What if the fighters at Pearl were scrambled on time?

I was reviewing the old threads on the Japanese attack on Pearl Harbor and comparing them with the official timeline on how the actual attack occurred.

At Pearl at the time of the attack on Pearl, there was a sizable Army Air Corps presence that could've been scrambled to meet the Japanese attack. It's been said that the last chance for this was when the Japanese planes were spotted on radar but unfortunately, this was shrugged off and ignored.

Now my question is this: What if the fighters at Pearl were scrambled on time? Was there still time to actually have the US pilots man their planes and take off to meet the Japanese attack?
If the Japanese attack had been interdicted by US planes, could the Japanese with their escorting Zero fighters fight their way through and carry on with their bombing and torpedo runs?

The key, I think, to this hypothetical aerial fight is the number of fighters the US could've scrambled in the limited time they had left before the Japanese planes made their actual attack. Was there actually enough time left to scramble the fighters? In 1940, How long does the US Army Air Corps take to scramble planes once a raid had been spotted?

At first glance, I personally thought that if the US fighters had bounced the Japanese raid over Pearl, the Japanese didn't have enough escorts to fight their way through. But when I thought about it some more, I realized that the inexperienced sailors, marines and soldiers manning anti-aircraft guns at Pearl would've likely shot down many US fighters as well given the confusion and shock of the attack.

 

One variable to be defined is how many pilots were near enough their planes. There was a fourty minute gap between the two attack groups, Yet only a little over a dozen US pursuit planes took off. A significant part of this small response was the large number of pilots who had been at liberty in the bars Saturday night. If the warning comes from the infamous radar spot around 0600 then theres only going to a handfull of pilots availalble. If the Japanese fleet is identified hours earlier from several spottings. Say a stray fishing or other comercial boat on the 5th or 6th, and confirmation by a unspotted reconissance plane late on the 6th, then a majority of the pilots could be rounded up out of the Oahu bars. So at least a hundred planes would have had pilots on hand when the radar intercept occured.

"the Japanese didn't have enough escorts to fight their way through."

The US intercept control was fairly primitive and not well rehearsed. With a hour warning it may not even be functioning. Even if stood up by ten hours warning things like errors in passing our radio frequencys, squadron identification, holding pattern location and related refrence points create confusion. The details of the air defense over Manila on 8, 9, 10 December indicate some of the problems that would be reproduced over Oahu. The one advantage of Oahu over Manilia is the target area is much more concentrated so there is less chance of the US pilots being too disperesed to make interceptions.

As for loss rates for each side: There is a small sample from the actual losses over Oahu. I dont recall the exact numbers but although only fourteen Japanese aircraft were shot down over Oahu (less than 5% of the total) a significant number were too badly damaged to fly off the carriers again within 24 hours. The overall strength of the Japanese air wing was reduced by roughly one third due to battle damage, breakdowns, and accidents. Again the air battle over Manila would provide a usefull sample for estimating possible losses of each side.

Of course ten hours warning by a late evening reconissance report allows the fleet to sortie and momenarily disapper from sight.

 

then the kill rate would have gone down from 8 battleships to maybe 4. at sea, 250 planes sank musashi. 350 sank yamato.

but battleships at anchor?

 

Plus the Japanese have to locate the sortied US fleet. It will easier if the fleet imeadiatly tries to head north to intercept the IJN group, but without the aircraft carriers concentrated that may not be the decsion. If the battleship line turns south or east Nagumos reconissance will take considerablly more time to locate it, if at all. A second complication is the ammo supply. The two strikes on Oahu used up roughly two thirds of the airwings bombs and torpedos. Nagumo will not have ammo for more than one more effective strike. If he muffs that his carrier group will be fleeing at high speed and with a disarmed air wing while the US carriers and battleships converge like angry bees. He can outrun them but hanging around for a third strike vs a dispersed enemy whos locations are unkown is a dangerous game.

 

Depends on how much damage was done by the first strike. I don't think the Americans would have gained altitude to affect the first strike group but it would have been able to bounce the second strike. So whatever damage was done by the first group, would have still happened but it would have cut down on the damage done by the second group. Good question.

 

I'm not sure it would have made that much difference. The first Japanese strike arrived piecemeal with the dive bombers and fighters getting to Ohau ahead of the strike bombers / torpedo planes. They had to loiter for about 10 minutes waiting for the later to catch up before attacking.
The US fighter response, whatever it might be would have had a couple of problems. The first, and most serious, was that the fighters would have been set on CAP at no more than 15,000 feet as this was about all any of them could manage altitude-wise on the early Allison engines. This means they find themselves below much of the strike and largely at the mercy of the Zeros that would have been able to do diving slashing attacks on them.
The second, was that unlike the USN / USMC pilots the USAAF pilots did not have the same tactical training and would have more readily tried to dogfight the Japanese. The few F4F available might have made an effective CAP for their numbers as they could have managed 20,000 + feet and using deflection shooting really put the hurt on the strike aircraft while evading the worst of the Zero's attentions.
Of course, the second strike would have come in loaded for bear and taken what remained of the flying US fighter defenses apart. The problem for the US overall in this scenario is that the fighters they have present are only marginally capable of taking on a Zero and then only if the pilot uses proper tactics; no mistakes.

 

WOW. That is pretty pathetic.

 

I'm taking the Philippines as the standard here for assessing what the USAAC would do at Pearl Harbor.

 

Thats as good a indicator as you are going to get. The air battles over the Phillpines were notable for bad coordination, bad tactics, and bad aircraft engines (low power) on the US side. Tho the Japanese aircraft showed a marked propensity to fall apart in flames when hit

The US interceptors will have a shot at the torpedo bombers coming in at low altitude, and those not engaged by the Zeros will have a chance at the dive bombers, after they complete their attacks.

Below will be the antiaircraft guns shooting at everyone indiscriminatly. My best guess is the Japanse air wing will return to the ships and recover about 50-60% of its pilots and planes still fit for combat, as opposed to the 70-80% in the actual attack.

 

For this what if, let's just focus on the radar warning that was historically ignored though I do appreciate the very thoughtfully stated points on what could've been if the Japanese were spotted earlier.

That's a good suggestion of comparing the air defense of the Philippines with Pearl Harbor. I'm going to take a second look. Thanks.

 

With a hours warning? Just getting the ground crew and pilots rounded up would have been a problem. Standing up the interceptor control would have been 'Difficult'. As it was less than a dozen fighters got into the air, and shot down maybe that many Japanese aircraft. Possiblly less. So if thirty disgrunteld and unbeliving pilots are aloft or ready to sortie then perhaps another two dozen Japanese planes would be lost to air interception.

On the ground side the same problem occurs in getting the AA guns manned. No one will want to believe it serious, and will think a drill conducted in such a half assed manner should be taken seriouslly. Of course that attitude vaporizes about the moment the second or third bomb his the deck. So on there will be more guns manned sooner. A extra ten minutes of effective AA fires may destroy another ten aircraft (Japanese & US).

The largest variable to look at is the Japanese plan B. There was a alternate action for he commander of the lead wave to take were suprise to be lost. If he percived that soon enough then the US scramble might be negated by Japanese actions. Unfortuanly I dont recall the plan

 

There was a plan B? That would be logical. Anybody out there knows what that plan is?

 

I read several refrences to it in books and magazine articals, and cant recall a single detail other, than the leader of the first attack had a radio signal and flare back up to use. If suprise was lost then the attack sequence and the targets changed for the first wave. But I cant remember any of it now.

That would mean every pilot would have to memorize two attack plans, and perhaps two target lists.

 

Here's a thread that answers some of this question:

http://www.ww2f.com/simulations-gaming/19704-pearl-harbor-scenario.html

 

An hour's worth of warning would have provided General Short's Army Personel to set up and arm a number of the new 37mm anti-aircraft guns that had just arrived, around the harbor. Likewise, the elements of two USMC Defense Battalions at PH could have used the time to set up their 3-inch, 75mm AAA guns and their other automatic weapons as well. The time could also have been used to retrieve ammunition from the Alimanau Crater Depots, so that the Army Coastal Forts could shoot at the Japanese air attackers as well.

 

Personnaly, I not to sure if getting our aircarft up in time would have made that big of a difference. I'm mean sure they might have shot down a few planes but remember the American pilots weren't fully aware of the abilities of the Zeros. Sure they may have gone in and attacked the torpedo bombers and dive and high level bombers but as they did they Zeros would have chewed they to shreds. Another factor we have to consider is the mindset of the pilots on both sides. If the American pilots are told to attack an attacking air group they might not be in the mindset of let's shot them down. During the actually attack that was the mindset of many Americans, they just wanted to shot them down as they had attacked us. The Japanese on the other hand would have also been prepared and upon seeing there buddies getting shot down would have just gone into a rage and attack with anger and revenge. As a result I believe if we had got our fighters in the air the result would sort of look like what happened at Midway when the Japanese bombed the island.

 

I checked the thread and it was, indeed, useful.

 

Looks like a lot more than one question to me.

If they were scrambled in time to intercept the first raid I believe the Japanese plan was not to strike with the second wave. So that alone would have had a considerable impact. If they had intercepted the Japanese the US would probably have lost about the same or fewer fighters than they did historically but quite a few more pilots. The Japanese would likely have lost considerably more bombers and the raid would have been far less effective (a good part of this being due to all the defences being on altert)

A fair number would likely have gotten off some of them might have been able to intercept the Japanese in particular the torpedo bombers and low level attackers. However in some cases ammo and fuel were not immediatly available. One of the defenders that did get airborne for instance didn't have any 50 cal ammo. This alternative probably decreases by a significant amount the loss of US aircraft as some will get in the air and out of the way and others will be moved so that they aren't ideal targets. US proably looses additional pilots over the historical case but the Japanese will loose some more planes too. The torpedo bombers may be significantly less effective.

Yes they could have and probably would have. However there was a marked tendency during Midway for the Japanese fighters to mob US fighter. If, as is likely, the US intercept is piecemeal this may result in the intial interceptors being very badly handled but the latter ones getting at least a couple of passes at the bombers before they also have to deal with the Zeros. Net result is the raid looses bombers on the way in and is less coordinated. With the AA defences on higher alert and the ships water tight less damage to the fleet is very probable.

Since some actually got air born historically the answer is clearly yes. However there probably wouldn't have been a intercept of the level bombers prior to them completing their bombing runs and a good chance not even then. The torpedo bombers might have been however. The dive bombers would also likely be intercepted but probably not until they dropped. The Zeros would likely have gotten a fair amount more of attention particularly those that were assigned to strafe airfields as some of the fighters would likely end up trying to protect additional planes trying to get in the air.

I'm not even sure there is a good answer to this. A lot of it will be unit dependent. As mentioned ammo, pilots, and fuel were at varrying levels of availabilty. Also consider that some of the pilots that did get in the air almost got court martialed afterwards for taking off without permission.

 

One thing worth noting on this is the effect this might have on non-fighter aircraft. The US Navy could have certainly put a couple more PBY into the air along with the USAAF possibly getting some bombers or other search aircraft up. These would present a real threat to the Japanese fleet if they found their location.
This alone might have even caused Nagumo, who certainly seems to have been cautious in his actions, to cancel a second strike electing instead to retire after recovery of the first one.

 

I researched this some years ago when writing The Foresight War, which includes a Pearl Harbor in which the defenders are given an hour's more notice (not enough to get the battleships out to sea). The conclusion I came to was that the combination of more fighters in the air plus more AA guns manned and alert would have seriously disrupted the attack and reduced the damage caused (just closing all watertight doors on the ships would also have helped). But it's a controversial issue, and you'll never find agreement on it.