Naval CAP (Combat Air Patrol) Doctrine in WW2

[wingedhussar]

All:

Some friends and I are having a discussion around Naval CAP Doctrine during WW2. Did Aircraft Carriers have a doctrine for how planes covered the fleet? We've looked across the 'net and in to as many books as possible, finding information on doctrine for air to ground cover, but nothing so far on how the US protected the carriers.



Any help?

Thanks,
Phil

[Nikademus]

USN prewar naval CAP doctrine entailed the use of airborne fighter lookout patrols to detect incoming enemy groups. Since the primary mission of the CAP was the destruction of enemy search planes and strikes, this took up most of the available fighter assets. Once detected, the fleet would be warned and fighters vectored onto the threat for attack.


1942 saw the deployment of shipboard air search radar and the adoption of British techniques which saw the use of an FDO (Fighter Direction Officer) to exercise direct control of fighter operations. (centralized control for the TF)

Basic CAP organization were fighter divisions with their component two-plane sections. When in areas where enemy activity might be likely, the carriers retained in the air a full division of 4-6 planes. Use of radar could allow the FDO to deploy additional assets into the air in time (hopefully) to make an intercept. Standing patrol altitudes varied depending on weather conditions and cloud cover. 20k was usually an upper limit.

CAP doctrine evolved continuously as combat lessons were absorbed so there's much much more to the above, itself only a real basic overview. For more details I'd recommend the source of the above info: Lundstrom; The First Team Vol I (and vol II)

edit: Another curiosity you'll read about if you get the above was the use of SBD scout bombers as ersatz CAP fighters. Pre and early war USN CV's having roughly 1/2 the number of fighters they'd eventually ship later in the war there were never enough to do all the tasks needed (Escort and CAP) so some of the SBD's were utilized for "anti-torpedo plane patrols" in order to assist the fighters (and allow them to fly higher alt patrols to protect against dive bombers) The practice was mostly discontinued after the Coral Sea battle due to heavy losses suffered at the hands of escorting Zeros. The SBD's didn't do bad vs. enemy B5N's, but given their own losses it was quickly realized that the best solution was more genuine fighter aircraft. The folding wing F4F-4 helped alot that area.

[renrich]

Good post Nik, I see you are a disciple of Lundstrom. They are excellent books.

[freebird]

1942 saw the deployment of shipboard air search radar and the adoption of British techniques which saw the use of an FDO (Fighter Direction Officer) to exercise direct control of fighter operations. (centralized control for the TF)

losses it was quickly realized that the best solution was more genuine fighter aircraft. The folding wing F4F-4 helped alot that area.

Interesting, and a good thing that the airgroup at least was learning something from British experience. (Unlike Adm. King!) Now if only the British would have taken some ideas from the Americans too...

I've wondered why the British had so much trouble getting a decent number of fighter CAP on to their carriers, whether it was a problem with doctrine or with equipment. For example, on the "Pedestal" convoy from Gibraltar to Malta in Aug '42 they had 2 carriers for escort, (after the 3rd carrier "Eagle" was lost to a U-boat) but the convoy had heavy losses due to Axis air attack. A 4th carrier "Furious" had launched 40 Spitfires from 600 miles out to fly to Malta, then returned to Gibraltar. For air cover the "Indomitable" had 24 SeaHurricanes, 10 Martlets (Wildcats) & 14 Albacore TB's. The "Victorious" had 16 Fulmars, 6 SeaHurri's, & 14 Albacores.

The convoy had the same trouble as the Japanese at Midway, after disrupting a wave of enemy TB's, Ju 87's were able to hit "Indomitable" several times, and although because of the armoured deck it didn't sink, but the flight deck (& 40 aircraft) were now unusable. The convoy's CAP was now reduced to 8 Hurricanes, 3 Martlets & 10 Fulmars.

I would have thought it would have been better to load the Victorious with as many Martlet's & SeaHurri's as possible (the same ship had 60 Wildcats operating in 1943 when in the Pacific with the US fleet) to provide a stronger CAP. If it was really thought vital to have the Albacore TB's along, they should have been flown from Gibraltar to land on the "Furious" after launching the Spitfires, as the Italian fleet would not have been in range until after this time anyways.

I think that the British had gotten a large # of Wildcats delivered in 1941, did they not have enough or was it just not RN doctrine to have a large CAP, even when expecting heavy air attack?

[renrich]

The air groups on the US carriers typically comprised one VT, two VSB and one VF squadron early in the war. When they realised that they needed more VFs there was actually a shortage of combat ready Wildcats for a while as well as qualified pilots. That was one reason some SBD drivers converted over to Wildcats. One reason there was a shortage of fighters was because the Brits were getting some. Another reason was that thanks to the Brit's stubborness about wanting six guns on the F4F4, which in my opinion was stupid, the armament installation had to be redesigned thus slowing down the assembly line. Later the Navy went back to the four guns in the FM. The things we do for our allies!LOL

[freebird]

One reason there was a shortage of fighters was because the Brits were getting some. Another reason was that thanks to the Brit's stubborness about wanting six guns on the F4F4, which in my opinion was stupid, the armament installation had to be redesigned thus slowing down the assembly line.

What time frame are you referring to Ren? 1941? or 1942?

[Glider]

The air groups on the US carriers typically comprised one VT, two VSB and one VF squadron early in the war. When they realised that they needed more VFs there was actually a shortage of combat ready Wildcats for a while as well as qualified pilots. That was one reason some SBD drivers converted over to Wildcats. One reason there was a shortage of fighters was because the Brits were getting some. Another reason was that thanks to the Brit's stubborness about wanting six guns on the F4F4, which in my opinion was stupid, the armament installation had to be redesigned thus slowing down the assembly line. Later the Navy went back to the four guns in the FM. The things we do for our allies!LOL

Be fair Renrich. There were a lot more changes in the Wildcat than just the 6 x HMG's. The RN did accept a delay in delivery but the main reason was to get the folding wings which is a change worth having. Even then the RN accepted the first of the Martlet II's with fixed wing to keep up deliveries.

[freebird]

Be fair Renrich. There were a lot more changes in the Wildcat than just the 6 x HMG's. The RN did accept a delay in delivery but the main reason was to get the folding wings which is a change worth having. Even then the RN accepted the first of the Martlet II's with fixed wing to keep up deliveries.

When did the RN get the first Marlet II's with the folding wings? Did the first SeaHurri II's have folding wings or was that only later?

[Glider]

The first folding wing Martlet IIs were delivered in August 1941, the other big changes were of course the extra guns but also armour and Self Sealing fuel tanks.
These were all needed to make the plane fully combat worthy.

Re the Sea Hurricane II I am not so sure about re dates.

[freebird]

The first folding wing Martlet IIs were delivered in August 1941, the other big changes were of course the extra guns but also armour and Self Sealing fuel tanks.
These were all needed to make the plane fully combat worthy.

Re the Sea Hurricane II I am not so sure about re dates.

I couldn't find the info for the first date for folding-wing SeaHurri's

I found the listing for the Seafire which had folding wings, beginning in March 1942, with 165 delivered. In June '42 a further 375 Mk. IIC's were delivered, so I wonder why they were not available for such an important mission as Pedestal. Perhaps the Fulmar was as good a fighter as the Seafire? {I'm kidding!!!}

The Supermarine Spitfire

[maxs75]

The Sea Hurricane never had folding wings. Only Seafire had, from the MkII variant.

Max

[freebird]

Did the US have plans for a folding wing Wildcat already in the works? Or was the version that the British ordered the first folding wing fighter in the USN?

[renrich]

1942 is the period I am referring to. I am not being truly critical of our Brit cousins but the switch to six guns did cause a delay in production while the redesign took place and I feel the change was not only unecessary and wrongheaded, but was a negative. My opinion but also many naval aviators including Thach(he said "if you can't hit with four you will miss with six"). In an AC like Wildcat four 50s with 400 rounds each has got to be prefarable to six 50s with 240 rounds each. Perhaps the superior training of the US Navy pilots was responsible for that attitude. The folding wing was, I believe, an improvement desired by the USN so that more AC could be carried. I do not think that was initiated by the RN. The changes to the F4F which resulted in the F4F4 added around 1000 pounds to the weight.

[Glider]

1942 is the period I am referring to. I am not being truly critical of our Brit cousins but the switch to six guns did cause a delay in production while the redesign took place and I feel the change was not only unecessary and wrongheaded, but was a negative. My opinion but also many naval aviators including Thach(he said "if you can't hit with four you will miss with six"). In an AC like Wildcat four 50s with 400 rounds each has got to be prefarable to six 50s with 240 rounds each.

I don't know where the view that the redesign for the additional two guns was the only reason for the delay in production comes from. As mentioned in the earlier posting that particular version had a number of changes only one of which was the additional two guns.
I think its also worth remembering that Grumman had already designed the Wildcat to have six guns well before the RN became involved. The first nation to order the Wildcat were the French and they specified 6 x LMG, not 4 x HMG.
When the British took over the contract the British initiated the change on those aircraft to 4 x HMG. Clearly there is a big difference between 6 x LMG and 6 x HMG but the groundwork as to where to put the guns, had already been done.

Re wrongheaded its a debate, but its worth remembering that the P51 was upgunned from 4 to 6 HMGs and by European Standards, 4 x HMG was light for a fighter.

[freebird]

I don't know where the view that the redesign for the additional two guns was the only reason for the delay in production comes from. As mentioned in the earlier posting that particular version had a number of changes only one of which was the additional two guns.
I think its also worth remembering that Grumman had already designed the Wildcat to have six guns well before the RN became involved. The first nation to order the Wildcat were the French and they specified 6 x LMG, not 4 x HMG.
When the British took over the contract the British initiated the change on those aircraft to 4 x HMG. Clearly there is a big difference between 6 x LMG and 6 x HMG but the groundwork as to where to put the guns, had already been done.

Re wrongheaded its a debate, but its worth remembering that the P51 was upgunned from 4 to 6 HMGs and by European Standards, 4 x HMG was light for a fighter.

Yes it would seem to me that the design of folding wings would involve more design work than putting (back - as Glider says) the 2 extra guns. And while it may be true that 4 guns was fine for PTO where the Japanese aircraft were of a lighter design IIRC, but the stronger German AC could withstand MG's better.