1000 Pounders versus Battleships

[witpqs]

Okay, I'm a non-pilot here. I have a question to test my understanding of things aeronautical and another general one.

The table you gave as an example, I assume that in addition to correcting for KIAS versus KTAS it would also include a correction for the fact that allowable diving speed might actually be different at different altitudes due to thinner versus thicker air?

Second, do modern flight instruments have some sort of cross-link between the altimeter and the flight speed indicator that does away with the need to make KIAS-KTAS conversions based upon altitude?

[rtrapasso]

ORIGINAL: witpqs

Okay, I'm a non-pilot here. I have a question to test my understanding of things aeronautical and another general one.

The table you gave as an example, I assume that in addition to correcting for KIAS versus KTAS it would also include a correction for the fact that allowable diving speed might actually be different at different altitudes due to thinner versus thicker air?

Second, do modern flight instruments have some sort of cross-link between the altimeter and the flight speed indicator that does away with the need to make KIAS-KTAS conversions based upon altitude?

i think a lot of the modern flight instruments determine true speed based on radar determined speed over ground... ditto for altitude (radar determined height over ground, rather than aneroid barometric readings).

Of course, a lot of instruments still in use are not so fancy.

[Big B]

I don't believe so...

ORIGINAL: witpqs

Okay, I'm a non-pilot here. I have a question to test my understanding of things aeronautical and another general one.

The table you gave as an example, I assume that in addition to correcting for KIAS versus KTAS it would also include a correction for the fact that allowable diving speed might actually be different at different altitudes due to thinner versus thicker air?

I think TheElf is the best man to answer that one.

Second, do modern flight instruments have some sort of cross-link between the altimeter and the flight speed indicator that does away with the need to make KIAS-KTAS conversions based upon altitude?

[Nikademus]

witpqs, I have a document i can send you on the various airspeeds and how to calculate them....given to me by an aeronatucal engineer......if your brave enough. Its been known to cause migranes.
[;)]

[DuckofTindalos]

I'm getting one just reading the description of it...[:D]

[Tiornu]

Then again...Tiornu is a known troublemaker and party crasher who hogs the Kegger.

I don't make trouble. I just make it better.
And I don't get near kegs unless they contain my precious Diet Mountain Dew. Actually, I've had to give up Diet Mountain Dew. Too strong for me.

[Panther Bait]

ORIGINAL: rtrapasso


i think a lot of the modern flight instruments determine true speed based on radar determined speed over ground... ditto for altitude (radar determined height over ground, rather than aneroid barometric readings).

Of course, a lot of instruments still in use are not so fancy.

Most likely, and a lot of planes would use some combination of GPS and differential-GPS to calculate ground speed as well.

Also in reponse to a previous question, while thinner air would put less stress on the airframe for a given stick position, the pilot would also have to make larger stick movements to achieve the same manuever, i.e. he would have to pull back harder at high altitudes to pull out of a dive due to the thinner air (subject of course to the control surface stops cause you can only pull back so far). For a specific true dive speed, it takes a specific amount of force on the wings to pull you out of the dive. The density of the air and your control limitations determine how long it takes to apply that force, and applying it in too short a period of time can damage the airframe.

[Howard Mitchell]

ORIGINAL: witpqs

@Tiornu

I think the point is proved about the 200 mph dive. I sure am surprised.

BTW, how for away from the target track would they have to launch? I'm wondering how long they would have flown low & slow.


@Howard Mitchell

You mention that actual airspeed is a little higher than indicated airspeed. Why?

Hello witpqs,

Big B's given a far better and more technical explanation of the difference between IAS and TAS than I could.

Going back to Brukard Baron von Mullenheim-Rechberg's book, he doesn't say how close the Swordfish on the second attack came, but on the first attack on 24 May by Victorious' aircraft he says that some approached to within 400-500m at 2m altitude.

[panda124c]

From the book "Torpedo Bomber" by Ralph Barker about he RAF torpedo bombers (Beauforts and Beaufighter):

"All previous torpedo training had been carried out on Swordfish and Wildebeest, whose cruising speed was well under a hundred knots, and the method of attack for these aircraft had been to dive down towards the target from a comparatively safe height, flatten out, and launch the torpedo."


This was possible because coming out of a dive the Swordfish lost airspeed very quickly, the above quote is in relation to the characteristics of a Beaufort which picked up speed very quickly in a dive and did not lose it when flattening out.


Oh yea very good book about RAF Torpedo bombers in the Channel and the Med. Also good information of torpedo's and how they worked and the problems incountered when dropping one from an aircraft.

[witpqs]

ORIGINAL: Howard Mitchell

... he says that some approached to within 400-500m at 2m altitude.

Holy cow! Double checking that one - he said "2 meters" altitude? As in the height of a moderately tall man? [X(]

[DaveB]

They were probably flying a bit higher that day, to avoid swells....

[herwin]

ORIGINAL: DaveB

They were probably flying a bit higher that day, to avoid swells....

Not if they were using ground effect...

[mdiehl]

The fact is BBs were pretty vulnerable to air power of all types. They might not be easily sunk, but they could be rendered ineffective.

Exactly. And I would add:

They could be sunk by bombs. Most of the bomb hits on major BBs caused flooding because the shock alone could open hull plates or cause fires (in systems with flammable components) that necessitated flooding. Furthermore, there is compelling evidence from Yamato's final sortie that the first or second 1000lb to strike her started an uncontrollable fire in her secondary battery magazine, and this fire may have spread to a main magazine causing her subsequent explosion. Since her surviving crew have indicated that said fire "could not be put out" it is reasonable to surmise that Yamato would have been sunk by a bomb-induced magazine fire, had she not sunk due to torpedo-induced flooding first.

The plain fact is that any bomb of the 500-1000 pound type, even a GP one could mission-kill a BB, although probably multiple bomb hits would be required to mission-kill one. Multiple bombs of this kind could so attrit systems as to leave a BB fatally crippled and unable to escape subsequent attacks for ex by aerial or submarine launched torps, or shells from big guns.

[herwin]

ORIGINAL: mdiehl

The fact is BBs were pretty vulnerable to air power of all types. They might not be easily sunk, but they could be rendered ineffective.

Exactly. And I would add:

They could be sunk by bombs. Most of the bomb hits on major BBs caused flooding because the shock alone could open hull plates or cause fires (in systems with flammable components) that necessitated flooding. Furthermore, there is compelling evidence from Yamato's final sortie that the first or second 1000lb to strike her started an uncontrollable fire in her secondary battery magazine, and this fire may have spread to a main magazine causing her subsequent explosion. Since her surviving crew have indicated that said fire "could not be put out" it is reasonable to surmise that Yamato would have been sunk by a bomb-induced magazine fire, had she not sunk due to torpedo-induced flooding first.

The plain fact is that any bomb of the 500-1000 pound type, even a GP one could mission-kill a BB, although probably multiple bomb hits would be required to mission-kill one. Multiple bombs of this kind could so attrit systems as to leave a BB fatally crippled and unable to escape subsequent attacks for ex by aerial or submarine launched torps, or shells from big guns.

In a broader sense, airstrikes not even producing damage ('smothering' operations) could mission-kill a BB force on defence, simply because the continuous harassment disrupted refitting, refuelling, and rearming.

[John Lansford]

Other than Tirpitz, Arizona, Roma and perhaps Yamato, then, what other BB's were sunk by bomb attack alone?  Plenty of them were damaged, some severely, but none other than the ones above IIRC were actually sunk by a bomb.

[Nikademus]

[active] battleships sunk by SAP or AP bombs alone were:

Marat
Tirpitz
Arizona
Roma

(not counting the sinkings of the inactive remenants of the Japanese fleet sitting in their harbors, nor the two greek pre_dreadnought BB's sunk at their moorings)

[DuckofTindalos]

I would argue against placing Tirpitz in that category. Those were hardly ordinary bombs...

[Nikademus]

indeed. Those Earthquake bombs were capable of, and did, penetrate every deck of the ship...including the primary armor deck. Tirpitz was also in harbor as were two of the others.

[herwin]

I think you should consider battleships taken out of action for extended periods. That's a rather long list. Sure, battleships were survivable, but all you usually wanted was a mission kill. Anchoring a heavy ship within air attack range just so the ship would be available when needed--read what I wrote--was simply asking for a load of hurt. It couldn't stay ready, and it would get hit if it remained static for long enough.

[DuckofTindalos]

And Roma was sunk by a guided bomb, not a standard dumb one. That speaks against the general effectiveness of bombs against battleships underway.