How did the I-16 Really Perform in WWII?

[Airborne2001]

With the interest in the I-185 here, I think I can also introduce to this topic Polikarpovs planned further developments.:

The I-187 and I-188. The former was going to use the M-71(F?), and the latter would've used the M-90. They both had an interesting movable ducts, which could've closed itself like with the I-16, but instead would've blended into the cowling and the spinner. An armament of 4x20mm cannons was planned. This shows that, even in the face of everything he went through, Polikarpov wasn't willing to give up on his plans. What truly put the final nail in the coffin of the fighters that began with the I-5 was his passing in 1944.

 

[FulmenTheFinn]

Finland captured quite a few of them, though unlike with the I-153 I am not sure if they were used operationally:

They were not. The Finns operated three I-16s. The rest were not restored to airworthiness. They were as follows:

VH-201 -> VH-21: Captured in the Winter War of 30 November 1939-13 March 1940, this aircraft was apparently a Type 18. However on 30 October 1940 an order was given to restore captured I-16s to their original armament, which was cited as two fuselage MGs (7.62 mm) and two cannons in the wings (20 mm). This would imply a Type 17 or 24. It's possible this was a Type 18 whose armament the Russians had modified. EDIT: Looks like it was a Type 27.

31 December 1940, State Aircraft Factory (VL) hands a/c over to Air Depot
12 March 1941, Air Depot hands a/c over to Squadron 24, a/c flown from VL in Tampere to Sq. 24 at Vesivehmaa Airfield
1 April 1941, flown back to Tampere
15 April 1941, returned to Air Depot
21 April 1941, loaded aboard steamship Ariel, shipped by German military officials to Stettin, Germany, destination Die Erprobungstelle der Luftwaffe, Reshlin.
A/c not returned, phases and final fate in Germany unknown.

Known FAF flight time 3 h 25 min, official FAF flight time 6 h 20 min.

IR-101: Shot down during the battles over Suursaari in late March 1942, this Type 6 or Type 5 aircraft was recovered by the Finns and found to be in airworthy condition.

31 March 1942, flown from Suursaari to Kotka
15 April 1942, flown from Kotka to VL Tampere
23 April 1942, relinquished to Air Depot
29 April 1942, relinquished to VL Kuorevesi
25 July 1942, relinquished to Air Depot 1
31 July 1942, received by Air Depot 1
1 August 1942, relinquished to Sq. 6's 3rd Flight
16 November 1942, relinquished to Sq. 30's 2nd Flight
11 June 1943, relinquished to Air Depot for storing
22 June 1943, received by Air Depot
23 June 1943, relinquished to VL Kuorevesi for repairs
25 June 1943, received by VL
26 June 1943, repairs cancelled by Air Depot Chief Lt. Col. Stenbäck, nonetheless Air Depot made a work order the very same day for inspection and repair of the a/c by VL. Instead of being flown over, the a/c had been disassembled and shipped by rail due to overheating of the engine. The work order had an urgency rating of 3.
2 July 1943, a/c ordered to be stored, repairs halted the same day
17 September 1943, FAF HQ orders a/c to be struck
22 September 1943, relinquished as scrap to Air Depot 2
23 September 1943, a/c recommended to be struck
2 November 1943, a/c struck

Known FAF flight time 6 h 50 min, official FAF flight time 6 h 35 min.

VH-22 -> UT-1: This two-seater I-16UTI based on the I-16 Type 10 EDIT: I-16 Type 15 UTI-4 was captured near the Svir in September 1941.

6-7 September 1941, evacuated from Troitsankontu Airfield by Field Air Depot 4
17 October 1941, relinquished to Air Depot
27 October 1941, relinquished to VL Tampere
30 October 1941, received by VL Tampere
31 March 1942, relinquished to Air Depot 1 after repairs
1 April 1942, received by Air Depot 1
10 April 1942, relinquished to Sq. 48
10 August 1942, relinquished to Replacement Sq. 35
11 September 1942, relinquished to Air Force scrap storage in Parola, a/c flew from Vesivehmaa Airfield to Parola at 10:30-11:15 am
16 July 1944, recommended struck due to poor general condition
9 August 1944, struck
15 December 1944, relinquished by Air Depot to Air Combat School

Known FAF flight time 39 h 50 min, official FAF flight time 43 h 25 min.

Source: Atso Haapanen (2008): Punatähdestä hakaristiin [From the Red Star to the Swastika].

EDIT: Corrected a/c types. See the posts below this one.

 

[bf109xxl]

VH-201 -> VH-21: Captured in the Winter War of 30 November 1939-13 March 1940, this aircraft was apparently a Type 18. However on 30 October 1940 an order was given to restore captured I-16s to their original armament, which was cited as two fuselage MGs (7.62 mm) and two cannons in the wings (20 mm). This would imply a Type 17 or 24. It's possible this was a Type 18 whose armament the Russians had modified.

Most likely, this is an I-16 type 27 - a modification of the I-16 type 17 with an M-62 engine, structurally similar to the I-16 type 18. About 60 of them were produced.

IR-101: Shot down during the battles over Suursaari in late March 1942, this Type 6 or Type 5 aircraft was recovered by the Finns and found to be in airworthy condition.

The I-16 Type 6 is a training aircraft with an M-22 engine, 20 of them were produced in 1934-1935. It cannot be confused with the I-16 type 5. I assume that a regular I-16 Type 5 was shot down.

VH-22 -> UT-1: This two-seater I-16UTI based on the I-16 Type 10 was captured near the Svir in September 1941.

Most likely, a conventional UTI-4 (type 15).

 

[FulmenTheFinn]

Most likely, this is an I-16 type 27 - a modification of the I-16 type 17 with an M-62 engine, structurally similar to the I-16 type 18. About 60 of them were produced.

Perhaps, though Haapanen excluded the possibility of it being of another series than the already mentioned 17, 24 or modified 18. He based this on the time period the aircraft was captured in, which I'm not sure makes sense as the Type 27 appears to also have seen action in the Winter War.

This website does call it a Type 27, and also mentions that the wing cannons were replaced with machine guns, something Haapanen does not mention specifically (perhaps they were at some point, hence the order to restore the original armament?).

Worth pointing out is that according to the Russian Wikipedia page on the I-16, the Type 17 existed in both M-25V and M-62 configurations, so the engine alone does not rule out the possibility of it being a Type 17.

The engine was an M-62 series A-7, number 725. Maybe that will give some clues?

EDIT: Saw your edits now regarding the other two I-16s. Will have to respond to those later.

 

[bf109xxl]

Perhaps, though Haapanen excluded the possibility of it being of another series than the already mentioned 17, 24 or modified 18. He based this on the time period the aircraft was captured in, which I'm not sure makes sense as the Type 27 appears to also have seen action in the Winter War.

This website does call it a Type 27, and also mentions that the wing cannons were replaced with machine guns, something Haapanen does not mention specifically (perhaps they were at some point, hence the order to restore the original armament?).

Worth pointing out is that according to the Russian Wikipedia page on the I-16, the Type 17 existed in both M-25V and M-62 configurations, so the engine alone does not rule out the possibility of it being a Type 17.

The engine was an M-62 series A-7, number 725. Maybe that will give some clues?

I looked at Maslov's book, which contains photos and descriptions of this aircraft. Maslov writes that this is a Type 27 with its weapons removed - Browning guns were installed instead later. Maslov points to the large windows for ejecting ammunition links on the underside of the wings, which allows the aircraft to be clearly identified as a Type 27.

EDIT: Saw your edits now regarding the other two I-16s. Will have to respond to those later.

As for the other two aircraft, the data provided by Maslov fully corresponds to my assumptions: they were an I-16 Type 5 with the number "15" from the 11th IAP of the Baltic Fleet Air Arm and an UTI-4.

 

[Steamed_Banana]

Does anyone have a video of a WW2 fighter taking off on skis?

 

[Juha3]

Does anyone have a video of a WW2 fighter taking off on skis?

View: https://www.youtube.com/watch?v=tltS1vH26vs

But only a landing of a Fokker C.X co-op aircraft on skies at 3:15

 

[FulmenTheFinn]

I looked at Maslov's book, which contains photos and descriptions of this aircraft. Maslov writes that this is a Type 27 with its weapons removed - Browning guns were installed instead later. Maslov points to the large windows for ejecting ammunition links on the underside of the wings, which allows the aircraft to be clearly identified as a Type 27.
View attachment 860240

As for the other two aircraft, the data provided by Maslov fully corresponds to my assumptions: they were an I-16 Type 5 with the number "15" from the 11th IAP of the Baltic Fleet Air Arm and an UTI-4.
View attachment 860242

Gotcha, thanks.

Regarding the two-seater, it seems you are correct about that one as well, but what are the indicators that allow us to tell it is a UTI-4?

Kalevi Keskinen, Kari Stenman & Klaus Niska in their 1977 Suomen Ilmavoimien Historia 7 give a brief production history of the I-16 UTI-4 and I-16UTI, but call the captured aircraft an I-16UTI specifically. This is what I was looking at when I made my initial post. Atso Haapanen in his 2008 Punatähdestä hakaristiin does not exactly say which type it was, but quotes a 28 November 1941 letter from Air Depot 1 that mentions that the aircraft is likely a UTI-4. Finally, both Hannu Valtonen in his 2010 Albatrosista Pilatukseen and the Finnish Aviation Museum today, where the aircraft is still stored, call it a Polikarpov I-16 Type 15 (UTI-4).

I'll make the appropriate corrections into the initial post.

 

[bf109xxl]

Gotcha, thanks.

Regarding the two-seater, it seems you are correct about that one as well, but what are the indicators that allow us to tell it is a UTI-4?

1. There is a picture of this aircraft.

2. IIRC, Maslov personally saw this aircraft in Vantanaa, but I can't swear to that - sometimes memory can be unreliable.
3. The UTI-4 is the most common type of I-16; in 1941, it was the main training fighter, and I find it hard to imagine that an exotic aircraft with an M-22 engine was flying in 1941. Therefore, I personally estimate the probability that the two-seater I-16 in 1941 was a UTI-4 at 100%.

 

[Boom]

Does anyone know if the I-16 was ever tested with a 3 blade propeller? And if so, did it improve climb rate or speed?

One would think it should have given the positive experiences of the early Bf 109, Spitfire and Hurricane adaptations.

 

[Shortround6]

I don't know if any were tested but the improvement would only be marginal and may depend on the model of engine fitted.
3 blade props are needed to get the necessary prop blade area to handle higher powered engines.
The 700-800hp M-25 powered planes may not have gotten much benefit from a 3 bladed prop.

At higher altitudes (thinner air) a prop with more blade area offers better performance also.
The M-25 used a single speed supercharger and offered max power at under 3000 meters (?)
The M-62 engines offered 1000hp for take-off but only around 800hp at 4200 meters.
The M-63 offered a bit more, 930hp at 4500 meters.

The Merlin III was offering 1030hp at 4950 meters. It needed more 'bite'.
The 109s with the 700hp (?) Jumo 210s used two bladed props. The 109E with the roughly 1100hp engine got the 3 bladed propellers.

With the 3 different engines and the change over from fixed pitch to two pitch props things get somewhat confusing.
Also the M-25s, many M-62s and some M-63s used direct drive (prop turned the same RPM as the engine).
Not sure if all I-16s used direct drive or not. This may also have affected propeller selection.

 

[bf109xxl]

Does anyone know if the I-16 was ever tested with a 3 blade propeller? And if so, did it improve climb rate or speed?

One would think it should have given the positive experiences of the early Bf 109, Spitfire and Hurricane adaptations.

Actually, the TsKB-12, the very first prototype of the I-16, had a Hamilton Standard three-bladed propeller. After the accident, the propeller was replaced with a two-bladed one, and there was no deterioration in performance. After the replacement of the two-bladed propeller with a three-bladed one on the Dewoitine D.510 yielded virtually no advantages, doubts about the need for a three-bladed propeller only increased. But the I-180 already had a three-bladed propeller, apparently due to the higher engine rpms.

 

[bf109xxl]

Also the M-25s, many M-62s and some M-63s used direct drive (prop turned the same RPM as the engine).
Not sure if all I-16s used direct drive or not. This may also have affected propeller selection.

All mass-produced M-25 and M-63 engines were direct-drive, only the M-62 was mass-produced with a reduction gear (ASH-62IR), but it was not installed on the I-16 as a standard feature.

 

[Shortround6]

All mass-produced M-25 and M-63 engines were direct-drive, only the M-62 was mass-produced with a reduction gear (ASH-62IR), but it was not installed on the I-16 as a standard feature.

Thank you.

But the I-180 already had a three-bladed propeller, apparently due to the higher engine rpms.

The M-87/88 engine (M-88 planned ?) may have required a 3 blade propeller due to the higher power?
RPM may have something to do with it?

 

[bf109xxl]

The M-87/88 engine (M-88 planned ?) may have required a 3 blade propeller due to the higher power?
RPM may have something to do with it?

To efficiently convert power into thrust, you need the right total blade area, which for a more powerful engine can be achieved by increasing the blade radius, increasing the blade width, or increasing the number of blades. The propeller radius is limited by the height of the landing gear struts - they cannot be made too high for many reasons. The aerodynamics of wide blades had not been sufficiently studied, so the latter option (more blades) was the simplest at the time - to a certain extent.
In addition, a large propeller radius can cause undesirable effects, as the blade tips begin to move at a speed close to the speed of sound, so the propeller must match both the power and the output shaft speed. The greater the number of blades, the greater the interference effects, so installing a three-bladed propeller is not always justified.
There was no real need for the I-16 to use a three-bladed propeller.

One of the reasons why Yakovlev was unsuccessful with the M-82 was precisely the need to increase the height of the landing gear struts, which led to the need to make too many changes to the design, which in turn would have led to a significant reduction in production volumes, which was unacceptable in wartime conditions.

 

[YavorD]

Thank you.

The M-87/88 engine (M-88 planned ?) may have required a 3 blade propeller due to the higher power?
RPM may have something to do with it?

Almost entire series of M-85/86/87/88, descending from the Gnome et Rhône 14 K, were produced as geared engines. Naturally, a 3-blade propeller with a reduced diameter was a better fit for an aircraft the size of I-16 and I-153 with a geared engine, e.g. I-180.
On the contrary, the only geared version of the M-62/63 family, the M-62IR, provided a gear ratio suitable for aircraft like DC-3 and Antonov-2. With a direct drive M-62/63 engine the I-16 was not able to do better than 470 km/h in level flight because propeller tip speed was exceeding Mach 1.1 and the propeller efficiency was low. The same applied for the P.Z.L. 24 and Loire 46 with a direct-drive Gnome et Rhône 14 K. The Brewster F2A-1 was re-designed into F2A-2/3 with a geared engine for the same reason.

 

[bf109xxl]

Almost entire series of M-85/86/87/88, descending from the Gnome et Rhône 14 K, were produced as geared engines. Naturally, a 3-blade propeller with a reduced diameter was a better fit for an aircraft the size of I-16 and I-153 with a geared engine, e.g. I-180.

The I-180 was designed for installation of a geared version of the M-88, but was tested only with direct drive engines.

On the contrary, the only geared version of the M-62/63 family, the M-62IR, provided a gear ratio suitable for aircraft like DC-3 and Antonov-2. With a direct drive M-62/63 engine the I-16 was not able to do better than 470 km/h in level flight because propeller tip speed was exceeding Mach 1.1 and the propeller efficiency was low.

The main reason for the lack of speed was the unsuccessful engine cowling. The I-16 Type 24 with plywood wing skin reached a speed of 489 km/h.

 

[YavorD]

The main reason for the lack of speed was the unsuccessful engine cowling. The I-16 Type 24 with plywood wing skin reached a speed of 489 km/h.

Improved engine cowl, wing skin, as well as enclosed cockpit can provide another 15 ... 20 km/h in maximum speed, and 500 meter increase in ceiling, but hardly more.
For a fighter aircraft of 1940 one may need to look for a geared engine with a two-speed supercharger.
For 1942, the bar is raised to a two-stage supercharger with an intercooler, and a careful design of the airflow around air-cooled engine cylinders ...

 

[YavorD]

...
Source:
View attachment 857974
It is clear that the low technological level of production did not allow for any improvements to be implemented. It is also worth noting the factory's lack of interest in manufacturing prototypes.

Just as a side note - I have a different edition of the same book.

Михаил Александрович Маслов (2007)
Истребитель И-16 : Норовистый "ишак" сталинских соколов
Коллекция, Яуза, ЭКСМО, Москва, 2007, твердый переплет, 192 стр. илл. Тираж: 3000 экз.
ISBN 9785699256600

 

[bf109xxl]

Improved engine cowl, wing skin, as well as enclosed cockpit can provide another 15 ... 20 km/h in maximum speed, and 500 meter increase in ceiling, but hardly more.

Why? Could you provide your calculations?

For a fighter aircraft of 1940 one may need to look for a geared engine with a two-speed supercharger.

Polikarpov did not need a geared M-88, or more precisely, the M-88 with the reduction gearbox used in the mass-produced version. It required a propeller with a diameter of more than three meters, and Polikarpov considered 2.9 m to be the maximum, which required a different gearbox. But even the gearless version with a three-bladed propeller met the requirements. Both the M-62 and M-63 had a two-speed supercharger.

For 1942, the bar is raised to a two-stage supercharger with an intercooler, and a careful design of the airflow around air-cooled engine cylinders ...

For the realities of the Eastern Front, a two-stage supercharger was neither a primary nor even a secondary necessity.