What do all of the controls in an F16 fighter jet's cockpit do?

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(A GOOD INFORMATIVE READ)

By

Tim Morgan, Commercial pilot (ASEL, AMEL, ASES, IA), military aircraft enthusiast
I'm starting to feel like I'm being baited into these questions. And as the description mentions, I am being asked about my most favorite fighter jet, so this one should be a cinch. I might not even need to pull out my -1 (the flight manual)! (I'll try not to wax toopoetical about the joys of the F-16's usability while I type this up.) This will also probably end up being my longest answer, since modern fighters are so complicated … so buckle up.

The General Dynamics F-16 Fighting Falcon, affectionately called the "Viper," is a fourth-generation multirole fighter jet built for the US Air Force and flying today for many countries. It's a pretty unique fighter for its time in that it is single-seat, single-engine. As a multirole fighter, it's capable of a large variety of air-to-air and air-to-ground missions. As a fourth-generation fighter, it has an advanced avionics suite with onboard computers and digital displays. To cover the various functions of the digital displays would fill a book, so we'll stick to the knobs and switches.

And as in both previous answers (What do all the controls in an airplane's cockpit do? andWhat do all the controls in a fighter jet's cockpit do?), before we can discuss the switches, we must learn the systems. The F-16, as a modern fighter aircraft, has many systems, and we'll cover those now.

There are multiple variants of the F-16, and each has different equipment installed. We'll invent an F-16 to learn about. This one will be an F-16C block 50.

Engine: The F-16C is powered by a single GE F110-GE-100 turbofan engine with six-stage afterburner. The engine has two engine computers, the digital electronic engine computer (DEEC) and a mechanical secondary engine computer (SEC) as backup. These computers schedule fuel flow and airflow into the engine for optimum performance. They also schedule the position of the movable exhaust nozzles. The engine is started by a jet fuel starter (JFS), which is powered by onboard compressed air accumulators. The accumulators are charged by the hydraulic system when the engine is running.

Fuel system: The F-16 has left and right wing tanks, two forward fuselage tanks, an aft fuselage tank, and two reservoir tanks. The right and forward tanks drain to the forward reservoir and the left and aft tanks drain to the aft reservoir. The engine feeds from the reservoir tanks. Electrically-powered fuel pumps ensure that fuel is available even during negative-g maneuvers. The F-16 has provisions for up to three external drop tanks: one under each wing and a centerline tank. The centerline drop tank empties first, to the forward fuselage tank. Then the wing drop tanks drain to the wing tanks as the wing tanks empty. Transfer of fuel from external tanks is powered by pressurized air from the environmental control system (ECS).

Environmental control system: The ECS provides air-conditioning and pressurization functions, as well as other functions such as avionics cooling and canopy sealing. It uses bleed air from the engine compressor. The cabin is kept pressurized but at altitudes about about 10,000 feet an oxygen mask must also be worn.

Electrical system: The F-16 has AC and DC power generators (main and standby) connected to the engine that provides power while the engine is running. An onboard battery is used during ground operations and engine failure. Emergency power is available from the EPU (emergency power unit). The emergency power unit is powered by engine bleed air, and provides emergency electric and hydraulic power to the flight controls. In the event of an engine failure, a hydrazine rocket motor is activated, which provides EPU power for less than an hour.

Flight controls: The F-16 is unique for its time in that it has an all-electric digital flight control system (FLCS). A computer reads the pilot's control inputs and uses hydraulic-electric motors to move the flight surfaces. There is no backup mechanical linkage — without electricity, the aircraft is uncontrollable. The FLCS is powered by the aircraft's electrical system normally. It will be powered by the EPU during an engine or electrical failure. The FLCS also has its own series of batteries it can use for a short period of time. Along with normal flight controls, the F-16 also has computer-controlled leading edge flaps and trailing edge flaps (LEFs and TEFs) that operate simultaneously with the landing gear, as well as aerodynamic speedbrakes.

The FLCS also has a protection function, in that it prevents the pilot from maneuvering the aircraft into an unrecoverable spin, via the FLCS limiters. The FLCS can also modify the stick "gain" (sensitivity to pilot input) depending on the situation: cruise gains and takeoff/landing gains. There is also a "standby gains" mode for FLCS system failures.

Hydraulic system: The F-16 has two independent engine-driven hydraulic systems, A and B. Both systems are used by the FLCS simultaneously to power the flight controls and LEFs. The A system also powers the speedbrakes. The B system powers everything else: gun, air refueling, landing gear, brakes, and nosewheel steering. The EPU also has an emergency hydraulic pump that powers the A system.

Landing gear: The F-16 has retractable tricycle landing gear. Ground steering is accomplished with nosewheel steering and independent brakes on each main wheel. The brakes are hydraulically powered, with anti-skid and parking brake capability. Brake pedals are electrically powered from two of four FLCS inverters, split into two channels (CHAN 1 and CHAN 2). In the event of a hydraulic system failure, the gear can be lowered using an emergency compressed air bottle. A red light on the gear handle (the "tomato") and an audible horn warn the pilot when the aircraft is about to land with the gear up. For emergency landings, a tailhook can be lowered for use with a ground-based emergency arresting system.

Autopilot: The F-16 has a simple two-axis autopilot that (for pitch) can maintain a pitch or altitude and (for roll) maintain a heading or bank.

Pitot-static system: Airspeed and altitude are measured using an electric central air data computer (CADC) with anti-ice probe heating capability.

Warning system: The voice message system (VMS) provides audio cues to the pilot of warnings ("Pull Up," "Caution," etc.). The distinctive female tone is nicknamed "Bitchin' Betty." Labeled caution and warning lights illuminate for major failures, and a pilot fault list (PFL) display is used for getting a detailed list of faults and system failures.

Lighting system: The F-16 has a flashing anti-collision light, navigation lights, formation lights, and air refueling slipway lights (so the boomer can see the plane during a night refuel). For interior lighting, there are console, panel, and flood lights.

Oxygen system: Pilot oxygen is provided by an onboard oxygen bottle. The regulator in the mask can deliver 100% oxygen or a mixture of ambient air and oxygen. A partial-pressure breathing for g (PBG) function is available to reduce pilot fatigue during high-g maneuvering. The pilot can wear an anti-g suit which is inflated during high-g maneuvers to keep blood in the head.

Communications system: The F-16 has UHF and VHF comm radios. The UHF radio has HAVE QUICK anti-jamming capability. Either radio can be encrypted with a KY-58 secure voice module. The F-16 also has datalink capability, where aircraft in a flight can transmit their position and target information to each other over the comm radio, which is then displayed on the multifunction displays (MFDs).

Radionavigation system: The F-16 has a single TACAN transmitter/receiver that is used to measure bearing and distance from TACAN stations. The TACAN also has an air-to-air mode allowing it to measure distance (and sometimes bearing) to other aircraft that also have TACAN systems. The F-16 also has an instrument landing system (ILS) allowing it to follow a radio signal down to a runway in poor visibility conditions.

Position/navigation system: The F-16 has an onboard inertial navigation system (INS), which uses three gyroscopes to measure acceleration in each axis. This is integrated over time to track changes in position. The INS is initialized and corrected using an onboard GPS receiver. The F-16 can also carry a forward-looking infrared (FLIR) pod that provides cockpit infrared video of the view ahead.

IFF system: The F-16 has an IFF (identify friend/foe) transponder that operates in four modes. Mode 1 and mode 2 are military modes used to identify this F-16's squadron and mission. Mode 3 is used by air traffic control to identify the aircraft. Mode 4 is an encrypted mode used to identify the aircraft as friendly to other aircraft. The IFF is capable of interrogating other aircraft and responding to interrogations.

Radar system: The F-16 has an AN/APG-65 radar with air-to-air and air-to-ground targeting capability. The radar also provides terrain-following autopilot capability and a ranging feature for gun and bomb attacks.

Radar warning system: The F-16 has a radar warning receiver (RWR) that detects incoming radar signals, analyzes their source, and provides warnings to the pilot.

Weapons systems: The F-16 has nine pylons which can carry a large variety of missiles, bombs, and other loadouts. Weapon release is managed by the modular mission computer (MMC) and fire control radar (FCR), which calculate weapons solutions and provide cues to the pilot for launching and releasing weapons. In addition to the nine pylons, two hardpoint attachments are available on the fuselage for attaching additional sensors, such as a video camera targeting pod.

Countermeasures system: The F-16 has onboard chaff and flare dispensers for spoofing radar-guided and infrared-guided missiles. It can also carry an ECM (electronic counter measures) pod (such as the AN/ALQ-184) that provides the ability to jam enemy radar.

Okay, that should be about all you need to know to understand the various switches, knobs, dials, and gauges in the cockpit. So without further ado, let's get to it! As before, we'll start from the left side and work our way around the cockpit to the right side.

Let's begin with the left console:

The top left console is the test panel, and contains switches for testing various systems:

 

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The FIRE & OHEAD DETECT button, when held, tests the fire detection circuits. The pilot should see the FIRE and OVERHEAT cautions light up.

The OXY QTY switch tests the oxygen quantity gauge. The pilot should notice the OXY LOW caution illuminate.

The MAL & IND LTS button, when held, illuminates all cockpit panel and warning lights, and sounds all VMS alerts. The pilot uses this to check the functionality of the VMS, and to ensure that no bulbs have burnt out.

The PROBE HEAT switch has three positions. When on, it heats the angle of attack and pitot probes to prevent ice formation. In TEST, it tests the circuit; the pilot should notice the PROBE HEAT caution flashing on and off.

The EPU/GEN switch is used to test the EPU and its generator. While holding down this switch, the pilot advances the throttle until the EPU is receiving enough air to power its generator. The pilot then verifies that the EPU is generating power and the FLCS relays are functioning.

The FLCS PWR lights lights are used to verify that each of the four flight control computers that make up the FLCS are functioning.

The bottom switch is the FLCS mode switch. In NORM, the FLCS operates normally. In TEST, the FLCS power output is tested on either the generator or the battery (depending on which is active). The MAINT mode is used by ground crew.

Moving down, we have the anti-g panel:

The TEST button inflates the g suit and begins partial-pressure breathing for g (PBG). This is used by the pilot to test the functionality of these systems.

Back up and moving forward, we have the FLCS control panel:

The DIGITAL BACKUP switch selects backup FLCS software, in case there is a fault with the main software system.

The ALT FLAPS switch only functions when the FLCS is in standby gains. If the FLCS is in standby gains and the ALT FLAPS switch is in NORM, the trailing edge flaps will extend and retract along with the landing gear. In EXTEND, the flaps extend no matter what. (If the FLCS is operating with normal gains, the TEFs are scheduled by the computer.)

The MANUAL TF FLYUP switch controls a protection feature of the terrain-following system. When the terrain following system is in manual mode (i.e., not on terrain-following autopilot), it still monitors the terrain ahead of the airplane, and can initiate an automatic "fly-up" if the aircraft gets too close to terrain. This switch enables or disables that feature.

The LE FLAPS switch controls the leading edge flaps. The LEFs are controlled automatically by the FLCS when in AUTO mode, or can be held in their current position by putting the switch in LOCK.

The FLCS RESET switch can be momentarily placed in the RESET position to reset the FLCS's internal database of system failures.

The BIT switch performs a FLCS built-in test. While the test is running, the RUN light illuminates. If the test fails, the FAIL light illuminates.

Below this panel we have the trim panel, which controls aircraft trim. The aircraft is in trim if it does not drift when the pilot is "hands off" of the controls.

Normally trim is controlled by a four-way hat on the stick (which we'll get to later). By putting the TRIM/AP DISC switch in DISC, the stick trim is disabled, and trim must be controlled using the ROLL TRIM and PITCH TRIM wheels on this panel. (The autopilot is also disabled.) Each wheel has an indicator that shows where the trim is compared to center. Yaw trim is not controllable by the stick and must always be set using the YAW TRIM knob.

Back up and moving forward, we have the fuel controls:

The MASTER FUEL switch, when on, opens the main engine fuel shutoff valve and the EEC (electronic engine control) fuel shutoff valve. These valves can be closed in the event of a fire.

The TANK INERTING switch, when activated, opens a valve that supplies halon gas to the fuel tanks as they empty. This anti-explosive gas reduces the chance of a fuel fire. It's typically used before entering combat. An initial amount of halon is provided for 20 seconds, then a continuous trickle of halon thereafter.

The ENG FEED knob controls which fuel reservoirs (and thus, which fuel tanks) are feeding the engine. In BOTH, the engine feeds from both reservoirs, and all tanks drain. In AFT, only the aft reservoir feeds the engine (and only the right wing and aft fuel tanks drain). In FWD, only the forward reservoir feeds the engine (and only the forward and left wing tanks drain). In OFF, all electric pumps are disabled. The engine still receives fuel from the gravity-fed proportioner. By switching between AFT and FWD, the pilot can shift the center of gravity of the airplane and correct for fuel imbalances.

The AIR REFUEL switch prepares the aircraft for air refueling operations. The air refueling slipway door is opened, revealing the refueling receptacle, and the air refueling valves are opened. Tank pressurization is reduced and external tanks are depressurized (allowing the tanks to refuel). The FLCS is placed in takeoff and landing gains, making it less sensitive to pilot input. Air refueling lights are enabled.

Below the fuel panel are the IFF and back-up TACAN controls:

The IFF MASTER knob sets the IFF master mode. In OFF, the IFF is unpowered. In STBY, the IFF is powered but does not respond to interrogations. LOW and NORM have the same function: The IFF operates normally, responding to interrogations. In EMER, the IFF responds to interrogations with a special emergency code that lets air traffic controllers know the aircraft is in distress.

The M-4 CODE switch controls how the IFF responds to mode-4 interrogations. (Remember, mode-4 is the encrypted mode that is used to determine if an aircraft is friendly or not.) In A/B, the IFF uses the normal secret code it's stored (either code A or code B). In ZERO, both code A and code B are erased from memory. This is also normally done when the aircraft is powered off. If the switch is in HOLD, the power-off zeroization is temporarily disabled, and the aircraft remembers its mode 4 codes next time it's turned on.

The IFF MODE 4 REPLY switch has three positions: In "A" or "B," it replies to mode-4 interrogations with either code A or code B. (If for example you rotate through codes once a day, the F-16 might need to store two codes if it has an overnight mission.) In the OUT position, the IFF does not respond to mode-4 interrogations.

The IFF MODE 4 MONITOR switch determines what should happen if the IFF receives a mode-4 interrogation but does not respond because of the position of the previous switch. In the AUDIO position, the VMS enunciates an audible "IFF" warning informing the pilot that he is not appearing as friendly to an incoming interrogation. This feature is disabled when the switch is positioned to OUT.

The CNI switch controls how the pilot should tune the TACAN radio. Remember these are the backup TACAN controls — normally the TACAN is tuned using the up-front controls, which we'll get to later. This is the case when this switch is in UFC. In BACK UP, this panel is used to tune the TACAN.

The backup TACAN controls consist of a channel selector, which lets you dial in one of 127 TACAN channels split into two bands (X and Y). Next to it is the TACAN mode switch. In T/R (transmit/receive), the TACAN both receives bearing information from the station and transmits signals allowing it to calculate distance to the station. In REC, only bearing information is received, no distance. The A/A TR position is used to receive bearing and distance from an airborne TACAN station (typically an airborne refueling aircraft).

Below the AUX COMM panel is the EXT LIGHTING panel:

The ANTI COLLISION switch toggles the flashing anti-collision light on the tail. The left POSITION switch toggles between flashing or steady-burning position lights. The middle switch toggles the wing- and tail-mounted red/green/white position lights. The right switch toggles the red and green fuselage position light.

The FORM knob controls the brightness of the formation lights, used for nighttime formation flying. The MASTER switch turns off all lights when in the OFF position, for combat operations. The AERIAL REFUELING knob controls the brightness of the aerial refueling lights.

Back up and further forward are the EPU controls:

 

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The HYDRAZN light illuminates when the EPU is using its hydrazine rocket motor to provide emergency power. Since the rocket's exhaust gases are hotter than 1500 °F, you want to make sure no one's standing around the aircraft if it is on the ground. The AIR light illuminates when the EPU is using engine bleed air for emergency power.

The green light illuminates when the EPU is running.

The EPU power switch, in NORM, will automatically start the EPU during an electrical failure. In ON, the EPU runs regardless. The OFF position terminates EPU operation unless there's an electrical failure. (The exception is that if you turn the EPU off before takeoff and leave it off — then the EPU will never run.)

Below the EPU panel is the electrical panel:

The MAIN PWR switch, in OFF, disconnects the battery and the generator. (The battery cannot be disconnected in flight.) In the BATT position, the battery is connected and the generator is offline. In the MAIN PWR position, the battery and generator are both connected and providing power (the generator is on standby if the engine is not running).

The CAUTION RESET light resets the main and standby generators, resets some circuit breakers, and clears the ELEC SYS caution light.

The FLCS PMG light illuminates if one of the FLCS branches is not receiving power from the FLCS generator.

The MAIN GEN light illuminates when the generator has failed, and the battery is draining or the standby generator is in use.

The STBY GEN light illuminates when the standby generator fails.

The EPU GEN light illuminates when the EPU is on but the EPU generator is not functioning.

The EPU PMG light illuminates when the EPU is on but the EPU FLCS generator is not functioning, so the FLCS is not receiving power from the EPU.

The ACFT BATT TO FLCS light illuminates when the aircraft battery is powering the FLCS and voltage is too low.

The ACFT BATT FCLS RLY light illuminates if one of the FLCS power branches' voltage is too low or disconnected.

The ACFT BATT FAIL light illuminates if the battery voltage is too low or the battery fails to charge.

Moving down, we have the controls for the audio-video tape recorder (AVTR), which consists of the gun camera, display recording, audio recording, and a VHS tape deck.

The cockpit TV system (CTVS) and audio video tape recorder (AVTR) lights illuminate when recording. The TEST button tests the lights. The master switch toggles the AVTR on and off, and in the AUTO position automatically records 30 seconds of audio and video any time the trigger is depressed. The DISPLAY SELECT dial chooses which camera is recorded to tape: The HUD camera, or left/right multifunction displays. (The AFT position is only used in two-seat models.)

Back up to the top, we have the throttle:

The cutoff release is used to move the throttle back below the idle detent, where fuel is cut off to the engine and the engine stops. The throttle is moved forward past this detent to start the engine.

The communications switch is a four-way switch:
UP - Pilot transmits over UHF radio
DOWN - Pilot transmits over VHF radio
OUTBOARD (press) - Toggles on and off datalink symbology on the multifunction displays
OUTBOARD (hold) - Commands a datalink update
INBOARD - Transmits the current air-to-ground target over datalink

The manual range knob, when turned, has a couple of functions depending on the current weapons mode. In air-to-air modes, it toggles between a 700-foot and 1500-foot manual gunnery range. In air-to-ground modes, it controls the radar gain (sensitivity).

When the manual range knob is pressed in, different functions occur. When an air-to-air missile is active, it uncages the missile (a "caged" missile follows the radar; an "uncaged" missile tracks its own independent target). When an air-to-ground missile is active, it removes the protective cover from the missile camera.

The antenna elevation knob manually controls the elevation of the radar antenna. This allows the pilot to use the radar to scan for aircraft above or below him.

The dogfight/missile override switch is a three-position switch. The middle position is normal. When moved outboard, the airplane goes into dogfight override mode. The avionics are immediately prepared for a visual dogfight. When moved inboard, the airplane goes into medium range missile (MRM) override mode. The avionics are prepared for a beyond-visual-range missile engagement.

The speed brake switch is also three-position. The middle position does not move the speed brakes. Switch forward closes the speed brakes, and aft opens them. The aft position is momentary only and must be held in.

The cursor enable control is a four-way joystick with a press capability. The joystick moves the radar cursors (or the cursors of whatever format is active on the active MFD). The z-axis (press) toggles between weapon launch modes (depending on the active weapon). For most missiles it toggles between slave mode (follows radar) or boresight mode (looks straight ahead).

The black-out switch toggles night vision goggle-compatible lighting. Next to the throttle is a "slap switch", which runs a preset emergency countermeasures program designed to spoof incoming radar-guided missiles. (Countermeasures programs are discussed later.)

Next to the throttle we have the engine controls:

The JET FUEL switch toggles the jet fuel starter. In START 1, one compressed air accumulator is used to run the JFS. In START 2, both are used. (You might need to use both on hot days or high altitudes to get enough air pressure for a start.) The RUN light illuminates when the JFS is running.

The ENG CONT switch toggles between using the primary digital electronic engine computer or the secondary hydro-mechanical engine computer. Normally the SEC is used automatically if the DEEC fails.

The next switch is a three-way switch with both top and bottom positions being momentary. In the ENG DATA position, eight seconds of engine data are recorded to the engine monitoring system computer (EMSC). The pilot would hit this switch if he hears mysterious noises, and tell the ground crew to investigate the data.

The AB RESET position, and the MAX POWER switch, do nothing for F-16s with the GE F110 engine (though it's still fun to flip on MAX POWER every so often).

Below the engine controls, from back to front, we start first with the electronic countermeasures (ECM) panel:

 

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This panel controls the ECM pod (jammer pod), if the F-16 is carrying one. The actual layout of the panel depends on which kind of ECM pod is loaded; the one shown is for the AN/ALQ-131. The top-left switch controls power to the pod: In OPR, the pod is allowed to operate, and in STBY it's powered on and warms up, but not allowed to transmit. OFF is off (of course).

The XMIT switch controls which mode the pod transmits in. The meaning of these operational modes appears to be classified, but is likely related to how the ECM software chooses jamming techniques and which radio bands to jam. One source I read claims that modes 1 and 2 activate two sets of automated jamming programs, and mode-3 is a "manual" mode where the pilot selects which bands to jam using the 1-5 pushbuttons.

The DIM knob controls the brightness of the pushbutton lights. The RESET button temporarily halts jamming when held down, allowing the pilot a "look-through" period where he can use his own radar unaffected by his own jamming signal. It also attempts to clear any detected faults.

The BIT button, when held, performs the interruptive control integrated test system (ICITS) tests. These tests are comprehensive and interrupt the normal jamming process. The jammer continuously performs the continuous CITS tests, without interruption to normal jamming.

Pushbuttons 1-5 are used to enable or disable different radio bands when in mode-3 operation. They also have "S", "A", "F", and "T" lights. The "S" light activates when the jammer is powered and ready to transmit on that band. The "A" light illuminates when in mode-3 and that band is activated. The "F" light activates if a fault is detected in that band. Finally, the "T" light activates when the pod is transmitting on that band.

The next pushbutton has had its label scratched out in the photo, but the label is "ALT". It toggles between high-altitude and low-altitude antenna angles. It has two lights; "HI" and "LO".

The "FRM" button toggles on a cooperative jamming mode, where multiple aircraft in a formation can coordinate their jammers, a technique that helps confound ECCM (electronic counter-countermeasures) software. The "A" light activates when formation mode is active. The "C" light activates when a CITS test is being performed.

The "SPL" (special) button activates an override mode that cancels out the normal transmit and formation modes. The "A" light illuminates when this override mode is active. The "IC" lamp illuminates when there's a fault in the pod/computer interface control. The "RP" light illuminates for a fault in the receiver/processor. The other lights are not used.

Moving forward, we have the audio panel:

The INTERCOM knob controls the volume of audio to the pilot's headset. The TACAN knob controls the volume of the TACAN audio signal. The TACAN transmits a morse code identifier that can be listened to. Likewise with the ILS.

The rightmost switch has three positions. In the HOT MIC position, the pilot can communicate to ground crew via a headset jack in the airplane's nose, or to the boom operator of a refueling plane via an audio connection in the refueling boom. In the CIPHER position, unsecured communications are not allowed, and the pilot can only transmit over whichever radio is connected to the KY-58 secure voice module.

Moving forward again, we have the audio 1 panel:

The COMM1 and COMM2 knobs control the volume of the UHF and VHF radios respectively. Moving the knob out of OFF turns the radio on.

Below each knob is a radio mode knob corresponding to that same radio (UHF or VHF). In the OFF position, squelch is turned off — this allows the pilot to listen to background noise for a weak signal. In the SQL position, squelch is on and background noise is filtered out. In the GD position, the radio listens to the "guard" frequency: a universal frequency that two aircraft can use to talk to each other when they have no other common frequency. (UHF guard is 243.0 MHz and VHF guard is 121.5 MHz.)

At the forward left edge of the left console is the manual pitch control:

The MANUAL PITCH switch, when held in the OVRD position, allows the pilot to override the FLCS limiters and exert manual control over aircraft pitch. This is used to recover from a deep stall. FLCS limiters operate normally in the NORM position.

To the right of that panel is the UHF radio backup controls. Normally the UHF radio is controlled by the DED, but if the CNI switch is in BACK UP (discussed earlier), the UHF is controlled from this panel:

The CHAN window displays the currently selected UHF preset. It's set by the knob to the left. The UHF radio stores up to 20 preset channels, which the pilot can write on the handy paper in the upper left.

To manually tune a frequency, the four tuning knobs are used, and the frequency is read in the center window. The leftmost knob can be set to "2" or "3" (for tuning a frequency between 200 and 399 MHz), or can be put into anti-jam frequency-hopping mode with "A."

The TEST DISPLAY button illuminates all the numeric displays.

The STATUS button toggles the main display between showing the manually tuned frequency and showing the frequency corresponding to the preset selected in the CHAN window.

The master mode switch (bottom left), in OFF, powers off the UHF radio. In MAIN, the UHF radio is on. In BOTH, the UHF radio listens on both the selected frequency and the guard frequency simultaneously. The ADF position has no function.

The VOL knob is nonfunctional — volume is controlled from the AUDIO 1 panel (discussed earlier).

The bottom-right switch, when in MNL, uses the manually-tuned frequency in the main window. When in PRESET, it uses the preset frequency chosen in the CHAN window. In GRD, it tunes and activates the guard frequency.

The T-TONE switch has two momentary functions related to anti-jam frequency hopping. To ensure that two aircraft's radios hop to the same frequencies at the same time, they both must have synchronized clocks. Moving the switch to the TONE position transmits a time-of-day (TOD) signal over the radio, for other aircraft to synchronize to. Moving the switch to the "T" position listens for a TOD signal from other aircraft.

The SQUELCH switch toggles and off the squelch function.

The frequency preset card lifts up to display additional controls:

 

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The MN SQ button screw-knob controls the level cutoff between signal and background noise for manually-tuned frequencies, and the GD SQ screw-knob for guard frequency.

The ZERO switch deletes all MWOD (multiple word of the day) data. A word of the day is a secret number that determines which frequencies the radio hops to in anti-jam mode. This data must be erased if it could fall into enemy hands.

The LOAD button loads the currently tuned frequency into the currently selected preset.

The FILL port is used to load frequency presets and MWOD data from a data tape.

Done with the left console! And we're just getting started — let's move now to the left side aux console:

Let's start with the big panel at the top. The EMER STORES JETTISON is a glass-covered button. Pound the glass and press to jettison all external stores in an emergency. To the right we have the gear lights, which turn green when each wheel is extended and locked in place. Further right is the emergency tailhook lever.

The GND JETT switch, when in ENABLE, permits jettisoning of external loads while on the ground. The BRAKES switch toggles between using FLCS channel 1 (FLCS computers A and C) or channel 2 (B and D) for controlling the wheel brakes. The switch to the right, when in PARKING BRAKE, enables the parking brake, and when in ANTI-SKID, turns on the anti-lock braking system.

Next row — the STORES CONFIG switch determines how much maneuvering the FLCS lets you perform. In CAT I, the FLCS assumes you have a lightly-loaded aircraft and will permit maximum angle of attack maneuvers. In CAT III, the FLCS assumes you have bombs or large missiles and will permit less maneuvering.

The HORN SILENCER button temporarily silences the landing gear warning horn.

The switch to the right, in LANDING LIGHTS, turns on the taxi and landing lights. In TAXI, the taxi lights are turned on.

To the right we have the landing gear lever. Normally the landing gear cannot be raised while on the ground (for good reason), but you can override this feature by holding down the DN LOCK REL button. (By the way, this still won't raise the gear on the ground because of the weight-on-wheels switch.)

The SPEED BRAKE window changes to the word "OPEN" when the speed brakes are deployed.

Next let's cover the chaff/flare panel, below. In the photo above, the panel for an ALE-40 self-protection system is shown, but I'd like to cover the Countermeasures Dispenser System (CMDS) panel, since it's a little more modern:

The panel is split into four columns, for the chaff, flare, and "other 1" and "other 2" dispensers. (Other 1 & 2 are not currently used.) At the top are status windows for each of the four dispensers (GO, NO GO, RDY, and DISPENSE when dispensing).

Each dispenser has its own on/off switch and above it a status display showing how many chaff/flare/etc. remain. "LO" is displayed when fewer than 10 rounds remain.

The RWR switch turns on an interlink between the CMDS and the RWR. When ON, the RWR can automatically initiate countermeasures programs against threats it detects.

The JMR switch turns on an interlink between the RWR the ECM pod (if carried). When ON, the RWR can automatically initiate jammer programs against a detected threat.

The MWS switch turns on the missile warning system (if installed). This is a series of cameras mounted around the aircraft that look for missile smoke trails, and warn the pilot on the RWR display (covered later).

The JETT switch jettisons all flares.

The PRGM switch selects between one of four preprogrammed dispense programs. These programs can dispense certain patterns of chaff and/or flares that are tuned to fool specific types of missiles. In BIT, a built-in test is performed.

The MODE switch sets the countermeasures mode: In OFF, the countermeasures system is inactive. In STBY, power is on but no dispensing occurs. In MAN, the pilot must initiate all dispensing programs manually. In SEMI, the VMS sounds an audible tone ("DISPENSE") when it wishes to dispense against (or jam) a detected threat, and the pilot must approve it with the CMS button (discussed later). In AUTO, the aircraft will automatically dispense chaff and flare, and initiate jam programs, against detected threats. In BYP, programmed features are disabled, and running any program will result in one chaff and one flare being dispensed.

Below and to the left is the THREAT WARNING AUX panel:

This panel has auxiliary controls for the radar warning receiver. The main panel is discussed later.

The SEARCH button toggles the display of search radars on the RWR scope (radars that are scanning but not actively tracking targets). The "S" light illuminates any time a search radar is detected, regardless of whether display on the RWR is enabled.

The ACTIVITY POWER light illuminates any time any radar activity is detected.

The ALTITUDE button toggles on and off RWR priority to low-altitude threats. When on, threats more dangerous to low-altitude flying are prioritized on the RWR scope. The LOW ALT light illuminates when it's on.

The POWER button turns on/off the RWR. The SYSTEM POWER light illuminates when the RWR is on.

The DIM knob controls the brightness of the status lights.

To the left of this panel is the alternate gear extension handle.

Pulling this handle fires compressed air bottles that manually lower the landing gear in the event of a hydraulic failure.

To the right of the RWR aux panel is the helmet mounted-display panel. This panel controls the brightness of the helmet-mounted display symbology if one is installed. Our F-16 does not have one.

Now we move to the center console, containing the HUD, two multifunction displays (MFDs), the up-front controls (UFC), the data entry display (DED), and the engine and backup flight instruments:

Let's start with the left side eyebrow lights:

The MASTER CAUTION light, top, illuminates for any caution. Pressing it acknowledges the caution. Below it is a grid of four specific caution lights. The top-left is TF FAIL, which illuminates when the terrain following system is inoperative. The other three lights have no function.

Below the eyebrow lights are the eyebrow buttons:

 

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Pressing the F-ACK button cycles through detected faults on the pilot fault display (discussed later). Repeated presses displays each new fault.

The IFF IDENT button performs an IDENT function over the mode-3 IFF, making the aircraft bloom on ATC radar displays. It's used by ATC to identify an aircraft they're talking to.

The other two buttons have no function.

Moving down to the extreme left panel:

The RF switch controls the amount radio emissions this aircraft is creating. In NORM the radar, radio altimeter, etc. are all allowed to operate normally, at the risk of making this aircraft visible to enemy RWRs. In QUIET, most radio emitters are disabled but some critical ones are allowed to transmit (such as the IFF). In SILENT, no radio transmissions of any kind are created.

The ECM light enables whenever the ECM has consent to jam. If the ECM detects a threat, it will jam that threat only when consent is allowed by the pilot.

The LASER ARM switch arms the targeting laser, which is used for laser-guided bombs and laser ranging.

The ALT REL button is an alternative pickle button in case the stick's pickle button fails.

The MASTER ARM switch allows weapons to be fired when in ARM. In SIMULATE, the aircraft symbology is the same as if it were in ARM (weapons can be activated and targeted), but no firing occurs.

The ADV MODE button toggles the terrain-following mode of the autopilot. The STBY light toggles to ACTIVE when the TF autopilot is active.

The next two switches control the autopilot. When the PITCH switch is in A/P OFF, the autopilot is off. When in ALT HOLD, the aircraft maintains it's current altitude. When in ATT HOLD, the aircraft maintains its current up or down pitch amount. When the ROLL switch is in HDG SEL, the aircraft flies the heading dialed into the backup horizontal situation indicator (discussed later). When in ATT HOLD, the current bank angle is maintained. When in STRG SEL, the aircraft flies to the current steerpoint (navigation point in the flight plan).

Moving back up and right, we have the RWR display and panel:

RWR consists of an audio and video component. Each time a new threat is detected, the radar signal is converted to an audio wave and played to the pilot, and a symbol is placed on the RWR display.

The HANDOFF button cycles between threats in priority order. Normally, the highest-priority threat is displayed, and its radar audio is heard. Pressing this button moves the indicator to the next-highest priority threat and plays its audio. The "H" light illuminates whenever the current threat is not the top priority threat.

The MISSILE LAUNCH light illuminates whenever a missile radar is detected by the RWR, or the MWS detects a missile smoke plume.

The MODE button toggles between PRIORITY and OPEN mode (indicated by the lights). In PRIORITY mode, only the five top priority threats are displayed. In OPEN mode, up to 16 threats are displayed.

The ship icon button, when pressed, increases the priority of known ship radar signatures. The UNKNOWN light illuminates whenever an unidentified radar signature is detected.

The SYS TEST button initiates a built-in test. The light illuminates while the test is performed.

The "T" button spreads out overlapping target icons to make them easier for the pilot to differentiate them. The TGT SEP light illuminates when this is on.

At top center is the HUD, which displays critical flight symbology to the pilot. The HUD has many different modes of operation which we will not spend all day documenting.

To the left and right of the HUD are the indexer lights:

On the left are the AOA indexers, which are used to control aircraft speed during landing. When the red light illuminates, the aircraft is approaching the runway too slowly and must speed up. The yellow light tells the pilot that the aircraft is too fast. The green light illuminates when the aircraft is at the proper landing speed.

On the right side are the refueling status lights. The RDY light illuminates when the air refueling door is open and the aircraft is ready to receive fuel. The AR NWS light illuminates when the aircraft is connected to the refueling boom. It also illuminates on the ground when nosewheel steering is enabled. The DISC light illuminates when the aircraft disconnects from the boom.

The multi-function displays (MFDs, also called DDIs or digital display indicators) are surrounded by 15 option select buttons (OSB) and brightness controls. Each MFD is capable of displaying one of many different formats (essentially programs), such as a radar display, video from a targeting camera, etc. The function of the buttons is labeled by the format and differs depending on the current format and page. Documenting all formats and their button functions would make this answer longer than War and Peace.

The BRT rocker controls MFD brightness, and the CON rocker contrast. The GAIN rocker, when in the air-to-ground radar format, controls radar gain (along with the gain knob on the throttle). The SYM knob controls the brightness of symbology overlying video on video-displaying formats (such as weapon cameras).

In the center, below the HUD, is the up-front controls (UFC):

The up-front controls are used to control the data entry display (DED), just to the right:

As with the HUD and MFDs, the DED has many different modes, and it would take a while to document them all. I'll talk about the UFC controls but not about the DED modes.

Along the top, the circular buttons have a variety of different functions.

The COMM 1 button puts the DED into COMM 1 mode, where the pilot can tune the UHF radio. The COMM 2 button does similarly for the VHF radio.

The IFF button puts the DED into IFF mode, where the pilot can enter IFF codes and enable different IFF modes.

The LIST button displays the DED page shown above, where the pilot has a menu of other DED pages to choose from. (The MISC option displays yet another list of pages…)

The A-A and A-G button put the airplane into the air-to-air or air-to-ground master modes, preparing the aircraft for an A/A or A/G engagement.

The SYM wheel controls HUD symbology brightness. The BRT wheel controls the brightness of the FLIR video signal which can be placed on the HUD. The DEPR RET button controls the height of the depressed reticle, which is a backup collimated sight that is displayed on the HUD if the HUD fails. The CONT wheel controls the contrast of the HUD FLIR display

The numeric keypad is used to enter numeric data in the DED. ENTR submits it and RCL cancels it. Each number button also has an alternate function, that selects a different DED page if the DED is not in a number-entry mode. For example, pressing the "1" button goes to the TACAN/ILS page, where the pilot can tune in TACAN and ILS frequencies on the DED.

The dobber is the four-way switch at bottom center. Moving it up and down moves the cursors on the DED to different fields where numbers can be entered. The rocker switch on the left increments or decrements DED data. The switch on the right, when moved to the DRIFT C/O (cutout) position, prevents the flight path marker from drifting outside of the HUD field of view. The FPM is a small symbol on the HUD that shows where the aircraft is going. Moving the switch to the WARN RESET position (momentary) acknowledges any active warnings (discussed later).

The right column controls the HUD FLIR video. The WX button activates terrain following radar weather mode, which reduces the likelihood that the terrain-following radar will be confused by clouds or rain. The GAIN/LVL/AUTO switch controls FLIR signal gain and level. In AUTO, gain and level are automatic. In either GAIN or LVL, the rocker switch above manually controls gain or level.

Next let's cover the backup flight instruments, used if the HUD is not functioning:

 

[Thunder Bolt]

At the top left is the airspeed indicator. The dial indicates airspeed in 100s of knots, and the window indicates mach speed. The knob sets the green index.

Top right is the altimeter. The large window is a digital altimeter. The knob sets current sea-level air pressure, used to calibrate the altimeter. The pressure value is shown in the small window. The "PNEU" flag illuminates when a failure of the central air data computer (CADC) forces the altimeter to revert to pneumatic mode. The two-way switch at bottom right toggles between electric (CADC) and pneumatic altitude sensing.

The middle left window displays the current angle of attack in degrees. The middle right window displays the current rate of climb or descent in hundreds of feet per minute.

The middle center window is the attitude director indicator (ADI), displaying a representation of the horizon. The yellow bars indicate ILS signal guidance. Keeping the bars centered when flying an ILS will fly the aircraft down to the runway. The knob sets the "W" shaped aircraft indicator height, used to calibrate pitch indication on the ground. Below the attitude indicator is a small ball in a track; this indicates sideslip. The ball is centered when the airplane is flying straight through the air. Below that is a small white indicator on a track below two black index marks. This is the rate of turn indicator. The aircraft is not turning when the indicator is centered.

The LOC and GS flags appear on the ADI when no localizer or glideslope signal is being received. The OFF flag appears when the ADI is not functioning, and the AUX flag appears when the INS fails and the ADI is running off its auxiliary gyroscope. The vertical scale to the right indicates vertical deviation from the desired ILS glideslope, and the ticks along the bottom of the ADI indicate bank angle.

Bottom center is the horizontal situation indicator (HSI). The face is a gyroscopic compass with the current heading read at the top. The needle indicates the selected course to or from a TACAN station. The middle part of the needle deflects left or right as the airplane flies off course. The small bug at 310° is the heading bug, used by the autopilot HDG mode. The HDG knob sets the heading bug, and the CRS knob sets the course needle. The OFF flag appears when the HSI is not functioning, and the small red flag in the center appears when a TACAN signal is not being received.

The top-left MILES display indicate distance to the TACAN station and the top right display indicates the currently-selected course.

Below the HSI is an air vent.

Left of the HSI, we have the navigation mode knob. In TCN, the course arrow is used to set the course for the tuned TACAN station. In NAV, the course arrow sets the course for the currently selected steerpoint. In ILS/TCN and ILS/NAV the ILS bars are activated as well.

The HDG knob calibrates the HSI when the INS fails and AUX mode is activated. Pushing it left or right moves the current heading left or right. The pilot should calibrate the current heading against the magnetic compass (discussed later).

Below this panel, the PEDAL ADJ handle is pulled out to allow the pilot to move the rudder pedals forward or backwards for comfort.

To the right of the HSI, we have the fuel quantity knob. This knob sets what value the fuel quantity totalizer (discussed later) needles indicate. In TEST, a test value of 6,000 pounds is displayed and the needles each indicate 3,000. In NORM, the needles indicate the internal tank totals. In RSVR, the needles indicate the amount of fuel in the reservoir tanks. In INT WING, the needles indicate the amount of fuel in the wing tanks. In EXT WING, they indicate the amount of fuel in the wing drop tanks. In EXT CTR, they indicate the amount of fuel in the centerline drop tank.

The EXT FUEL TRANS switch controls the order that fuel is fade from external drop tanks. In NORM, the centerline tank drains first. In WING FIRST, the wing tanks drain first.

Moving back up to the top, right of the UFC:

We have the DED, backup backup attitude indicator (!), and fuel flow gauge, which indicates fuel flow in pounds per hour. The backup backup attitude indicator has a knob that sets the pitch index, and the knob has a PULL TO CAGE function that cages its gyroscope so it doesn't tumble.

To the right of that, we have the right-hand eyebrow lights:

The lights are, top to bottom and left to right:
ENG FIRE - The engine's on fire. Bad news.
ENGINE - Indicates an engine fault of some kind.
HYD/OIL PRESS (double height) - Hydraulic or oil pressure is low.
FLCS - Indicates FLCS fault.
DBU ON - FLCS is running on digital backup software
TO/LDG CONFIG (double height) - Aircraft appears to be landing and is not configured for landing (gear or flaps aren't down)
CANOPY - Canopy is open or pressurization failure

The bottom right light has no function.

Below the eyebrow lights on the extreme right are the engine gauges:

The top gauge indicates oil temperature. Next down is exhaust nozzle position, then engine RPM (as a percent of maximum RPM), and finally fuel turbine inlet temperature or FTIT (pronounced "eff-tit"), in hundreds of degreed Fahrenheit.

Moving further down, we have the right aux console:

Top left is the magnetic compass. To its right is the fuel gauge, with two needles (see the fuel totalizer switch discussed previously), and a totalizer window that displays total fuel quantity digitally.

Below the mag compass is the pilot fault display (PFD), a digital display that describes aircraft faults and is used with the F-ACK button described previously. To its right are the hydraulic pressure gauges for the A and B systems.

Below the PFD are the caution lights. There are many of them:

Most are self-explanatory. Don't worry too much about the "NUCLEAR" one — it just means that the NUCLEAR CONSENT switch is armed (discussed below).

To the right of the caution panel is the liquid oxygen gauge which measures how much oxygen is remaining. Below is the EPU fuel gauge which measures how much rocket fuel the hydrazine motor has. Below that are two gauges. The left measures the cabin pressure altitude (the altitude at which the air pressure would be the same as it is currently in the cabin). The right is the clock.

Then we have the stick:

The trigger fires the gun. It's actually a two-stage trigger: The first stage starts the camera and activates the laser (if using laser ranging), and the second stage fires the gun. The weapon release button fires missiles and drops bombs (everyone calls it the "pickle" button).

The trim hat (the "nipple") is a four-way hat that controls elevator and aileron trim. The pinky switch, in most MFD formats, toggles the zoom level of whatever's displayed on the active MFD. The paddle switch turns off the autopilot.

The side button with the long name is so named because it has a bunch of functions. On the ground, it toggles nosewheel steering. When refueling, it disconnects the aircraft from the boom. In missile-firing modes, it steps between different missiles of the same type. When held down, it toggles between different types of missiles. In bomb modes, it toggles between different bomb dropping modes.

The target management switch (TMS) is also a four-way hat. What each position does depends strongly on what format is displayed on the active MFD. I'll take one example, the radar format:
Forward - Locks on the target under the radar cursors
Aft - Unlocks the target and returns to search
Left - Commands IFF interrogation
Right - Steps between targets

The display management switch (DMS) manages the MFDs and the sensor of interest (SOI). The sensor of interest is whichever sensor is being used to lock targets.
Forward - Moves SOI to HUD. The pilot uses the HUD to locate and lock a target visually.
Aft - Toggles SOI between left and right MFD. E.g.: If the radar is displayed on the left MFD and the left MFD is SOI, the radar is used to locate and lock a target.
Left/Right - Cycles between formats on the left or right MFD.

The countermeasures management switch (CMS) controls countermeasures dispensing:
Forward - Runs the countermeasures program selected by the PRGM knob on the CMDS (discussed earlier).
Left - Runs an emergency countermeasures program.
Aft - Gives the jammer consent to jam.
Right - Removes consent to jam and consent for automatic chaff/flare dispensing (if the CMDS is in AUTO mode).

Okay, home stretch. Let's do the right console now:

 

[Thunder Bolt]

We'll start on the forward end with the sensor power panel:

The LEFT and RIGHT HDPT switches control power to the left and right fuselage hardpoints. As I mentioned earlier, these hardpoints accept external sensors such as cameras or radar receivers.

The FCR switch powers on the fire control radar. The RDR ALT switch powers on the radio altimeter. In STBY mode the radio altimeter is powered but not transmitting.

Moving aft, we have the HUD control panel:

The top left switch toggles between HUD display of the vertical velocity and velocity/altitude/heading tapes, just velocity/altitude/heading tapes, or no tapes. (A "tape" is a linear scale displayed on the HUD.)

The next switch to the right toggles between display of the flight path marker (FPM) and pitch bars, just the flight path marker, or neither.

Moving right, the pilot has the option to repeat the DED display on the HUD, display the PFL on the HUD, or neither. The top-right switch toggles display of the backup depressed reticle using the primary or standby HUD image generators. In STBY, all other HUD symbology is removed.

The bottom-left switch toggles between HUD display of calibrated airspeed, true airspeed, or groundspeed. The ALT switch toggles between the display of barometric or radar altitude (altitude above sea level or ground level). The next right switch toggles between day or night HUD brightness mode. The bottom right switch, in ON, displays a test pattern on the HUD. Moving the switch momentarily to TEST STEP steps between different test patterns.

To the left of this panel is the zeroize panel:

The ZEROIZE switch erases from memory sensitive data. In the OFP position, the operational flight program is zeroized (GPS keys, IFF keys, mission data, RWR threat database, etc.). In the DATA position, some OFP data is spared from erasure.

The VOICE MESSAGE switch controls the VMS. In INHIBIT, Bitchin' Betty is silenced.

To the right of the HUD panel is the nuclear consent panel:

The NUCLEAR CONSENT panel controls consent for nuclear weapons release. Placing this switch in ARM/REL gives the airplane consent to arm and release nuclear weapons (if loaded). In REL ONLY, the airplane will release but not arm nuclear weapons.

The switch below controls which radio is sent to the KY-58 radio encryptor. In CRAD 1, the UHF radio is encrypted. In CRAD 2, the VHF radio is encrypted. In PLAIN, neither radio is encrypted and all transmissions are in the clear.

Below the HUD panel is the interior lighting panel:

The PRIMARY CONSOLES knob controls the brightness of the console text backlighting. The PRIMARY INST PNL knob controls the brightness of the backup flight instruments and engine instruments. The DATA ENTRY DISPLAY knob controls the brightness of the DED.

The FLOOD CONSOLES light controls the brightness of the floodlight that illuminates the left and right consoles. The FLOOD INST PNL light controls the brightness of the floodlight pointed at the backup flight instruments.

The MAL & IND LTS switch controls the brightness of the indicator and caution lights (bright or dim).

Below this panel is the air conditioning panel:

The TEMP knob allows the pilot to set the air conditioning level. The MAN range manually sets the ventilation air temperature, and in the AUTO range, the ECS uses ventilation air to maintain a set temperature.

The AIR SOURCE knob sets where the ECS gets its air from:
OFF - Engine bleed air valves are closed; no A/C, avionics cooling, or pressurization functions are available.
NORM - Normal ECS operation; all functions available.
DUMP - Cockpit air pressure is dumped. Used to clear smoke from the cockpit. Cockpit is ventilated by conditioned air.
RAM - Cockpit air pressure is dumped and bleed air valves are shut off. The cockpit and avionics are ventilated from ram air (air collected directly from outside, not the engine). Used when a leak spoils the bleed air.

Moving aft, we have the KY-58 secure voice control panel:

This panel controls radio encryption. The MODE knob sets the KY-58 mode. In P(lain) mode, the KY-58 does not encrypt. In C(ipher) mode, encryption occurs. In LD (load) mode, the KY-58 accepts encryption keys over the fill port. In RV (receive variable) mode, the KY-58 will accept encryption keys over the radio.

The FILL port is used to load secret encryption keys on the ground.

The rightmost knob selects which encryption key to use. A key received over the air is always placed in slot 6. The Z1-5 position zeroizes the keys stored in slots 1 to 5. The Z ALL position zeroizes all keys.

The VOLUME knob controls decrypted signal volume.

The bottom right knob is the power knob (ON/OFF). In TD (time delay) mode, the KY-58 adds a time delay to cipher signals to account for delay in satellite-based communication.

Below the control panel is space to write reminders as to which key is stored in which slot.

Getting closer! Moving aft and top, we have the anti-ice/antenna panel:

 

[Thunder Bolt]

he ENGINE switch controls the engine anti-ice function. In AUTO, anti-ice air is turned on when the ice detector detects ice. In OFF, anti-ice air is inhibited. When ON, the anti-ice function is activated. (Hot bleed air is directed over the engine air intake to melt ice.)

The ANT SEL switches determine which IFF and UHF antennas are used for transmission. In NORM, the antenna with the strongest received signal is used for transmission. The pilot can also manually select the upper or lower antenna.

Below is the avionics power panel:

Each of these switches controls power to different components: The flight control computer, stores management system, multifunction displays, up-front controls, global positioning system, datalink, and digital terrain map.

The INS switch sets the inertial navigation system mode. The INS must align its gyroscopes before it can be used for navigation, a process taking about 8 minutes.
OFF - INS is off
ALIGN STOR HDG - INS turns off but remembers its alignment information. Next time it is turned on, it can skip most alignment procedures (assuming the aircraft is not moved).
ALIGN NORM - The INS aligns. The aircraft must not be moved.
NAV - The INS provides navigational data to the flight computer. This is the normal mode after alignment.
CAL - Nonfunctional
IN FLT ALIGN - Performs an emergency in-flight alignment. The pilot must fly the plane straight and level for about a minute.
ATT - Reverts to an emergency attitude-only mode. No navigation data is provided, only attitude data. Takes about 10 second to align.

Moving aft, we come to our final panel, the oxygen regulator:

The FLOW indicator turns white when oxygen is flowing. To its right is the oxygen pressure gauge.

The red lever, in NORM, provides normal oxygen pressure below 30,000 feet, and positive pressure above that altitude when high-pressure oxygen becomes required. In the EMER position it provides 100% oxygen under pressure (used to test for leaks). The TEST MASK position does the same thing.

The diluter lever (white) toggles between 100% oxygen and a mixture of oxygen and air depending on cockpit altitude (increasing amount of oxygen as altitude increases).

The mode lever (green) turns on and off the oxygen supply to the mask/helmet and anti-g suit. In PBG it also activates the pressure breathing for g function, which supplies high pressure oxygen during high-g maneuvers to reduce fatigue.

 

[LJQC]

Hi. If you're interested in F-16 systems, especially weapons & avionics, go search for MLU M1, M2, M3 pilot manuals, which are all available online. You'll find some good read about GPS/INS weapons, LINK16, HMCS info in MLU M3 manual.