Mitsubishi C5M2 BABS

[Fatboy Coxy]

Hi all, I'm looking for information on the Mitsubishi C5M2 BABS, the last operational IJN version, which had a 950 hp Nakajima Sakae 12 engine fitted. Despite the increase in power, this model was, I read, a bit slower that the Mk I, due to extra equipment added.

 

[Wurger]

To begin with .. The C5M1 and C5M2 were the IJN designations for the Ki-15-I (Army Type 97 Command Reconnaissance Aircraft Model 1) and Ki-15-II (Army Type 97 Command Reconnaissance Model 2). The data below denies the C5M2 was slightly slower than the C5M1.

C5M1
Engine: Mitsubishi Zuisei 12 fourteen-cylinder air-cooled radial
Power: 780hp at take-off, 875hp at 11,810ft
Crew: 2 (pilot and radio-operator/ observer/ gunner)
Wing span: 39ft 4 7/16 in
Length: 28ft 6 17/32 in
Height: 11ft 4 13/32 in
Empty Weight: 3,538lb
Loaded Weight: 4,844lb
Max Speed: 291 mph at 14,040ft
Climb to 9,845ft in 4 min 51 sec
Service Ceiling: 27,000ft
Range: 725 miles
Armament: One flexibly mounted rear-firing 7.7mm Type 92 machine-gun

C5M2
Engine: Nakajima Sakae 12 fourteen-cylinder air-cooled radial
Power: 940hp at take-off, 950hp at 13,780ft
Crew: 2 (pilot and radio-operator/ observer/ gunner)
Wing span: 39ft 4 7/16 in
Length: 28ft 6 17/32 in
Height: 11ft 4 13/32 in
Empty Weight: 3,781lb
Loaded Weight: 5,170lb
Max Speed: 303mph at 14,930ft
Climb to 9,845ft in 3 min 58 sec
Service Ceiling: 31,430ft
Range: 691 miles
Armament: One flexibly mounted rear-firing 7.7mm Type 92 machine-gun

the info source: Mitsubishi C5M

 

[Fatboy Coxy]

Hi Wurger, thank you for this.

I also understand the C5M2 has the same engine as the A6M2 model 21, which must have helped with their logistics and maintenance.

I'm always confused by what the range of an aircraft is, my understanding is how far can it fly, but operationally you obviously want to return (hopefully), and so we would discuss its radius of operations. This then becomes quite fuzzy with whether we have maximum fuel, or maximum payload, and also how fuel efficient an aircraft can fly to and from target area. Oh and we haven't discussed loiter time over target.

The History of War web site Wurger has linked shows a range of 691 miles for the C5M2, but I know that flying out of Soc Trang, south French Indo-China (Vietnam) they were doing recon missions over Singapore, a distance of 580 odd miles. Does anyone know if the C5M2 operate with drop tanks or extra fitted tanks, or is 691 miles an operational radius.

 

[Wurger]

The Wikipedia site suggests the range: 2400 km what is about 1500 miles or 1300 NM. Judging by the info , the 691 miles is the operational range.

 

[Fatboy Coxy]

Aah, that makes a lot more sense.

 

[Shinpachi]

The C5M2 or its equivalent Ki-15-II could narrowly fly between Saigon and Singapore without the drop tank but it would be safer with it.

Ki-15-II_spec(fuel tank)

Source: Ki-15-II manual

 

[Wurger]

 

[Fatboy Coxy]

Hi Shinpachi, thank you for this, but as you mention the drop tanks, I have a question. The C5M1/2 originated from the Army Ki-15, did the Naval version use the same drop tank as the Army version, and were they the same tanks as those used by the Ki-27 Fighter. The reason why I ask is I am working through the Japanese Monograph 55, South East Area Air Operations Phase I, Nov-1941 - Feb-1942. The 3rd Air Brigade was tasked with attacking the airfields in Kelantan, Malaya, including Kota Bharu. The 59th Sentai equipped with Ki-27 fighters, was operating out of Konpong Trach, a distance of about 340 miles. I think they may have been using drop tanks, but there were concerns among the 3rd Air Division, as the numbers of drop tanks were low.

 

[Shinpachi]

Hi Shinpachi, thank you for this, but as you mention the drop tanks, I have a question. The C5M1/2 originated from the Army Ki-15, did the Naval version use the same drop tank as the Army version, and were they the same tanks as those used by the Ki-27 Fighter. The reason why I ask is I am working through the Japanese Monograph 55, South East Area Air Operations Phase I, Nov-1941 - Feb-1942. The 3rd Air Brigade was tasked with attacking the airfields in Kelantan, Malaya, including Kota Bharu. The 59th Sentai equipped with Ki-27 fighters, was operating out of Konpong Trach, a distance of about 340 miles. I think they may have been using drop tanks, but there were concerns among the 3rd Air Division, as the numbers of drop tanks were low.

Capacity of the drop tank for IJN aircraft like A6Ms was 330L (later 320L for wooden tank)
200L wooden wing drop tank was common between IJN and IJA.
They did not drop tanks if not necessary to do so.

 

[Shinpachi]

The first step of Malaya Campaign for IJA ground forces was to occupy the airfield in Singora, Thai.
Ki-27's flight range was 627 km (392 miles) with a drop tank or 350 km(219 miles) without it.
Distance between Kampong Trach FIC and Singora is about 573 km(358 miles).
They would not fly without drop tanks.

 

[Fatboy Coxy]

Hi Shinpachi, working from JM 55

page 20 of the PDF

I'm guessing they were flown in by transport plane

 

[Shinpachi]

I have not heard that they flew in by transport plane.
They only had to fly to Singora to gather for the next step in Malaya.

One way flight to Singora

Source: Aviation Fortress (航空要塞 1945)

 

[Fatboy Coxy]

Hi Shinpachi, thank you for this, but as you mention the drop tanks, I have a question. The C5M1/2 originated from the Army Ki-15, did the Naval version use the same drop tank as the Army version, and were they the same tanks as those used by the Ki-27 Fighter. The reason why I ask is I am working through the Japanese Monograph 55, South East Area Air Operations Phase I, Nov-1941 - Feb-1942. The 3rd Air Brigade was tasked with attacking the airfields in Kelantan, Malaya, including Kota Bharu. The 59th Sentai equipped with Ki-27 fighters, was operating out of Konpong Trach, a distance of about 340 miles. I think they may have been using drop tanks, but there were concerns among the 3rd Air Division, as the numbers of drop tanks were low.

Hi Shinpachi, I think I have misled us all, what I posted in bold is incorrect, I think the 59th Sentai was equipped with Ki-43 Hayabusa, and flying from Phu Quoc Island, and had to provide fighter cover over Kota Bharu. I also think the 64th Sentai, also out of Phu Quoc, but a different airfield, provided cover over Singora. The 1st and 11th Sentai, equipped with Ki-27, were either also at Phu Quoc, or staged out of there to land at Singora as soon as it was captured. I'm not sure about where the 77th Sentai operated, I need to research more on that.

 

[Shinpachi]

The 77th Sentai did not appear in Siemrea(JP pronunciation) of FIC until December 15, 1941