Stab change

[FLS]

Mace I found a USN parts list for the F4u that shows the tailplanes bolted separately to the fuselage with no common spar. In that particular case losing one side shouldn't affect the strength of the other side.

Dirtdart keep in mind that the tailplane is on a lever arm from the center of lift and center of gravity on the main wing. Because it's at the end of the lever and the pivot is at the other end not the middle, the force required for the tailplane to pitch the nose up is not that great. The limiting factor in pitching up is Angle of Attack not elevator force.

[BoilerDown]

I am wondering... is the removal of weight from the tail of the airplane (or any part of the airplane) factored into the code for how the aircraft performs when the part is shot off?

[dirtdart]

Wow, great and very intelligent observations.  This has been a fun post.  I think I am going to run the math on this.  Should be "fun", it has been ages since I had to do any thinking.  Anyone have F4U-1a tailplane schematics.....lol.  Thanks fellas, fun discussion. 

[OOZ662]

Anyone have F4U-1a tailplane schematics.....lol.  Thanks fellas, fun discussion. 

Considering there's a player roaming around here that rebuilds the engines, there must be something. Try the Aircraft and Vehicles forum.

[FLS]

Wow, great and very intelligent observations.  This has been a fun post.  I think I am going to run the math on this.  Should be "fun", it has been ages since I had to do any thinking.  Anyone have F4U-1a tailplane schematics.....lol.  Thanks fellas, fun discussion. 

This is an F4u-4 not a -1 but I think the construction is similar.

[Krusty]

Keep in mind that in AH the thing is clean gone, but in the real thing you'd have parts of it still bolted onto the frame. It's just that for all intents and purposes it's "blown off"

You'd see a number of planes missing part or most of a single stabilizer in WW2 photos even though it looks like it should never be able to support itself with just 1.

You wouldn't think that something like this could fly and get back, would you?



It did. Of course, it wasn't pulling 3 Gs in dogfights after that happened, but it happened.

Here're some more:










I fully recognize that it was rare, that for every 1 that made it back like this, probably 10 never did. I'm not saying AH has it right, as I don't really know my feelings on AH's version of things just yet. I am saying that things like this did happen and the plane didn't fall apart under the stress of a single control, or massive damage. I am definitely FOR having separate damagable h-stabs, and losing 1 without the other. The end flight characteristics are what I'm undecided on so far.

[jay]

SOME planes have it where the parts stay there like on the IL2 or the B25H

[whiteman]

yea i'm guessing my damage would have looked more like it does on the planes with the newer damage. something would have been there but not much.

[rvflyer]

This is an F4u-4 not a -1 but I think the construction is similar.

  I am pretty sure you will find a full spar.  Without a full spar you would need struts.

[Krusty]

You don't have struts or full spars on many aircraft. Some did, sure, but not all.
Not even the massive stabilizers on the B-17...

[Wiley]

Just to throw some more speculation on the fire, I was flying my F4U-1A last night, which I've had half of the horizontal stab knocked off of before, and it happened again last night.

The interesting thing about last night, based on previous experience I figured I would be maneuvering like a three toed sloth on ludes, so I turned for home directly.  Someone with superior E caught up with me, and forced the fight on me.  I found my maneuvering capability to be pretty decent.  Not fully good, very definitely not better, but not as bad as I'd noticed it in the past when I lost half a stab.

A couple of theories went through my brain.  I am not an engineer by any stretch, but logically speaking would it make a difference which side was gone as compared to engine torque?  I can't remember which side was gone in my case last night, and I'm wondering if there's some emergent behavior from having one side gone versus the other compared to propeller rotation direction to give it more authority or more volume of air over it, or something along those lines?  I'm thinking of the way propwash would 'corkscrew' over the body of the aircraft.  Or, maybe just simple engine torque would affect the way the plane was pulling against the lopsided stabilizer when you pull up?  If it was on the opposite side, to the way torque wants to pull the aircraft it would seem to me it would give it a touch more authority, wouldn't it?

The other thing that crossed my mind-  are there maybe 'slightly' blown off stabilizers and 'very' blown off stabilizers?  Kind of like the little oil leaks versus the big oil leaks?

Just thinking out loud.  A third possibility is, there was an update in between...  Maybe something changed there? 

Wiley.

[DH367th]

Man this is what the BBS were meant for IMHO. Great read thx gents. 

[FLS]

Wiley I think that engine torque and torque from the mass of the spinning prop is negligible compared to the torque from the spiral slipstream. You can see the gyroscopic precession from the prop when you push the nose down quickly or pull it up quickly. You'll notice the nose moves slightly to one side or the other. When you reduce torque by pulling power for maneuvering I believe it's the reduced slipstream that you're noticing.
With the spiral slipstream pushing the top of one stab and the bottom of the other I imagine that there would be a slight reduction in the torque on the fuselage regardless of which side was lost.

[Wiley]

Ah, ok.  I guess the term 'spiral slipstream' was what I was actually talking about.  I was just thinking in terms of it making a difference which side was gone versus which way the prop turns, and all the associated effects that go with it.  Learned my thing for the day, thanks!

Maybe I wasn't quite clear in my point-  I was wondering if the torque/spiral slipstream might make a difference in how much authority half your stabilizer and elevator would have when you pull back on the stick.  Basically, if your plane tends to want to roll to the left due to the spiral slipstream, would having the right side of the horizontal stabilizer still attached give you more authority than having the left side of the horizontal stabilizer still attached?  Logically, it seems to me it might.  And vice versa on an aircraft with the opposite rotation on the prop?

Basically I'm curious why all my previous instances of having half my tail shot off have seemed to me that it was a heckuva lot mushier than it was last night.  One other possibility that crossed my mind is airspeed may have played a factor.  In previous times I generally was slow and turning and was barely getting any response at all, which is what I'd expect.

Is there a .blowpartoff type dot command that can be used offline for testing?

Wiley.

[FLS]

I doubt it makes a difference if a stab is pushed up on one side or down on the other. Keep in mind that you're countering the torque with your undamaged ailerons.

I'm not aware of any undocumented dot commands.