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Natflyer
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Does The Usaf Fly Cat II/III Approaches?

Tue Sep 09, 2014 10:05 pm

Wondering if the USAF does not do Cat.II/III approaches. A friend called and told me that a C-17 inbound to Keflavik (KEF) diverted to the Reykjavik downtown airport as KEF was below cat.I minimums (low ceiling but visibility not too bad.)
Appreciate any answers.
 
KC135Hydraulics
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RE: Does The Usaf Fly Cat II/III Approaches?

Tue Sep 09, 2014 11:14 pm

I work on C-17s and KC-135s and I am almost certain they are not certified or equipped for such approaches. I can inquire with our avionics guys for more information if desired.

[Edited 2014-09-09 17:05:27]
MSgt, USAF
KC-135R / C-17A Pneudraulic Systems Mechanic Supervisor
 
thegman
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RE: Does The Usaf Fly Cat II/III Approaches?

Tue Sep 09, 2014 11:40 pm

Depends on the equipment of the aircraft.

AFMAN 11-217V1 does have procedures for CAT II and III approaches, but I am not sure which aircraft are equipped properly.
 
solarflyer22
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RE: Does The Usaf Fly Cat II/III Approaches?

Wed Sep 10, 2014 12:17 am

I thought the C-17's were equipped for this but maybe not. Not sure about the C-5s unless its the recently upgraded ones.
 
ThePointblank
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RE: Does The Usaf Fly Cat II/III Approaches?

Wed Sep 10, 2014 2:22 am

Generally, US military aircraft can fly precision approaches, but they use a different technology than the civilian CAT II/III systems. US bases are equipped with precision approach radars which controllers use to help the pilot make adjustments to their course for precision landings.

This technology is expected to be superseded by JPALS, which uses a form of real-time differential correction of the GPS signal, augmented with a local area correction message, and transmitted to the user via secure means. This system, which is currently undergoing testing, is extremely accurate, is extremely portable and easy to set up.
 
cargotanker
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RE: Does The Usaf Fly Cat II/III Approaches?

Wed Sep 10, 2014 10:43 am

C-17s are equipped and its crews are trained to fly Cat II approaches. Not sure why the crew in the OP chose to divert.
 
thegman
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RE: Does The Usaf Fly Cat II/III Approaches?

Wed Sep 10, 2014 11:43 am

Quoting ThePointblank (Reply 4):
US bases are equipped with precision approach radars which controllers use to help the pilot make adjustments to their course for precision landings.

That is just a PAR approach where the controller just tells the pilot what to do.
 
aklrno
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RE: Does The Usaf Fly Cat II/III Approaches?

Wed Sep 10, 2014 10:21 pm

Quoting thegman (Reply 6):
That is just a PAR approach where the controller just tells the pilot what to do.

Is that the same as GCA, Ground Controlled Approach? I thought that was obsolete, but here is one reason for the military to prefer it to ILS:

In the United States PAR are used mostly by The Navy. This is because they present a more covert type of precision approach for use on Aircraft carriers. An ILS installed on a ship could provide guidance to enemy missiles but a PAR does not provide accurate guidance without controller instruction.
 
INFINITI329
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RE: Does The Usaf Fly Cat II/III Approaches?

Wed Sep 10, 2014 10:32 pm

Quoting aklrno (Reply 7):
An ILS installed on a ship could provide guidance to enemy missiles

Interesting...Could ILS signals be technically encrypted?
 
thegman
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RE: Does The Usaf Fly Cat II/III Approaches?

Thu Sep 11, 2014 12:46 am

Quoting infiniti329 (Reply 8):
Interesting...Could ILS signals be technically encrypted?

Maybe? But at what extra cost? Especially when a controller talking over a UHF frequency can do it without worry of the enemy breaking the code and shooting a missile right up your ass?

Quoting aklrno (Reply 7):
Is that the same as GCA, Ground Controlled Approach? I thought that was obsolete, but here is one reason for the military to prefer it to ILS:

I suppose. Never heard of the term GCA. We in the AF use ASR (Airport Surveillance Radar) or PAR for (Precision Approach Radar). They definitely exist at civilian airports and most military, I'm just not sure any civilians train on using them. Basically how it works is the controller gives instructions on what heading to fly and when you are on course. With the PAR they also give glideslope info.

Are they used much? Not in my experience. I have heard of fighter jocks getting them so they don't have to deal with an actual instrument procedure. They are also useful if you have lost your gyro system and are down to a mag compass and ADI because you can request no-gyro vectors and they will give start turn and stop turn instructions to get you under the weather.
 
JohnM
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RE: Does The Usaf Fly Cat II/III Approaches?

Thu Sep 11, 2014 2:13 pm

Sure they do. The original C-5A and B had autoland for example. Rarely used, but it was there. The autoland function was not enabled when the planes went through AMP mod, which includes the current C-5M. The C-17 in question might have had a crosswind limitation or possibly a failure of one of its subsystems related to ILS.
 
AAR90
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RE: Does The Usaf Fly Cat II/III Approaches?

Thu Sep 11, 2014 3:27 pm

Quoting aklrno (Reply 7):
n the United States PAR are used mostly by The Navy. This is because they present a more covert type of precision approach for use on Aircraft carriers. An ILS installed on a ship could provide guidance to enemy missiles but a PAR does not provide accurate guidance without controller instruction.

Not true concerning being "more covert." The PAR radar is something that can "hull-tech" a ship meaning any decent electronic warfare system can not only specify the location of the radar, it can specify which ship that radar is located upon: i.e. CVN-65 vs CVN-76 vs CGN-39, etc. For that reason alone, it is vary rarely used aboard US CVN's (early 1980's, only turned on for annual system qualifications).

An ILS is an ILS is an ILS. Except the USN calls it ICLS = Instrument Carrier Landing System. The ICLS is a much smaller (than civilian) system with a much much lower powered transmitter. IF one can capture the low powered beam of energy, one can follow it to.... something. But you won't know what you are being guided to as EVERY USN vessel has an ICLS installed --if for no other reason than deceptive electronic warfare. You MIGHT be going to a CVN, but you just as likely will be going to a CG, DG, FFG (all of which will happily shoot you down), supply ship, landing craft or... a motor whaleboat.   
*NO CARRIER* -- A Naval Aviator's worst nightmare!
 
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Moose135
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RE: Does The Usaf Fly Cat II/III Approaches?

Fri Sep 12, 2014 7:31 am

Quoting thegman (Reply 9):
I suppose. Never heard of the term GCA. We in the AF use ASR (Airport Surveillance Radar) or PAR for (Precision Approach Radar).

I think Ground Controlled Approach is more of a generic term, not a specific approach, with PAR and ASR being types of GCAs.


Quoting thegman (Reply 9):
Are they used much? Not in my experience.

I flew them during instrument phase of UPT, but never in the KC-135.
KC-135 - Passing gas and taking names!
 
thegman
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RE: Does The Usaf Fly Cat II/III Approaches?

Fri Sep 12, 2014 12:55 pm

Quoting moose135 (Reply 12):

I flew them during instrument phase of UPT, but never in the KC-135.

That's why I said not much in my experience. We do them a few times in the sim and it is a special syllabus requirement to do it once in the aircraft. (I'm in UPT right meow)
 
j.mo
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RE: Does The Usaf Fly Cat II/III Approaches?

Fri Sep 12, 2014 5:05 pm

ASR is a type of RADAR usually co-located at an airport for approach control functions. It uses secondary RADAR (beacon codes) in place of raw radar returns.

PAR is a RADAR system with limited range and limited functionality and usually uses raw RADAR returns interpreted by a controller. As mentioned, with the help of a controller/operator, control instructions are given to the pilot all the way down final with the controller talking/giving vertical and lateral corrections every 3-5 seconds.

ASR is the RADAR that feeds multiple controllers displays used to separate aircraft in the Class B/C/D surface areas and turn aircraft on final to intercept the ILS or waypoints for GPS approaches.

2 very different systems.

Also, the airplane can be CAT II or III certified but the pilot has to be too, I believe.
 
covert
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RE: Does The Usaf Fly Cat II/III Approaches?

Sat Sep 13, 2014 6:56 am

Quoting natflyer (Thread starter):
Wondering if the USAF does not do Cat.II/III approaches.

Yes, as mentioned above, some aircraft are equipped and some crews are trained. It depends on the community (fighter vs transport), mission, and sometimes the pilot themselves. The USAF has different weather minimums for different pilots depending on their experience level.

In the fighter world, generally no. In training, never. In my civilian instrument training, it is encouraged to seek out actual IMC to train in. The AF has the opposite outlook that it's far too risky, and in a lot of wings it takes the Ops Group commander's approval to fly down to CAT I. And usually, that's only done in combat, not training.
none
 
Cross757
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RE: Does The Usaf Fly Cat II/III Approaches?

Sat Sep 13, 2014 7:30 am

Quoting ThePointblank (Reply 4):
Generally, US military aircraft can fly precision approaches, but they use a different technology than the civilian CAT II/III systems. US bases are equipped with precision approach radars which controllers use to help the pilot make adjustments to their course for precision landings.


The lowest compatible approach minimums (ceiling and visibility) for a PAR approach are usually equal to a CAT I ILS or higher, so a PAR typcially cannot be used if the weather is below CAT I ILS minimums. PAR's are never used in conjuction with an ILS. And because its old technology, its expensive to maintain. PAR systems at most USAF fields are actually being decommissioned. The one at my home airfield was dismantled over two years ago.
As you said, GPS-based precision approaches are on the horizon (and active in some cases).

Quoting covert (Reply 15):
and in a lot of wings it takes the Ops Group commander's approval to fly down to CAT I. And usually, that's only done in combat, not training.


New fighter pilots, based on their relativley limited experience, usually have approach weather minimums of 700/2 (i.e. 700 foot celiing, 2 miles viz) when they are fresh out of their B-course training. Once they are complete with mission qualifcation training (MQT) and are deemd combat mission ready (CMR), this typically drops to 500 and 1 1/2. Around the 500-hour experience point (or sometimes sooner if the pilot was a previous FAIP), this is further reduced to 300/1, which is usually the lowest minimums that most fighter pilots are qualified to use. Just like you said, approval to use the published approach minimums (such as 200 and 1/2 mile) can be granted by the OG/CC if an operational need exists. For example, in Korea, due to the notoriously bad weather, this was done quite often otherwise A-10's/F-16's would rapidly run out of options of where to land.
Interestingly, T-38 pilots in AETC are allowed to fly down to published CAT I ILS approach minimums (200 and 1/2) without OG/CC approval per se. The question would honestly be if it is expected that you may have to fly down to CAT I approach minimums before the mission even starts, you better have a good operational reason to go flying in the first place.
 
thegman
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RE: Does The Usaf Fly Cat II/III Approaches?

Sat Sep 13, 2014 12:34 pm

Quoting j.mo (Reply 14):

ASR is a type of RADAR usually co-located at an airport for approach control functions. It uses secondary RADAR (beacon codes) in place of raw radar returns.

PAR is a RADAR system with limited range and limited functionality and usually uses raw RADAR returns interpreted by a controller. As mentioned, with the help of a controller/operator, control instructions are given to the pilot all the way down final with the controller talking/giving vertical and lateral corrections every 3-5 seconds.

ASR is the RADAR that feeds multiple controllers displays used to separate aircraft in the Class B/C/D surface areas and turn aircraft on final to intercept the ILS or waypoints for GPS approaches.

2 very different systems.

Also, the airplane can be CAT II or III certified but the pilot has to be too, I believe.

Cool. But who said they were the same in the first place? Or caused confusion for you to stress the radar point? Because my post clearly used the terms airport surveillance radar and precision approach radar.

Here is more info if anyone is still curious:
http://forums.jetcareers.com/threads...-asr-and-par-approach-review.4099/
 
jgarrido
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RE: Does The Usaf Fly Cat II/III Approaches?

Sun Sep 14, 2014 10:22 am

Quoting j.mo (Reply 14):
ASR is a type of RADAR usually co-located at an airport for approach control functions. It uses secondary RADAR (beacon codes) in place of raw radar returns.

Sorry if i'm misunderstanding but you seem to say that ASR only provides secondary radar and not any primary radar. ASR provides primary radar and is usually paired with a beacon interrogator for secondary radar. In my experience a radar that only provides secondary radar is called an SSR.
 
cargotanker
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RE: Does The Usaf Fly Cat II/III Approaches?

Sun Sep 14, 2014 2:11 pm

Quoting ThePointblank (Reply 4):
Generally, US military aircraft can fly precision approaches, but they use a different technology than the civilian CAT II/III systems. US bases are equipped with precision approach radars which controllers use to help the pilot make adjustments to their course for precision landings.

This is mostly false. The overwhelming majority of instrument approaches conducted by military aircraft are the same as civilian approaches (ILS, Localizer, VOR and a few others) The ASR/PAR approaches are an older system that is rarely used and never offered CAT II or CAT III minimums.

Quoting j.mo (Reply 14):
ASR is a type of RADAR usually co-located at an airport for approach control functions. It uses secondary RADAR (beacon codes) in place of raw radar returns.

PAR is a RADAR system with limited range and limited functionality and usually uses raw RADAR returns interpreted by a controller. As mentioned, with the help of a controller/operator, control instructions are given to the pilot all the way down final with the controller talking/giving vertical and lateral corrections every 3-5 seconds.

ASR is the RADAR that feeds multiple controllers displays used to separate aircraft in the Class B/C/D surface areas and turn aircraft on final to intercept the ILS or waypoints for GPS approaches.

2 very different systems.

Again, mostly false. I think you are referring to a similar definition of ASR. An ASR approach is very similar to a PAR approach, but the PAR offers glideslope. You can google "airport surveillance radar" a few times and find two distinct definitions, focus on the older one. The ASR used for approaches is a primary radar and does not even require a transponder, only 2 way radio communication. Lots of benefits in emergency situations.
 
j.mo
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RE: Does The Usaf Fly Cat II/III Approaches?

Sun Sep 14, 2014 5:22 pm

Quoting thegman (Reply 17):
Cool. But who said they were the same in the first place?
Quoting moose135 (Reply 12):
I think Ground Controlled Approach is more of a generic term, not a specific approach, with PAR and ASR being types of GCAs
Quoting jgarrido (Reply 18):
Sorry if i'm misunderstanding but you seem to say that ASR only provides secondary radar and not any primary radar. ASR provides primary radar and is usually paired with a beacon interrogator for secondary radar. In my experience a radar that only provides secondary radar is called an SSR.

ASR provides primary radar as well. But you don't control from it. It's paired with the secondary beacon. Usually turned down as to not even see it. Used to align the radar and then turned down, at least in my experience.

Quoting cargotanker (Reply 19):
Again, mostly false. I think you are referring to a similar definition of ASR. An ASR approach is very similar to a PAR approach, but the PAR offers glideslope.

So not false information, just wrong ASR. My bad. An ASR approach is available because of the co-located ASR antennae at the airfield.

Trained and used a PAR but those are fading away..
 
cargotanker
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RE: Does The Usaf Fly Cat II/III Approaches?

Mon Sep 15, 2014 1:40 am

Quoting j.mo (Reply 20):
So not false information, just wrong ASR. My bad. An ASR approach is available because of the co-located ASR antennae at the airfield.

No, you're talking about AIRPORT surveillance radar, we're talking about APPROACH surveillance radar. Same ASR acronym, but two completely different things with completely different functions.
 
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kc135topboom
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RE: Does The Usaf Fly Cat II/III Approaches?

Tue Sep 16, 2014 2:53 pm

Quoting moose135 (Reply 12):
moose135

Originally the KC-135 was only qualified for CAT-I ILS approaches, including an autopilot coupled approach (no auto-throttle or flair capability). However some RC-135s were capable of CAT-IIIc ILS and had all the auto-pilot equipment needed. A few RC-135s the TC-135, and a few KC-135s were at one time equipped with an MLS system and practiced MLS approaches at VDZ and BOS.

In February 1985 RC-135T (trainer) 55-3121 was lost on a MLS approach to VDZ. All 3 crewmembers were lost and the wreckage was not found until August 1985.

http://aviation-safety.net/database/record.php?id=19850225-3

Because it took so long to find theRC-135T, all MLS training in the KC and RC was suspended. Eventually MLS fell out of favor for a better GPS type approach and landing.

One style of non-precision approach we use to practice in the KC-135 (and other USAF aircraft) was an ARDA, airborne radar directed approach. The ARDA was directed by the crew's Navigator. It was felt that in times of war some airports would turn off their nav-aids and this was one way to approach the airport in moderate weather.
 
GlobalMoose
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RE: Does The Usaf Fly Cat II/III Approaches?

Tue Sep 16, 2014 10:44 pm

The C-17 is fully certified to fly ILS CAT-II approaches down to a HAT of 100 ft / RVR 1200 (or higher, as published).

The aircraft commander is authorized to fly said approaches once they have reached 100 hours PIC and fully current (1 CAT-II appch every 6 months), there are no other restrictions.
When it absolutely positively has to be there ... at some point.
 
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kc135topboom
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RE: Does The Usaf Fly Cat II/III Approaches?

Sat Sep 20, 2014 9:39 pm

All of the 89th AW aircraft (C-20, VC-25, C-32, C-37, and C-40) are CAT-IIIc capable too.
 
mmo
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RE: Does The Usaf Fly Cat II/III Approaches?

Sat Sep 20, 2014 11:06 pm

Quoting KC135TopBoom (Reply 24):
All of the 89th AW aircraft (C-20, VC-25, C-32, C-37, and C-40) are CAT-IIIc capable too.

Just to be somewhat pedantic, while CAT IIIC exists in theory, there are no CATIIIc approaches anyplace in the world. I know of no one, I do mean no one who trains for CATIIIc approaches. .
If we weren't all crazy we'd all go insane!
 
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TWA772LR
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RE: Does The Usaf Fly Cat II/III Approaches?

Mon Sep 22, 2014 5:43 am

Quoting mmo (Reply 25):

Quoting KC135TopBoom (Reply 24):
All of the 89th AW aircraft (C-20, VC-25, C-32, C-37, and C-40) are CAT-IIIc capable too.

Just to be somewhat pedantic, while CAT IIIC exists in theory, there are no CATIIIc approaches anyplace in the world. I know of no one, I do mean no one who trains for CATIIIc approaches. .

Well, in case it ever does happen, at least the crews know what to do!
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mmo
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RE: Does The Usaf Fly Cat II/III Approaches?

Wed Sep 24, 2014 8:35 pm

Quoting TWA772LR (Reply 26):
Well, in case it ever does happen, at least the crews know what to do!

So, how do you train if there are no established procedures? Sort of a big problem...   
If we weren't all crazy we'd all go insane!
 
donniecs
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RE: Does The Usaf Fly Cat II/III Approaches?

Thu Sep 25, 2014 10:49 pm

Quoting KC135TopBoom (Reply 24):
All of the 89th AW aircraft (C-20, VC-25, C-32, C-37, and C-40) are CAT-IIIc capable too.

The AF C-20's and C-37's are only certified and maintained to CAT I standards. CAT III is not an option from Gulfstream (most biz jets are not since you can usually wait or select a better airfield). The C-37's that are HUD equipped are able to reduce CAT 1 minimums by 1/2 but I don't believe the AF has a training program for that. The Gulfstreams on the north end of the field are CAT II certified and do have a HUD reduced minimum training program in place.
Charlie - Gulfstream flight mechanic

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