A6M Reisen Performance

[Laurelix]

• A6M2 Mod 21

Empty Weight: 1754kg
Loaded Weight: 2421kg
Wing Area: 22.44m2
Engine: Sakai 12
Take off: 940hp / 950hp at 4200m
-
Max Speed: (Military Power)
510km/h at 4400m
-
Rate of Climb: (Military Power)
Time to 6000m: 7:27
-
Turn Time:
14 sec
-
Maximum Safe Dive Limit:
630km/h IAS
-
Armament:
2x 7.7mm Type 97 (680 rounds per gun)
2x 20mm Type 99 Mk 1 (60 rounds per gun)

—————————————-

• A6M3 Mod 32

Empty Weight: 1841kg
Loaded Weight: 2510kg
Wing Area: 21.54m2
Engine: Sakai 21
Take off: 1130hp / 1100hp at 2850m / 980hp at 6000m
-
Max Speed: (Military Power)
545km/h at 6000m
-
Rate of Climb: (Military Power)
Time to 6000m: 7:05
-
Turn Time:
15 sec
-
Maximum Safe Dive Limit:
670km/h IAS
-
Armament:
2x 7.7mm Type 97 (700 rounds per gun)
2x 20mm Type 99 Mk 1 (100 rounds per gun)

————————————

• A6M3 Mod 22

Empty Weight: 1863kg
Loaded Weight: 2678kg
Wing Area: 22.44m2
Engine: Sakai 21
Take off: 1130hp / 1100hp at 2850m / 980hp at 6000m
-
Max Speed: (Military Power)
541km/h at 6000m
-
Rate of Climb: (Military Power)
Time to 6000m: 7:19
-
Turn Time:
15 sec
-
Maximum Safe Dive Limit:
630km/h IAS
-
Armament:
2x 7.7mm Type 97 (700 rounds per gun)
2x 20mm Type 99 Mk 1 (100 rounds per gun)

————————————-

• A6M5 Mod 52

Empty Weight: 1873kg
Loaded Weight: 2689kg
Wing Area: 21.3m2
Engine: Sakai 21
Take off: 1130hp / 1100hp at 2850m / 980hp at 6000m
-
Max Speed: (Military Power)
565km/h at 6000m
-
Rate of Climb: (Military Power)
Time to 6000m: 7:01
-
Turn Time:
16 sec
-
Maximum Safe Dive Limit:
670km/h IAS
-
Armament:
2x 7.7mm Type 97 (700 rounds per gun)
2x 20mm Type 99 Mk 2 (100 rounds per gun)

———————————-

• A6M5 Ko / Otsu

Empty Weight: 1873kg
Loaded Weight: 2689kg
Wing Area: 21.3m2
Engine: Sakai 21
Take off: 1130hp / 1100hp at 2850m / 980hp at 6000m
-
Max Speed: (Military Power)
562km/h at 6000m
-
Rate of Climb: (Military Power)
Time to 6000m: 7:01
-
Turn Time:
16 sec
-
Maximum Safe Dive Limit:
740km/h IAS
-
Armament:
Ko:
2x 7.7mm Type 97 (700 rounds per gun)
2x 20mm Type 99 Mk 2 (100 rounds per gun)

Otsu:
1x 7.7mm Type 97 (700 rounds)
1x 13.2mm Type 3 (230 rounds)
2x 20mm Type 99 Mk 2 (125 rounds per gun)

———————————-

• A6M5 Hei

Empty Weight: 1873kg
Loaded Weight: 2689kg
Wing Area: 21.3m2
Engine: Sakai 31
Take off: ???hp / 1100hp at 2850m / 980hp at 6000m
-
Max Speed: (Military Power)
559km/h at 6000m
-
Rate of Climb: (Military Power)
Time to 6000m: 7:01
-
Turn Time:
16 sec
-
Maximum Safe Dive Limit:
740km/h IAS
-
Armament:
1x 7.7mm Type 97 (700 rounds)
3x 13.2mm Type 3 (230 rounds per gun)
2x 20mm Type 99 Mk 2 (125 rounds per gun)

———————————-

• A6M8 Model 54

Empty Weight: ???
Loaded Weight: 3300kg
Wing Area: 21.3m2
Engine: Kinsei 62
Take off: 1500hp / 1350hp at 2000m / 1250hp at 6000m
-
Max Speed: (Military Power)
591km/h at 6000m
-
Rate of Climb: (Military Power)
Time to 6000m: 6:50
-
Turn Time:
18 sec
-
Maximum Safe Dive Limit:
740km/h IAS
-
Armament:
2x 13.2mm Type 3 (230 rounds per gun)
2x 20mm Type 99 Mk 2 (125 rounds per gun)

 

[Ivan1GFP]

Hello Laurelix,

Your dive speed limitations are a little bit off: Listing from Old Thread

Mitsubishi A6M - Maximum Diving Speeds:
Long Wing Versions - 340 kts (391 MPH) - 630 KPH
A6M2 Model 21
A6M3 Model 22

Short Wing Versions - 360 kts (414 MPH) - 666 KPH
A6M3 Model 32
A6M5 Model 52

Thicker Wing Skin Versions - 400 kts (460 MPH) - 740 KPH
A6M5 Model 51a
A6M5 Model 51b
A6M5 Model 51c

- Ivan.

 

[Laurelix]

Hello Laurelix,

Your dive speed limitations are a little bit off: Listing from Old Thread

Mitsubishi A6M - Maximum Diving Speeds:
Long Wing Versions - 340 kts (391 MPH) - 630 KPH
A6M2 Model 21
A6M3 Model 22

Short Wing Versions - 360 kts (414 MPH) - 666 KPH
A6M3 Model 32
A6M5 Model 52

Thicker Wing Skin Versions - 400 kts (460 MPH) - 740 KPH
A6M5 Model 51a
A6M5 Model 51b
A6M5 Model 51c

- Ivan.

corrected now

 

[taly01]

A6M5 Hei .......

A6M5 Hei
Empty Weight: 1970-2150kg
Loaded Weight: 2955-3170kg
Take off: 1210hp
Max Speed: (Military Power)
541km/h at 6000m
Rate of Climb: (Military Power)
Time to 6000m: 7:35-7:58
Armament:
1x 7.7mm Type 97 (700 rounds) < gun was removed (proof is no gas vent port can be seen on pictures).

I spent some time researching "1945" Zeros like A6M5c/A6M7 earlier this year, and found about Sakae 31 it was a Sakae 21 with improvements from Homare engine program (as cylinders were the same just more of them). Sakae 31 used Homare valve timing for a bit more power and without water injection had 1 min emergency whereas the water injection (possibly only ever on trials machines) gave in 10 min emergency power time.

Actual 1945 Zero armour fitted and fuel tank configuration is conflicting in many sources which may explain differing weights and climb times!

 

[Laurelix]

Hello Laurelix,

Your dive speed limitations are a little bit off: Listing from Old Thread

Mitsubishi A6M - Maximum Diving Speeds:
Long Wing Versions - 340 kts (391 MPH) - 630 KPH
A6M2 Model 21
A6M3 Model 22

Short Wing Versions - 360 kts (414 MPH) - 666 KPH
A6M3 Model 32
A6M5 Model 52

Thicker Wing Skin Versions - 400 kts (460 MPH) - 740 KPH
A6M5 Model 51a
A6M5 Model 51b
A6M5 Model 51c

- Ivan.

You know those dive limits? A guy is arguing that they are impossible and that they must be TAS and not IAS.

however if they are TAS it would be stupid low and on the other hand at which altitude would their IAS be stated at?

 

[Ivan1GFP]

You know those dive limits? A guy is arguing that they are impossible and that they must be TAS and not IAS.

however if they are TAS it would be stupid low and on the other hand at which altitude would their IAS be stated at?

Hello Laurelix,

These kind of dive speed limitations are typically stated in IAS.
Altitude really doesn't matter because it is really the dynamic pressure that is important.
Sometimes the limitations are slightly different with differing altitudes but I believe that is usually because of some kind of Mach speed limitations / Compressibility effects such as on the P-38.

Your friend can argue that these numbers are impossible, but if an air service chooses to publish these numbers as a guide for their pilots to use operationally, then they probably were just guesses.
Please also note that when the A6M2 captured in the Aleutians was tested against US fighters, the Japanese were not kind enough to provide a manual and it was actually pushed beyond some of these limitations and did not fall apart.

- Ivan.

 

[Laurelix]

Hello Laurelix,

These kind of dive speed limitations are typically stated in IAS.
Altitude really doesn't matter because it is really the dynamic pressure that is important.
Sometimes the limitations are slightly different with differing altitudes but I believe that is usually because of some kind of Mach speed limitations / Compressibility effects such as on the P-38.

Your friend can argue that these numbers are impossible, but if an air service chooses to publish these numbers as a guide for their pilots to use operationally, then they probably were just guesses.
Please also note that when the A6M2 captured in the Aleutians was tested against US fighters, the Japanese were not kind enough to provide a manual and it was actually pushed beyond some of these limitations and did not fall apart.

- Ivan.

As I learnt it does change over altitude.

This is P-51D max speed limitation

compared to SL and 20,000ft, the IAS limitation has 120mph difference

 

[Ivan1GFP]

Hello Laurelix,

Please read the last sentence of my first paragraph. Speed limitations may differ with differing altitude because of Mach speed limitations / Compressibility Effects. Without knowing what those were for the A6M series, all we have to go on is the stated IAS limits in the manuals.
One also needs to know what happens if those Compressibility speeds are exceeded. With the P-38 and P-47 and Typhoon, it is a loss of control and ability to recover from the dive until the aircraft reaches denser air at low altitudes. It may be uncomfortable riding a lead sled, but those aircraft were not known for falling apart after entering Compressibility.

- Ivan.

 

[DarrenW]

I agree with Ivan that it is indicated air speed. My guess would be that the maximum dive speed you stated would be below 10,000 feet (in line with many airspeed limitation charts I've seen). The chance of entering compressibility increases as altitude increases but so does position error, which steadily increases the higher you go (at sea level IAS =TAS). Both of these are discussed in the chart you provided. Below 10,000 feet there is less chance of compressibilty, and less instrument error as well. These charts help a pilot realize a safe dive speed for recovery purposes but also protects the airframe from undue strain.

Do you happen to have an airspeed indicator correction table for the Zero? Without figuring this error in, 460 mph indicated at 15,000 feet would be even faster than the safe diving speed for a P-47D (the pilot manual shows a maximum of 450 mph at this altitude). I cannot see a Zero of any type being rated with a higher safe diving speed than a Thunderbolt or Mustang at any altutude, can you? If it were then the designers were definitely asking for trouble. I think the boys at Mitsubishi were smarter than that.

In conclusion, I believe that all manufactures were cautious in regards to airspeed limitations and were conservative in their estimations, the allied nations probably even more so. On paper the thick-skinned Zeroes were only about 20-40 mph slower in a dive, but in reality the difference was probably much greater.This would explain why it was never difficult for allied pilots to engage or break-off combat using high speed diving tactics even against these heavier built late-war Zeroes.