Military Review

Active light camouflage system Compass Ghost (USA)


F-4C fighter in standard camouflage

During World War II, the interests of the Marine aviation The US Navy was developing the Yehudi Lights light camouflage system, which made it possible to hide the aircraft against the background of a bright sky and reduce the visibility range. However, the end of the war and the widespread use of radar made such a development useless. The idea of ​​light-hiding aircraft returned after several decades, based on the experience of the Vietnam War.

Progress and regress

During the Vietnam War, the main means of detecting enemy aircraft were land-based, ship-based and air-based radars. However, with all its advantages, modern and progressive radars could not completely replace the visual detection method. So, fighter pilots in search of enemy aircraft still had to turn their heads and use observation devices such as "Eye Mk 1".

In the course of numerous air battles, it was noticed that the Vietnamese MiG-17 or MiG-21 fighters have an unusual advantage over the American F-4 Phantom II. With their smaller dimensions and cross-section, such aircraft turned out to be less visible to the naked eye. The American Phantom was larger and also left a noticeable trail of smoke. Accordingly, the Vietnamese pilot had a chance to notice the enemy earlier and successfully build an attack.

For some time, such questions remained without much attention. It was not until 1973 that the Pentagon launched the Compass Ghost research program, which aimed to reduce the optical visibility of the production F-4. The Compass Ghost program was considered as a potential part of larger promising projects - its results could be used both to modernize existing equipment and to develop completely new ones.

The main requirement for the "Circular Ghost" was to reduce the optical signature from all angles. For this, we decided to apply the basic ideas of the Yehudi Lights project - but at a new technical level.

Ideas and their implementation

It was established quite a long time ago that any aircraft in daytime conditions looks like a dark spot against the background of a bright sky. Lightening the color schemes did not give the desired result, and therefore had to use "active" methods. The Yehudi Lights project envisaged equipping the frontal projection of the aircraft with a set of lights of a given brightness, directing the light flux forward.

The artificial light had to merge with natural light and thereby masked the aircraft, reducing the distance of its detection from the front hemisphere. All this has been confirmed by a series of tests.

Active light camouflage system Compass Ghost (USA)

Compass Ghost lantern layout

The Circular Ghost was based on the same ideas, but revised towards improvement. So, it was proposed to place the illumination lights not only on the frontal projection, but also on other surfaces of the aircraft. This made it possible to provide camouflage from different angles and gave obvious advantages over the "Yehudi Lights".

For the Compass Ghost, a special elongated canopy was developed, suitable for mounting on the fuselage and wings of an F-4 fighter. Together with the lanterns, a control system was used to maintain the power of the lanterns at the level of natural light.

The project involved the installation of nine lanterns. Five were installed on the fuselage: one under the nose, two on the sides of the air intakes and two under the nacelles. Four more products were fixed under the wing - at the level of the center section and the raised tip. The active camouflage was supplemented with a camouflage paint. The upper surfaces of the aircraft were to be painted blue, the lower surfaces gray.

Justifying the name of the system, the lanterns shone down and to the sides at the same time. Their light did not completely cover all the projections of the aircraft, but created characteristic light spots on them. Combined with the new paint job, the Compass Ghost was supposed to blur the plane's outline and distort its proportions. Thus, instead of an F-4 fighter, the enemy had to observe a smaller aircraft in the sky or even a strange set of colored spots.

Practical results

Also in 1973, McDonnell Douglas converted the existing F-4 fighter into a flying laboratory. The plane was repainted, and also equipped with lanterns, a control system, etc. In this form, he went out for tests, during which it was planned to carry out observations and measurements.

During the tests, the flying laboratory performed flights at different altitudes and speeds on different courses. On the ground were observers with various optical means, whose task was to detect the aircraft at the maximum possible range. Then a comparison was made between the detection ranges of the aircraft with the camouflage system turned off and on.

Tests have confirmed the deterioration of visibility from the front and side hemispheres. The same effect was observed from a light bottom with lanterns. On average, the new paintwork and Compass Ghost reduced the visual detection range by 30% in different weather conditions - with different levels of natural light, clouds, etc.

Modern F-35 in gray "camouflage"

However, depending on the optics used, the detection range, even with the lights on, reached several miles. In addition, the "Circular Ghost" could not hide the characteristic "exhaust" of the engines. All of this showed that the lantern system and new paintwork alone were not sufficient to protect aircraft.

Project without prospects

The developments on the Compass Ghost theme were of great interest in the context of the further development of tactical aviation, and it was planned to take them into account when creating new aircraft. In parallel, research was conducted on the topic of stealth for radar and infrared detection equipment. All this eventually led to the creation of the modern concept of "stealth" and its main solutions.

Based on the results of various studies, it was decided to focus efforts on countering radar, and active light camouflage was considered unnecessary. However, this did not exclude the need to search for optimal coatings and paint schemes. By the end of the seventies, all work on lighting systems was stopped due to the lack of real prospects and interest from the customer.

In the future, new attempts were made to create camouflage illumination, incl. successful in terms of technology and performance. The aircraft literally disappeared at the end of the runway and reappeared only on the glide path. However, these developments did not interest the military - for the same reasons as in the mid-forties.

The only real result of the Compass Ghost project was the appearance of a new paint for aircraft. The combination of shades of gray in itself reduced the fighter's visibility compared to the standard green spotted camouflage. Later, the "Ghost" was spread in the US Air Force.

Failure of direction

All American combat aircraft light camouflage projects have proven their potential, but have not produced real results. The Yehudi Lights project was closed in the mid-forties, and work on the Compass Ghost began and finished three decades later. It is curious that these projects were united not only by the main idea, but also by the main reason for the failure.

Yehudi Lights appeared late enough. When this system was ready, radars became widespread, which reduced the value of optical systems. In the early seventies, the military again became interested in light camouflage, but by the middle of the decade, they again showed increased attention to radar - and the means of protection against it.

As a result, the "Circular Ghost" remained in a single copy. Active optical camouflage retained the status of a technical curiosity without real practical prospects. Technologies for reducing radar and infrared visibility received development, and in the field of optical camouflage, henceforth, they only managed to use camouflage colors.
Photos used:
Popular Science, US Air Force
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  1. Mytholog
    Mytholog 9 August 2020 06: 33
    But how much money was pocketed by corporations on these two projects - they don't even remember))
  2. The leader of the Redskins
    The leader of the Redskins 9 August 2020 06: 48
    Interesting. As well as the development of the 40s, the article about which the author posted earlier. Unpromising, but interesting.
    1. Nikolaevich I
      Nikolaevich I 9 August 2020 07: 44
      Quote: Leader of the Redskins
      Interesting. As well as the development of the 40s, the article about which the author posted earlier. Unpromising, but interesting.

      This is like ...Correspondent I. Vishnyakov on the pages of a popular publication described in detail the first flight of the miracle machine. According to him, an airplane that strongly resembled the U-2 was rolled out onto the airfield from a special hangar. Following him, two I-16s appeared from neighboring hangars. It was assumed that the fighters would accompany the flight of the stealth plane, and their passengers would film the unique action with a movie camera. The moment of takeoff has come. The monoplane easily lifted off the ground and quickly took off into the air. The first minutes of the flight, nothing surprising happened. The plane was clearly visible in the blue sky. But then the monoplane released a jet of gas and in the next instant slowly dissolved into the air. The fact that the miracle machine was still circling in the air was clear only thanks to the characteristic chirp of the engine. The fighters were immediately ordered to return to the airfield so as not to inadvertently shoot down the stealth plane. ?
      1. The leader of the Redskins
        The leader of the Redskins 9 August 2020 08: 24
        Yes, I read this inexplicable miracle!)) laughing
  3. Maximilian37
    Maximilian37 9 August 2020 08: 16
    Oh, how did they try to hide the sound of the engines?
    1. English tarantas
      English tarantas 9 August 2020 13: 49
      What's the point? It is useless for air combat. For camouflage from the ground, too, not very good, if you hear the engine, then finding a point-plane in the sky is still not easy.
  4. Maki maki
    Maki maki 9 August 2020 09: 51
    In general, the idea is interesting - to mix natural lighting with artificial. Thanks to the author hi
    By the way, the article recalled: it is better to quartz rooms with ultraviolet light at night, then ultraviolet light is not "diluted" by daylight and is more effective.
    1. spech
      spech 9 August 2020 13: 54
      And without a moonlit night, the efficiency of the UV lamp is 150% good
  5. Petrol cutter
    Petrol cutter 9 August 2020 18: 37
    What a twist!
    Thanks to the author.
    To be honest, I noticed that our cars are silver. And the capitalists are camouflage. But, I did not attach importance to why it was done.
    And then it turns out - that's it. Once again I am imbued with respect for our designers and other comrades who worked in those old / good days. hi
  6. Tochilka
    Tochilka 9 August 2020 20: 06
    I believe that they could well be mistaken for UFOs. Flies, shines, lights in all directions.
  7. Vladimir Mashkov
    Vladimir Mashkov 10 August 2020 17: 19
    Aviation camouflage is a very interesting topic. Especially WWII camouflage. I will be glad if someone dares to write a series of articles about him. yes