MiG-21 precursors and developments

[blackkite]

Kremlin's requirement for a new fighter in autumn 1953 were......
(1) A frontal fighter with speed of Mach2 at 20000m.
(2) Carring guns, guided missiles and a radar ranging sight.
MiG planned following two types of prototype with different wing (Slender swept wing and delta wing with a horizontal tail).
Ye-1 : Swept wing and AM-5A engine.
Ye-1A : Swept wing and AM-9 engine plus S-155 booster rocket.
Ye-2 : Swept wing and AM-9B engine.
Ye-2A : Swept wing and AM-11 engine.
Ye-4 : Delta wing and AM-9B engine.
Ye-5 : Delta wing and AM-11 engine.

Ye-1's AM-5A engine was insufficiently powerful, Ye-1 was abondoned.

Ye-2.

https://www.reddit.com/r/AviationHistory/comments/7xkbp2

View: https://www.reddit.com/r/AviationHistory/comments/7xkbp2/on_this_day_in_1955_the_mikoyangurevich_ye2_mig21/

.

 

[blackkite]

Hi!
http://blog.livedoor.jp/janome_gotyou/archives/32894621.html

 

[blackkite]

Hi! Ye-4, Ye-4/2 and Ye-5.

The Ye-4 was the true progenitor of the MiG-21, becoming the Ye-4/2 with airflow fences.​

The Ye-5 was essentially similar to the Ye-4/2 apart from the more powerful AM-11 engine.
http://www.aviastar.org/air/russia/mig-e4.php

 

[blackkite]

Hi! Ye-5 model.
https://www.1999.co.jp/image/10639334

 

[hesham]

From, MiG fifty years

 

[Pioneer]

Sorry, but in a nutshell, can anyone explain the circumstances that convinced OKB MiG Design Bureau to adopt the delta-wing design vs the traditional swept-wing arrangement for their MiG-21 design?


Regards
Pioneer

 

[blackkite]

Sorry, but in a nutshell, can anyone explain the circumstances that convinced OKB MiG Design Bureau to adopt the delta-wing design vs the traditional swept-wing arrangement for their MiG-21 design?


Regards
Pioneer

When designing a front fighter, the MiG Design Bureau thought that a pure delta wing could not be equipped with a high-lift device and the runway would be long, so it was not suitable for a front fighter.

The MiG Design Bureau could not decide whether to use a swept wing or a delta wing with a horizontal tail stabilizer, and made a prototype Ye-2 with a swept wing and a Ye-4 with a delta wing with a horizontal tail stabilizer, and conducted a flight test. The Ye-2 did not experience wing tip stall or aileron reversal and recorded a maximum speed of Mach 1.8. On the other hand, the maximum speed of Ye-4 was Mach 1.2. It was thought that the cause was that it did not meet the area rule.

After that, the Ye-5, which was equipped with a more powerful engine and had a delta wing with a horizontal tail stabilizer, changed the shape of the rear part of the fuselage, was completed and recorded a maximum speed of Mach 1.85.

In the comparative evaluation, the delta wing with a horizontal tail stabilizer was selected because it could be manufactured 200 kg lighter than the swept wing, had a small turning radius, and had a high rollover rate.

 

[blackkite]

http://jpcolliat.free.fr/ye50/ye50.htm
The Ye-50 mixed powered interceptor was studied in 1954. Although belonging to the Ye-2/Ye-2A family, the ancestors of the Mig-21, it differed in many ways. The GMP consisted of a 3,724 daN (3,800 kgp) Mikouline AM-9Ye reactor and a Dushan S-155 liquid propellant rocket engine of the 274 daN (l 300 kgp). Also external details, such as the lengthening of the fuselage required by the three propellant tanks of the rocket engine (fuel, acid A, hydrogen peroxide T) and the installation of the combustion chamber above the fuselage core.

At the foot of the drift, which was raised, were the control of the accessories and the turbopumps supplying the combustion chamber of the rocket engine. The reactor and rocket engine necks were on the same plane. Beneath the fuselage were two pipes, plated on the coating, whose interior was treated for acid corrosion and which were intended to be used as a vacuum in combat if necessary. They ended up in the plane of the reactor pipe pass.

The AM-9Ye reactor distinguished itself from the standard AM-9B by modifications expanding its range of use in combat (altitude and speed), given the addition provided by the rocket engine.

However, the nose part of the fuselage, the wing, the stabilizer and the landing gear were not modified, as these elements had been thoroughly studied on the Ye-2 and had been well controlled by the manufacturing units. The Ye-50 is armed with two NR-30 guns. Three prototypes were built between 1955 and 1957.

The Ye-50-1, released in December 1955, made its maiden flight on January 9, 1956 (the same day as the Ye-5) piloted by V.G. Moukhine, which belonged to the LU MAP (The Ministry of Aeronautical Industry's Institute for Flight Testing), and the first rocket-engine flight took place on June 8, 1956. The Ye-50-1 constructing test ended on July 14, 1956 after the 18th flight, with the pilot landing before the runway threshold and the aircraft destroyed.

The second prototype, the Ye-50-2, was quickly completed and led by A pilot from the LII MAP, V.P. Vassine, who was in charge of the tests. It differed from the Ye-50-1 by the modified shape of the rear end of the fuselage and by a so-called "knife" addition to the rudder trailing edge intended to increase the overall surface area of the vertical tail.

Several records of altitude and unofficial speed were broken with the rocket engine on. On 17 June 1957, Vassine reached an altitude of 25,600 m and, a little later, a speed of 2,460 km/h (Mach 2.33).

 

[blackkite]

The Ye-50-3, built in 1957, differed from its predecessors in the increased capacity of the kerosene tanks for the reactor by installing a metal tank with a transfer pump in place of the bladder and reducing the capacity of the oxygenated water tank. In addition, the nose of the fuselage was elongated, the lips of the air intake thinned.

The air intake cone had a double bevel and the aft end of the fuselage was modified again.

During a high-altitude flight on this third prototype, piloted by N.A. Korovine (NII VVS), part of the vertical tail structure burned. The plane, which had become uncontrollable, went into a spin. The pilot ejected. Unfortunately, the canopy separation mechanism refused to function and the pilot was killed. After studying many imperfections of the rocket engines and their systems, it was decided to stop testing the Ye-50, but the development of a future generation of fighters equipped with auxiliary thrusters continued after a fundamental revision of the basic data before such an engine was realized.

For example, it was recommended that the rocket engine control system be more efficient and that aircrew or maintenance personnel be better ensured, on board aircraft or on ground storage facilities, to prevent them from coming into contact with the active and toxic components of rocket engine propellants.

 

[blackkite]

Hi!

 

[Pioneer]

Sorry, but in a nutshell, can anyone explain the circumstances that convinced OKB MiG Design Bureau to adopt the delta-wing design vs the traditional swept-wing arrangement for their MiG-21 design?


Regards
Pioneer

When designing a front fighter, the MiG Design Bureau thought that a pure delta wing could not be equipped with a high-lift device and the runway would be long, so it was not suitable for a front fighter.

The MiG Design Bureau could not decide whether to use a swept wing or a delta wing with a horizontal tail stabilizer, and made a prototype Ye-2 with a swept wing and a Ye-4 with a delta wing with a horizontal tail stabilizer, and conducted a flight test. The Ye-2 did not experience wing tip stall or aileron reversal and recorded a maximum speed of Mach 1.8. On the other hand, the maximum speed of Ye-4 was Mach 1.2. It was thought that the cause was that it did not meet the area rule.

After that, the Ye-5, which was equipped with a more powerful engine and had a delta wing with a horizontal tail stabilizer, changed the shape of the rear part of the fuselage, was completed and recorded a maximum speed of Mach 1.85.

In the comparative evaluation, the delta wing with a horizontal tail stabilizer was selected because it could be manufactured 200 kg lighter than the swept wing, had a small turning radius, and had a high rollover rate.

Thank you for answering my question blackkite. It explains and answers much.


Regards
Pioneer

 

[kocovgoce]

Maybe it would be better for the MiG-21 to have wings at an angle of 35 to 45 degrees like the MiG-19.

The Е-50A version is quite interesting with a rocket engine

 

[blackkite]

Ye-50A had a conformable rocket engine fuel tank under the fuselage to increase rocket engine burning time.
But Ye-50A was cancelled when under the construction phase.

This photo is a Ye-50A composite photo using the Ye-50 photo.
https://www.valka.cz/Mikojan-Gurevic-Je-50A-t54215

 

[blackkite]

Hi! Ye-6T/3 for Ye-8 front wing test.
https://f104.ath.cx/mig21/mig21.htm

 

[kocovgoce]

MIG-21 Analog Experimental aircraft for development of TU-144

 

[blackkite]

Hi! Ye-2,Ye-2A, Ye-4 and Ye-5.

 

[blackkite]

Hi!

 

[blackkite]

Ye-6 was a MiG-21 production model prototype. The first flight of Ye-6 was in 1958/5/20.
This picture shows Ye-6/3.
http://asasdeferro.blogspot.com/2016/04/mikoyan-gurevich-mig-21-fishbed.html

 

[kocovgoce]

Ye-6 was a MiG-21 production model prototype.
http://asasdeferro.blogspot.com/2016/04/mikoyan-gurevich-mig-21-fishbed.html

The bumpers on the wing are visible in order to separate the various layers of air when moving at high speed because if they are not bumpers there will be large vortices on the wing. Sorry if I am bored with the posts

 

[blackkite]

Hi!

 

[blackkite]

Hi! Ye-6/2.
This aircraft had double delta wing (leading edge sweep back angle of 57°/48°) to install R-3S(K-13) missiles at the wing tip. MiG OKB thought that this wing reduce wing tip eddy making resistance and increase maneuverability by large wing area. But experienced flutter by missile and this attempt terminated.

 

[archipeppe]

Hi! Ye-6/2.
This aircraft had double delta wing (leading edge sweep back angle of 57°/48°) to install R-3S(K-13) missiles at the wing tip. MiG OKB thought that this wing reduce wing tip eddy making resistance and increase maneuverability by large wing area. But experienced flutter by missile and this attempt terminated.

Cool!!
Such wingtip arrangment makes the Ye-6 oddly similiar to F-16....

 

[blackkite]

Hi! You can see Ye-6T/3 and Ye-6/2 partial plan view in this drawing.

https://rarebooksjapan.com/?p=9337

 

[kocovgoce]

It is interesting that it uses S-5 57 mm missiles which were first designed as anti-aircraft missiles to fight the B-47 and B-52

 

[blackkite]

MIG-21 Analog Experimental aircraft for development of TU-144

MiG-21I Analog No.1 aircraft(MiG-21I/1) had a different shape wing.
https://ruslet.webnode.cz/technika/...-technika/a-i-mikojan-a-m-i-gurjevic/mig-21i/

 

[kocovgoce]

MIg-21 PD vstol

 

[blackkite]

Hi! MiG-21 series typical inner structure.
http://www.karaya.pl/en/rvresin/0/m...48-detail-scale-aircraft-drawings-rv1021.html

 

[blackkite]

Hi!

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

 

[kocovgoce]

mig-21 pd vstol fighter based on vietnam experiences. With two vertically mounted jet motors for vertical take of

 

[blackkite]

(1) MiG-21I Analog showed outstanding agility,especially at high altitude.
(2) Test pilots suggested to Mikoyan that Mikoyan should build a fighter version.
(3) The only negative feature were that accelerating to supersonic speed took longer that for a MiG-21S and
decelerating with airbrake was tricky.
(4) On 28 July 1970, MiG-21I/1 lost control doing unauthorized acrobatics at low level and crushed.

 

[blackkite]

Hi! MiG-21PD three side view drawing.
https://blueprintbox.com/categories.php?cat_id=224&page=11
The lift engines were only used to reduce the aircraft's take-off and landing run were not operating in flight and the flap remained closed. The tricycle landing gear was fixed. The MIG-21PD made its maiden flight on June 16, 1966, piloted by P.M. Ostapyenko and then B.A. Orlov, re-left for the manufacturer flight tests that ended in 1967. The MiG-2 IPD made its first public appearance at the Domodyedovo Air Festival in July 1967. As the advantages of the formula proved to be far less than its disadvantages, the development of the device was not pursued.

 

[kocovgoce]

(1) MiG-21I Analog showed outstanding agility,especially at high altitude.
(2) Test pilots suggested to Mikoyan that Mikoyan should build a fighter version.
(3) The only negative feature were that accelerating to supersonic speed took longer that for a MiG-21S and
decelerating with airbrake was tricky.
(4) On 28 July 1970, MiG-21I/1 lost control doing unauthorized acrobatics at low level and crushed.

Mig-21 analog similar to saab JAS 37 vigen

 

[blackkite]

You mean Draken?

 

[kocovgoce]

Yes look more like a jas 35 dragon in the wings but still when the MiG-21 analogue appeared it is the same period when the jas -39 Vigen appeared

 

[blackkite]

Hi! Ye-8.
1. In spring 1961, Kremlin planned a version of MiG-21 capable of intercepting hostile aircraft at night or all weather
using Volkov Sapfir-21 radar(RP-22).
2. It was intended to enter service as the MiG-23.
3. A small RP-22 radar anntenna found practical to MiG-21 air inlet cone, but MiG design team decided to
use variable-geometry two-dimensinal air intake under the fuselage.
4. Also design team decided to have canard foreplane, a destabilizator free to weathercock but locked at Mach1 and
over. This canard increased sustained turn acceleration from 2.5g to 5.1g and maximum lift coefficient in all flight
regimes.
5. The engine was R-21 which had dry thrust of 4700kg and afterburning thrust of 7200kg.
6. The programme was disrupted by the engine. On 11 September 1962, the third high pressure compressor stage
disintegrated and the pieces were not contained. Test pilot was injured on ejection.

 

[blackkite]

Hi!
This aircraft had a foldable ventral fin?

 

[kocovgoce]

Soviet eurofighter

 

[kocovgoce]

Hi! MiG-21PD three side view drawing.
https://blueprintbox.com/categories.php?cat_id=224&page=11
The lift engines were only used to reduce the aircraft's take-off and landing run were not operating in flight and the flap remained closed. The tricycle landing gear was fixed. The MIG-21PD made its maiden flight on June 16, 1966, piloted by P.M. Ostapyenko and then B.A. Orlov, re-left for the manufacturer flight tests that ended in 1967. The MiG-2 IPD made its first public appearance at the Domodyedovo Air Festival in July 1967. As the advantages of the formula proved to be far less than its disadvantages, the development of the device was not pursued.

Probably due to high fuel consumption during a vertical flight, they abandoned this aircraft

 

[blackkite]

Hi! MiG-21PD was a STOL experimental aircraft. Not a VTOL aircraft.

 

[overscan (PaulMM)]

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