Ju187 tail

[R Pope]

Most write-ups about this project state that the tail "rotated" to get the vertical surface below the fuselage to clear the gunner's field of fire. They take that to mean that it turned on a fore-and-aft axis, and the horizontal surface went with it. The drawings suggest to me that the vertical tail pivoted on a crosswise hinge and moved through an arc of about 45 degrees. What was the leading edge becomes parallel with the fuselage top surface, and the erstwhile bottom edge protrudes into the airstream, becoming the leading edge below the fuselage. This would greatly simplify the control linkage, not to mention the aerodynamic nightmare involved in rotating the whole tail assembly.
The artist's impressions I have seen also show the dark upper surfaces of the horizontal tail still on top after the fin has done its migratory movement, reinforcing my assumption.
What do you guys think?

 

[Capt. Vick]

A waste of engineering that would have been problematic in operations.

 

[tyrodtom]

From the drawings it looks like the whole tail just rotated.

The controls to the tail wouldn't have to be that complicated. Could be just a swashplate like a helicopter uses to control pitch on the main rotor.
It would be interesting during the transition though.

 

[vikingBerserker]

It was always my understanding that the whole tail unit would rotate as well, however looking at Ju-87 from Dive-Bomber to Tank-Buster 1935-1945 by Eddie Creek on page 280 there is a model of a Ju-187 used in a wind tunnel test in 1943. You might have a point as it shows the Vertical Stabilizer on the bottom of the aircraft but the Horizontal Stabilizer in it's normal position based on the bracing strut of the Horizontal Stabilizer (I realize this was for a wind tunnel so they might have just moved the Vertical Stabilizer to see if it would work).

Right below this photo however is a drawing of the Ju-287 (before the designation was moved to the Jet Bomber) which clearly shows the Vertical Stabilizer pivoting completely downwards.

 

[davebender]

I think people are far too enamored with Ju-187 and it's rotating tail. It's one of dozens of WWII paper designs that didn't have a prototype much less mass production.

If Germany were serious about building a new late war dive bomber then Henchel production of Me-410 would have been pushed to completion rather then halted when factory tooling was 80% completed.

 

[GrauGeist]

Soviets captured the prototypes being constructed, along with the windtunnel test airframe...

Doing a search might show up some of the small concept models that were made, too.

 

[R Pope]

I never said it was a good idea, just wondering how it worked. It seems a twin fin setup with most of the surface below the stabilizer would have been much simpler.
It just looks to me that the only reason for the rudder hinge line to be angled forward as it is would be so it would be angled rearward the same amount when the fin and rudder swung straight down.....

 

[tyrodtom]

I don't think there's any words in the German language that could be translated into " make it simple".

 

[GregP]

I've seen sketches of it and have seen three different possible apparent approaches.

In one, the horizontal tail was set forward and stayed fixed while the rudder and fin alone rotated.

In the another, the vertical tail appeared to be starting in front of the horizontal tail trailing edge, but the depiction of the in-flight view again showed the horizontal tail normally and the fin and rudder underneath with no explanation. One possibility is for the fin and rudder to pivot backward until the formerly-horizontal edges that ostensibly sit on top of the fuselage are vertical and, at the same time, behind the horizontal tail's trailing edge. Then it rotates 180°and pivots forward until the front of the fin fits against the belly.

A third possibility is for the fin and rudder to slide backward until they clear the gorizontal, then rotate and slide forward again.

I have wondered about this myself from time to time, and have no real definitive answer. But I have thought that it would only work if:

1) All three surfaces pivoted, or
2) The fin and rudder were behind the horizontal so they alone could rotate, or
3) The fin and rudder moved aft somehow, then pivoted, then moved forward again, or
4) The fin and rudder somehow pivot untli they clar the horizontal, povit, then rotate again to lie flat.

If anyone knows for sure, please chime in here. Got any other possibilities in mind? Anyone?

Update:

Came across this guy building a paper model of it and it depicts a notch in the elevator for the fin's leading edge to clear the elevator when rotating. Maybe that is the answer? Seems simpler than the Rube Goldberg possibilities of sliding backwards, pivoting, and then sliding forward again, doesn't it?


View: https://www.youtube.com/watch?v=tii9qtGyCuw

 

[GrauGeist]

I don't think there's any words in the German language that could be translated into " make it simple".

The only thing that even comes close is the 1950's through 1966 VW Bug...but even that grew to be complex and over-engineered from '67 onward.

But at least for a time, it proved they could do something that was:
(A) affordable
(B) simple in terms of mechanical and design
(C) not required to be dive-bomb capable.

 

[Capt. Vick]

(C) not required to be dive-bomb capable.

 

[R Pope]

The whole thing was a big waste of time anyway. It couldn't have survived in the air environment that would have been prevalent by the time it entered service, good field of fire or not.