FLUFF: AIRCRAFT CARRIER TACTICS ~ 1931.
If one wants to understand the actual state of aircraft carrier tactics either in this AU or in the RTL, ~1931; one must accept that no-one knew what they were doing. As late as 1944 in the RTL, both the IJN and the USN had not evolved a set of drills that could be fundamentally applied to aircraft carriers as easily as torpedo and gun tactics could be applied to surface ships or hunting pack tactics could be applied to diesel electric submarines.
Part of the problem was that there was no standard aircraft carrier in use. The US used large plane capacity aircraft carriers, the British used moderate plane carrying capacity flattops and the Japanese fell in between the two extremes. Even the way planes were serviced and launched on the different carriers was non-standard among the three navies; with no one settled system in use. The Japanese and the British tended to want to keep the decks clear of obstruction so that planes would not foul takeoff and landon runs. These two navies, the British inventing and the Japanese imitating them and adopting some unique own practices, struck aircraft below for maintenance, fueling and arming. The Americans, with their own ideas, and with extremely crowded hangers, had started to park planes on the edges of the flight deck and work on the birds above the hanger. Mainly it was a question of working space and elbow room for the three navies. The British and the Japanese went for the plane by plane strike below, service in the hanger, raise and spot for takeoff method. The Americans went for the land them all, shove them forward, serve them higgly piggly at the bow, then roll them toward the stern and spot them for takeoff method above the hanger. That was the USS Langley method writ large. It was the only way to service more than 40 planes in an hour.
Which 1931==> method was superior? RTL at Coral Sea and at Midway the Japanese and American sortie tempos were almost indistinguishable. Initial strike packages of 30-50 planes per carrier took about an hour and a half to get off after an all nighter and none of the combatants was able to mount more than two strike package sorties per day per carrier. (Hiryu). Later the Americans would make a turnaround of 90 minutes the fleet goal (rarely met) but you do not see it in practice until post war or until Korea after the fleet digested its WW II operational experience.
Slow and ill-organized to launch a strike package is the American norm. Slow and methodical is the Japanese norm. Neither of them though in 1931 has figured out exactly how to bomb and torpedo an enemy fleet yet. The British, meanwhile, are off to the one side trying to use carriers as a battleship aid. They are a big believer in the torpedo plane as a ship crippler at this stage of aviation development. As for fighters and scouts, these planes they believe have their places as Zeppelin killers, and spotter planes for the British battle line's artillery.
insofar as that is a doctrine, the British tactical emplopyment method is to tack the one aircraft carrier on as auxiliary unit to the rear of the main body and use it like any other scout and opportunity attack platform to support the battle-line.
It works. It is the defacto Japanese doctrine that will prevail until someone (Genda and Yamamoto) recognizes that massed airpower can wreck a fleet at its anchorage.
American doctrine is based on some experiments conducted by William Mitchell and
some rather startling RTL deficiencies. The USN had torpedo planes, but both the planes and the torpedoes were appallingly terrible. The Bliss Leavitt Mark VII 45/short was designed in 1920 and its delivery aircraft was the Martin T3M-2 at about this time (1927).
General characteristics
Crew: three
Length: 41 ft 4 in (12.60 m)
Wingspan: 56 ft 7 in (17.25 m)
Height: 15 ft 1 in (4.60 m)
Wing area: 883 ft² (82.1 m²)
Empty weight: 5,814 lb (2,643 kg)
Loaded weight: 9,503 lb (4,320 kg)
Powerplant: 1 × Packard 3A-2500 liquid-cooled V-12 engine, 770 hp (574 kW)
Performance
Maximum speed: 109 mph (95 kn, 175 km/h)
Range: 634 mi (551 nmi, 1,020 km)
Service ceiling: 7,900 ft (2,400 m)
Wing loading: 10.8 lb/ft² (52.6 kg/m²)
Power/mass: 0.081 hp/lb (0.13 kW/kg)
Climb to 5,000 ft: 16.8 min
Armament
1 × flexibly mounted 0.3 in (7.62 mm) machine gun in rear cockpit
1 × torpedo or bombs under fuselage
Imagine that trying to tangle with a Nakajima A4N?
Specifications (A4N1)
Data from Japanese Aircraft, 1910–1941
General characteristics
Crew: 1
Length: 6.64 m (21 ft 9¼ in)
Wingspan: 10.00 m (32 ft 9½ in)
Height: 3.07 m (10 ft 1 in)
Wing area: 22.89 m² (246.4 sq ft)
Empty weight: 1,276 kg (2,813 lb)
Loaded weight: 1,760 kg (3,880 lb)
Powerplant: 1 × Nakajima Hikari 1 nine cylinder air-cooled radial engine, 545 kW (730 hp)
Performance
Maximum speed: 352 km/h (190 knots, 219 mph) at 3,200 m (10,500 ft)
Cruise speed: 233 km/h (126 knots, 145 mph)
Range: 847 km (457 nautical mile)
Endurance: 3½ hours
Service ceiling: 7,740 m (25,393 ft)
Wing loading: 76.9 kg/m² (15.74 lb/(sq ft))
Climb to 3,000 m (9,840 ft): 3 min 30 s
Armament
Guns: 2× fixed, forward-firing 7.7 mm machine guns
by contrast the RN was equipped with the Blackburn T-8 Baffin
General characteristics
Crew: two
Length: 38 ft 3 3⁄4 in (11.68 m)
Wingspan: 44 ft 10 in (13.67 m [6])
Height: 12 ft 10 in (3.91 m)
Wing area: 683 sq ft (63 m2)
Empty weight: 3,184 lb (1,447 kg)
Loaded weight: 7,610 lb (3,459 kg)
Powerplant: 1 × Bristol Pegasus I.M3 9-cylinder radial engine, 565 hp (421 kW)
Performance
Maximum speed: 118 kn (136 mph, 219 km/h) at 6,500 ft (1,980 ft)
Range: 426 nmi (490 mi, 789 km)
Endurance: 4 1⁄2 hr
Service ceiling: 15,000 ft (4,570 m)
Rate of climb: 600 ft/min[7] (3.0 m/s) at 5,000 ft (1,500 m)
Armament
Guns:
1 × forward firing fixed 0.303 in (7.7 mm) Vickers gun
1 × 0.303 in (7.7 mm) Lewis gun in rear cockpit
Bombs: 1 × 1,800 lb (816 kg) 18 in (457 mm) torpedo or 1,600 lb (726 kg) of bombs.
And the British Mark VII and Mark VIII torpedoes worked.
In 1931 Mister Hoover's Navy will have to embrace dive bombers as a way of life. In the RTL that would be the Curtis Falcon.
General characteristics
Crew: two (pilot, observer/rear gunner)
Length: 27 ft 2 in (8.28 m)
Wingspan: 38 ft 0 in (11.58 m)
Height: 10 ft 6 in (3.2 m)
Wing area: 353 ft² (32.8 m²)
Empty weight: 2,875 lb (1,304 kg)
Max. takeoff weight: 4,476 lb (2,030 kg)
Powerplant: 1 × Curtiss D-12E (V-1150-5) V-12 liquid-cooled engine, 435 hp (324 kW)
Performance
Maximum speed: 139 mph (223.7 km/h)
Cruise speed: 110 mph (177 km/h)
Range: 628 mi (1,010 km)
Service ceiling: 14,100 ft (4,298 m)
Rate of climb: 948 ft/min (289 m/min)
Armament
Guns: 4 × forward-firing .30 in (7.62 mm) M1919 Browning machine guns and 2 × flexible 0.30 in (7.62 mm) Lewis machine guns on a Scarff ring.
Bombs: 200 lb (91 kg) of bombs mounted on lower wing racks
This is the kind of plane that shoots King Kong off the Empire State Building.
So whether AU or RTL, aircraft carriers using this quality of stuff are not going to displace battleships as the queens of the sea. The British have the tactics for the era just about right for the aircraft capacity available and to be expected for the near future.
This quality is going to change soon.