Tail spars

[Jigster]

Generally, how high does the tail spars rate amoung the strongest parts of a plane?

I believe it's usually 2nd or 3rd, structurally?

[Toad]

Which spars?

You talking about the horizontal stab spar?

The vertical stab spar?

The elevators themselves? The fuselage tubing to which the tailfeathers attach?

[Jigster]

the (3 in most cases) main structural supports in the tail (i.e. spars), of the (again in most cases) left and right horizontal stabilizers, and the vertical stabilizer.

I been finding some oddities in AH lately and I don't think using a preconceived notion that may or may not be based on fact (because dang if I can remember which) is very wise so I'm doing a little back ground study first  

This particular one is the treatment of both the left and right tail spars as one in the damage model, yet if this was so the vertical stabilizer should come off as well do to the interconnection of the three, correct? (i.e. if it has enough force to rip off both spars then the joint would come off too, where the vertical stabilizer spar is connected, in most cases)

I am taking into account that the damage model in AH does represent varying degrees of damage, although they are not shown (if it's damaged enough to impair flight, it comes off) But even if the tip of one side is hit of the horizontal stabilizer, all direction stability is lost.

Because of the amount of force excerted on the tail in flight, I have the preconceived notion that, while it would be greatly hamperd, SOME control should still exiest, due to the strength of tail spars.

Sooo...just curious if that assumption on the strength of spars is correct.  



[This message has been edited by Jigster (edited 12-08-2000).]

[Citabria]

jigster,

ive shot off half a tail spar on on an f4u1c.

it flew level just fine and could have ecaped it seemed. but then it started pulling 5g maneuvers and ripped off his remaining h-stab on his own.

or so it would seem

[Toad]

Tough one, Jig. Mainly because of differing construction/design techniques used in the different aircraft.

In my experience, the spars themselves are very similar to what you see in the wings. In other words, in most WW2 aircraft I've been involved with as far as restoration, the design/technology/matierials of the tailfeathers are very similar to what you find in the wing. It's just that they are scaled down to suit the overall plan.

For example, my PT-19 tail spars are of the same type as the wing spars...just smaller. The attachment fittings for the wingspars to the center section are WAY more robust however than the vert stab attach and quite a bit more robust than the stab attach fittings. The scaling seems significantly different in this area. I attribute this to the difference in size of the respective surfaces being attached.

I've not seen enough of the inside of many different WW2 fighters to really provide any insights other than that.

As far as failures, any major damage to a spar close to the fuselage..wing, stab or tail is a serious problem. The closer to the fuselage it occurs, the worse the situation.

Obviously, knocking the last 6" off a spar tip is less serious than nearly cutting it 2" out from the fuselage attach point due to leverage.

Sorry I can't be of more help.

[Jigster]

No biggie, I've just noticed that usually one good cannon hit, anywhere on the three stabilizers cuts it off completely. From what I've seen of most conventional-tailed fighters, it would be nearly impossible to take off both stabs due to the intersection of the vertical spar (where most likely the whole tail would come off, but it would take a golden BB or big shell to actually destroy the spar intersection)

But this of couse is highly dependent on the indiviual aircraft design. I've never seen a single severing as of yet, although both left and right stabs are included in the damage list.

Of course this is usually worse on the 38 because of the size and length of it's horizontal stab, the weakest part of the plane, damage wise, other then the engines.

[Citabria]

if you are in a ffa and snipe someones hstab off on the ground yet the other one remains intact. it will remain on the plane till they take off and then it seems to fall off from the stick forces or somthing

[Lephturn]

Yep, I've seen that before.  Once you lose half of the H-stab, you will lose enough control to pitch the plane violently.  The resulting forces on the remaining part of the H-stab rip the other half off.

As to how "right" this is.  I dunno. <shrug>

------------------
Lephturn - Chief Trainer
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