F-22 cockpit

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When the aircraft was introduced in January 2003, the F-22 cockpit represented a zenith in the so-called “glass-cockpit” without any traditional flight instruments and was a marked improvement on the cockpit design of previous advanced aircraft ^[1] The leading features of the F-22 cockpit, which continue to be emulated or matched by other modern military fast jets, include: simple and rapid start-up, highly developed HMI, lighter helmet, large anthropometric accommodation and highly integrated warning system. Of particular note also is the large single piece canopy and improved life support. Much information about the cockpit is available in the public domain.^[2][3][4]

Contents 1 Description 1.1 Start Up 1.2 HMI 1.3 Cockpit Display Symbology 1.4 ICAW 1.5 HOTAS 1.6 Lighting 1.7 Anthropometric Accommodation 1.8 Ejection Seat 1.9 Life Support 1.10 Canopy 2 Incidents 3 References

[edit] Description

[edit] Start Up

There are only three steps to take the F-22 from cold to full readiness for takeoff: the pilot places the battery switch 'on,' places the auxiliary power unit (APU) switch momentarily to 'start' and then places both throttles in 'idle.' The engines start sequentially right to left and the APU automatically shuts down. All subsystems and avionics are brought on line and built-in tests are made. Navigation information and pilot's personal avionics preferences are loaded automatically. The airplane can be ready to taxi in less than 30 seconds after engine start.^[4]

[edit] HMI

The monochrome Head-Up Display (HUD) by GEC offers a wide field of view (30 degrees wide and 25 degrees deep) and serves as a primary flight instrument for the pilot. The HUD is approximately 4.5 inches tall with standardized symbology compatible with that used head down.^[2]

The HUD is planned to also benefit from added protection (a rubber buffer strip) that will effectively shield the polycarbonate of the canopy when it flexes during a bird-strike and should prevent it shattering. Design is also underway for a HUD that will collapse during a bird-strike.^[2]

The Integrated Control Panel (ICP) is the primary means for manual pilot entry of communications, navigation, and autopilot data. Located under the glare shield and HUD in the upper centre of the instrument panel, this keypad entry system also has some double click functions, much like a computer mouse, for rapid pilot access/use.^[2]

There are six liquid crystal display (LCD) panels in the cockpit. These present information in full colour, are fully readable in direct sunlight and offer less weight and size than traditional CRT displays. Two Up-Front Displays (UFDs) (3"x4") located to the left and right of the ICP are used to display Integrated Caution/ Advisory/ Warning (ICAW) data, communications/ navigation/ identification (CNI) data and also serve as the Stand-by Flight instrumentation Group and Fuel Quantity Indicator (SFG/FQI). ^[2]

The Stand-by Flight Group also presented on LCD, shows basic flight information, such as artificial horizon, needed to fly the aircraft in Instrument meteorological conditions (IMC). The SFG is tied to the last source of power in the aircraft, so if everything else fails, the pilot will still be able to fly the aircraft.^[2]

The colour Primary Multi-Function Display (PMFD) (8"x8") is located in the middle of the instrument panel, under the ICP. It is the pilot's principal display for aircraft navigation (including waypoints and route of flight) and Situation Assessment (SA).^[2]

Three Secondary Multi-Function Displays (SMFDs) (6.25" x 6.25") are located on either side of the PMFD and under the PMFD between the pilot's knees. These are used for displaying tactical (both offensive and defensive) information as well as non-tactical information (such as checklists, subsystem status, engine thrust output, and stores management).^[2]

[edit] Cockpit Display Symbology

Enemy aircraft are shown as red triangles, friendly aircraft as green circles, unknown aircraft as yellow squares, and wingmen are shown in blue. Surface-to-air missile sites are represented by pentagons, along with an indication of missile type and lethal range. An in-filled triangle means that the pilot has a missile firing-quality solution against that target. The pilot has a cursor on each screen, and he can use this to request extra information on tracks and targets. Pilot manipulation of target symbols by means of XY cursor is clearly shown in a sequence from the F.22 cockpit demonstrator.^[5]

The Inter/Intra Flight Data Link (IFDL) allows a number of F-22s, in a flight or between flights, to be linked together to trade information without radio calls having to be made between them.^[2]

[edit] ICAW

To reduce pilot workload in flight, the uniquely designed integrated caution, advisory and warning (ICAW) system can display a total of 12 individual ICAW messages at one time on the up-front display and additional ones can appear on sub pages of the display.^[4]

All ICAW presented faults are filtered to eliminate extraneous messages and inform the pilot specifically and succinctly what the problem is. For example, when an engine fails, the generator and hydraulic cautions normally associated with an engine being shutdown are suppressed, and the pilot is provided with the specific problem in the form of an engine shutdown message. ICAW also incorporates an electronic checklist. If multiple ICAWs occur, their associated checklists are selected by moving a pick box over the desired ICAW and depressing the checklist button. Associated checklists are automatically linked together.^[4]

[edit] HOTAS

The F-22 features a side-stick controller (like the F-16) and two throttles that are the aircraft's primary flight controls. The GEC-built stick is located on the right console with a swing-out, adjustable arm rest. The stick is force sensitive and moves only about one-quarter of an inch. The throttles are located on the left console. HOTAS switches, both shape and texture coded, are used to control more than 60 different time-critical functions.^[4]

[edit] Lighting

The cockpit interior lighting is fully Night Vision Goggle (NVG) compatible, as is the exterior lighting. The cockpit panels feature extended life, self-balancing, electro-luminescent (EL) edge-lit panels with an integral life-limiting circuit.^[4]

[edit] Anthropometric Accommodation

The cockpit accommodates the 0.5 to 99.5 percentile range, i.e. the body size of the central 99% of the USAF pilot population. This represents the largest range of pilots accommodated by any tactical aircraft now in service. The rudder pedals are adjustable. The pilot has 15-degree over-the-nose visibility as well as excellent over-the-side and aft visibility.^[2]

[edit] Ejection Seat

The Ejection Seat is an improved version of the ACES II (Advanced Concept Ejection Seat) used in nearly every other USAF jet combat aircraft, with a centre mounted ejection control. Improvements over the previous seat models include:

• An active arm restraint system to eliminate arm flail injuries during high speed ejections.
• An improved fast-acting seat stabilization drogue parachute system to provide increased seat stability and safety, which is located behind the pilot's head and is mortar-deployed.
• A new electronic seat and aircraft sequencing system that improves the timing of the ejection event sequence.
• A larger oxygen bottle providing more breathing air to support ejection at higher altitudes.

The system utilizes the standard analogue three-mode seat sequencer that automatically senses the seat speed and altitude, and then selects the proper mode for optimum seat performance.^[4]

[edit] Life Support

The F-22 life support system integrates all critical components (previously designed and produced separately) of clothing, protective gear, and aircraft equipment necessary to sustain the pilot's life while flying the aircraft and once ejected, including:

• An on-board oxygen generation system (OBOGS) that supplies breathable air to the pilot.
• An integrated breathing regulator/anti-g valve (BRAG) that controls flow and pressure to the mask and pressure garments.
• A chemical/biological/cold-water immersion (CB/CWI) protection ensemble.
• An upper body counter pressure garment and a lower body anti-G garment acts a partial pressure suit at high altitudes.
• An air-cooling garment, also to be used in the U.S. Army's RAH-66 Comanche helicopter providing thermal relief.
• Helmet and helmet-mounted systems including C/B goggles and C/B hood; and the MBU-22/P breathing mask and hose system.^[4]

Escape-system tests have proven the life-support system to wind speeds of up to 600 knots. Current life-support systems are designed to provide protection only up to 450 knots.

The head mounted portions of the life-support system are approximately 30 percent lighter than existing systems, which improves mobility and endurance time for pilots. With its advanced design, the HGU-86/P helmet that will be used by F-22 pilots during EMD reduces the stresses on a pilot's neck by 20 percent during high-speed ejection compared to the current HGU-55/P helmets. The F-22 helmet fits more securely as the result of an ear cup tensioning device and is easily fitted to the pilot's head. The helmet provides improved passive noise protection and incorporates an Active Noise Reduction (ANR) system for superior hearing protection.^[2]

The chemical/biological/cold water immersion clothing meets or exceeds USAF requirements and fit a wider range of sizes and body shapes (the central 99%).

[edit] Canopy

The canopy is approximately 140 inches long, 45 inches wide, 27 inches tall, and weighs approximately 360 pounds. It is a rotate/translate design, i.e. comes down, slides forward, and locks in place with pins. It is the largest one-piece canopy in production today.^[2]

The canopy's transparency (by Sierracin) features the largest piece of monolithic polycarbonate material being formed today. It has no canopy bow and offers the pilot superior optics (Zone 1 quality) throughout (not just in the area near the HUD) and offers the requisite stealth features.^[2] The 3/4 inch polycarbonate transparency is actually made of two 3/8 inch thick sheets that are heated and fusion bonded, with the sheets melding to become a single-piece and then drape forged, i.e. not laminate as in the F-16.^[2]

Post-ejection canopy-seat-pilot collision has been designed out as the framed canopy weighs slightly more on one side than the other and slices nearly ninety degrees to the right as it clears the aircraft. The canopy is resistant to chemical/biological and environmental agents, and has been successfully tested to withstand the impact of a four-pound bird at 350 knots. It also protects the pilot from lightning strikes.^[2]

[edit] Incidents

On 10 April 2006, at Langley Air Force Base pilot Captain Brad Spears, was locked inside the cockpit of his aircraft for five hours. No one in the U.S. Air Force or from Lockheed Martin could work out how to open the aircraft's canopy. At about 1:15 pm, fire-fighters equipped with chainsaws cut through the F-22's three-quarter inch-thick polycarbonate canopy and freed the pilot.^[6]

[edit] References