brick-shaped object into water at high speed will end badly for the brick. Throwing a dart into the water will go much better. Think about high diving; if you belly-flop, you'll probably crack some ribs. If you enter the water properly though you're fine. It seems streamlining on a vehicle/torpedo does the same thing.

[Phaelen Bleux]

Originally Posted by copeab

I'm glad you mentioned a torpedo, because under the collision rules an airdropped torpedo should be destroyed when it impacts the water. I'd be comfortable saying that a certain level of streamlining divides effective water collision speed by a certain factor in a controlled entry. If the streamlining of Mantas divided effective crash speed by, oh, 10, that would drop DR to around 15 for 100 mph or 30 for 200 mph. Still a little high, but not outrageous.

The main thing after that is not having the wings get ripped off--which will probably need to be a handwaved feature--if the fuselage survives impact, so do the wings.

I like the concept of needing to make a Piloting roll to enter the water--similar to a Swimming roll to change water from Hard to Soft in the (3e) falling rules. Miss the roll and its a belly-flop.

Edit: And I would assume the pilot would enter the water at something just over stall speed.

I was thinking of using the Streamlining factor as a "pseudo-slope" factor for DR vs. water entry. I'll probably still have to buff up the frontal DR and go with an extra-heavy frame, too.

I like where this is going. . .thanks everyone. . .and any other ideas are still welcomed!

Lastly, the plane in the movie has British rondels. . .must be made by Super(duper)marine, eh?

[copeab]

Originally Posted by Phaelen Bleux

The main thing after that is not having the wings get ripped off--which will probably need to be a handwaved feature--if the fuselage survives impact, so do the wings.

That's probably the easiest way to do it.

I like the concept of needing to make a Piloting roll to enter the water--similar to a Swimming roll to change water from Hard to Soft in the (3e) falling rules. Miss the roll and its a belly-flop.

I was going by the collision rules on p.W154. U suggest a successful Piloting roll allow the normal -2 per die for water. A failure by 1-3 means a slightly "off" entry with only -1 per die. Failure by -4 or more means there is no reduction in collision damage for water.

Edit: And I would assume the pilot would enter the water at something just over stall speed.

In the movie, it looked like higher speeds, especially for the P-40.

I was thinking of using the Streamlining factor as a "pseudo-slope" factor for DR vs. water entry. I'll probably still have to buff up the frontal DR and go with an extra-heavy frame, too.

The thing is, damage uses vehicle HPs, not weight, so increasing frame strength increases HP, which increases damage the plane inflicts on itself ...

(IIRC, this was from VE2, not original to MVDS)

I would suggest dividing speed by 1 for no streamlining, 5 for fair, 10 for good and 25 for very good to get effective collision speed. This seems to give .. cinematically plausible? ... results.