VISIBLE INVISIBLE PLANE (LOCKHEED F-117A)

VISIBLE THE INVISIBLE PLANE (THE LOCKHEED F-117A)What only nicknames and designations were attributed to it (sometimes intentionally) that, until recently, a top-secret aircraft, “Lame Goblin”, “Ghost”, “Ghost”, “Rocket bat”, “Blue Mary”, “Nighthawk”, “Aurora”, CSIWRS, COSIRS, CSIRS, F-19, RF-19, A-19, AR-19, F-25. Now it is know as the F-117A “night hawk” (“Nighthawk”)… the History of the airplane has its roots in the beginning of 70-ies. Development of technological methods for creation of stealth aircraft / vehicles began in the United States, likely in the mid 60-ies. The next step in this direction was the attempt of building with application of the developed technology aircraft low level giveaways, i.e. demonstrators.

The “godfather” of the first aircraft demonstrator HT (Experimental test set-up the stealth technology) of the company “Lockheed”, as established on its base the F-117A, can rightly be considered a Soviet physicist Peter Ufimtseva, who developed a simple and reliable method of calculating the effective surface scattering (ESR) of geometric shapes, which was published in the article “Method of edge waves in the physical theory of diffraction” in 1962.
 
This method was the basis for Denis Overholser, mathematician and expert in the field of radar Separation promising projects “skunk Works” of the company “Lockheed”, the development of computer programs for the calculation of EPR. In the future this largely determined the success of the “Lougheed”.
 
In 1975, the U.S. air force and the Department on the development of NIR for military use in the U.S. Department of defense (DARRA) announced a competition among aircraft manufacturing companies to create a stealth aircraft. The competition was attended by five leading American firms, including the “Northrop”,”Douglas” and “Boeing”. In the same year they were joined by “Lockheed” in the face of the Department “skunk Works”. The competition consisted of several stages, the last of which included the construction and testing of aircraft with low visibility (radar, infrared, acoustic and visual) to demonstrate the effectiveness of the technology used and the correctness of the chosen concept.
In October of the same year was declared the winners of the first stage of the competition. They were of the firm “Northrop” and “Lockheed”, which received contracts for 1.5 million dollars. to build the models they have developed variants of the aircraft to measure ESR.
 
In early April 1976, after the test models, “Lockheed” was the winner of the next stage of the competition — values of the EPR model was many times less. During the following phase, the program received the code name “Have blue”. In the framework of the firm “Lockheed” was to build two flight experimental aircraft.
 
The first KHBT НВ1001 (“Kev blue” No. 1001), began in the “skunk Works” in July 1976. The first race of the engines it was made 4 APR 1977 in Bernanke. To provide the required secrecy of the plane established between the two trailers stretched over them a camouflage net.
 
Lockheed F-117A
Lockheed F-117A
 
The Lockheed F-117A:
I – fold additional engine intake 2-guided bombs GBU-10, 3 — guided bombs GBU-27, 4 – receivers of air pressure, 5 – block optic-electronic sensors (IR station forward view and rangefinder-designator), 6 canopy, 7 — air intake grille engine, 8 – retractable radio antenna, 9 — intake ventilation of the engine compartment 10 to the external elevon, 11 — inner elevon, 12 — alyumoferritnoy console tail, 13 — the lower edge of the engine nozzle, 14 – ventilation grille, 15— Nisha IR-station review of the lower hemisphere, 16 -fold the front landing gear, 17 – fold main landing gear, 18 — sash bombolyuka, 19 — retractable fuel consumer system in-flight refueling, 20 hood cooling systems high-frequency equipment, 21 — solar panel, 22 indicator display information on the windshield, AN/АVQ-28, 23 to the primary display, 24— retractable pylon mount bombs, 25 — landing light.

 
Created for calculations of EPR computer program “Echo-1” allows for calculations using only two-dimensional surfaces. These limitations led to the creation of aerodynamic layout of the aircraft with the outer lines representing exclusively straight lines, and the outer surface — a large set of planes, oriented in space in such a way that the incoming energy is reflected in any other direction except the direction to the radiation source.
 
For testing НВ1001 was partially disassembled (undocked wing), shipped overnight on a cargo plane C-5A and taken to a secret flight test center (PERSONS) in the town of Grum lake, in a remote and desert area of Nevada. Here, at the time tested such games devices like U-2, A-12, SR-71 reconnaissance UAV GTD-21, which was also the fruits of creative activity “skunk Works”.
built three aircraft, two of which were sent to Groom lake, and the third left at the factory for static testing, during which it was destroyed.
 
НВ1001 first flight took place on 1 December 1977. It was piloted by bill Park, a well-known test pilot of the company “Lockheed”, the first to reach the aircraft the SR-71 design speed (Mach number more than three) and the first effected the landing of the aircraft and-2 on the deck of an aircraft carrier.
 
НВ1001 was intended for research of flight characteristics, stability and controllability, while НВ1002 — to demonstrate low visibility. Until the end of 1977 НВ1001 carried out 36 flights, and on 4 may 1978 crashed. Bill Park had to leave the plane, the pilot received serious injuries and was later forced to withdraw from flight operations.
 
20 July 1978, he took flight a second instance IT НВ1002, who piloted the US air force Norman deason. He later and performed most of the planned work. Within 12 months НВ1002 made 52 flight. Basic tests for radar signature ended in September 1978 against the integrated air defense system in July 1979. During the tests the aircraft showed the characteristics of low visibility in the face of opposition systems of ground and air basing, and also low acoustic signature. Results in reducing the visual visibility was not good enough because of the mottled gray-blue coloring.
 
11 July 1979 НВ1002 crashed caused by a failure in the hydraulic system. Deason who was piloting the plane, was forced to leave the burning car.
 
Despite the loss, the company “Lockheed” demonstrated the viability of the chosen concept — aircraft-summer-PI and was really unobtrusive. The U.S. air force took the decision to develop a full-scale version of the original sample as part of a secret program “Senior Trend” which began in September 1978.
 
By this time, were defined the main fighting tasks for the aircraft that allowed the company “Lockheed” to narrow the focus when designing. The aircraft with low ESR are ideal for attacking ground objects subject to specific requirements, namely: stealth penetration through the enemy’s defenses and destroying high-priority targets with the weapons precision-guided munitions.
 
It was necessary to make the aircraft fully Autonomous — not depending on any external communication when performing combat tasks. Required to provide almost Neprikasaemye in the calculation of the EPR, to significantly reduce infrared radiation, to reduce observability of the aircraft due to the geometric dimensions and color, and visibility of specific exhaust of the power plant and the contrail when flying at medium altitudes.
 
In December 1978, after the approval of the program by US President Jimmy Carter Department “skunk Works” has formally begun the full-scale development of the aircraft, which later received the designation of the U.S. air force F-117A “night hawk”. In fact, the work began somewhat earlier, November 16 — from the moment of signing of the contract with the air force.
 
Although the initial requirements of the U.S. air force was limited to a modest purchase of 20 aircraft, the US Congress insisted on buying more machines to form the wing. In the result, it was purchased 59 F-117A.
 
18 June 1981 YFР-117, the prototype F-117A was first flown in INDIVIDUALS Groom lake. It was piloted by Hal Farley, chief test pilot of the company “Lockheed”. Flight (unlike many others) took place during the daytime. The first production F-117A (01) took to the air on 15 January 1982. For him every 8-10 weeks followed by delivery of other production cars.
 
For the generated wing were treated to a special airbase near the abandoned silver mining town of Tonopah and conducted relevant activities to ensure secrecy. Upon completion of the formation of the warhead was designated “37th tactical fighter wing”.
 
During its existence, the F-117A secretly visited various parts of the world (UK, Panama, Saudi Arabia, Netherlands, South Korea and other countries), where they were moved with the aim of developing possible theatres of war, and to participate in combat (Panama, 1989; Persian Gulf, 1990— 1991). In different degrees of preparation were plans to use aircraft F-117A against Lebanon, Nicaragua, Grenada (1983), Libya (1986) and Bosnia (1995).
 
TECHNICAL DESCRIPTION OF THE AIRCRAFT
 
The fuselage — semi-monocoque construction consists of three sections: nose, Central and tail. The bow contains the front and outside equipment bays, the cockpit and the niche of the front landing gear. In the front compartment mounted electronic equipment fly-by-wire flight control system and optic-electronic station, sighting and navigation complex IRADS. Ahead of the forward section has four rod receivers of air pressure.
 
In the area of the nose landing gear has a recess in which is placed the turret with IR sensor-station front-view of the lower hemisphere (operating in the infrared range) and a laser rangefinder-designator. The niche is closed by a transparent mesh conductive screen, not transmitting radar radiation, but freely transmits radiation in the infrared range.
 
The screen is attached with lining sawtooth shape along the perimeter to dissipate incoming radar radiation from enemy radar.
 
Directly under the windshield of the flashlight is a niche in which under the same conductive screen — turret with IR sensor-system forward view in the upper hemisphere and a laser rangefinder-designator.
 
The canopy — almost triangular shape, but with the inclusion of the very narrow windshield installed (taking into account possible reflections) with a large slope. To reduce the component of the EPR from the cockpit the cockpit glass has a multilayer metallized reflective coating.
 
In the Central section located air intakes with air duct, engines, weapons bays, fuselage fuel tanks and niches main landing gear. Power circuit section includes a few wide one-piece frames.
 
The intakes are located behind the cockpit and above the wing are rectangular in shape with an oblique cut of the inlet and lateral walls. During irradiation of the bottom plane in the forward hemisphere they are escaped with the wing. The inlets permanently closed thin-walled bars with small cells made of composite material with radar-absorbing properties. The existence of such lattices provides shielding compressor blades of the engine, the radar radiation is partly absorbed and partly scattered around the grate and inside the air channel.
 
Air intakes equipped with two doors for more air intake. They are located in the upper part of the air channel and opens inside at low speeds, taxiing and at high angles of attack of the aircraft. At the entrance to the inlets of the flow of cold air separated. Passing through the channels along the engine, forming the ejector, it falls right into the wide flat output nozzle, where it mixes with the hot gases and partially cool them.
 
The tail section includes a wide flat nozzle output, niches brake parachute and landing hook. There is equipment electronic countermeasures and attached the V-tail.
 
The output nozzle have a cross-section variable cross-section, their shape changes from cylindrical (behind the engine) to wide slot, divided into 12 channels with baffles with a height of about 150 mm. It is “platypus” device ends an outstanding back and raised the bottom edge of a titanium alloy, lined with heat resistant ceramic tiles (used in reusable spacecraft “Shuttle”), This nozzle design is optimized for formation of a flat jet exhaust and accelerate its mixing with the surrounding air.
 
The wing has a constant sweep on the leading edge (67,5°) and non-traditional profile. The front edge is sharp, without mechanization, and is a continuation of the fuselage. The wing is made mainly from aluminum alloys. In the area of endings formed by several flat surfaces, set navigation lights, lenses which are made with a view to minimize radar reflection.
V-tail is mounted at the very rear point of the fuselage directly in front of the nozzles. The camber angle of the consoles is 85°. The tail is covered by RPMS and has a profile of double diamond. Console all-moving tail, with hydraulic drive, is used for directional control and not related to running height.
 
The landing gear include a conventional tricycle landing gear with oil-air shock absorbers, the braking parachute and brake hook. Chassis has one nose support with one control wheel and two main (also balancing). All three legs retracted forward into a recess of the fuselage. Fold the niches of the pillars are composed of two parts, the front part of the prismatic after the release of the support closes again.
 
Brake wheel main landing — disc, equipped with machine guns anti. To reduce the length of the landing brake parachute is used which is placed on top of the aircraft in the niche between the root parts of the V-tail is Closed alcove with two doors.
 
On the lower surface of the tail section of the fuselage in a closed niche is the brake hook for landing on airfields equipped with means of emergency braking.
 
The power plant consists of two nonafterburning turbojet engines F404-GE-F1D2 company “General electric” with the thrust of 4890 kg.
 
Fuel capacity (7000 l) is in two fuselage and four wing tanks. During long flights can make use of the additional fuel tank placed in the compartment of weapons. The aircraft is equipped with a system of refueling in flight. Retractable rotary fuel consumer type is located at the top of the fuselage, behind the cockpit.
 
Flying the F-117A has a compartment of weapons, which can be mounted ammunition weighing up to 2270 kg. the length of the compartment is 4.7 m, width — 1.75 m. Used controlled (corrected) aerial bombs (UAB) type GBU-10, GBU-12 and GBU-27 laser-guidance systems.
 
The F-117A can carry guided missiles (UR) AIM-9 “side-Inder” class “air — air” AGM-65 “Maverick” General purpose ground attack, protivorechiya certification missiles AGM-88 HARM anti-ship missiles AGM-84 “Harpoon” and a small collection of weapons with increased accuracy and some characteristics of low visibility. Although the above list looks pretty convincing for the aircraft for such purpose as the F-117A, the real confirmation of his currently available!.
 
If necessary, plane F-117A can be modified under standard tactical aviation nuclear bombs B61 or В83.
 
Work on the improvement of the first stealth combat aircraft and the creation of its variants continues, consider the possibility of operating from aircraft carriers.
 
JAWORSKI

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