Aircraft limitations of Japanese carriers?

[Dili]

Yes i also use JAAF Bn supporting Army planes and IJN base forces to support Navy planes.

army fighters on Takao do not have the range to escort bombing missions.

IRL longe range missions were for the Navy, also the Army build air bases in Philippines just after the first landings.

Navy Air Force Operations in Philippines
http://www.ibiblio.org/hyperwar/AAF/USS ... JO-15.html


http://www.history.army.mil/books/wwii/ ... P1/ch6.htm

As a result of these considerations, Imperial General Headquarters decided to throw the entire effort during the first few days of hostilities into a powerful and sustained air offensive against the major concentrations of enemy air strength. Since these were located principally in the Manila area and farther south, beyond
the range of Japanese Army planes operating from southern Formosa, it was necessary to obtain the cooperation of naval air strength, including long-range bombers based in southern Formosa, as well as seaplane and carrier forces. The boundary of air operations between the Army and Navy was to be fixed at 16 degrees N. Lat., placing all the enemy's major bases in the Manila area within the Navy's operational sphere. (Plate No. 16)

Imperial General Headquarters estimated that enemy air resistance would be sufficiently neutralized within two to four days to permit execution of the next step in the operational plan: the landing of advance detachments on northern and southern Luzon with the mission of seizing air bases at strategic points and quickly preparing them for operational use by the Japanese forces. The airfields at Aparri, Laoag and Vigan were designated as the initial objectives on northern Luzon, while the southern Luzon force was to seize the airfield at Legaspi. Prior to the advance landings on Luzon Proper, occupation of Bataan Island, 150 miles north of Aparri, was planned as a preliminary step to facilitate fighter cover of the north Luzon landings.14

[Dili]

One more info for the database

There is another carrier that is confirmed could take B7 Grace besides Taiho and Shinano : CVL Ibuki with 15 A7m and 12 B7

[SenToku]

Wasn't the limit in IJN carriers created mainly by the 11 meter square elevator?

I know that Val caused problems (12+ meter wingspan), but in theory you could fly anything expect A7M and B7A (15 meter limit) from Hosho. D4Y judy for instace would have fitted into the elevator. I don't see any problems taking off as the first spotted plane (ie. forward plane in group taking off) from Shokaku only had 100 meters to take off. Granted, it was usually lighter fighter type not heavily loaded bomber.

Of course the launch rate would suffer as you would have to bring one or two planes at the time to deck and let them take off and then bring next pair and so on.

This aside I am pretty sure fully loaded Kate with 1700 kg torpedo under it had no way of taking of from 120-140 meters distance, so they had to sacrafice fuel or reduce load to fly missions, limiting Hosho in game as ASW platform with Kates on board. After all, Nvl Srch and ASW patrols use reduced load and fly missions "one plane at the time" so that would fit the technical problems presented by shorter deck.

Japanese of course never did so, choosing to use Hosho as trainer instead like USS Wolverine in USN service. Wolverine also had about 150-180 meter deck, but it still managed to fly the heaviest planes, such as Corsairs and Avengers, so the length isn't really the problem.

Another thing, Unryo class CV's had 15 meter re-designed rear elevator, so they could have flown any aircrft in IJN carrier inventory.

[Erkki]

ORIGINAL: SenToku

Wasn't the limit in IJN carriers created mainly by the 11 meter square elevator?

I know that Val caused problems (12+ meter wingspan), but in theory you could fly anything expect A7M and B7A (15 meter limit) from Hosho. D4Y judy for instace would have fitted into the elevator. I don't see any problems taking off as the first spotted plane (ie. forward plane in group taking off) from Shokaku only had 100 meters to take off. Granted, it was usually lighter fighter type not heavily loaded bomber.

Of course the launch rate would suffer as you would have to bring one or two planes at the time to deck and let them take off and then bring next pair and so on.

This aside I am pretty sure fully loaded Kate with 1700 kg torpedo under it had no way of taking of from 120-140 meters distance, so they had to sacrafice fuel or reduce load to fly missions, limiting Hosho in game as ASW platform with Kates on board. After all, Nvl Srch and ASW patrols use reduced load and fly missions "one plane at the time" so that would fit the technical problems presented by shorter deck.

Japanese of course never did so, choosing to use Hosho as trainer instead like USS Wolverine in USN service. Wolverine also had about 150-180 meter deck, but it still managed to fly the heaviest planes, such as Corsairs and Avengers, so the length isn't really the problem.

Another thing, Unryo class CV's had 15 meter re-designed rear elevator, so they could have flown any aircrft in IJN carrier inventory.

The weight of the plane is not a problem - the thrust-to-weight ratio in full fuel and ordnance load and required takeoff velocity at that load is. F4U and F6F were both absolutely huge and heavy but could take off with ordnance from a CVE because they had much better power to weight ratio available than most attack aircraft. The best engines were usually spared for fighters.

The IJN aerial torpedo Type 91 weights 1700 lbs, which is only 800-ish kilograms. Though still 37% of the weight of an empty plane.

Notice that maximum takeoff weight for B5N is the same as an empty Avenger's and mere 50% of Avenger's fully loaded weight. Plus B5N has both better power-to-weight ratio when loaded and lower wingloading. All that would imply to a shorter required takeoff run both loaded and especially when unloaded.

B6N was much heavier without having any more wing area(25% more fully loaded weight), but also had 80%(!) more takeoff engine power(N2 model, at least on paper).

Now one thing is that just like the USN CVEs, the Hosho was fairly slow, which didnt help with takeoffs.


edited typos

[SenToku]

Weight most certainly is limiting factor.

Take the SBD-3. Take-off distance on SBD went down about 100 feet for every 500 lbs weight reduced. Pilot Manual, SBD3.

All aircraft do behave the same, like F6F. In 25 kts head-wind Hellcat for instance needed about 200 feet of deck for take-off with clean load of less than 10´000 lbs. Fully loaded to 13k lbs the distance was 400+ feet and american CVE's, converted cargo ships, were only capable of doing 18 kts (less than true warship Hosho). So neither Hellcat or SBD could take-off from US CVE with full load, so I don¨t think that Avenger was any different. Same must be true to IJN CVE's (I have somewhere A6M3's technical manual, I didn't find it right now).

[Erkki]

ORIGINAL: SenToku

Weight most certainly is limiting factor.

Take the SBD-3. Take-off distance on SBD went down about 100 feet for every 500 lbs weight reduced. Pilot Manual, SBD3.

All aircraft do behave the same, like F6F. In 25 kts head-wind Hellcat for instance needed about 200 feet of deck for take-off with clean load of less than 10´000 lbs. Fully loaded to 13k lbs the distance was 400+ feet and american CVE's, converted cargo ships, were only capable of doing 18 kts (less than true warship Hosho). So neither Hellcat or SBD could take-off from US CVE with full load, so I don¨t think that Avenger was any different. Same must be true to IJN CVE's (I have somewhere A6M3's technical manual, I didn't find it right now).

No, absolute weight alone does not matter as I tried to explain. Length of the takeoff run and min speed for liftoff do, and they both depend on thrust-to-weight ratio and wingload(simplified). Changing weight does not effect takeoff run length or time linearly, but I guess a rule of thumb could be made for estimations. Speed of the launch platform and headwind help. As do catapults. [:)]

I think Sangamons were the only USN CVEs to have SBDs of SB2Cs aboard in action, probably because of the launching issues. Heres some TBFs on a CVE. No idea if they could be launched in maximum load even in best conditions:



If someone wished by a HR to restrict the use of certain planes on certain IJN CVEs for history/realism reasons I think such HR should also limit USN CVEs.

[Dili]

I agree Erkki


Following SenToku information i made just a fast search Ikoma an evolution of Unryu will take B7 Grace with complement bellow. So maybe Unryus were able too.

18 + 2 Mitsubishi A7M
27 Aichi B7A
6 Nakajima C6N(on deck)

From here: http://www.j-aircraft.org/smf/index.php?topic=10094.0
Edit:

Launching the B5N1 on this carrier with a torpedo of 800 kg bomb probably would require consierable WOD (wind over the deck). The B5N2 required 226 metres of flight deck for take-off with no wind and 85 metres with 27.213 knots of WOD. The B5N1 would require much more which would probably be the origin of the statement that the B5N could not handle the torpedo on the Ryujo. At this time Ryujo’s flight deck was 156.5 metres long.

[Dili]

Some more data now on CVL elevators :http://www.j-aircraft.org/smf/index.php?topic=3157.0

As to the CVLs elevators, here are their sizes (Length x Width, in meters) from Grand Prix - Anatomy of Japanese Carriers, page 134 :CV Forward elevator After elevator
HOSHO (1922~1944) 12m80 x 8m50 13m70 x 7m00
HOSHO (1944) 12m80 x 8m50 13m70 x 11m00
RYUJO 11m10 x 15m70 10m80 x 8m00
SHOHO-class 13m00 x 12m00 12m00 x 10m80
RYUHO 13m00 x 12m00 13m00 x 12m00
TAIYO-class 12m00 x 13m00 13m00 x 12m00
SHINYO 12m00 x 13m00 13m00 x 12m00
KAIYO 13m00 x 12m00 13m00 x 12m00
CHITOSE-class 13m00 x 12m00 12m50 x 12m00


[Edit : added HOSHO pre-1944 refit after elevator dimensions as provided by Jon in this post ]

Best Regards,

Gilles Canales

It seems that Ryujo could spot Dive Bombers in forward elevator, but of no practical use since it was too forward.