Introduction: Origins in the Analogue Cockpit
Since Air Force planes transitioned from the simple biplanes of World War I, they have become increasingly sophisticated and cockpit instrumentation reflects this. There is a bewildering array of cockpit instruments in even the most basic propeller-driven trainer or scout aircraft in the Air Force inventory today. There are at least four classes – flight and engine instruments, navigational and communication equipment – and three others are present in all fighting aircraft: weapons stores, threat receivers, and the heads-up display (HUD).
Analogue instruments (or their electronic representation) remain the rule. This is especially true for the core set, which consists of flight instruments. Critical for night-time flying or in conditions of poor visibility, these are the dial-type altimeter (to display height above sea level), the Attitude indicator (to show both “wings level” and whether the nose is pointed above or below the horizon), the Airspeed indicator, the Magnetic compass, the Heading indicator (also known as the Horizontal Situation Indicator) to correct for true north, the turn indicator, and the vertical speed indicator (to reveal rate of climb or descent).
Amongst larger military aircraft such as transports, tankers, and fighter-bombers, two other important flight instruments include the course deviation indicator (to show how well the aircraft is holding to a preset course or one provided by radio-signalling instruments on the ground) and the combination radio magnetic indicator/automatic direction finder (ADF), both of which provide bearing to known beacons on the ground or aircraft carrier at sea. Such is the multiplicity of aircraft controls and instruments that a multi-mission aircraft like the Phantom F-4 series needed both sides of the cockpit to fit in more information displays and control instruments.
Ergonomic Needs in Modern Military Aircraft
The two principal requirements for cockpit instrumentations have been, in order, quick access in combat (more on this in the next section) and ease of transition from one aircraft class to another.
To ease transitional training, virtually all aircraft designed since the Korean War put the four most vital Blind Flying instruments in a standard “T layout”. The attitude indicator is in the centre of the top row, the Airspeed indicator is to the left, the altimeter on the right, and the gyrocompass or heading indicator in the centre of the second row completes the “T”. Given the cramped nature of most cockpit layouts, the turn and vertical speed indicators commonly fill out the second row. That other vital flight instrument, the magnetic compass, is set apart from the T layout and may usually be found on the centrepost of the windscreen.
Requirements for Multi-Mode, Touchscreen Cockpit Displays
The time has come for the completely “glass cockpit” where all displays and instrumentation are shown in integrated, multi-modal glass monitors. On the most advanced aircraft already deployed by the U.S. Air Force, the F/FA-22 Raptor, cockpit clutter has already been swept aside in favour of five principal and four minor video displays (GlobalSecurity.org, 2008). This paper proposes to go beyond that and integrate all instrumentation into just one master multi-function display panel, greatly reducing clutter and minimizing the amount of precious metal needed to shield flight avionics from the electromagnetic pulse effects of a nuclear airburst. On two-seat aircraft such as the old B-52, the more recent B-2 and F-117 stealth bombers, one would of course have two displays to accommodate pilot and co-pilot in their variable roles as navigator, aircraft commander, bombardier, and defensive weapons operator (see, e.g., Waterloo, 2008). However, the principle remains the same: providing one large video display where a touch on the appropriate icon or screen segment triggers zooming-in on contacts or switches to the subsidiary screens for flight, engine, navigational, communication weapons stores, and threat management subsystems.
Regardless of the sequence in which the screens display, it is essential that the navigation panel conform to the familiar T layout (see “Ergonomic Needs” above).
In military use, the multifunction display (MFD) is a colour cathode ray tube (CRT) display at least 6 X 6 inches in size. It is driven by a 1750 processor and vector generator that can display a variety of video formats, e.g. bright colours during night-time operations or high-contrast formats in the daytime (Weindorf, 1992). While the earlier models relied on “soft buttons” arranged along both sides of the screen, all newer models are not only touch-sensitive across all sections of the MFD but also respond to multi-touch sequences and, being able to discriminate left from right hand as it does, any unique hand-finger combination the installer wishes to programme. The technology was developed by FingerWorks earlier in the decade by two University of Delaware professors and subsequently bought out by Apple Inc. (STL Innovations (2007). Making the fullest use of the technology therefore means paying Apple Inc. a license but then, this is a small price to pay for leading edge technology and budget is not a constraint in the given case.
An obviously-related development is the sweep-to-scroll feature that Avidyne (2009) licensed and adapted to allow pilots to pan and zoom anywhere on a moving map though with panning keys. With the QuickPan™ feature, the pilot can easily switch views between the plane’s current position and a destination airport, say, or a bombing run target.
Amidst the stress and multiple distractions of aerial combat, the threat monitor system must autonomously flash a blinking icon in red regardless of what panel is on display, trigger an audio alarm to the pilot’s headset, and display the main threat panel. This should show the location, altitude and heading of air-to-air or surface-to-air missiles (SAMs). Since threats are three-dimensional in nature – SAMs pointed straight at the aircraft, Phoenix-type missiles flying on ballistic paths and heading downward at the end of their flight path, enemy aircraft firing short-range missiles from any quarter – a “Rotate View” should flash on any of the four sides, ready to be touched and rapidly shift the display to the desired perspective. Pressing the icon for the oncoming missile should enable a distance and seconds-to-impact readout tag to display right underneath. And it would be convenient if the same panel were to give access to countermeasure controls, either at the very bottom of the screen or on another one when the pilot gives the spoken command for it. In turn, the countermeasures screen should display all options already arranged in decreasing priority of effectiveness, with each already blinking green for “Armed” and a second press on the appropriate weapon symbol immediately triggering the “Launch” command. Obviously, therefore, the pilot gains access to the entire defensive suite in one master control screen: lasers to blind TV-guided missiles, lock breakers for missiles guided by radar of the hostile aircraft, a cloud of projectiles or “smart pebbles” to deal with multiple incoming missiles from the rear, flares that scatter along a horizontal dimension to decoy infrared missiles, even self-propelled decoys that shoot off on perpendicular paths while emitting an exaggerated range of radar and heat signatures to attract self-guiding missiles, etc. Turning to offensive air-to-air mode, the targeting panel should show a “God’s eye view” of the surrounding “bubble” for around a hundred and fifty miles (the effective range of long-range missiles like the Phoenix). This will show all hostiles (contacts that do not flash the required Identify-Friend-or-Foe (IFF) recognition code in red. Then, all a pilot has to do to start an attack run is press each one in the desired sequence. At once, the second panel opens up with the three principal missile options for short-, medium- and long-range missiles. The missile most suited for the enemy’s range displays in bright green and the rest are in standby gray. An inset window has simultaneously opened up with either the “shoot” light (when all proper parameters of radar lock, range and aspect requirements for the target have been met) or a directional box displaying range and bearing to target so the pilot immediately knows which way to turn (Downs, 2007).
Bibliography
Avidyne (2009) Avidyne announces new EX600 multi-function display [Internet] Web.
Downs, E. (2007) Power of presentation: How technology tackles the fighter cockpit conundrum.
GlobalSecurity.org (2008) F-22 Raptor cockpit [Internet] Web.
STL Innovations (2007) Muti-touch touchscreen technology behind the Apple iPhone revealed [Internet] Web.
Waterloo, M. (2009) McDonnell Aircraft F-4H-1 (F-4B, F-4N) Phantom II main pilot’s cockpit instrument panels [Internet] Web.
Weindorf, P. (1992) The C-17 multifunction display: A building block for avionic systems. Aerospace and Electronic Systems Magazine, 7 (7) pp. 32 – 39.