Anyone ever use a Ground-controlled Approach?

[kicktireslightfires]

I recently saw some mention GCAs and curious if any VFR pilots have ever used them and under what conditions? How does it work? And how do you know which airports have the equipment to be able to help you out with a GCA? My assumption is that it's only used by VFR pilots in the event of poor planning or a surprise storm and suddenly there is nowhere VFR to land anywhere within range and that's when you request a GCA over the radio. Is that right?

 

[Groundpounder]

I have done GCA's because I was based at a joint ANG base, and the controller needed practice. They also had PAR approaches available there, but the operator I worked for at the time was not approved to do them. They are a military thing, I believe. Not sure where they are listed, but I haven't really looked for them. I am sure @Velocity173 would know more about it than me.

I should have said ASR, not GCA.

 

[Velocity173]

I’ve done them both VFR and IFR. Given maybe 1,500 GCAs as a controller.

The AIM and WIKI have a decent overview in how they work. In a nutshell, you call up approach that serves the airfield that has the GCA and request one. They will radar ID you and then simply vector you for the intercept to final. They might hand you off to a separate GCA / arrival controller but most likely, you’ll get handed off to the radar final controller (RFC). The RFC will take the handoff from approach and essentially talk you down. If it’s a ASR approach then it’ll be a non precision that will take you to an MDA and missed approach point (usually 1 mile from runway). If it’s a PAR, then it’s a precision approach (glide path) that’ll take you down to a decision height. That decision height is usually between 100-200 ft above the threshold. Phraseology is pretty standard in that they’ll provide vectors and course trend information and in the case of the PAR, glide path trend information. Just listen to what they say, follow directions and at the end of the approach you’ll either hear “after landing contact tower” or if doing another “remain this frequency for approach/arrival/ GCA.”

To determine if the field has one look in the front of an approach plate under radar instrument approach minimums. If you are using something like Fore Flight, they’re listed in approach data.

No need to be IFR or VFR in bad weather. If you’re VFR and want to do one for practice, give approach a call and ask. There might be restrictions if it’s a military base. Some allow it, others don’t. Most allow with the restriction of low approach only.

 

[Tools]

Yep, flew them in the military. Why? It’s all we had! Yep, t-2s and a-4s had NO vor or ils equipment. Had a tacan and a uhf radio and that was it.

the s-3 had that and a UHF ils, which was considered non precision and pretty much only carrier based. We had one more thing called needles. A fire control radar and primitive data link thingy also only carrier based.

oh ya, and everything also had a uhf ndb. Not real common either.

Asr and par approaches are really very neat. Try a “no gyro” version some time!

tools

 

[Velocity173]

This scene always makes me laugh. I would have loved to give a PAR with this phraseology but would have gotten a counseling statement out of it. Starts at 1+00.

 

[luvflyin]

I recently saw some mention GCAs and curious if any VFR pilots have ever used them and under what conditions? How does it work? And how do you know which airports have the equipment to be able to help you out with a GCA? My assumption is that it's only used by VFR pilots in the event of poor planning or a surprise storm and suddenly there is nowhere VFR to land anywhere within range and that's when you request a GCA over the radio. Is that right?

That would be pretty much so although I’ve never heard of a non instrument rated pilot getting saved by one. Maybe I will soon.

 

[Tools]

Hmmm... to fly one well you pretty much need to use your VSI as a pitch instrument.

of course light civil speeds changes things.

We flew them in the military from the get go, and instrument training included maneuvers well suited to gca approaches. Not sure how someone not trained would do. Really might not be that big of a deal.

 

[luvflyin]

Hmmm... to fly one well you pretty much need to use your VSI as a pitch instrument.

of course light civil speeds changes things.

We flew them in the military from the get go, and instrument training included maneuvers well suited to gca approaches. Not sure how someone not trained would do. Really might not be that big of a deal.

So much is required of the Aviate part of Aviate, Navigate, Communicate that it being pulled off by a GCA Controller who wasn’t also a pilot I think would be pretty iffy. I’m talking about a VFR pilot who has had no instrument training other than the bare minimum required for PPL

 

[FastEddieB]

How is this different from a “DF Steer”? I realize the ground controllers used direction finding equipment rather than radar, but how does it differ from a pilot’s point of view? I did some DF Steers decades ago in S FL for practice. Don’t even know if they still exist.

 

[Tools]

The controllers are amazing. Flew these things down to 200’ more times than I can remember. In a touchy old single seat jet, it felt good to have that voice down there.

a very cooperative event, the pilots job was to be consistent. As you figured out, the controller has the lions share in figuring out each pilot, and adapting.

small caveat was at the navy jet bases with students on both ends! That was just fun!

Tools

 

[luvflyin]

I’ve done them both VFR and IFR. Given maybe 1,500 GCAs as a controller.

The AIM and WIKI have a decent overview in how they work. In a nutshell, you call up approach that serves the airfield that has the GCA and request one. They will radar ID you and then simply vector you for the intercept to final. They might hand you off to a separate GCA / arrival controller but most likely, you’ll get handed off to the radar final controller (RFC). The RFC will take the handoff from approach and essentially talk you down. If it’s a ASR approach then it’ll be a non precision that will take you to an MDA and missed approach point (usually 1 mile from runway). If it’s a PAR, then it’s a precision approach (glide path) that’ll take you down to a decision height. That decision height is usually between 100-200 ft above the threshold. Phraseology is pretty standard in that they’ll provide vectors and course trend information and in the case of the PAR, glide path trend information. Just listen to what they say, follow directions and at the end of the approach you’ll either hear “after landing contact tower” or if doing another “remain this frequency for approach/arrival/ GCA.”

To determine if the field has one look in the front of an approach plate under radar instrument approach minimums. If you are using something like Fore Flight, they’re listed in approach data.

No need to be IFR or VFR in bad weather. If you’re VFR and want to do one for practice, give approach a call and ask. There might be restrictions if it’s a military base. Some allow it, others don’t. Most allow with the restriction of low approach only.

Last I heard Los Alamitos KSLI does it and they have PAR. A non IR pilot requesting one would be crossing the line though.

 

[Tools]

Probably differs in that you get heading changes down to 2 or 3 degrees. And you get glide path calls requiring 50 fpm rate changes or less!

you get LOTS of calls in probably 5 to 10 second intervals at most, and you don’t acknowledge them at a certain point.

a good controller will essentially drive your scan.

tools

 

[flyingron]

How is this different from a “DF Steer”? I realize the ground controllers used direction finding equipment rather than radar, but how does it differ from a pilot’s point of view? I did some DF Steers decades ago in S FL for practice. Don’t even know if they still exist.

A DF steer isn't an approach. It's not done by radar but by radio direction finding. It's nowhere near as accurate. They're mostly gone anyway. As I recall from being in the Leesburg AFSS twenty years ago was they were just decommissioning the last DF unit in their area. Lost pilots they had two strategy: 1. Get a squawk code from approach/center and see if the lost person shows up on a scope somewhere, 2. They had a plotting board (a sheet of glass over a sectional) that they could walk the pilot through some VOR radial readdouts.

Getting back to GCA, there's a pretty good depiction of one at the end of the original Airport movie.

 

[luvflyin]

How is this different from a “DF Steer”? I realize the ground controllers used direction finding equipment rather than radar, but how does it differ from a pilot’s point of view? I did some DF Steers decades ago in S FL for practice. Don’t even know if they still exist.

Quite a bit different in accuracy.

 

[RussR]

The presence of a "GCA" approach (actually there are two different types, "ASR", i.e. Surveillance Approaches which only provide lateral guidance (but the controller will provide recommended altitudes at each point), and PAR, Precision Approach Radar which provide lateral and vertical guidance) is indicated in a couple of ways. If you are familiar with approach charts, it is shown in the upper left corner. If it says "ASR" then that means the airport has radar approaches.

But as a VFR pilot, you may not be familiar with approach charts, and regardless it's a lousy way to find where they are if you don't already have some idea. So for that, you need to go to the TPP (the "chart books") available in many places of course, but from the FAA at https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dtpp/

Click on your region (there is a link above the individual files with an index) and go to page N1. This will list all airports in that region with radar approaches. It may not be very many, and as a VFR pilot you may not know what all the information means, but at least you know that they are available at those airports.

I will say it's not like every airport has them, not at all. I clicked on the "EC1" file (because it's the first one on the list) which covers Michigan and there are only 2 airports with radar approaches. The book with OK and AR (my region) has 8, but two of those are military bases.

And predominantly what you'll be seeing are the ASR type of radar approaches. These use the existing ATC radar and that's why they can only give you left/right guidance and recommended altitudes. PARs, on the other hand, require specialized ground equipment and are virtually exclusively a military thing (I know of no exceptions but would be happy to have one pointed out) - and even then, the military seems to be gradually getting ride of them too. At least for the Air Force, they used to be primarily at fighter bases (since fighters often didn't have much in the way of approach capability). In OK/AR, there are zero PARs, and there are quite a few military bases in these two states.

That said, you have to be pretty decent with basic IFR skills to be able to fly one. The controller is going to give you headings, and if you can't hold one it's going to be really hard for them to get you on the right one.

 

[Bill]

you get LOTS of calls in probably 5 to 10 second intervals at most, and you don’t acknowledge them at a certain point.

My crusty old curmudgeon CFII had me fly a few radar approachs (I think they were ASR) during my IR training. He said I'd probably never need one, but it's good to experience it and know it's a tool in the bag. And, as a retired controller, he said the controller probably wouldn't mind logging one. I especially remember that at some point the controller tells you not to ack instructions, just follow them.

 

[luvflyin]

Probably differs in that you get heading changes down to 2 or 3 degrees. And you get glide path calls requiring 50 fpm rate changes or less!

you get LOTS of calls in probably 5 to 10 second intervals at most, and you don’t acknowledge them at a certain point.

a good controller will essentially drive your scan.

tools

I’m sure you’ve heard the “if no transmissions received for 5 seconds on final..blah blah” speech many times. It’s 5 for PAR and 15 for ASR.

 

[luvflyin]

My crusty old curmudgeon CFII had me fly a few radar approachs (I think they were ASR) during my IR training. He said I'd probably never need one, but it's good to experience it and know it's a tool in the bag. And, as a retired controller, he said the controller probably wouldn't mind logging one. I especially remember that at some point the controller tells you not to ack instructions, just follow them.

They do.

5−10−10. TRANSMISSION ACKNOWLEDGMENT
After contact has been established with the final controller and while on the final approach course, instruct the aircraft not to acknowledge further transmissions.
PHRASEOLOGY−
DO NOT ACKNOWLEDGE FURTHER TRANSMISSIONS.

 

[iamtheari]

As others have noted, ground-controlled instrument approaches are much more commonly flown by military pilots since some of their planes don't have anything else. Being a civilian pilot, I've only flown a no-gyro ASR approach under the hood for practice. The airport I was going to had, amongst its approach plates, one called Radar Minimums. Here is what that looks like: https://skyvector.com/files/tpp/2102/pdf/NC1RAD.PDF

I seem to recall that all of the information from the approach plate was also given to me over the radio.

This type of approach could be a lifesaver for a proficient instrument pilot who loses navigational equipment but still has a working comm radio and transponder. It could also get a VFR pilot out of a bind, although you would have to have tried pretty hard to get into the bind in the first place, otherwise your ability to maintain your assigned altitude and heading should have resulted in vectors to VMC instead of deeper into the clag looking for a runway.

 

[Velocity173]

That would be pretty much so although I’ve never heard of a non instrument rated pilot getting saved by one. Maybe I will soon.

We had it happen at our facility (NBC) in the mid 90s. PA28 went IIMC and non instrument rated. We decided his best course of action would be a PAR at the air station vs trying an LOC/ILS. It worked and the RFC got an award for the save.

We also made sure the SPs knew the aircraft was an emergency and not to throw them on the ramp and point M-16s at them.

 

[Warlock]

Saved my ass while flying an AH-1 when my front seater which happened to my Battalion commander who put us in the clouds low level on the way to a meeting...after I initiating a climb to minimum obstruction altitude and rolling the transponder to 7700 a goddess from Ramstein Approach initiated a call on guard to us. She gave immediate vectors for obstacle clearance and offered a PAR...my battalion commander who was old school Vietnam and was a graduate of the combat instrument course and had never really flown instruments, his first action was to give me the controls and fire up a cigarette...

 

[Tools]

....his first action was to give me the controls and fire up a cigarette...

Fine, sprayed coffee everywhere... BWAHAHAHA

A man’s got to know his limitations.

I can just picture this...

Tools

 

[luvflyin]

The controllers are amazing. Flew these things down to 200’ more times than I can remember. In a touchy old single seat jet, it felt good to have that voice down there.

a very cooperative event, the pilots job was to be consistent. As you figured out, the controller has the lions share in figuring out each pilot, and adapting.

small caveat was at the navy jet bases with students on both ends! That was just fun!

Tools

Don’t know if I’d agree with you who had the lions share of figuring out the other. I’ve given many, many PAR’s, listened to many and flown a few. Some controllers are lacking in giving good ‘trend’ information. They’ll tell ya when yer above and when yer below and maybe throw in a coming down. More trend info helps. Comin down, comin down slowly, still comin down

 

[luvflyin]

Saved my ass while flying an AH-1 when my front seater which happened to my Battalion commander who put us in the clouds low level on the way to a meeting...after I initiating a climb to minimum obstruction altitude and rolling the transponder to 7700 a goddess from Ramstein Approach initiated a call on guard to us. She gave immediate vectors for obstacle clearance and offered a PAR...my battalion commander who was old school Vietnam and was a graduate of the combat instrument course and had never really flown instruments, his first action was to give me the controls and fire up a cigarette...

Allow me to continue. Fired up a cigarette, grabbed his lunch bag and said “this is one sheety last meal.”

 

[Stan Cooper]

When I was a student pilot getting ready for my check ride in the early sixties, my instructor had me do several surveillance radar approaches under the hood into Hill AFB in Ogden, UT. The controller provided lateral guidance (headings), but only recommended altitudes during the approach. Every time we did these, my CFI would say, "take off the hood" and I'd be right on runway heading on a stable approach at around 300 feet. It gave me confidence as a VFR pilot that I could get safely back on the ground if I ever got lost or accidentally flew into IMC.

 

[luvflyin]

We had it happen at our facility (NBC) in the mid 90s. PA28 went IIMC and non instrument rated. We decided his best course of action would be a PAR at the air station vs trying an LOC/ILS. It worked and the RFC got an award for the save.

We also made sure the SPs knew the aircraft was an emergency and not to throw them on the ramp and point M-16s at them.

Aw c’mon, SP’s need training to. I’m gonna assume that even if the final controller wasn’t a pilot, there was someone there with enough pilot experience to help the pilot get set up for what was coming.

 

[luvflyin]

The presence of a "GCA" approach (actually there are two different types, "ASR", i.e. Surveillance Approaches which only provide lateral guidance (but the controller will provide recommended altitudes at each point), and PAR, Precision Approach Radar which provide lateral and vertical guidance) is indicated in a couple of ways. If you are familiar with approach charts, it is shown in the upper left corner. If it says "ASR" then that means the airport has radar approaches.

But as a VFR pilot, you may not be familiar with approach charts, and regardless it's a lousy way to find where they are if you don't already have some idea. So for that, you need to go to the TPP (the "chart books") available in many places of course, but from the FAA at https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dtpp/

Click on your region (there is a link above the individual files with an index) and go to page N1. This will list all airports in that region with radar approaches. It may not be very many, and as a VFR pilot you may not know what all the information means, but at least you know that they are available at those airports.

I will say it's not like every airport has them, not at all. I clicked on the "EC1" file (because it's the first one on the list) which covers Michigan and there are only 2 airports with radar approaches. The book with OK and AR (my region) has 8, but two of those are military bases.

And predominantly what you'll be seeing are the ASR type of radar approaches. These use the existing ATC radar and that's why they can only give you left/right guidance and recommended altitudes. PARs, on the other hand, require specialized ground equipment and are virtually exclusively a military thing (I know of no exceptions but would be happy to have one pointed out) - and even then, the military seems to be gradually getting ride of them too. At least for the Air Force, they used to be primarily at fighter bases (since fighters often didn't have much in the way of approach capability). In OK/AR, there are zero PARs, and there are quite a few military bases in these two states.

That said, you have to be pretty decent with basic IFR skills to be able to fly one. The controller is going to give you headings, and if you can't hold one it's going to be really hard for them to get you on the right one.

It’s over to right of the briefing strip on the newer charts. KNYL. There may be other joint use airports. Maybe they won’t give them to Civil Aircraft, I dunno. But that would just be a command prerogative

 

[RussR]

It’s over to right of the briefing strip on the newer charts. KNYL. There may be other joint use airports. Maybe they won’t give them to Civil Aircraft, I dunno. But that would just be a command prerogative

It does appear that the military puts them on the right side for military charts. FAA charts have it on the left.

 

[luvflyin]

It does appear that the military puts them on the right side for military charts. FAA charts have it on the left.

View attachment 95017

Ah. I was lookin at NYL charts and jumped to a conclusion. My bad

 

[Timbeck2]

This scene always makes me laugh. I would have loved to give a PAR with this phraseology but would have gotten a counseling statement out of it. Starts at 1+00.

Thanks for that. That guy had some super PAR scope with recommended pilot actions instead of recommended altitudes. At the very end when he shouts "NOW" was the funniest part. Only time I was able to do that was in Saudi Arabia when we could open the door to the TPN-19 and see the runway. It was a day when nothing else was going on (hence opening the door) and I told the guy I was working with (and fellow fly killer...another story) that when he got to decision height he would open the door. So it went like this: "On course, on glidepath....at decision height (opens door) over landing threshold on course...(I look out the door) touching down... (see the touchdown) NOW.... Contact tower on roll out."

 

[RussR]

Thanks for that. That guy had some super PAR scope with recommended pilot actions instead of recommended altitudes. At the very end when he shouts "NOW" was the funniest part. Only time I was able to do that was in Saudi Arabia when we could open the door to the TPN-19 and see the runway. It was a day when nothing else was going on (hence opening the door) and I told the guy I was working with (and fellow fly killer...another story) that when he got to decision height he would open the door. So it went like this: "On course, on glidepath....at decision height (opens door) over landing threshold on course...(I look out the door) touching down... (see the touchdown) NOW.... Contact tower on roll out."

Was this at PSAB?

 

[Timbeck2]

It was

Was this at PSAB?

It was indeed. The new tower/radar facility was being built at the time so we were on the little hill across the runway with the porta johns in 120 degrees.

 

[Velocity173]

Thanks for that. That guy had some super PAR scope with recommended pilot actions instead of recommended altitudes. At the very end when he shouts "NOW" was the funniest part. Only time I was able to do that was in Saudi Arabia when we could open the door to the TPN-19 and see the runway. It was a day when nothing else was going on (hence opening the door) and I told the guy I was working with (and fellow fly killer...another story) that when he got to decision height he would open the door. So it went like this: "On course, on glidepath....at decision height (opens door) over landing threshold on course...(I look out the door) touching down... (see the touchdown) NOW.... Contact tower on roll out."

At 1:36 I love that “G D don’t drift!” WTH does that even mean. If I was Charlton Heston I’d be like, is this guy gonna give us a vector some time today or just yell at us about our flying skills?

Yeah I did some tactical stuff by the runway as well. Once you hear the jet noise go by you knew you were good for “contact tower.”

 

[Timbeck2]

I didn't see the movie but was the PAR "controller" a pilot that just happened to be walking by? "Get that nose up" in controller speak would have been, "going below glide path" and "kick that right rudder" would have been, "drifting right of course, turn left heading..."

Pushing Tin is another movie controllers just laugh at because hardly any of that ever happens in a real IFR room.

 

[luvflyin]

It was

It was indeed. The new tower/radar facility was being built at the time so we were on the little hill across the runway with the porta johns in 120 degrees.

porta johns. pfft, typical Air force luxury

 

[Timbeck2]

Hey I joined the Air Force so I wouldn't have to sleep with my head in the mud. But I would have rather had that set up rather than porta johns. I'll tell you why. The 120+ heat inside them notwithstanding, the flies are abundant and fearless in Saudi Arabia. They are down in the hole walking around on turds when you enter. As your pee disturbs them, they fly out and the only place they want to land is your lips and there isn't anything you can do about it.

 

[RussR]

It was

It was indeed. The new tower/radar facility was being built at the time so we were on the little hill across the runway with the porta johns in 120 degrees.

Spent a deployment at that facility, then another one when we were in the new facility. Aug 1998 to Jan 1999 and then Dec 2000 to March 2001. Couldn't figure out why they said "bring your field jacket" to Saudi Arabia in the summer, but man that TPN-19 was kept cold...

 

[jsstevens]

I worked on an F-5 flight sim in the mid 80's I wrote all the instructor station software including a page with the glide slope and lateral display so the instructor could be the controller for PAR approaches. Fun times.

 

[Tarheelpilot]

I have done GCA's because I was based at a joint ANG base, and the controller needed practice. They also had PAR approaches available there, but the operator I worked for at the time was not approved to do them. They are a military thing, I believe. Not sure where they are listed, but I haven't really looked for them. I am sure @Velocity173 would know more about it than me.

I should have said ASR, not GCA.

I’ve done PAR approaches into Seymour Johnson AFB. Could not land but the controllers were not picky about letting civilians do them to a low approach. They liked getting the practice apparently so I started taking my instrument student over there at night just to have exposure to the PAR. It was neat because of how it was...

This was all over twenty years ago so I have no idea if it’s still available.

 

[luvflyin]

Hey I joined the Air Force so I wouldn't have to sleep with my head in the mud. But I would have rather had that set up rather than porta johns. I'll tell you why. The 120+ heat inside them notwithstanding, the flies are abundant and fearless in Saudi Arabia. They are down in the hole walking around on turds when you enter. As your pee disturbs them, they fly out and the only place they want to land is your lips and there isn't anything you can do about it.

C'mon now. Youse guys is "Fly Killers"