The Design of the MiG 15   - an engineering commentary          Prof. Prodyut Das

22 February 2026

Should he set his mind to do so, enough information exists on the internet for an engineer to be able to design and build a fair working replica of the MiG 15. The design flew about 80 years ago and is not even transonic so is a study of it at all relevant today? Surprisingly, yes!  Aircraft design is a “curry” of analysis blended with information, knowledge and wisdom. The analysis (stress, aerodynamics) figures are case specific to the type, the knowledge, methodology and wisdom is mutable and long lasting - particularly as markers, standards, signposts and cautions in the march to a new design. I will not spoil by suggesting (and sparking outrage) that given the advent of AAM +AI the transonic regimen of the MiG 15 is an area we may be forced to re-investigate,

Enter the Sabre

Any discussion on the MiG 15 brings in the North American F 86 Sabre, an all-time great. Between the first flight in 1949 until the arrival of the Mk 6 Hunter in 1956 the Sabre was quite possibly the world’s best fighter- and in my view the last US Fighter designed as a fighter and not as a piece of merchandise. It was utterly modern with all the mod. cons., with an axial engine and   transonic performance; it’s handling at low speeds often trapped the unwary opponent; even the superior Hunter had to deal with it with skill and respect. Its high mounted cockpit canopy, reflecting wartime experience with the Mustang, was the last word in visibility and possibly a model even to this day. Comprehensively equipped with a ranging radar, its side mounted six-gun deployed in a twin flak vierling pattern gave it the maximum area of lethal density, immensely strong structurally, it could go “through the barrier” in a shallow dive and yet it had faultless controls, the PAF pilots of that era claimed that they could maintain full control at speeds as low as 90 knots in a descending scissors maneuver.    

It is paradoxical that praising the Sabre’s is flattering the MiG 15. The Sabre was after all a Meisterstuck by a Gildemeister- Ed Schumed was the Chief Designer of the legendary Mustang. The Sabre was also the product of an Industry whose facilities had not only been unharmed by war but also had prospered in every way along with access to captured German Research data and prototypes. It had to be superlative!

Russian fighters, whose designers thought differently but perhaps more profoundly, were often nose wrinkling derided. Take the case of armament. The typical Russian Istribityel (Interceptor) carried half the guns of an opposing FW 190 or Me 109. On paper that was “bad”. In reality Airforce pilots of both sides were raw recruits who opened fire from ranges too great to be effective doing little except to warn a hitherto unwary target. The greater number of guns meant reduced performance from excess weight and drag besides wastage of ammunition. So, was fewer guns “bad”? You see the difficulty in hasty “more is better” assessments? Sometime less is “better”. Read Taguchi!

The “brilliance” of the MiG 15 was in it’s tautology in engineering. It did much with little.  It was an effective “challenger” from Russia much of whose Industry had been destroyed to the ground by prolonged enemy occupation, a population that had lost a third of its workforce, using an engine so embarrassingly “old technology” that Britain did not think selling about 25 Nenes (and 40 Derwents) to the Russians would be much of “enabling” security threat. Certainly, British Nene engine fighters were not of eye watering performance. Experience wise the MiG’s Chief Designer was young with about 15 years of actual aircraft design  experience including the MiG 1/3 and some prototype jets best forgotten/ Indeed he was, along with P.O. Sukhoi, ranked low in the pantheon of Soviets wartime designer - Tupolev, Ilyushin, Yakovlev, Lavochkin, Petlyakov (who had perished in a bad weather air crash rushing to a summons by Stalin- an occupational hazard with anyone working for that last named gentleman).

Before the MiG 15 Russians designs were supposed to be somehow below par. In the MiG 15 Mikoyan, despite the difficulties, turned in a fighter so brilliant that it swept it past the European Master designers and much of the US Industry to draw equal with the best of the US. Just how good the MiG 15 was can be best summarized by the table below which compares the MiG with the work of best European Designers of the time using the same Nene engine or with engines very similar e.g. The Lockheed P 80 (I 40) and the SAAB J 29 (DH Ghost). The Sabre is in the table because it is a “benchmark” and it used the J 47 axial.

Table 1

1	Aircraft	Designer	FF date	Empty weight	Max load	Max speed	Climb ratem/min	Range
2	Lockheed P 80	Kelly Johnson	8/01/44	3593	3389	966 S/L	6100/5,5	1328
3	Hawker Sea Hawk	Sir Sydney Camm	2/09/47	4208	3127	964	29m/sec	29/m/sec
4	Supermarine Attacker	“Joe’ Smith	17/06/43	4496	3400	949sl	9150/6.66 min	1915
5	Saab J 29	Lars Brising	1/8/48	4300	1700	1060	4845	2700
6	I.Ae. 29 Pulqui 2	Kurt Tank	1951	3600	1900	1050	29.8/sec	2030
7	Dassault Ouragon	Marcel Bloch/ Dessaix (?)	28/02/ 49	4800	2150	930	3000/3.15 min	836
8	North American F 86 A	Ed. Schumed	11/0/47	4780	2650	1093	37.9m/sec	531r
9	MiG 15	Mikoyan/ Gurevich	2/06/47	3523	1425	1050	5000/2.5	1176

 

 If you draw up a more elaborate table adding say WL/, T/W, A.R. etc and chew the cud on it many interesting facts come out. It seems that sweeping the wings contribute to about 90 km.p.h additional speed. Of particular interest (not included in the table) is the Supermarine 510 which was an Attacker fuselage with swept wings showing again that same increase.  All the above, barring the Sabre used the same Nene /Nene type centrifugal flow engines and were the work of those who deserve respect and reverential study. Whilst it would be shallow to compare one against the other for declaring a “winner” but, in sum, if you had to dogfight the Sabre you had better select the MiG 15 from this lot.

Some interesting design choices

Intake: The MiG 15, as with sl.no 5, 6, 7, 8 used a simple Nose intake. The earliest of intake configuration, it is still the “best” intake for many well-known reasons. Today the large size of AI radars has caused designers to move to side intakes but for certain scenarios, e.g. stealth snipers- it may still be a choice worthy of a careful ponder with the customer! It is naturally stealthy. See a Sabre cut away.

The intake system of the MiG 15 differs from all the others (sl.no 5,6,7,8,) with the nose intake. They all chose a low or shoulder wing; they have a flow divider which splits the intake stream into two vertical channels and leads the air around the cockpit enclosure into a plenum chamber and the engine feeds from that air. In the MiG 15 the air stream first divides vertically as with the others but then divides horizontally just behind the cockpit to enter the intake plenum chamber. Forced to use a large diameter engine Mikoyan decided to have his design cake and eat it too because the passage areas were very large the mass flows quite small circa 45 kg/sec so duct losses were low and it permitted him to have a mid-wing for a low structural penalty. He simply ran the main spar torsion box through the fuselage. Mind you he should have lost on ram pressure at the Nene intake but if you look at the Nene engine, the impeller “eye” is completely blocked by the accessories drive gearbox so it was a bold brilliant decision because it permitted him to use a mid- wing which give you the following points on the MiG 15;

The advantages of a mid-wing lay out is partly aerodynamic and partly common-sense mechanics.

1Aerodynamic:  wing- fuselage interference drag. Though the mid wing has four “corners” (looking from the front) and therefore four sources of interference drag they are all obtuse angle between the round fuselage surface and the wing and the excess drag penalty, if at all, is marginal especially as you may get away with relatively small root fillets saving drag there. In this context the “groove” one sees in the TEDBF proposals between the canard and the wing is probably horrible and makes me wince every time I see it.

2. Mechanics; the mid wing keeps the aircraft CG, thrust line and the wing drag forces all very close. That gives pleasant handling, minimizes trim changes with speed, low rolling inertia and a high roll rate is common sense for a quick change in direction. It is no coincidence that Hunter, Canberra, MiG 21, Lightning were mid wingers. IF you can get away with it don’t hesitate to use a mid-wing though there are advantages in other layouts and one must have the patient knowledge to understand what fits you! One flaw of the mid wing is that if the U/C is wing mounted; it requires careful design to restore the torsional stiffness of the wing.

Just to illustrate how much of good design is non- numerical and “common sense” case specific : You wouldn’t of course use a mid- wing in the J 29 because that used a De Havilland Ghost in which Halford kept the impeller eye very clear of accessories gear box to take full benefit the ram effect and Brising saw to that need. This is why the J 29 had a wing at the top of the fuselage/ plenum chamber. This is another lesson. One has to be careful both when choosing what to copy and also when you try to run down the Slav’ s designs. They are quite careful about details and may require more respect than is generally given them- often because one is too impatient to be able to understand an alternate thinking; but that doesn’t make that their solution is rubbish.

 The Gun Installation

Another noticeable boldness the MiG 15 is the location of the gun. The cannon muzzles are located right on the intake lip. Not at all a recommended position, Mikoyan “got away with it” – he did not even use a blast suppressor because if you can imagine the relatively long intake duct dividing as described acting as a pulsation damper and with the plenum chamber actually working like a capacitor thus taming the pulsation surges. Also, the centrifugal flow engines were more tolerant of inlet flow distortions. It is again a case of a canny Designer, using the characteristics of the aggregates with understanding to create a reliable solution. The 37 mm calibre NR selected as a bomber destroyer was almost the size of a Bofors 40 mm and yet the gun/engine system was utterly reliable, a plethora of such patient quiet details making the very rugged and serviceable MiG 15 popular as a Soldat Samolyot- “ soldier aircraft”. By the way, the lack of blast suppressors on the guns may have saved about 15 to 20 kilos- quite handsome- almost a half % empty weight in such a light aircraft.

Gun Pack: Mention must also be made of the “Gun pack”. It was a tray in which the 2 x23 and the 1x37 NRs and their ammunition boxes were mounted and could be winched down to the ground for servicing and replenishment for quick turnaround. My guess is Mikoyan had had a good look at the external gun packs the Germans were so addicted to- e,g, HS 129, Me 110, and gone one better by making it internal and self-serviceable by adding built in winching. Let me take the risk and say Sir Sydney Camm had had a look at the MiG 15 pack and was sufficiently impressed to copy it for the Hunter Aden pack. 

The time lines

Delay a project and you delay learning and conclusions. Delay long enough and you produce junk. Speed, taking careful risks, is the essence Citius Altius commoda periclus sapientas! The specifications for the MiG -15 may have been issued somewhere around 1945 end and asked for an Istribiteyel (interceptor) capable of operating from sparsely equipped bases in Russian weather. The anticipated task was the destruction of the B 29 and B 50 atom bombers of the USAAF. A top speed in excess of 1000 km.p.h. and a climb to 5000 mts in less than 3 minutes was sought and a service ceiling was 15,000 mts and a range 1000 kms was required. An armament of 1x 40 mm with 40 rds and 2x 23 mm with 120 rds, giving a firing time of 6 seconds was specified. As happens with specified equipment the 40 mm was changed to 37 and the change was accepted with demur. Originally designed around a RD 10 (copy of axial flow Jumo 004; engine dia. 900 mm).  During the process of prototyping with the RD 10 the incredible (to the Soviets point of view) offer of the Nene from UK was a boon that necessitated massive redesign; The then under-design MiG 15s fuselage diameter had to be increased by 400 mm  to accommodate the 1300 mm dia Nene and after excessive jet pipe losses were reported the fuselage length was shortened by 1,8 mts, the stabilizer moment arm being retained by a highly swept fin. Never missing a step, the MiG team was able to go for a first flight by mid- 1947 2^nd June 1947 within 18 months of sanction.

 Those who think “specifications changes” are sufficient excuse for delays might take note.

Can we design and fly an aircraft in 2 years is not the correct question ? The defensive answer would be that the MiG 15 was a “simple” aircraft; The correct question to ask would be: can our Industry today build a “simple” “MiG 15” even today in two years? It has been done before! If not why not? We note that YK and his team prototyped the HJT 36 in just three years despite all the same handicaps so frequently mentioned. It is for the Government to examine why a few of the bureaux are consistent in their failure to deliver platforms- Why are certain projects- specifically their platforms- are being delayed almost into obsolescence? The answer will be with the government in the records and minutes.

The engines of choice.

The imported Nenes were allotted to the Mikoyan Bureau for flight testing but Klimov got down to making a copy of the Nene. The original Nene had been designed and developed over a period of 18 months. It was also license (from the Russians!) manufactured in China and during a visit to China as (note) a consultant, the “original “designer, Stanley Hooker, after examining a Russian built Klimov VK 1A, convulsed his Chinese hosts by exclaiming “They have even copied my mistakes”, That was not quite true. Klimov who had taken a similar approach with the piston Hispano Suiza HS 12 Y in developing his VK 105 core engine for the Yaks and early Lavochkins, started with the basic Nene, enlarged the combustion chambers, increased the height of the turbine blades to absorb the greater mass flow and “cleaned up” the jet pipe and generally made the design “easy to manufacture” which is a diksha in itself. Slave to engineering TLC that turbomachines are, the Engine thrust went up from 2400 to 2700 kgs. The improved producibility of the engine was rather helpful because about 89,000 were built including Chinese production.

A comparison of engine choices

Schumed had a choice between the Nene type I 40 and the J 47 and Mikoyan had the Hobson’s choice of the Nene. It is interesting to compare the two engines and see how the choice affected the design.

Sl.No	Engine	Config.	Length	Dia	Weight	Mass flow	Thrust	sfc	TET
1	Nene	1C+1T	2459	1257	726	40-45	22,2	1,014	1170
2	Klimov VK 1A	1C+1T	2600	1300	884kg	48.2	26.7-33	1.07	1170
3	GE-47-25	12C+1T	3700	930	1158	42	22-26.56	1.014	1320

 

The smaller diameter of the J 47 is noteworthy. The “sore thumb” lesson from this table is that an advanced technology, in this case the J 47 at an early stage of development may actually give a lower contribution compared to a old technology e.g. Nene, driven hard. Again (!) a case of more is not better. The J 47 allowed Schumed to go up to the Sabre H which could embarrass all of the US Century series (even when those were fitted with guns,  in simulated dog fights but Mikoyan fitted an afterburning VK1F to his MiG 17 which could repeatedly embarrass the best of US fighters in actual combat so I am not sure whose approach was better. Both worked so it would depend on what your total scenario was – not necessarily more technology is better,

 

Some aerodynamics

Spanwise flows are a problem with swept wing leading to loss of control at the ailerons amongst other things like pitch up at transonic speeds etc. The Gnat corrected that by a combination of conical camber and a curved baseline of the tip aerofoil. Possibly the Sabre wing took the same route.  The MiG 15 had prominent fences. What could be the reason? My guess is that Mikoyan knew Russian manufacturing accuracies would not be good enough to have a reliable cure that required delicate manufacturing. There were problems with valojka -different wings giving different amounts of lift due to poor manufacture in the Ilyushin IL 28 bomber and so he chose an “inefficient” aerodynamic solution to overcome what was in root a “production” and not a “design” problem. So I hold that the MiG 15 was more profoundly designed. I presume Schumed  (to whom due genuflections!) chose the best solution for his Sabre knowing his industry could carry it out.

The transonic behaviour of the Sabre was impeccable. It could “bang through the barrier” in a shallow dive. The MiG was limited to M 0.92 by bad handling ( snaking ) and indeed the airbrakes – which were found to be undersized and area had to be increased (again note) - operated automatically at that Mach no to prevent things going out of control. Both aircraft had wings swept at 35 degrees and the MiG’s section thickness was 10.2 % and the Sabre ‘s was at 9.8 % so that could hardly have been the entire matter. The clue to the Sabre’s better transonic capability lay in the smaller diameter of its engine 0.9 against the Mig 15’s 1.3 mts dia. With corresponding larger fuselage diameters- transonic drag is proportional to cross section area.. To make matters worse the MiG’s fuselage length was a stubby 9 mts against the Sabre’s  11.74 mats. So the fuselage finesse ratio was much better in the Sabre. These are the numbers and they make sense.

But I think possibly the Sabre had a secret. It is generally believed that ‘Area Rule” was invented by Von Karmann and Whitcomb in the late 1940s and it is applicable only in transonic flight. My take is that “area rule” was an extension of the work on car aerodynamics of the 1920s by the Germans – Rumpler, Kamm. Jaray et al and is applicable at every velocity, becoming critical at the transonic regime. In their quest for a Cd₀ of 0.1 for Cars (typical car of the 1960s 0.35) they had found that important amongst the ten requirements such as frontal suction, Kamm Back etc were a “constant” cross section. If you look at the Sabre side view you will notice that the high canopy ends just as the wing LE begins and the fuselage is sharply tapered etc. Imagine the areas and the aircraft like the Gnat is “area ruled” without wasp waist-ing. May be this informal “area ruling” was a factor in the Sabre’s transonic performance. 

A reckoning in the field.

The MiG 15 was very extensively flown in Combat in Korea and it’s appearance was a shock because it completely outclassed all Western aircraft- P 80s, Grumman Panthers, Gloster Meteors so much so that the early Sabres had to be rushed in to restore balance. Popular lore had it that the Sabre won a 14; 1 victory over the MiG 15. These claims have not aged very well. The figures were based on the US claims of losing 78 Sabres against a shooting down of 784 MiG 15s. Whilst the USAF can be certain of its own losses, we know that even given the best of intentions it is impossible to know exactly how many the enemy has lost. To cut a long story short the present admission is something like this: When up against the Russian flown MiG 15s the losses were about equal. Many of the Russian pilots, like most of the Americans, had flown in WW2 and were known as Honchos, ( Japanese word for “Boss”) the appellation being  indicative. Against the less experienced Chinese and the Koreans the loss rate was about 1 is to 4. In its designed role as a bomber interceptor the MiG 15 was absolutely lethal inflicting heavy casualties on the B 29s and 50s in daylight operations. The MiG 15 could outclimb and out accelerate the Sabre but the Sabre could out dive and was marginally faster so everything depended very largely on the relative skill of the pilots.  However, the MiG was no miracle. It had lacunae that reduced it’s combat effectiveness. The following is an abridged list indicating how small details and lack of systems reduce combat effectiveness :

MiG 15 lacunae

1.      Lack of powered controls. Rolling requires the most “muscles” and yet a rapid part roll is the first step to a turn.

2.      Lack of a ranging gun sight. The ranging had to be done by stadiametric estimation i.e. estimating range from the wing span filling circles on the reflector. This made compensating from ballistic drop and therefore accurate shooting very difficult.

3.      The mixed calibre 2x 23 and 1x37 had different ballistic drops and made concentrated weight of fire difficult to bear save in a narrow bracket. Not happy against fighters vs fighter but no problem with Bombers.

4.      The early ASP gunsight though gyro enabled to compute lead was prone to toppling.

5.      The poor handling at M > 0,8 and the tendency to flick into a spin during dog fight though spin recovery was possible.

6.      Canopy de-misting was poor.

7.      Lack of gun heating caused jams. Strange the Russians missed that one out. Possibly because they fought the entire WW2 at low altitudes!

8.      Lack of a g- suit system.

9.      Lack of IFF so GCI would be poorer.

This partial list I have shown that how much effort has to be put in to get a even a brilliant platform to become an effective platform. If it is flying it isn’t enough. It must fight! All those above difficulties, rooted not in the aircraft but in the systems, robbed it of many possible successes/

The Sabre?

The Sabre’s Achilles heel, if it had any, was the armament of 6 x 0,50 caliber. It had 112 seconds of firing time and the flak vierling zwilling disposition was murder as against high octane fuelled Luftwaffe ME 109s and FW 190s at low altitude would light up like a Ronson even if the calibre was by itself too light to destroy the structure. A hit would ignite. Against the sturdy jet airframes of the MiG 15, at the rarefied air of the high altitudes, with the paraffin based early jet fuel that very same armament did not work. The Sabres were expending 1024 rounds to bring a MiG down the problem being to hold down the MiG long enough in the sights.

The lesson is that it is not enough to develop a platform and think the job is done. Small unattended details and improvements can bring down the efficiency of the aircraft.

 

MiG 15 The Farmer’s Knife

The tale is told of the farmer’s knife which has it that it is very useful and you change the handle thrice and the blade four times and it lasts a hundred years. That applied to the MiG 15. It served for almost 40 years ending, amongst other things in service with the Afghan Air Force in the 1980s which is four decades. The PAF found it to be an useful trainer for long. But that was just the entrée. The basic airframe which had given such a shock to the West in the 1950s was given a thinner, more swept (in three steps) wing of reduced area and the same ancient technology engine but fitted with a crude afterburner re- emerged as the MiG 15 /45 ( the 45 after the wing sweep angle) aka MiG 17. Deceptively ancient, it caused great trouble to the highly proficient and professional air Force of America and Israel who found it a handful even in their latest Western technology aircraft. The evolution of the design and it’s still latent possibilities would be another story.