This aircraft challenge mission is relatively easy - if you know what to do. Your objective is simple - sink the core of the enemy fleet.
You have two airfields, one each to the northeast and southeast of the center of the map. Both have three kinds of aircraft: the Ki-43, the G3M, and the G4M. The latter two are bombers, and the Ki-43 is the only plane that can attempt to stand toe-to-toe with the enemy fighter wing.
The enemy fleet consists of 5 ships: the HMS Hermes, the Repulse, and the Prince of Wales, escorted by two Fletcher-class destroyers (flying the White Ensign) - the HMS Electra and the Vampire. The Hermes spawns four squadrons of three Hawker Hurricanes each - these lethal planes are more than capable of shredding any aircraft to pieces. Attacking the battleships is hard as it is - the Hurricanes make it almost impossible.
- Sink the HMS Prince of Wales and the HMS Repulse before they escape across the eastern border.
- Sink the HMS Hermes
The HMS Hermes
As mentioned before, the Hermes is the biggest threat to your operation, so deal with it first. It may seem odd, dealing with the hidden objective first before the primary ones, but accomplishing the hidden objective makes the primary objective considerably easier.
For starters, have all four squadrons rendezvous in the space a little west to the space between the airfields. Have them fly bombers and load them with multiple bombs. Although the G4M carries more bombs than the G3M, the enemy will be in no position to stop you, so it becomes irrelevant.
Once all your bombers are at the rally point, have them mesh and loop around a little bit to mix them up a little before sending every last one at the Hermes - all at once.
Immediately the hurricanes will rise to stop you, but the bomber's machine guns will at least keep them occupied long enough for your bombers to drop a massive torrent of bombs over the enemy carrier. If you're lucky, you may even score a kill with your bomber's machine guns.
The Hermes should sink after a single wave of bombers. Mop up any remaining Hurricanes with a squad or two of Ki-43s. Henceforth, the skies are yours.
Other players like deploying Oscars with bombs to sink the Hermes, but the idea remains the same: overwhelm the Hermes with bombs until it sinks, then use Oscars to mop up.
If you want to, you can take control of the bombers machine guns and personally take down the hurricanes as they fly behind you. To take control of the bomber's machine guns, press while in control of the bomber. Aim with and fire with .
With the skies completely yours, all you have to do is prepare massive torpedo campaigns on the enemy battleships to send them to the bottom. Attack the enemy warships from the sides to present a large, suitable target and drop the torpedo at point-blank range to ensure a hit.
Battleships have extremely tough deck plating, so bombs won't work here. Only torpedoes will. The good news is that your bombers sport torpedoes. The bad news is that you have to use the carpet bombers, which are slow, easy targets. The only thing you'll have on your side for the most part, therefore, are numbers. Send bombers in massive groups, consisting of about 4 squadrons each, on the battleships. Don't worry if most of them get shot down - both the G3M and the G4M have torpedoes, and when you run out of one aircraft type you can switch to the other. The G4M is far superior, however - not only can it take more hurt and is smaller, it is also considerably faster - allowing you to rush in and out with torpedo attacks.
The other warships - the Electra and the Vampire - are of the Fletcher class, which sport all kinds of antiaircraft weapons. The important thing is to either ignore them or don't spend too much time on them - you'll definitely be hard pressed for time regardless of what you do, so don't waste too much time on the destroyers. Although they occasionally block the AI torpedo shots, as destroyers they can only take at most two torpedo hits before sinking.
One tactic that works a lot is a torpedo dive - that is, diving out of high altitude like a dive bomber, but levelling out at the last second - right in front of the enemy - and release your torpedo. It has a high chance of failing, due to how sensitive torpedoes are to the angle at which they're dropped, but a successful manoeuvre almost guarantees a torpedo hit.
As mentioned before, the key to this mission is speed - how fast you can take down the battleships and how fast you can get to them to drop your torps. Don't bother with the Nells - not until you're finished with the Betties anyway. The Betties are MUCH faster than the Nell, and send them in first since they have a higher speed - and more speed translates into getting closer to drop a torpedo - and thus a more accurate hit.
Your bombers may accidentally strike one of the destroyers. Getting rid of one of the destroyers might be a good idea, but as mentioned earlier, never spend too much time on them. Your main target for now anyway should be the Repulse, which is 5 knots faster than the Prince of Wales.
Drop the torps at point-blank range to ensure a hit. Hopefully by the time all your Betties are shot down, you'll have sunk one and heavily damaged the other - ideally also, you'll also be down a destroyer. This leaves the last battleship a sitting duck. Once all its escorts are gone, just deploy wave after wave of bombers until the Prince of Wales sinks as well.