Military History/Weapons Questions

#4 is Rickover....and from what I understand he was a real SOB....

Who was "Kilroy"?

BugsyR wrote:Who was "Kilroy"?

Hyman Rickover was right & he was supposed to have been a real tough guy to work for, but brilliant!

Kilroy........The only thing I remember was during WWII there would be signs posted saying "Kilroy Was Here".....Dont know if he was a real person, a unit or just imaginative???

No guess on the other's Mike?


Submarine Questions:

1. WWII US overall sub commnder in the Paciifc?

2. Why did many of our torpedoes fail to detonate early in the war?

3. What was the predominant "Class" of US WWII subs?

4. What naval officer is considered the "Father" of the nuclear sub?

5. Name (& class) of the fist US SSBN

2.) I remember seeing a story on the history channel about this. It was something to do with the depth at which they were operating.

coalkirk wrote:2.) I remember seeing a story on the history channel about this. It was something to do with the depth at which they were operating.

Right...If memory serves they were found to be running to deep. to set off the magnetic trigger. A real problem that cost alot of lives early in WWII

Jumping forward in time a bit...Breaking the sound barrier:

1. Who was Ridley?

2. What plane? (designation & mfger)

3. What British pilot had just been killed attempting to break it when we did?

4. What was the aeronautical key to beaking the barrier?

5. First US production plane able to break the sound barrier in level flight?


Edit: Interesting sidenote....In the early 1950's, a British movie was made (I think it was called "Breaking the sound barrier")
in which the British were (erroneously) shown to have done it first, & the key to doing it (in the movie) was for the pilot to reverse the controls when he felt the buffetimng......total BS!. In the book "The Right Stuff" (a great book btw & a fair movie) Tom Wolfe points out that Chuck Yeager was once asked by the Sec. of the Air Force if that was the way to get through the sound barrier....Reversing the controls. Yeager, dumfounded that the Sec. of the AF would'nt know this was BS told him that if a pilot actualy did reverse the controls......He would be dead!! It was just movie BS

Devil5052 wrote:No guess on the other's Mike?


Submarine Questions:

1. WWII US overall sub commnder in the Paciifc?

2. Why did many of our torpedoes fail to detonate early in the war?

3. What was the predominant "Class" of US WWII subs?

4. What naval officer is considered the "Father" of the nuclear sub?

5. Name (& class) of the fist US SSBN

No guess...sorry, the navy gave me CRS (Can't Remember Sh..)

Kilroy from what I remember reading about is an unknown. Can't confirm if it was really a person or not. I have read that the common "Kilroy was here" cartoon may have started onboard I believe the "liberty ships" and possibly could have been a work inspector's signature to show that the work was inspected. Instead of the worker actually waiting for the inspector to arrive and inspect/approve the job, the worker would leave the area and if/when the inspector arrived to do his job they would basically chalk or grease pencil their initials. Well it may be possible that Kilroy was actually an inspector, troops saw the signature/drawing, and when the troops went ashore over seas they took Kilroy along wherever they went....last actual sighting I believe was in Afghanistan just recently.

The aeronautical trick to keeping an airplane flyable when exceeding Mach 1 [speed of sound] was to sweep the leading edge of the wings, tail and horizontal stabilizer back at at least 20-30*...
the reason is that as the airfoil, wing, tail etc goes through the sound barrier there is a pressure 'wall' created.. at the point where the speed of sound is first exceeded.. Air has to accelerate around a surface, bump or object.. so as this pressure wall or wave moved along the wing,,or the horizontal stab. the pressure wave would interfere with the moveable control surface on the trailing edge of the wing [ailerons] the tail [rudder] and horizontal stabilizer [elevator]... the pressure wave would cause violent vibrations, violent flutter, and pieces would come off the plane.. there were instances where the controls did 'reverse' but only for a few seconds..

When the wing or control surface is swept back at an angle,, the pressure wave only hits part of the wing or surface at a time.. so the entire pressure wave was not on the entire wing all the time.. the pressure wave was leaving the trailing edge of the wing a little at a time.. and was effecting the control surfaces very little..

Even today, with swept wings,, I've experienced what is called 'aileron buzz' when near the aircraft's speed limit.. most private jets and airliners fly at between .75 and .90 of the speed of sound.. because somewhere the air is near the speed of sound...

Greg L

Submarine Answers:

1. WWII US overall sub commnder in the Paciifc?---Admiral Lockwood

2. Why did many of our torpedoes fail to detonate early in the war?--Ran to deep

3. What was the predominant "Class" of US WWII subs?....Gato

4. What naval officer is considered the "Father" of the nuclear sub?..Hyman Rickover

5. Name (& class) of the fist US SSBN....George Washington

LsFarm wrote:The aeronautical trick to keeping an airplane flyable when exceeding Mach 1 [speed of sound] was to sweep the leading edge of the wings, tail and horizontal stabilizer back at at least 20-30*...
the reason is that as the airfoil, wing, tail etc goes through the sound barrier there is a pressure 'wall' created.. at the point where the speed of sound is first exceeded.. Air has to accelerate around a surface, bump or object.. so as this pressure wall or wave moved along the wing,,or the horizontal stab. the pressure wave would interfere with the moveable control surface on the trailing edge of the wing [ailerons] the tail [rudder] and horizontal stabilizer [elevator]... the pressure wave would cause violent vibrations, violent flutter, and pieces would come off the plane.. there were instances where the controls did 'reverse' but only for a few seconds..

When the wing or control surface is swept back at an angle,, the pressure wave only hits part of the wing or surface at a time.. so the entire pressure wave was not on the entire wing all the time.. the pressure wave was leaving the trailing edge of the wing a little at a time.. and was effecting the control surfaces very little..

Even today, with swept wings,, I've experienced what is called 'aileron buzz' when near the aircraft's speed limit.. most private jets and airliners fly at between .75 and .90 of the speed of sound.. because somewhere the air is near the speed of sound...

Greg L

Thanks Greg. (I defer to our airline pilot as the expert on this subject!)

Question: After seeing many shows on this subject, I had always heard it was the development of the "Flying Tail" that really allowed for the sound barrier to be conquered. No?
My understand was/is that the air turbulance caused by approaching the sound barrier, caused the airstream to pass above, or somehow to negate the positve effects of the horizontal stabilizer & thus required the actual moving (up or down) of this stabilzer in order to regain control in the "pitch" axis. (That's what 10 hours of flight training gets you! )

I stand corrected....I think!


Frm Wikipedia:

supersonic speeds. Note that the aircraft is subsonic, and traveling significantly below Mach 1.0, when it experiences this effect.[1]


Shock wave on upper surface of wing moves rearwards as aircraft mach increasesInitially as airspeed is increased past the critical Mach number, the wing develops an increasing amount of lift, requiring a nose-down force or trim to maintain level flight. With increased speed, and the aft movement of the shock wave, the wing’s center of pressure also moves aft causing the start of a nose-down tendency or “tuck.” If allowed to progress unchecked, in an aircraft not designed for supersonic flight, Mach tuck may occur. Although Mach tuck develops gradually, if it is allowed to progress significantly, the center of pressure can move so far rearward that there is no longer enough elevator authority available to counteract it, and the airplane could enter a steep, sometimes unrecoverable dive.[2] In addition as the shockwave goes towards the rear, it can impinge upon the elevator control surfaces and this can greatly exacerbate the nose down tendency. Partly for this reason, supersonic and subsonic aircraft often have an all-moving tailplane (a stabilator) which lacks separate elevator control surfaces.[3]

Recovery from a mach tuck is not always possible.[dubious – discuss] In some cases as the aircraft descends the air density increases and the extra drag will slow the aircraft and control will return.

Hi Richard,, well we are both right,, you more than me.. My comment about sweeping the wing and tail surfaces ACTUALy applies more to decreasing drag as the airplane approaches Mach.. the drag rise is less abrupt and easier to power through the sound barrier..
The 'full flying tail' IS definitly part of controlability.. But it is interesting that it is more a 'full trimming tail' is what helps.. the normal way to trim a 'low speed' elevator is with a trim tab on the trailing edge,, not only is a trim tab a pretty high-drag item,, but it really hates going through the sound barrier.. the airflow around the tab is terrible.
So the engineers trim the horizontal stab. and the elevator is clean, with no trim tab...

What is also interesting is to look at the X-15 in the Smithsonian, or at Wright-Patterson airforce Museum... the stab and rudder look like thin wedges.. the trailing edge is squared off !! the whole surface moves.. a 'full flying tail. But, many later aircraft that are capable of exceeding Mach 1 have a more conventional tail..

this is pretty interesting.. I had to dig real deep in my memory.. I took a short class on high speed aerodynamics when I went to Sabreliner school... it had a 35* sweep in the wing.. basicly the same wing and flight surfaces that the F-86 Sabre had... it was a sweet flying plane.. but had a few 'idiosyncracies'... like all planes..
Several Falcon business jets have been taken into 'trans-sonic' flight,, above Mach 1, but just barely.. they have a trimmable stab, but still an elevator,, not a full flying tail.. BTU the falcon has full Hydralic control for it's flight surfaces,and the falcons are built like a tank..

Also, in your quote from Wikpedia.. it pretty much disputes what Yaeger said about reversing controls.. If a person KNEW what was going on,, to reverse Mach Tuck, the pilot could push down on the wheel.. and theoreticly the controls were reversed..

The tendency to 'mach tuck' is an infamous problem with Lear jets... their wing is almost straight.. only about a 10* sweep I think,, can't remember... I didn't like the plane very much.. we called it an 'executive mailing tube'.

gotta go fly..
Greg L

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Answers:


1. Who was Ridley?--An aeronautical engineer who worked with Chuck Yeager

2. What plane? (designation & mfger) Bell X-1

3. What British pilot had just been killed attempting to break it when we did? Geoffrey DeHavilland

4. What was the aeronautical key to beaking the barrier? Flying Tail

5. First US production plane able to break the sound barrier in level flight? F-100 (North American)

New Question:

Did the infamous German battleship "Bismark" have a sister-ship &, if so, what happened to it?