MiG-21 vs Mirage/Kfir & Phantom

Кстати, Полл, откуда дровишки про сотни захваченных Ф-5 во Вьетнаме? Кондоуров говорит о всего нескольких штуках.

И насчет вашего вопроса по авионике. После ответов ряда товарищей об этом, я подумал вам это уже не интересно.

Так мужики, готовлю данные по авионике Ф-5Е. Вроде есть интересные вещи. По крайней мере на мой непросвещенный взгляд. Скоро выложил бы, да жена мешает. И что с этими женами делать? Но думаю скоро выложу.

А по аэродинамике и механике есть гораздо больше подробностей. Ф-5Е был очень интересной и совсем непростой машинкой. Непростой - в смысле, непримитивной.

101-й, а вы бы действительно сообщили эти данные. Я лично без понятия где это можно найти. Было бы очень интересно.

Окей, Полл, попробую выполнить вашу просьбу. Правда, никаких технических параметров в количественной форме по авионике там не приводится (за редким исключением), но как я понял вас как раз больше интересует сам концептуальный подход к этому делу, а на этот счет кое-что есть. Не знаю насколько будут полезны вам эти данные, но как говорится – чем богаты, тем и рады. А вообще то по аэродинамике и механической части там есть гораздо больше информации.
Ну ладно, поехали.

Avionics development.

The F-5A aircraft was simple, easy to maintain and compatible with the capabilities of developing nations that could not maintain sophisticated avionics. The fighter possessed superior agility and stability, and was configured for bombs, rockets, guns and AIM-9 air-to-air missiles. Aircraft stability made high accuracy possible with a simple, manually depressible reticle-type sight system.


The gunsight.

Northrop developed for the F-5A the simplest and most reliable gunsight conceivable. The low-cost, optical-mechanical reticle display was manually adjustable from 0 to 200 mils depression. It was collimated to avoid sighting errors. The gunsight was acceptable for aiming AIM-9B missiles, guns, rockets and bombs.

Although the F-5A provided outstanding air-to-ground weapon delivery accuracy and won over 90% weapon delivery meets entered, it did not contain a fire control system which would provide adequate intercept capability and success against small, highly maneuverable MiG-family fighters. Air-to-air gunnery capability with fixed sight was limited without computing devices. Air-to-air missiles were often launched out of lethal envelope. Two-mile visual detection range against small fighters was not adequate for target interception.

Lead computing gunsights were introduced into air-to-air combat in the Spitfire. The original Ferranti gunsight doubled the kill ratio and had a definite impact on the outcome of the Battle of Britain. However, the original approach provided only linear lead prediction and was not effective against agile and evasive targets. No really new approaches were developed during the 30 years between 1940 and 1970. The critical need to develop a better approach to the problem of air-to-air gunnery became clear during Vietnam operations.

No lead computing optical sight system in existence provided the capability to hit evasive maneuvering aircraft of the MiG type. The need for a new approach to air-to-air gunnery presented a challenging and complex task.

Requirements for the new computing gunsight:

A computation and optical display for aiming twin 20-mm cannons to hit highly evasive targets in air combat and to determine when targets are within AIM-9 missile lethal zone.

A manually-depressed reticle display for air-to-ground weapon delivery.


Limitations of the existing state-of-the-art linear predictors were fully explored and Northrop analytic and simulation studies indicated the need for a non-tracking solution. The key to the eventual success of the F-5E Lead Computing Optical Sight System (LCOSS) was blending the tracer display approach with the lead-computing gyroscope approach.

Development of capability to hit highly maneuverable targets:

Investigation of second-order lead-computing gyroscope approach led to capability against constant-G maneuvering targets.

Investigation of tracer-display approach led to increased capability against evasive targets which cannot be tracked.

Blending two above approaches led to capability better than either approach alone.

Extensive simulation to optimize above approach led to maximized probability of hitting all targets.


During the sixties more than a dozen countries received the F-5A and learned to successfully employ and maintain it. Gradually they came to desire increased operational capabilities with more sophisticated fire control, weapon delivery and navigation systems. There was no night capability without radar.

In 1966 the decision was made to integrate an advanced fire control system into the F-5. As no one country could afford to fund the development of the complete fire control system, it was decided on gradual development of the system on a country-by-country basis. The system had to be decentralized with elements predesigned to integrate as a compatible whole. Each element had to be worthwhile and marketable as a stand-alone subsystem. Each element would provide enough improvement to the aircraft to make it desirable to incorporate as an entity. The elements included computing gunsight, radar with search, range track and angle track modes, missile launch computer, gyroscopic platform and air data inputs.

The fire control system was to provide essential capabilities without undue complexity, high cost and loss of reliability. It had to be reliable, easy to test, repair and maintain. It had to be accurate enough to achieve mission objective with margin for field degradation. Mistakes made in prior fire control systems were carefully reviewed to avoid common pitfalls. Following the F-5 design philosophy for ease of maintenance, ground rules were imposed on each F-5 fire control system element to achieve specified maintenance requirements. Mean-time-to-repair demonstrations were required of each supplier.

The drawbacks of the prior fire control systems:

They needed too many adjustments.
LRUs [Line Replaceable Units] were not interchangeable.
Modules within LRU were not interchangeable.
Circuits drifted excessively.
Margins for field degradation were not adequate.


Maintainability concepts applied to the new F-5 fire control system:

To minimize and even eliminate adjustments of devices.
To introduce interchangeable LRUs [Line Replaceable Units]
To enable each subsystem to conduct quick self-test for revealing problems.
To create failure monitors on critical functions.
To set up measures for preventing damage.

Air data for the F-5A were supplied by seven separate transducers. While these transducers were adequate for the limited F-5A applications, they did not provide the accuracy, range or output format required for fire control, weapon delivery, navigation or altitude reporting.

Air data requirements for increasing capabilities of the F-5A.

Input data required for lead computation: Altitude, true airspeed, true angle of attack.

Input data required for missile launch envelope computation: Altitude, true airspeed, Mach.

Inputs for aircraft: Servoed altimeter, angle-of-attack indicator, landing gear warning,
IFF/Altitude reporting, stability augmenter, automatic flap control, take-off doors.


The first element of the fire control system to be incorporated into the F-5 was the gyroscopic platform or Attitude and Heading Reference System (AHRS). As a stand-alone element, it provided the pilot with vital information under all-attitude, air-combat maneuver conditions.
Because of the intense competition for the International Fighter F-5E the AHRS had to be the lowest-cost, off-the-shelf item.

The gyroscopic platform was to provide:

Accurate pitch and roll data to stabilize radar antenna search pattern and radar display.

Accurate roll data to stabilize sight depressed reticle and avoid pendulum effect.

Accurate pitch and roll data for attitude indication and air-to-ground weapon delivery.

Accurate gyro-stabilized heading data for instruments and pilot navigation.

Proper functioning during all air combat maneuvers without gimbal limiting or tumbling.


The gyroscopic platform had to be compatible with the F-5A existing and new systems under conditions of all air combat maneuvers. Extensive development was avoided by selecting an existing platform. Several two-gyro platforms were available which could be modified to meet F-5 requirements. The penalties were limited growth and precession error during sustained acceleration.

Northrop selected the standard Bendix two-gyro platform for the Skoshi-F-5 project. An improved attitude indicator was incorporated. The platform provided pitch and roll outputs for future radar space stabilization, computing sight roll stabilization and automatic bombing. Canada decided to install on their F-5s the Canadian Sperry two-gyro platform The Netherlands chose the Bendix high-accuracy, two-gyro platform to achieve ¾% Doppler navigation accuracy.


Radar system.

The requirements for the F-5 radar system were to provide for air combat missions in a GCI controlled environment utilizing AIM-9 missiles and 20-mm cannons to their fullest effectiveness. The trade offs between detection range, search coverage, range accuracy, space, weight, reliability and maintainability were carefully evaluated to develop specifications for a radar that was optimal for the F-5 at that time.

Radar requirements:

Search for detecting targets beyond visual detection range.

Space-stabilized display for getting into position for successful attacks.

Accurate range and closing-rate data for gun and missile computations.

Angle tracking with data display for interception of penetrating enemy threats.

Display for radar mapping of prominent terrain or ships at sea.

Capability to function at any speed, altitude, attitude, maneuver or load factor.


In the F-5A the task of estimating when the target was within the AIM-9 lethal launch envelope was left to the pilot. Vietnam combat experience showed that the pilot’s concentration became riveted on the aerial combat and could not be diverted to launch envelope estimation. The need for a valid and reliable missile launch computer became recognized.
The opportunity to incorporate the missile launch computer arose with the IFA competition, which specified the requirement. The unique idea of restructuring the lead-computing gunsight to do missile launch computations when in the missile mode saved the cost and weight of a separate computer.


The next opportunity to incorporate one of the elements of the fire control system arose during the configuration definition phase for the Canadian F-5. Following the ground rule that each element had to be worthwhile on a stand-alone basis, study results were presented to the Canadian Design Authority. The analysis showed that Canadian cost of ownership for central air data computer (CADC) was lower than for seven separate air data transducers. It presented only one unit to install, only one unit to test, gave more functions, occupied less space, weighed less, ensured higher accuracy. CADC provided 1% true airspeed accuracy for future navigation and missile launch envelope computations. It provided 0.2% altitude accuracy for future missile launch envelope, lead computation and altitude reporting. CADC provided true angle of attack for future guns, rockets and bomb aiming computations. Three built in test-problems functions minimized maintenance time and costs. Value engineering cycle reduced original cost over 50%. The Canadians were pleased to be able to incorporate a more accurate altimeter, provisions for altitude reporting and inputs for a lead-computing sight and for a Doppler navigator, both of which were being considered for growth.


The IFA competition made it necessary to impose difficult design requirements and demanding cost constraints on potential radar suppliers. The outcome, however, was that the F-5E radar provided outstanding search and ranging accuracy, detection range adequate for air combat at a fraction of the cost of contemporary radars.

Original F-5E radar concepts:

Radar must be ingeniously simple with design-to-cost $35K (1970). [35 тысяч долларов в ценах 1970 г.]

Reliability must exceed 100-hour mean time between failures compared to 25 hours for other 1970 radars.

Radar must not require flight line adjustments compared to 100+ flight line adjustments on F-104 radar.

Radar must provide highly accurate (30 feet) range data for air-to-air fire control.

Radar must provide “eyeball extension” for detection of enemy and conversion to rear-hemisphere attacks.

Northrop teamed with Emerson Electric to devise and build a prototype model which won the competition for the IFA radar. Then the two proceeded to develop the APQ-153 and APQ-157 radars.

Key designers were asked to exercise creativity in concept and innovation in design of fire control elements. As a result, unique approaches were formulated to provide much simpler system design than the current conventional design techniques.

Examples of design for simplicity:

Conventional unreliable antenna drive concept of drive motors with gear trains and hydraulic or mechanical linkages was discarded. Instead, a simple magnetic coupling torquer drive was used which solved the problem.

Direct view storage tube eliminated need for electronic integration and processing of radar signal returns.

Range programmed receiver attenuation eliminated clutter at short range.

Logarithmic receiver eliminated need for conventional automatic gain control.


The simplified radar initially specified for the IFA had limited intercept capability and imposed a heavy workload on the pilot. Northrop and Emerson recognized the need for a better solution and built an Improved radar.

To increase the effectiveness of the radar, the following solutions were implemented:

For greater intercept capability – angle track, off-boresight acquisition, longer range.

For better detection and reduced clutter – frequency agility, flat plate antenna, tapered-thickness radome, 40 n.m. scale.

Emerson and Northrop jointly developed prototype and demonstrated improvements to potential customers. The Swiss and Saudi pilots were the first to evaluate the new radar and they verified predicted performance improvements. Subsequently, the radar was put into production as APQ-159.

Inertial platform and navigator.

The Saudi F-5 program gave an opportunity to replace the conventional Attitude and Heading Reference System (AHRS) with a high quality Inertial Navigation System (INS). The Saudis required precise navigation to avoid border incidents and the INS was the answer. The production of the INS elements was a very challenging task and Northrop with Litton jointly developed facility, workmanship, assembly and test disciplines required for manufacturing high quality inertial components.


F-5 avionics growth.

Future customers desire further improvements in avionics and the state-of-the-art advances in microprocessors and more capable digital equipment make it possible. The great achievements in the sphere of microminiaturization allow to build microprocessors and new families of small and highly reliable digital equipment. This new avionic equipment will make it possible to give future F-5s additional mission capabilities and flexibility without any loss in reliability and maintainability.

Potential mission requirements:

Look-down, shoot-down capability.
Improved weapon delivery.
Defensive warning and jamming.
Reconnaissance.

Вот ещё у меня было засэйвано.

“Design for Air Combat” (1989) by Ray Whitford

The Northrop F-5, with its excellent record for high-angle-of-attack handling, was one of the first types to incorporate a maneuver flap system. This has developed via the introduction of a leading-edge flap on the F-5A to increase maximum lift, through the single-setting maneuver flap on the NF-5, to the advanced arrangements on the F-20 and another Northrop-designed type, the F-18. The ability to vary the flap deflection allowed to obtain a 17% increase in lift at Mach 0.8. As Mach number increases, however, this benefit declines. So that at Mach 0.9 the lift increase is down to 10%. The F-18 and F-20 both incorporate a flap system fully automated through the air data computer so that the flaps deploy automatically to the degree demanded by the angle of attack and Mach number. This produces a smooth minimum drag envelope, resulting in improved maneuverability. Programmed flap deflection has become the norm for contemporary fighters (F-16, Mirage 2000).

In the mid-1960s, Northrop began work on improving the maneuver-ability of its F-5. The company had been the leading exponent of the art of com-bining moderate sweep and low taper to achieve good flow characteristics and spin resistance, as typified by the T-38 supersonic trainer. When the F-5A ap-peared in 1963 it differed from the T-38 in having a very small leading-edge ex-tension (LEX), intended basically to alter the cross-sectional distribution and so reduce wave drag for maximum transonic acceleration. The Northrop designers were aware of the vortices that the LEX would produce and the induced-drag penalty that would result. However, not only was the wave drag reduced, but a 10% increase in usable lift appeared at high angles of attack, which markedly im-proved turning performance. The size of the LEX on the F-5E was increased to 4.4% of the basic wing area when the intakes were extended forward. This fur-ther improved the area ruling and, more important still, increased the maximum lift by 38%. Further development of the F-5E has led to the F-20, which, with increased LEX area and higher thrust/weight, has a 25%-higher sustained turn rate. Both aircraft have instantaneous turn rates comparable with that of the F-15, which achieves 14 grad/sec at Mach 0.9 at 4,500 m, mainly by virtue of its much lower wing loading.
Impressive though the above figures are, the greatest advance in the application of vortex lift to combat aircraft came in 1966, when Northrop began work on the F-5 derivative which ultimately became the F-18. Its basic wing planform displayed the virtues of the classic moderately swept wing (low induced drag, good stability characteristics, and high spin-resistance). Its combination with a much larger LEX turned it into a truly hybrid wing, with the LEX generating a very strong vortex field not only on itself but also on the parent wing. The maximum lift capability of the hybrid wing reveals a 50% increase in lift at subsonic speed for just 10% more wing area.
On the debit side, the separated nature of vortex flow results in a loss of leading-edge thrust, which increases drag at low (AoA) angles of attack. This can be, however, rectified by the use of maneuver flaps. The combination of LEX and maneuver devices produces very large drag reductions at typical maneuvering AOA, giving an improvement of as much 25% in sustained turn rate. In addition, aileron effectiveness is maintained up to much higher AOA. In its test program the plane demonstrated a far wider range of flying attitudes than had ever before been attained by a comparable aircraft: designed to remain fully controllable up to 45 grad. angle of attack, it was in fact flown to 63 deg. without showing any sign of departure tendencies. The use of large leading edge flap deflection was very beneficial at high angles of attack and also improved lateral and directional stability.

Далеко не всё гладко с надежностью двигателя было и у МиГ-21.

Вот некоторые выдержки из книги Николая Васильевича Якубовича «МиГ-21» (Москва: Астрель, 2001 г.):

«Трудности с доводкой машины и её силовой установки сильно задержали передачу машины [МиГ-21] на госиспытания... Кроме неустойчивой работы двигателя, увеличение его веса привело к смещению задней центровки...

Первый полет на самолете Е-6 состоялся 20 мая 1958 г, а 28 мая, при выполнении седьмого полета, произошла катастрофа, унёсшая жизнь летчика В.А. Нефедова. Отказал двигатель...
(Летчик-испытатель Степан Анастасович Микоян в своей книге "Воспоминания военного-летчика испытателя" упоминает этот эпизод и пишет, что это был помпаж воздухозаборника. Двигатель выключился и вновь не запустился.)

Испытания продолжили на второй машине. Однако, доработки ВЗУ выполнили только на третьей машине. Одновременно с увеличением диаметра цилиндрической части ВЗУ, установили противопомпажные и взлетные створки на фюзеляже...

В ходе испытаний выявилось, что при стрельбе реактивными снарядами АРС-212М обрезался (авиажаргон – выключался) двигатель. Для предупреждения этого явления установили клапан сброса давления горючего в топливной системе при стрельбе НАРами.

Несмотря на значительное несоответствие летных характеристик заданным, МиГ-21Ф приняли на вооружение.

В декабре 1959 г было принято решение прекратить выпуск МиГ-21Ф и начать производство МиГ-21Ф-13. К этому времени на самолете была устранена самопроизвольная остановка двигателя при включении и выключении форсажа.
Эта модель выпускалась около трех лет большими сериями. Одна из этих машин потерпела катастрофу в июне 1962 г из-за обрыва лопаток спрямляющих аппаратов 4-й и 5-й ступеней компрессора ТРД.

Трудностей с освоением МиГ-21ПФ хватало. К марту 1964 г его применение в строевых частях было сильно ограничено по причине того, что глох двигатель при стрельбе реактивными снарядами на боевых режимах полета.

В 1961 г произошло 7 летных происшествий с МиГ-21, а в 1964 г – 19 происшествий. В 1963-64 гг в странах Варшавского Договора произошло 6 летных происществий: 2 в Венгрии, 3 в ГДР, 1 в Польше. А также 1 происществие имело место в Финляндии и одно в Сирии. Все они связаны с отказами двигателей Р11Ф-300, кроме Финляндии, где отказ был из-за прогара лопаток соплового аппарата. В СССР из-за отказа ТРД в 1964 г было две аварии самолетов МиГ-21Ф-13 в строевых частях и одного на заводе в Тбилиси. В это же время по аналогичным причинам были аварии и самолетов МиГ-21ПФ.

А вот что пишется в изданной в Англии, в 1996 г? книге “MiG-21 Fishbed” by E. Gordon:

«...любое отклонение в направлении движения самолета от линии продольной оси самолета приводило к серьезным нарушениям в работе двигателя, в частности, к разрушительным остановкам компрессора и даже разворачивало поток воздуха в воздухозаборнике в противоположном направлении. Мало что можно было поделать с этой проблемой в вертикальной плоскости, случавшейся под перегрузкой при выходе из пикирования и в учебных боях. Увеличенный хвостовой стабилизатор значительно уменьшил рысканье самолета. Но всё-таки даже у пилотов, знающих о данной проблеме и старающихся не допускать рысканья, проблема оставалась. У более поздних моделей самолета хвостовой стабилизатор был ещё больше увеличен, а 20 лет спустя в киевском Институте ВВС испытали полностью измененный воздухозаборник».

А к чему все это? - на этапе испытаний проблем хватало у всех самолетов. А катастрофы постоянно происходят на отработанных, серийный - абсолютно надежной техники не существует.


>>>«...любое отклонение в направлении движения самолета от линии продольной оси самолета приводило к серьезным нарушениям в работе двигателя, в частности, к разрушительным остановкам компрессора и даже разворачивало поток воздуха в воздухозаборнике в противоположном направлении.

А здесь свежесть бесподобная: получается, что МиГ-21 не может летать под углом атаки - бред полный!

Галс, я тоже размышлял над этой фразой. Там видимо имеется в виду нечто другое. Типа, когда имеет место рысканье.