Here´s my take:
June 1941: Brig.Gen. Becker is temporarily replacing MG Martin as CO of the Army´s air units. BG Becker is doing something unusual, he´s making his plans based on the opponents known capabilities, rather than his perceived intentions.
- Threat identification and assessment:
Targets: First and foremost the US Pacific Fleet, secondly units protecting it.
-sabotage: Highly likely, but limited effects. Particularly the Fleet is safe from it.
-submarine attack: concerns the USN
-carriers based air raid: worst case scenario, not likely, but possible
Sabotage: Barb wire, lighting the perimeter, increased patrolling
Air raid:
-recon: Upon asking BG Becker learns the USN is concentrating its limited number of PBY´s in the southeast, therefore B-17 and B-18 are watching the northeast sector as part of their routine training ops.
-Dispersion of planes and use of camouflage, construction of dummy planes: The former makes sabotage easier, but the latter can be implemented without problems.
-readiness: 24/7 high readiness is not possible. The timing of an attack has to be narrowed down. The main target of an air raid would be the Fleet. Analysis of Fleet movements show a month long patter of the Fleet returning on Friday or Saturday and never leaving PH before Monday. Logical conclusion: A hypothetical attack will occur on a Sunday.
Now USN carrier Admirals and pilots are being contacted to tell the Army how they would attack a major naval base. Answer: Keep your distance on D-Day minus one to avoid detection, steam at full speed to the target after dusk, launch planes at dawn.
The rest is simply math. Assuming the speed and range is Japanese CVs is similar to American ones an attacking fleet will be y mile out on D-1 and x mile on D-Day. Based on sunrise, estimated time to launch the planes and their speed and range the planes will hit the target z minutes after sunrise.
In the following month, as the US-Japanese tension rise, the readiness of the Hawaiian Air Force is gradually increased until it reaches the level below:
December 6th, evening:
The regular fight of B-17 and B-18 on recon returns. The search of the northeast approaches has come up negative.
December 7th, before dawn:
Several O-47B take off to be position for a search 150 to 200 miles off PH at dawn.
Disgruntled airmen start moving the planes off the runway, where they have to be put at night because of anti-sabotage measures ordered by higher ups. The fuelling and arming starts at dawn. Two fighters per squadron are kept ready for immediate take off, two more are ready with the pilots allowed to remain in the officers mess. The men are woken up. At weekends only half of the squadron’s personnel get´s to leave the base in the evening, the rest has to remain until the party goers have sobered up.
December 7th, dawn:
The fighter squadron´s AA-weapons are being manned.
An O-47B actually finds Kido Butai, the observer send a message, but it arrives only scrambled and before it can be repeated the Japanese CAP get´s the slow observation plane.
06:00 hrs: the recon plane launched by cruiser Chikuma is overlooked by radar operators.
06:15 hrs: two radar station report contact in the south, Air Corps liaison personnel – radar and AA-units are not under BG Becker’s command – call the Information Center. Lt. Kermit Tyler takes and the call, and as it fits the profile alerts Wheeler: Incoming unidentified airplanes! A pair of P-40B takes off to investigate
06:45 hrs: three other radar stations pick up a contact in the north A pair of P-36A fighters are send to investigate
07:20: The P-36A make contact and report … more than 100 Japanese airplanes!
07:22: The 18 fighters on standy-by take off, everybody else is running to their planes. Fighter pilots to intercept the enemy, bomber pilots on Hickam to get their planes out of harms way. Coast Atillery AA-units and the USN are informed of the confirmed presence of Japanese warplanes near PH. ETA: no later than 08:00!
With at least 100(out of 129 total) P-40(87) and P-36(39) in the air by 07:50 the Japanese run the gauntlet. Although more manoeuvrable, the Zero´s pilots are shocked at the little damage their 7.7mm machine guns on the P-40s(20mm guns are inaccurate and have little ammo). And being outnumbered by 2:1 means they can´t stop all attackers anyway. As a result the dive and torpedo bombers suffer the first losses. But once they reach the port it get really ugly. Every AA-gun is cocked and loaded and the planes fly into a hailstorm of bullets. And they have to do so at a lower speed and at a lower altitude than on the open sea, because otherwise the torpedoes would sink to deep and hit the bottom of the shallow port, regardless of technical modification on the torpedoes. The result of the attack is devastating, but it´s the attacker who are devastated. The combination of low speed and altitude makes them the perfect target and the AA(weak by 1944 standards) blows them out of the air one by one.
USS California is hit once and stays afloat, Oklahoma is unlucky, she’s hit three times, starts to capsize but counter flooding means she settles on her keel. West Virginia is hit twice and stays afloat. Nevada was the only BB to get under way and has already left the port, she escapes unharmed. The remaining BBs are hit by bombs, but since all are on general quarters they suffer minor damage - honk if you looove damage control!
On Wake Island VMF-211, the 1st and 4th Defence Battalions escape largely unharmed, too. The 1,500 construction workers and their heavy equipment allowed them to build shelters for the fighter planes and gun emplacements than have the think underbrush around them removed.
Only that pompous ass McArthur manages to get himself screwed anyway.