WesWorld

First, a front-line fighter from Polikarpov. Though similar in size to the I-34, it is substantially redesigned, using an inline engine. Due to its mission, it is designed to operate from austere bases.

Polikarpov I-37 all-metal monoplane fighter with enclosed cockpit and retractable landing gear
Wingspan - 8.8m; Length - 7.3m; Height - 3.0m; Wing Area - 14.4m2
Crew - 1; Engines - 1x 1,000HP Klimov in-line engine; Empty weight - 1,580kg; Maximum weight - 1,815kg
Armament - 2x 7.62mm ShTAS, 1 20mm ShVAK
Top speed - 360kts; Maximum altitude - 13,500m;
Maximum range - 470nm
Combat radius - 180nm

Revised to incorporate discussion below.



Il-2 all-metal monoplane torpedo bomber with retractable landing gear
Length - 9.10m; Wingspan - 11.6m; Height - 4.0m; Wing Area - 38.6m2
Crew - 2; Engines - 1x 1,300HP Mikulin M-35 in-line engine;
Empty weight - 4,145kg; Maximum weight - 6,125kg
Armament - 1x 14mm MG in spinner, 1x 14mm MG dorsal
Top speed - 220kts; Maximum altitude - 8,500m;
Maximum range - 1,100nm
Combat radius - 400nm

An important feature is that the crew and engine have the protection of a 12mm armored bathtub, protecting them from shrapnel and most machinegun fire.

What's the I-37 look like? Anything I'd recognize?

That should give an idea.

It's light, so producing large numbers of 'em won't use up too much aluminum.
(I figure the RF produces around 40,000 tons/year, growing to ~55,000 tons/yr by 1939. Soviet production in 1939 was 60,000 tons)

In other words, it looks like the head of a hammer caught mating with an engineer's level. (Or something a bit longer and thinner?)

The I-16 is a distinctive-looking kite. Don't think there's a plane in the world that can be mistaken for it...

Quoted

Originally posted by AdmKuznetsov
That should give an idea.

It's light, so producing large numbers of 'em won't use up too much aluminum.
(I figure the RF produces around 40,000 tons/year, growing to ~55,000 tons/yr by 1939. Soviet production in 1939 was 60,000 tons)

So something like the I-17?

It's EXTREMELY light, given that 1100 hp inlines weighed (generally) around 500-600 kg dry. The historical I-17's were in the same weight range, but had a good deal less range using a less powerful engine.

The stats are rather optimistic, especially with regards to speed.

You can't really shoehorn an inline engine into the I-16 because there is no space and moving the centre of gravity forwards would make it lethal instead of just dangerous to fly.

It's 378kts, not 387.

Fixed

Thats still extremely fast.

Compared to the CR.36 which is very marginal for weight with a lot shaved off, the I-37 is larger and draggier but somehow weighs considerably less and has considerably greater performance. Planebuilder can give some strange results.

With regards to construction - Russia has lots and lots of wood that is cheap and equally good as aluminium for most things.

The Il-2 is like the historical Il-2 but a bit smaller for some reason. 12mm armour around the entire cockpit instead of just the pilot (and it wasn't that thick on the Il-2) would put the weight up considerably.

I'm having a hard time getting the I-17s weight down that low, using the historical Klimov M-105 engine weight of 620 kg, without doing things like not having any weapons, and lowering the "do-not-exceed" speed to 400 kts. If you do that, yes, the weight in Planebuilder looks like what's quoted, but..... there's no armament and you can't dive.

I-37

General Type:
Airplane = 1
Airship = 2
Orbiter = 3
1

Year of First Flight: 1936.5

Description

Carrier or Rough Field
Monoplane with Struts
Conventional Fuselage

Single-engine Front-Line Fighter by Polikarpov

Characteristics:
Weight (maximum) 4,507 lbs
Weight (empty) 3,770 lbs Length 24.5 ft
Wingspan 30 ft
Wing Area 164 sq ft
Sweep 5 degrees
Engines 1
Klimov M-105 in-line Piston 1,100 hp at 16,000 ft
Crew 1
Typical cost $0.026 million in 1938
Total number procured 1000
Performance:
Top Speed 378 kts = 435 mph
at 16,000 ftOperational Ceiling 44,700 ft

Range 700 nm = 806 miles
with 58 lbs payload
61 lbs released at halfway point

Climb 4,315 fpm

Cruise 300 kts = 345 mph
at 37,000 ft

Corner Speed 226 KIAS =
242 kts at 5,000 ft
Mach N/A
Turning Rate 30.0 deg/sec
Radius 1,565 ft



Internal Data:

Intake / Fan Diameter 16.5 ft

Bypass Ratio 196

Engine Weight 1307 lbs
Overall Efficiency 22.75 percent

Structural Factor 1.00

Number of Wings 1.01
Number of Fuselages 1

Limiting Airspeed 470 kts
Wing Ultimate g Load 10.00 g
Wing Taper 0.3
Wing Thickness at Root 1 ft

Tail / Canard Factor 0.37

Number of Nacelles 0
Length 6 ft
Diameter 3 ft
Fullness 0.4

Fuselage Diameter 2.5 ft
Fuselage Fullness 0.3

Pressurized Volume 0 percent
Cargo Decks 0

Cleanness 87 percent
Unstreamlined section 1.33 sq ft

User equipment 413 lbs

I-37

General Type:
Airplane = 1
Airship = 2
Orbiter = 3
1

Year of First Flight: 1936.5

Description

Carrier or Rough Field
Monoplane with Struts
Conventional Fuselage

Single-engine Front-Line Fighter by Polikarpov

Characteristics:
Weight (maximum) 4,507 lbs
Weight (empty) 3,770 lbs Length 24.5 ft
Wingspan 30 ft
Wing Area 164 sq ft
Sweep 5 degrees
Engines 1
Klimov M-105 in-line Piston 1,100 hp at 16,000 ft
Crew 1
Typical cost $0.026 million in 1938
Total number procured 1000
Performance:
Top Speed 378 kts = 435 mph
at 16,000 ft
Operational Ceiling 44,700 ft Range 700 nm = 806 miles
with 58 lbs payload
61 lbs released at halfway point

Climb 4,315 fpm
Cruise 300 kts = 345 mph
at 37,000 ft

Corner Speed 226 KIAS =
242 kts at 5,000 ft
Mach N/A
Turning Rate 30.0 deg/sec
Radius 1,565 ft
Internal Data: Intake / Fan Diameter 16.5 ft
Bypass Ratio 196
Engine Weight 1307 lbs
Overall Efficiency 22.75 percent

Structural Factor 1.00

Number of Wings 1.01
Number of Fuselages 1

Limiting Airspeed 470 kts
Wing Ultimate g Load 10.00 g
Wing Taper 0.3
Wing Thickness at Root 1 ft

Tail / Canard Factor 0.37

Number of Nacelles 0
Length 6 ft
Diameter 3 ft
Fullness 0.4

Fuselage Diameter 2.5 ft
Fuselage Fullness 0.3

Pressurized Volume 0 percent
Cargo Decks 0

Cleanness 87 percent
Unstreamlined section 1.33 sq ft

User equipment 413 lbs

OK, I see 2 problems off the top:

1 - the prop diameter is insane: you've got a propeller that's bigger than a Thunderbolt's on this thing. For a engine in the 1100 hp range, you should be looking at a 8-10 foot prop.


2 - the fuselage diameter's too small. The Klimov itself is bigger than 2.5 feet across, as is the pilot. Most V-12s of this period and size are AT LEAST 3 feet across, and the pilot needs at least that much if not more like 3.5'. Kaiser Kirk was working me over on this front back a bit.


Something else that you can clean up: if it's a monoplane, you don't need the "monoplane with struts" it's showing now. That can be fixed by setting it to have 1 wing, not 1.01.


The armament weight looks a touch low as well (though it might be OK, haven't got Planebuilder on this Linux machine since it doesn't work with OpenOffice), and there's only barely enough payload to carry ammunition for the guns.

The fuselage is tiny as well. You want a couple more feet at least to give some stability. Cleaness is extremely high as well.