ILS

Just curious... I thought the F-18C didn't come with ILS. Is it older F-18's (A models) that didn't come with ILS? Or is this a military version of ILS and it doesn't work with the civilian version? This is what I thought I read in Hornets over Kuwait (i.e. Navy/Marines had own version of ILS and couldn't use civilian version.)

Also if I remember the military ILS system only worked on aircraft carriers.

Also if I remember the military ILS system only worked on aircraft carriers.

My understanding that it's not the "military ILS" but Navy ILS that are incompatible. USAF can use civilian ILS without issue.

F-18C (USN) doesn't have with ILS, exception Blue Angles. Instead it comes with ICLS which is functionally similar but incompatible. Aircraft that operate on shore (USAF, P-8) tend to have ILS while ship-landing airplanes have ICLS equipment.

I think all planes with ICLS or ACLS equipment do not have ILS and vice versa. It would take a big plane to hold all this equipment. I think there is a ground equipment of ICLS and ACLS to practice carrier approaches without the ship.

IIRC the ILS knob shown in Wags' video had 20 channels, which fits well with the AN/SPN-41A ICLS. Regular ILS was originally a 20 channel system with (LOC) frequencies from 108.1 to 111.9MHz with a channel spacing of 200kHz, but this was expanded to 40 channels (with the new channels placed 50kHz above the existing) sometime in the 1960-ies.

As for the technical aspects of the ICLS system, it's actually quite similar to the TILS system in the Viggen, with pulse coded scanning microwave beams, as opposed to the space modulated VHF/UHF signals of the regular ILS system.

As for the technical aspects of the ICLS system, it's actually quite similar to the TILS system in the Viggen, with pulse coded scanning microwave beams, as opposed to the space modulated VHF/UHF signals of the regular ILS system.

And there also exist TILS schemes that are compatible with regular ILS system, in what comes to airborne receivers. The principle of function is entirely different it appears, though, and for obvious reasons when it comes to the the antenna array size typically required by the ILS. These TILS systems function by interrogating the standard Mode 3 Transponder, determining the relative direction to the aircrarft, and providing a synthesized localizer and glideslope signals that don't need to be that neat directionally.

It of course follows that the flight crews using these must absolutely understand the function of the system, because the same "fake-ILS" signal is received by all the possible receivers. Imagine what that would do if you did have your standard autopilot approach mode armed out of habit and received the ILS picture meant for someone else perfectly on the beam...a perfect "what's-it-doing" really!

the RAAF FA18A and the Canadian CF18 came with civilian ILS and VOR DME. The USN ILS control box was still present on the left hand sill panel but inoperative. The HI had ILS and VOR options which are "boxed" to select steering. The UFC was used to tune the desired ILS or VOR freq. The Navy and civilian ILS systems are totally incompatible.

And there also exist TILS schemes that are compatible with regular ILS system, in what comes to airborne receivers. The principle of function is entirely different it appears, though, and for obvious reasons when it comes to the the antenna array size typically required by the ILS. These TILS systems function by interrogating the standard Mode 3 Transponder, determining the relative direction to the aircrarft, and providing a synthesized localizer and glideslope signals that don't need to be that neat directionally.

 

It of course follows that the flight crews using these must absolutely understand the function of the system, because the same "fake-ILS" signal is received by all the possible receivers. Imagine what that would do if you did have your standard autopilot approach mode armed out of habit and received the ILS picture meant for someone else perfectly on the beam...a perfect "what's-it-doing" really!

That sounds like the TLS; Transponder Landing System. I'm not too familiar with this system, and it's not mentioned in ICAO annex 10, but apparently it's certified for CAT I operation by the FAA. It has certain advantaged for sites where regular ILS doesn't work optimally, but I don't think it has been widely adopted (at least outside the US). Here in the frozen wastelands (Norway) we use a GBAS system (SCAT-1, not GAST-C/D; at least not yet) for precision approach at the airports where terrain conditions preclude the use of ILS.

 

It would take a big plane to hold all this equipment.

I'm doubting that "size" is an issue. I do believe cost was the factor they left out civi ILS.

That sounds like the TLS; Transponder Landing System. I'm not too familiar with this system, and it's not mentioned in ICAO annex 10, but apparently it's certified for CAT I operation by the FAA. It has certain advantaged for sites where regular ILS doesn't work optimally, but I don't think it has been widely adopted (at least outside the US). Here in the frozen wastelands (Norway) we use a GBAS system (SCAT-1, not GAST-C/D; at least not yet) for precision approach at the airports where terrain conditions preclude the use of ILS.

I quickly found this brochure (link - PDF) for a similar transponder-based system. I actually had never met the term TLS before, back in air force tech all the mobile (or more properly, re-deployable perhaps) systems were just under the label TILS. On larger airfields so equipped, PAR was historically used around here (Finland) as a primary mean if ILS was not usable. I think not all the military airplanes had mode 3 back then, nor necessarily any kind of civilian transponders, as even the civilian ATC utilized military primary radar data in their picture. Transponder-based system would effectively replace both the ILS and the PAR if so wished.

Of course, in case of Hornet, there were more...creative ways: I've been told that some guys were doing self-defined NDB approaches based on GPS fixes until they were told not to. :D One can also do a non-dependent radar approach using ground mapping mode and making a target to the end of the runway. They told me the fix on the HUD is actually quite stable and easily usable for this purpose.

I'm doubting that "size" is an issue. I do believe cost was the factor they left out civi ILS.

the RAAF FA18A and the Canadian CF18 came with civilian ILS and VOR DME. The USN ILS control box was still present on the left hand sill panel but inoperative. The HI had ILS and VOR options which are "boxed" to select steering. The UFC was used to tune the desired ILS or VOR freq. The Navy and civilian ILS systems are totally incompatible.

I remember on Jetstream Episode 4 they had a trip to Los Angeles Civilian Airport (LAX) and you clearly see how they land at night with ILS.

CF-18 does have ILS as used by LAX. They are not the same as F/A-18C in USN USMC standard use.

CF-18 does have ILS as used by LAX. They are not the same as F/A-18C in USN USMC standard use.

What about the USN F/A-18E?

I had a quick skim through the E/F flight manual, and I can't find any references to regular ILS there either.

What about the USN F/A-18E?

Can be equipped but generally aren't.

Looks like we need to rely on PAR for regular airfields then.

I'd figure the ICLS is fairly unique to the US fleet, it would perhaps make sense to model an ILS set as well, even if the rest of the layout would be USN?

Can be equipped but generally aren't.

Its called TACAN

How is TACAN related to a discussion about ICLS and ILS?

What about the USN F/A-18E?

Although, there is still no capability to fly a civilian ILS in the Super Hornet, RNAV capability was recently added to the Rhino fleet.

https://sofrep.com/68410/ask-fighter-pilot-hornet-vs-super-hornet/

Great article, thanks for sharing

Does the lack of ILS in the F/A-18C mean that it will be restricted to VFR landings at airports in NTTR and other maps?

Yup. Unless ED place Navy ICLS beacons at all the airports (like they did with the TILS for the AJS37).

https://sofrep.com/68410/ask-fighter-pilot-hornet-vs-super-hornet/

Interesting reading,thanks man. :thumbup:

Yup. Unless ED place Navy ICLS beacons at all the airports (like they did with the TILS for the AJS37).