Yakovlev Yak-3 for Fighter Squadron: SDOE

Version : 3.9

In the months since I started this project, I've discovered a great appreciation for Soviet aircraft designs.. despite being low cost and easy to produce they had brilliant designs that performed well. Definitely a case of doing a lot with a little!

The Yak-3 was one of the lightest, smallest fighters of the war. It has poor performance above 15,000 feet but is very fast and manouverable at low altitude. The wooden construction meant it was not quite as durable as the Yak-9.

I could easily spend years on just this one aircraft.. but it's reached a point where it is 'good nuff' for everyone to have fun with. I hope you have as much fun flying it as I did building it !

Requirements & Installation
The Yak-3 requires:

-the latest plane pack from http://tailslide.firelight.dynip.com
-the 'Nations' addon from http://members.xoom.com/fs_catp/

Add these lines to your FighterSquadron\media\startup.ppf file or use the startup.ppf included in the zip:

To install the Yak, unzip the yak3v27.zip file into your fighter squadron directory. To try out the plane, you can fly it from the hangar or training missions section.

Alternate Propeller

I've included Pachy's texture mapped propeller in a file names "onesidedprop.sm"
If you want to use it, just rename it to prop.sm and you are set.
If anyone gets the urge to build a two sided textured prop.sm file please it my way :o)

Pilot's Manual

Included in this directory is a (poorly) transated copy of the Yak-3 pilot's manual you can view in your web browser by clicking on "yak3manual.htm"

I'd like to thank all the people who helped make this plane possible.. Zoycite for the wonderful skin and reference files, JT for putting up with all my stupid Max questions, Spanky for the fantastic cutaway views, and the OPP crew for helping me test. Laika for background info and pictures of the yak, and for his amazing I-16 and R82 rockets. Pachy for the cool prop and spinner. Big thanks to Yevgeny 'Ivan the Bear' Ozhogin for the recording the russian radio calls. Of course none of this would be possible at all without Bryan's fantastic OPStudio. This plane was completely assembled with his software.

Change History

Version 3.9:
-switched to hires skin
-switched to hires canopy reflections, updated them to look better
-Fixed flickering seat
-Fixed texture crawl on cockpit walls
-Fixed canopy glitch at front right
-Rounded canopy frame more in inside view
-Fixed disappearing polygon in right side of tail

Version 3.8:
-used new properties in patched version of SDOE to reduce engine performance above 14,500 feet
-ceiling calibrated to 34,000 feet

Version 3.7:
-added bullet hole DM to wings

Version 3.6:
-horizontal stabs children of vertical stab, changed to be children of tail
-damage LOD for horizontal stabs positioned

Version 3.5:
-canopy frame fixed up a LOT, some poly optimization in frame too

Version 3.4:
-bjorn calculated fixed up DOF angles so I added those.. thanks Bjorn!

Version 3.3:
-found real airK values for wings, entered them (website, no source)
-positioned airPTs for all surfaces at middle of section span and 1/4 from leading edge
-after these changes plane became too stable so shifted CG back and altered airfoil. Can drop wing on landing like the real thing now.
-redid shadow with trasparent version looks nicer

Version 3.2:
-more cleanup of unused textures
-added real shadow with transparency
-reviewed and updated all texture flags for LOT, etc.
-redid the simple version of canopy from latest detailed canopy

Version 3.1:
-more LOD work, is more FPS friendly, more visible at distances, and better looking at distances or with object detail slider turned down.

Version 3.0:
-got shadow working (sort of)
-reduced drag on gear, landings easier now
-set AI landing and Va speed to the AI flies and lands really great now
-more improvements to far away LODs, looks bearable with object detail slider all the way down
-LOTS of goodies added to cockpit, I won't spoil the fun but keep your eyes on the dash
-simple and fancy canopy files created

Version 2.9:
-lots of cockpit upgrades
-GUNROF keyword was missing from loadout, caused machine guns to DO NO DAMAGE ! fixed
-removed all unnecessary texture references
Version 2.8:
-lots of cockpit upgrades
-replaced gear, lined it up
-improved far away LODs, fixed some of them displaying funny
-lowered RPM on prop, at certain rpm speeds openplane draws prop blur sideways (!)
Version 2.7:
-previous version had wrong loadout file so new rockets didnt show up, fixed
Version 2.6:
-updated with Zoy's new skin to match updated gear
-included original two-sided prop as well as Pachy's

Version 2.5:
-calibrated for climb and speed at altitude up to 15,000 feet
-PROBLEM: can't get speed to decline above 15k feet no matter what I try.

Version 2.4:
-measured area ratio of tip section to root section, used that to reassign airArea values
-made rudder and elevator stallable
-oops just checked OP doc, AR is for ENTIRE wing, changing it back to 5.7

Version 2.3:
- adjusted airadvantage to make the plane less touchy at high speeds and to reduce roll rate
- measured chord lengths in max for each wing section, applied values
- decreased AR of main section from 5.7 to 5.0 and increased on tip from 5.7 to 6.4
I know the average AR is 5.7 but I don't know it for each section. This should
bring it a little closer.

Version 2.2:
- seperated out canopy and tub into canopy.sm file

Version 2.1:
- added landing gear model
- fixed gear bay in wing
- seperated out prop into seperate prop.sm file

Version 2:

- added Pachy's MUCH improved yak spinner/propeller. THANKS PACHY! This one has the texture mapping fixed on the spinning and the "prop blur" on the front side only. The side of the prop facing the pilot is now invisible. I hope this is a good compromise between people who want to take pretty screen shots and those of us driven insane by the flashing prop graphic :o)

- added a new level of detail on cockpit frame interior that smooths the curve around the frame. Doesnt seem to impact frame rate at all.

- Added Laika's russian R82 rockets (THANKS LAIKA!)

- updated damage model now that obprob is fixed under opstudio. Borrowed/stole heavily from Laika's brilliant I-16 DM

- gave the Yak it's own airfoil which is just a copy of the FW190 airfoil for the time being. I tried the clarkyh airfoil from the i-16 (the yak also uses the clarkyh airfoil) but I couldn't get the yak to drop a wing at all with it so am stuck with the 190 foil for the time being.


Yakolev Yak-3
WingSpan: 30'3
Length : 27'11
Height: 9'10
Wing Area: 160 sq ft
Engine: Klimov VK-105PF-2 inline rated at 1290 hp

Loaded weight: 5,864lb
Wing Loading: 37 lb/ sq. ft
Maximum Speed: 407mph
Service Ceiling: 35,430ft
Rate of climb: 4.5 min to 16,400 feet
Range: 415 miles
Armament: 1 x 20mm ShVAK 2 x 12.7mm UBS

The Yak-3 was the last and most attractive member of the Yakovlev fighter family of the Second World War. Development of this fighter, which benefited from experience gained during the first two years of war, produced an essentially new aircraft. It represented the culmination of a considerable amount of work carried by the Yakovlev OKB, production plants and research organisations seeking to improve the aerodynamic characteristics, structure and combat performance of fighter aircraft, and embodied all changes incorporated in the earlier Yak-l, Yak-7 and Yak-9. When it reached the tactical regiments in the summer of 1944 the Yak-3 fitted with the VK-105PF was the lightest and most manoeuvrable of all fighters on both sides. By comparison with its brother, the Yak-9 , with VK-107A, the Yak-3 was marginally inferior in performance but had a better powerplant providing more reliable operation and greater capability. The Yak-3 VK-108 prototype reached 462mph (745km/h), the highest speed ever attained by a Soviet piston-engined aircraft and close to the pre-jet era limit.

The Yak-3's immediate predecessor was Yak-1M prototype, nicknamed 'Moskit'. Its wing was of similar construction to that of the Yak-9, comprising a set of metal stringers, metal and wooden ribs, and plywood skin- .' Compared with its predecessors, the wing area of the Yak-3 was reduced by 24.7ft' ( 2,3m') to 159.8ft' (14.85m'), and its span was reduced to 30ft 2in (9.2m). The outer wing panel attachments allowed a damaged unit to be replaced under field conditions. The fighter's control system, fuselage and undercarriage were taken from the production Yak-1. Unlike that machine, however, the Yak-3 had three fuel tanks with a total capacity of 595lb (270kg); two in the outer wing panels and a feeder tank in the wing centre section. The engine cooling system had a more powerful ventral coolant radiator with deeper accommodation in the fuselage. Two circular oil radiators arranged in parallel were installed in the wing centre section, beneath the cockpit floor, allowing the engine to have a smooth lower cowling and improving the aircraft's lines.

Armament, instrumentation and armour were nearly the same as those of the Yak-1 with improved pilot view, armour and armament. The Yak-1M's loaded weight was 5,853lb (2,655kg), roughly 551lb (250kg) less than a production Yak-1. This weight saving was achieved mainly by the reduction in wing area and substituting wooden longerons for duralumin ones (330lb -150kg). The prototype was completed in the middle of February 1943. Its refinement continued for the whole of the spring under the direction of chief engineer M Grigorev, who played an active role in the development and construction of the Yak-1M. The initial test flight was performed by Pavel Fedrovi, the chief pilot of the Yakovlev Design Bureau. Flight trials at the NII VVS continued for the whole of June 1943, with A Proshakov as senior pilot and A Stepanets as chief engineer. The aircraft displayed excellent performance, The design bureau believed that the potential of the aircraft was not exhausted. On Yakovlev's insistence additional tests were performed to evaluate the changes resulting from augmenting the boost of the M-105PF engine from 1,050 to 1,100mm Hg. Initially Vladimir Klimov, the chief designer of the engine, increased the boost in the first stage of the turbosupercharger. The additional tests revealed that the boost augmentation increased maximum speed by 3.7 to 4.3mph (6 to 7km/h) at low altitudes, reduced the time to reach 16,400ft (5,000m) by 0.1 minute, increased the altitude increment in a 360' turn by 164ft (50m), improved take-off performance and had no noticeable effect on water and oil temperatures. Later the supercharger's second stage was also augmented. The engine with its super- charging increased to 1,100mm Hg was designated M-105PF-2. Because of its excellent flying and combat capabilities the Yak-1M was among the best fighters at the end of Second World War. According to NII VVS test results it excelled the production Yak-9 in maximum speed by at least 15.5 to 21.7mph (25 to 35km/h) over the whole altitude range, the German Fw190A-4 at altitudes up to 27,250ft (8,300m) and the Bfl09G-2 at altitudes up to 18,700ft (5,700m). The Yak-1M displayed extraordinary superiority at low altitude, while at higher altitudes the German aircraft had the edge. At 23,000ft (7,000m), for instance, the Bf109G-2 was nearly 31mph (50km/h) faster than the Soviet fighter.

In climb rate up to 16,400ft (5,000m),' the Yak-1M was unrivalled among the worlds fighters, including various Bf109 sub-types. The reduction in wing area did not adversely affect the aircraft's take-off, diving and spinning qualities. Due to good handling qualities the Yak-1 M, like the Yak-1 and Yak-9, could be flown by pilots of average or lower abilities. The trial report noted: 'as far as control effectiveness and tractability are concerned (with regard to the effort exerted on control levers), the Yak-1M, like the Spitfire [which had been tested in the NII VVS in June 1943], is a model for any fighter either domestic or foreign'. Insignificant deficiencies typical of Yak fighters, such as oil overheating at the optimum climb rate, poor venting, oil leakages, and limited radio transmission range, did not mar the overall impression. ' In parallel with the state trials of the first Yak-l M, work on the second prototype was completed under the direction of Grigorev.

Construction of this aircraft was better in every respect. For example: fuel tank compartments were separated from the cockpit by hermetically sealed partitions; fabric skinning was replaced by plywood and the canopy was jettisonable. A VISh-105SV-01 propeller with a lightweight hub and profiled blade root section was used. Changes were introduced in the armament as well. The ShVAK cannon gave way to the ShA-20M experimental cannon designed by Boris Shpitalny, and a pair of 12.7mm Berezin UBS machine guns were installed using the same arrangement as in the Yak-7B. The navigation equipment was improved. Among the appreciated innovations was a remote radio control using a button on the throttle lever. The aerial mast was rejected on the second prototype in favour of a single beam antenna.

The take-off weight was kept the same at 5,864lb (2,660kg). After brief development tests the Yak-1M was moved to the NII VVS at the beginning of October 1943 for its state trials. These were successfully completed in ten days by pilot A Proshakov and engineer G Sedov. In addition to its enhanced performance (the second prototype reached 354 mph 570km/h at sea level and 404mph 651km/h at 14,100ft 4,300m, and completed a 360' turn at low altitude in only 16 to 17 seconds), an improvement in engine temperatures had been achieved by a more effective radiator bath
installation, modification of the intake duct profiles, and increasing the angle of air-duct flap deflection.

The Yak-1M became the first Yakovlev fighter capable of performing long duration level flight at maximum speed, as well as Climbing at the maximum climb rate with an engine operating at nominal revolutions of 2,700rpm. Thorough wiring and screening increased the radio reception range to 56 miles (90km), a noteworthy achievement for Soviet fighters of the time.

Test pilot V Khomyakov, who made the initial flight tests of the aircraft, wrote: 'The cockpit is comfortable. The forward vision is improved. The disposition of the instrumentation and control levers is suitable and almost completely meets the standard cockpit requirement. Handling is tractable: the aircraft is stable in flight and easy to handle. It has excellent climb rate and manoeuvrability in both the vertical and horizontal planes. By comparison with its predecessor the Yak-1M's performance has been markedly improved'. This report and others triggered a Government directive to launch production of the Yak-1M in its second prototype form under the designation Yak-3 in October 1943.
Preparations for Yak-3 production started immediately, but the production tempo could not be allowed to falter during conversion to the new aircraft. So Plant No.292 mastered the manufacture of the fighter in the winter of 1944 while maintaining its average monthly output of 250 Yak-1s. First production Yak-3 was rolled out on 1st March 1944.

Production aircraft differed from the second prototype in numerous but minor ways. Initial production Yak-3s had exactly the same armament as the Yak-l, as production of the ShA-20M cannon had not yet begun. Because of low manufacturing standards, production Yak-3s had poorer flight performance than the second prototype. The loss of speed was about 9.3 to 12.4mph (15 to 20 km/h), and time to attain an altitude of 16,400ft (5,000m) increased by 0.5 minute. Increased loads on the control surfaces had an adverse effect on horizontal manoeuvrability.
The new warplanes began to reach fighter aviation regiments during the summer of 1944, when the Soviet Command was preparing to launch large scale offensives. Yak-3 service tests were conducted by the 91st Fighter Regiment of the 2nd Air Army, commanded by Lt Colonel Kovalev, in June-July 1944. The regiment was tasked with gaining supremacy in sky. In the course of the L'vov operation almost half of its pilots flew their first combat mission, and all of the regiment's Pilots had begun a higher standard of training. During the service tests 431 missions were flown, including interception, on-call missions, missions for building up forces, and freelance operations. Twenty Luftwaffe fighters and three Junkers Ju87 bombers were shot down in air combats, while Soviet losses numbered two Yak-3s shot down, plus three that were damaged by German anti-aircraft defence but managed to reach Soviet-held territory.

Operations showed that the innovative Soviet fighter could catch its German counterparts in horizontal flight as well as in climbing and diving manoeuvres. The Yak3 gained a substantial advantage over the Fw190A within two nose-to-tail turns, and over the Bf109G within three turns.
A large dogfight occurred on 16th June 1944. Both sides built up their forces, with the result that 18 Yak-3s opposed 24 German fighters, and 15 Luftwaffe aircraft were shot down for the cost of one Soviet fighter destroyed and one damaged. Next day, Luftwaffe activity over that section of the front had virtually ceased. Service tests indicated that the Yak-3 appeared to be most suitable for air defence missions. Its use for close support of ground troops, bomber escort and so on was less worthwhile owing to its limited supply of fuel, average mission duration being limited about 40 minutes. The tests also revealed certain short-comings of the initial production Yak-3.

Instances were pointed out when a main undercarriage leg folded during take-off or landing and taxying, owing to failure of the undercarriage ram and oleo strut attachment. However, in general the Yak-3 was easy to operate, and maintenance crews and pilots found it easy to adapt to the new aircraft. Assessing the fighter, Lieutenant General Walter Schwabedissen wrote in the book "The Russian Air Force in the Eyes of German Commanders": 'Whereas the German Bf109G and Fw190 models were equal to any of the aforementioned Soviet fighter models in all respects, this cannot be said of the Soviet Yak-3, which made its first appearance at the front in the late Summer of 1944. This aeroplane was faster, more manoeuvrable and had better climbing capabilities than the Bf109G and Fw190, to which it was inferior only in armament'. Luftwaffe fighters in combat with the Yak-3 tried to exploit surprise. This happened on 17th September 1944, when Fw190s attacked a formation of three Yak-3s of the 66th Fighter Air Regiment over the Riga district of the front by coming out of the sun, shooting down two of the Soviet aircraft. On 23rd September the regiment gained its revenge when a Yak-3 formation led by Major I Vitkovsky shot down seven Fw190s in a single dogfight. During the autumn a set of modifications was introduced in Yak-3 construction. Starting from the 13th batch, the second 12.7mm UBS machine gun was reinstated, since such armament appeared to be more suited to the needs of service units. Starting from the 16th batch the capacity of the fuel tanks was increased by about 4.4 gallons (20 litres). Initially there was lack of close control of the loaded weight of production Yak-3s, which reached 5,974lb (2,710kg). From August 1944 to April 1945 the weight ranged between 5,795 and 5,934lb (2,629 and 2,692kg), these limits being regarded as satisfactory. To discover the reasons behind the deterioration in performance, an investigative study was undertaken by the Yakovlev Design Bureau in co-operation with the LII, TsAGI and the production plants. As result the performance level was restored in October 1944. This work was conducted in parallel with an escalation of production. While the Yak-3's share of the total output of the Saratov aircraft plant in May 1944 was 29%, in June it comprised 52%, in July it was 84% and in August it had already reached 100%. Thus the production line's conversion to the new fighter had proceeded without any reduction in overall output.

Plant No.31 in Tbilisi mastered the Yak-3 even more successfully. The fighters manufactured there were of higher quality and had more powerful armament than those made in Saratov. But most important was the weakening of the wing caused by unsatisfactory bonding of the wing skin with the structure. For this reason more than 800 Yak-3s built at Plant No.292 at the end of 1944 were withdrawn from operations at the order of A Novikov, Commander-in-Chief of the Red Army Air Force, and sent for repair. Fighters from one of Plant No.31's first batches were flown operationally and with success by the 303rd Fighter Division, commanded by Major-General Georgy Zakharov. The Division incorporated the French Normandy volunteer regiment. The Normandie-Niemen converted rapidly to the Yak-3, and shot down 29 Luftwaffe aircraft without any losses to themselves on 16th October 1944. M Alber, R De LaPuap, J Andrew and M Lefevre, pilots and commanders of the Normandy Regiment, were made Heroes of the Soviet Union. After the war's end the regiment departed for France with 40 Yak-3s that had been presented to it. These served in the regiment and then in French training schools until 1956, without an accident. One example has survived and is displayed in the Musee de 1'Air near Paris. In Russia, a single Yak-3 is preserved in the Yakovlev Design Bureau Museum. This aircraft was presented to Major Boris Yeremin by Ferapont Golovaty, a collective farmer. In total, 4,848 Yak-3s were produced, of which 3,840 were built at the Saratov main plant and 737 were delivered after the war.

"...The Yak-3 had three fuel tanks with a total capacity of 595lb (270kg); two in the outer wing panels and a feeder tank in the in the wing centre section...Armament, instrumentation and armour were nearly the same as those of the Yak-1 with improved pilot view, armour and armament...fuel tank compartments were seperated from the cockpit by hermetically sealed partitions...the ShVAK cannon gave way to the ShA-20M (initial production Yak-3s had exactly the same armament as the Yak-1, as production of the ShA-20M cannon had not yet begun) experimental cannon designed by Boris Shpitalny, and a pair of 12.7mm...operational range 528 miles (1943) / 658 miles (1944)...turn time 18-19 seconds..."


"Soviet Combat Aircraft of the Second World War"
Volume One: Single-Enginde Fighters
Yefim Gordon and Dmitri Khazanov
Midland Publishing (midlandbooks@compuserve.com - ?not tested yet?)
ISBN 1 85780 083 4

Armament: One 20mm ShVAK cannon
and two 12.7mm BS machine guns.
The early versions only had the 20mm and 1 12.7mm gun.

Rate of fire:

The Shvak cannon mounted in the prop cylinder carried
120 rounds, while the Berezin MG's carried 250 rounds.
The ROF for both was 13 rps. With a total muzzle load of 703 kw.(not sure what this is for)

Bomb: One 227 kg (500 lb)
and two 45 kg (100 lb) bombs