F-16.net

Newbie Joined: Aug 23, 2008 Posts: 11 Status: Offline

I would like to know the operation of some F-16 instruments. Here they are:

1. the HSI - the normal HSIs use something as a "slaved gyro" I think, right? But the F-16s HSI needs the INS for the HSI to work, so does the F-16 HSI have it's own gyro or it uses the gyros from the INS or what else? And does it need power?

2. VVI - normal VSIs measure the rate of change of altitude by detecting the change in air pressure (static pressure) as altitude changes and they don't need power for it. But the F-16s VVI needs power, and not only the battery power but the engine power or EPU power, so why does it need power and how does it work?

3. AOA indicator also needs power but I think I saw in some aircraft, like in a Learjet 45 AOA indicators without the need for power?

4. the altimeter, when the engine is shut down something appears above the 1000 feet numbers, I thinks it says PNEU or something, so does it work different with engine and without the engine?

5. the ADI, when battery power is on, the GS and LOC signs are gone but the OFF and AUX signs are still there. They vanish when INS aligns a bit, the OFF sign vanishes before the AUX sign, the AUX vanishes at something like 1 minute of INS aligning, so what does it mean AUX in the yellow box?

The ADI also needs INS to work, so does it have it's own gyro like in other aircraft, or it uses only INS?

6. The backup attitude direction indicator also has something over it before power is applyed but I think he doesn't use INS, so what about him? Own gyro or something else and does it need power?

7. On the MAGV page on the DED there can be entered informations about magnetic variation in the area, so for what it's used? Both HSI and the HUD heading tape show the magnetic heading and not the true heading, right? Is the MAGV information used just for INS positioning purposes to calculate true heading because it works with the GPS and displays GPS coordinates which need true heading?

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Newbie Joined: Aug 23, 2008 Posts: 11 Status: Offline

So, any real pilots familiar with these instruments? Any instruments? Anybody? Smile

Sorry, but I can't find any information about these F-16 instruments on the net, only about normal instruments but the F-16 has different instruments than normal aircraft and I'm very interested in it.

Enthusiast Joined: May 29, 2008 Posts: 66 Status: Offline

VVI the short answer; input pressures pass through the CADC and the CADC does not run in battery power. You need either external power applied or internal power.

Altimeter has 2 modes, electric and pneumatic (baro) modes. When you lose electrical power or your CADC your altimeter automatically switches to baro.

Enthusiast Joined: Feb 01, 2008 Posts: 82 Status: Offline

aim-120c5 wrote:

So, any real pilots familiar with these instruments?

Well, here it goes.

1. HSI: Viper's HSI is being driven by EGI/INS to display info. It doesn't have a gyro. But it needs power.

2. VVI: Viper has the CADC (a computer that receives all pneumatic/temp inputs and calculates speeds/altitudes/rates), which drives the VVI indicator. It needs power to move Very Happy

.

3. AOA: Same as above.

4. Altimeter: In the ELECT operating mode, it's driven by the CADC (As above Very Happy

) . In the PNEU operating mode, it's pneumatically operated by static pressure from the pitot-static system.

5. ADI: Uses only EGI/INS data, and the yellow AUX flag means that EGI/INS has failed or works with limited accuracy.

6. SAI: The standby attitude indicator uses a self-contained, electrically powered vertical gyroscope. It needs power, and the thing that you see over him is the OFF flag that comes on when it's out of power (or caged).

7. Indeed the jet shows mag heading. The manual input is not really needed, as it automatically calculates it's own mag variation for the present position. (*in MMC jets there's something different, just details though.)

Hope it helps, John.

Newbie Joined: Aug 23, 2008 Posts: 11 Status: Offline

It helps a lot.

So why are those electrical instruments that the F-16 uses and probably other fighters and commercial jets, more reliable and accurate than normal "Cessna 172" instruments? Instruments in general aviation aircraft like Cessna 172 have normal instruments and are still accurate as far as I know.

Quote:

*in MMC jets there's something different, just details though.

What's a MMC? Laughing

[/quote]

Enthusiast Joined: May 29, 2008 Posts: 66 Status: Offline

MMC is the Modular Mission Computer. It is basically the computer in charge of all avionics bus communications and fire control. Block 40's used to have the GAC (general avionics computer) and CCIP brought the 40's current witht the block 50.

I am assuming about the instruments here, but the fast jets have a lot more demanding specifications. Temperature, G-Force, and tolerances are a lot lower.

Salute!

OK, back when the Earth was still cooling .....

1) ADI was driven by the inertial, as was the "compass". The nav system calculated magnetic variation so's your HUD and steam gauge depiction was "magnetic".

2) The VVI in the HUD was based on inertial vertical velocity. The steam gauge VVI was based upon the basic pitot-static system and CADC. Unlike the B-2, the steam gauges had a different input than the FLCS.

3) The "standby" attitude indicator back in the early 80's was the same one we had in the late 60's. Little bitty "peanut" doofer. 28 VDC power ( so battery could power the thing). If power was lost, it could provide useable attitude info for 5-10 minutes or more due to the self-contained gyro.

4) Most of the cosmic stuff in the HUD depended upon an operational INS. A few things did not, such as barometric altitude, airspeed and angle-of-attack.

Lastly, the displays for the pilot came from a different source ( for the most part) than those used by the FLCS computers (unlike the B-2). The "steam gauges" were much more sophisticated than a Cessna 172 array. The CADC provided real true airspeed and altitude depending upon temperature and other stuff.

gotta go,
Gums sends ...

Newbie Joined: Aug 23, 2008 Posts: 11 Status: Offline

Quote:

I am assuming about the instruments here, but the fast jets have a lot more demanding specifications. Temperature, G-Force, and tolerances are a lot lower.

So are the electrical instruments in the F-16 more accurate than normal instruments? Why?

Newbie Joined: Sep 11, 2008 Posts: 4 Status: Offline

the radar of the F-16 is an AN/APG 66?hey want to say with AESA as radars which has the F-22 RAPTOR? that has characteristics? alguein knows? thanks my friends!!

goodbye!

SKYCAT_AR

Newbie Joined: Sep 11, 2008 Posts: 4 Status: Offline

someone knows?**

Newbie Joined: Sep 11, 2008 Posts: 4 Status: Offline

some of the equipment and avionics instrumentalque yop know are as follows:
*Modular Mission Computer: The MMC is devided into 4 functional blocks:

1. Data Processing Set (DSP) : weapons control and mux bus control.
2. Avionics Display Set (ADS) : interface with Head-Up Display.
3. Avionics I/O Set (AIOS) : interface with avionics.
4. Power Set (PS) : MMC power supply and conditioner and HUD low voltage power supply.

*Fire Control Radar: Westinghouse is the AN / APG 66? or another more modern version?
*Advanced IFF: identification friend or foe system is a development of the APX-111 in service on USAF F-16A.
It consists of a Beam Forming Network and a combined Interrogator/Transponder unit and operates via four (rather striking) Forward Fuselage Antennas mounted on the upper forward fuselage in front of the canopy. These "bird slicers" are probably the most noticeable exterior changes for the F-16A/B after completion of the Mid-Life Update. AIFF provides Mk. XV or Mk. XII interrogation and response.
*Air Inlet: The F-16's center hardpoint is station number 5. Block-15 aircraft have two hardpoints added to the chin of the air intake, designated stations 5L and 5R. The air inlet structure of the Block-10 aircraft was modified, due to the fact that the original inlet of the Block-10 aircraft did not allow for the implementation of hard points to carry equipment such as the Forward Looking Infrared (FLIR) pod. Along with adding hardpoints, the stores station 5 matrix will be modified.
Modification of the inlet structure was necessary for the 9 Dutch and 24 Norwegian Block-10 aircraft selected to receive the MLU modificat
*Cockpit Displays And Indicators: this includes the following components
-Wide-Angle Conventional Head-Up Display
-Multi-Function Display
-Enhanced Upgraded Programmable Display Generator
-Audio / Video Recorder
-Helmet-Mounted Display
-Up-Front Controls: Integrated Control Panel
-Up-Front Controls: Data Entry Display
-Data Entry / Cockpit Interface Set
-Instruments & Control Panels
-Interior Lighting

Enthusiast Joined: Feb 01, 2008 Posts: 82 Status: Offline

...The radar is APG-68.

John.

[quote="aim-120c5"]

Quote:

So are the electrical instruments in the F-16 more accurate than normal instruments? Why?

Electrical instruments are normal instruments these days. Very Happy

regards, OL

Enthusiast Joined: May 29, 2008 Posts: 66 Status: Offline

APG 66 hasn't been around for many years. Besides the block 60's we are at APG 68 V9

Newbie Joined: Aug 23, 2008 Posts: 11 Status: Offline

Quote:

Electrical instruments are normal instruments these days.

Ok, but I meant are those electrical instruments more accurate than "pitot" instruments and magnetic compass instruments?

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