What if: Force Z (HMS Prince of Wales and HMS Repulse) and a carrier named HMS Indomitable

Lordroel

1st point is unfortunately a big one. The Indomitable was slated to head for the Far East and did suffer damage from grounding while working up in the Caribbean. However even if it hadn't it wasn't due to arrive in Malaya until about March 42 so it wouldn't have been with Force Z unless you had an earlier butterfly.

If it had somehow been with force Z then it would make a hell of a difference, at least in the air action. As the article says it might have avoided the air attack altogether if scouting from the aircraft had prevented the diversion to Kuantan. Even if not the Japanese didn't send a fighter escort and I have read they may not have had the time. Hence, especially if warned by radar so the CAP could get into place and be reinforced then the losses of the fragile Japanese bombers could have been very high. In that case Force Z could well escape with minimal damage. [Note if so such an attack couldn't be repeated for a while as not only did the Japanese have few other torpedo bombers in the region they were using their entire stockpile of air launched torpedoes in the operation]. Especially since I have also read that the Japanese forces came in somewhat straggled over a period of time.

The big danger might be the powerful surface force the Japanese had in the region, especially if it was given Force Z's position. [Two old BCs/BBs, ~6 cruisers and a number of destroyers] I think an undamaged Force Z could at least hold its own against such a force, especially with air support but both sides could suffer a hell of a lot of damage.

Also if the force wins, or simply avoids heavy damage on the 10th Dec, as the largest allied force by a long way in the western Pacific, it would be the main force to defend Malaya and the Dutch colonies so its likely to only get a small breathing space before its overwhelmed, although possibly it could cause significant additional losses to the Japanese and delay in their operation.

  That would depend on:
a)  That they knew there was a carrier there.  Its likely but if it only arrived just before the war started they may not.

b)  That the Zeros had the range.  Not just possibly to where Force Z was attacked OTL but were the Japanese loitering for any amount of time or how long did they spend searching for the exact location of the force?  They may have known it was about somewhere but not exactly so quite possibly some time spent searching for it.  The Zeros could go a very long way, partly because of their low weight, due to lack of arnour and other items but also because they sometimes managed their fuel ratios, running a leaner mix to extend the range.  This meant extra strain on the pilots and engines plus they would have needed to up the fuel ratio before going into the dogfight else they would be way under power.

c)  That Zeros were kept back to support such a mission, rather than being used to support other bombing raids, say against northern Malaya, or even to transfer to captured ports in southern Thailand.  Until the Japanese know that the fleet is in range and roughly where it is their not going to send their bombers out and until then they won't know if they need Zeros for the mission.

  In the early battles almost certainly the Zeros.  As you say their pilots were very well trained and the a/c are highly maneuverable.  The Hurricanes, or just about any western a/c can't afford to get into a dogfight with them.  In the longer term the western pilots can learn to play to their advantages and things are a lot more even then.  The Hurricanes are a lot sturdier, both in terms of damage they can take and some of the high stress maneuvers they can undertake.  Also I think by this time most are cannon armed and the largely unarmoured Zeroes are extremely vulnerable.  Not to mention in a battle in this region, at least until the Japanese secure airbases in Thailand - which admittedly isn't long - damaged British a/c have a chance to limp home, especially if the carrier is still available while the Japanese have a much longer and more difficult trip.

  Furthermore in the longer term the Japanese will use up their elite crews and because of their lack of focus on recruiting new crews and less ability to train them will face increasing problems.  The British/imperial forces trained massive numbers of pilots and other aircrew, as did the US and generally had much better training mechanism.  Hence later in the war the turn towards the use of kamikazes, making use of barely trained pilots.

  It would be a somewhat bigger shock for Britain and also there is the loss of a new carrier when the RN was massively stretched by war but otherwise not massively different from OTL - which is what I guess you meant?

  If there are no Zeros and the bombers get badly mauled by the CAP then its likely that the force would be largely undamaged.  This would, unless it was defeated by surface forces, albeit probably with mutual heavy losses, force the Japanese to send more naval strength especially to support their vital operations against the DEI.  The two Java Sea battles aren't going to be as totally one sided as OTL although if the Japanese bring their main fleet south, which is likely the Anglo-Dutch defenders are likely to be overwhelmed with heavy losses.  As such your likely to see the DEI and Malaya fall pretty much as OTL but with markedly higher Japanese losses at sea and possibly in the air.

Taken from a Quora post on the thread (Could HMS Prince of Wales and HMS Repulse have stood a chance had the carrier HMS Indomitable managed to join them in time).

Two months after the sinking of the Repulse and the Prince of Wales, a similar force of land-based Japanese bombers found the American aircraft carrier Lexington sailing off the Solomon Islands. They attacked — and were wiped out, losing all but two of their bombers to the American fighter defence. The Lexington and her escorts were undamaged.

The Lexington carried 16 operational F4F Wildcat fighters, compared to the Indomitable's 12 Sea Hurricanes. The Japanese force attacking the Lexington was also smaller. As such, the odds against the hypothetical British Force Z-with-carrier would still be greater, and it would certainly not be guaranteed to obtain such a devastating victory as the Americans did in February 1942.

Even so, it must be realised how large a role chance can play in any military operation of this nature.

The first Japanese air attack on the Repulse and Prince of Wales took place at 11:13 on the morning of 10 December 1941. Eight aircraft attacked; seven of them missed entirely; one scored a hit which did minimal damage.

Half an hour later at 11:40, a much larger attack from seventeen bombers was launched. Sixteen of them missed entirely. One scored a hit -- but by chance this hit did critical damage, hitting the Prince of Wales right at the point where one propeller shaft exited the hull. This slowed the battleship's speed by 40%, and rendered her almost unable to steer. She also began to flood, causing her to list to one side and lose electrical power: this in turn prevented most of her anti-aircraft guns from firing.

Three quarters of an hour later, another attack took place, this one larger still. Twenty-six bombers attacked, and again nineteen of them missed entirely. Three, however, managed to score hits on the crippled and slowed Prince of Wales. The remaining bombers then concentrated on Repulse and scored four hits on her as well.


G4M ‘Betty’ bombers of the Kanoya Air Group

In total, the Japanese scored 8 hits out of 49 torpedoes launched, a success rate of 16%. If the second of those hits had not crippled the Prince of Wales and made her an easy target, their success rate might have been even lower. So luck (good for the Japanese, bad for the British) certainly played its part.

What effect would a squadron of Hurricanes have had on the battle? Potentially a major one. Experience in the Battle of Britain had shown that a small force of fighters could disrupt a much larger force of bombers, not only by shooting them down directly but also by breaking up their formation and forcing them to jettison their bombs (or torpedoes) in order to take evasive action. Given the small number of hits the Japanese achieved even with no aerial opposition, it wouldn't take much to tip the scales against them.


Sea Hurricanes in formation

However, there would be a couple of factors working against the British. One might be if the Japanese had sent fighter escorts along with the bombers. They did, in fact, have a squadron of twelve Zeroes (plus six aircraft in reserve) based with the 22nd Air Flotilla in Saigon. These aircraft were intended to join the air strike but arrived too late to take part.

The Zero was about on a par with the Hurricane in terms of combat ability -- slightly slower, less well-armed and more fragile, but a lot more manoeuvrable in a dogfight. Pilot quality would count for a lot — historically, elite Japanese pilots found themselves facing poor-quality Allied pilots in the early years of the Pacific War, but presumably the Indomitable's aircrews would be a higher standard than the RAF in Malaya. It would probably be an even fight, assuming the Japanese fighters actually managed to rendezvous with their bombers and protect them during the attack as they failed to do in reality.

The other issue is endurance. Early 1940s fighters could only stay airborne for an hour or two at most. This meant that if an aircraft carrier needed to keep a constant air patrol around itself and the fleet, it could only deploy a small fraction of its aircraft at a time, shuttling them into the air in turn while letting the others land and be refuelled and given maintenance. If a carrier launched all its fighter aircraft at once to repel an attack, then it could be left defenceless if a second attack came in a short while later —which is exactly what happened to the Japanese carriers at the Battle of Midway.

However, the British (and Americans) had an advantage the Japanese lacked: functional air search radar on their ships. Instead of having to keep a few aircraft constantly airborne on a shuttle basis, they could spot an attacking airstrike while it was still many miles away and launch their aircraft to meet it. This wasn't foolproof, of course -- it still wouldn't help if the defenders were swamped by multiple staged attacks, and early radar sets were prone to malfunctioning at awkward moments, especially in a humid tropical climate.

In short, then, the presence of HMS Indomitable certainly wouldn't guarantee the survival of Force Z. It would, however, have made it rather more likely.

And they will then be sunk later when they try to leave Singapore.

So if Force Z did hear the orders and instead turned back to Columbo as the Admiralty had apparently decided, would the reamin there ore head back to Europe.