Military Mins on Approach Plates

[deafsound]

You guys are all familiar with the #s....

328-1/2 200 (200-1/2). That's the mins for ILS 29 at KBED, btw.

The numbers in parenthesis are for military, and I thought they were supposed to be lower mins than for civilian. I was talking with very knowledgeable CFII today, and he said he's never been able to find out why that's considered a lower minimum than the civilian mins. Could it be that their (200-1/2) are MSL and not AGL?

Thanks for your informed answers.

 

[Everskyward]

Could it be that their (200-1/2) are MSL and not AGL?

I've never done much thinking about the military minimums but I know they are not MSL. At my home airport (KAPA) the ILS 35R mins are 6083-1/2 200 (200-1/2). If the 200 in parenthesis was MSL the person doing the approach would be way more than 6 feet under.

On another note, the military minimums for all the different variations of this approach seem to be rounded up, not down. I have never considered whether military minimums are normally lower than civilian minimums or not.

ILS 35R APA

 

[Bob Noel]

according to the legend for the IAP, the number in parathesis are not applicable to civil pilots. In your example above, it is "200 (200-1/2)" where the first 200 is the HAT (which is applicable to us civilian pilots).

check out http://www.naco.faa.gov/index.asp?xml=naco/online/d_tpp

 

[2256Q]

according to the legend for the IAP, the number in parathesis are not applicable to civil pilots. In your example above, it is "200 (200-1/2)" where the first 200 is the HAT (which is applicable to us civilian pilots).

check out http://www.naco.faa.gov/index.asp?xml=naco/online/d_tpp

I haven't flown for the military in a long time, but our mins used to be, usually, lower because our equipment was better. I don't think that's so much the case any longer and I really can't address it with any authority. As an example of how our equipment was better, the F-111A was able to set up an IFR approach and landing in zero-zero wx. There didn't even have to be any kind of ground equipment. It was all on-board. That's a long time ago and I can only imagine the equipment they have to work with these days. Wow!

 

[poadeleted20]

The numbers in parens are the weather mins (ceiling-vis) for the military folks to shoot the approach, not some special MDA/DH. Much like 135/121, if the weather isn't reported above mins, they're not allowed to start the approach with intent to land.

BTW, they raised the mins for the onboard system approach ("Airborne Radar Approach" or ARA) substantially after Ray left the F-111. When I got to the program in 1980, the mins for that were about the same as nonprecision approaches. Of course, we practiced them down to the runway in VMC with the WSO calling the shots and the pilot acting as safety observer and autopilot just in case the need ever arose, but for nonemergency/noncombat ops, we weren't allowed to fly ARA's in really low weather. The only case in which we had especially low mins for normal ops was for PAR's (but not ILS), where we were allowed to go down to 100 DH thanks to our side-by-side seating. That was also approved in the side-by-side A-6, but not the tandem F-4, where 200 DH was the limit for PAR's.

Of course, the introduction of the Automatic Carrier Landing System (ACLS) in the mid-70's changed everything -- hands-off approaches to touchdown on a pitching deck (or ashore, if the NAS had the equipment) in zero-zero conditions. Don't know if the Air Force ever got anything like it.

 

[2256Q]

The numbers in parens are the weather mins (ceiling-vis) for the military folks to shoot the approach, not some special MDA/DH. Much like 135/121, if the weather isn't reported above mins, they're not allowed to start the approach with intent to land.

BTW, they raised the mins for the onboard system approach ("Airborne Radar Approach" or ARA) substantially after Ray left the F-111. When I got to the program in 1980, the mins for that were about the same as nonprecision approaches. Of course, we practiced them down to the runway in VMC with the WSO calling the shots and the pilot acting as safety observer and autopilot just in case the need ever arose, but for nonemergency/noncombat ops, we weren't allowed to fly ARA's in really low weather. The only case in which we had especially low mins for normal ops was for PAR's (but not ILS), where we were allowed to go down to 100 DH thanks to our side-by-side seating. That was also approved in the side-by-side A-6, but not the tandem F-4, where 200 DH was the limit for PAR's.

Of course, the introduction of the Automatic Carrier Landing System (ACLS) in the mid-70's changed everything -- hands-off approaches to touchdown on a pitching deck (or ashore, if the NAS had the equipment) in zero-zero conditions. Don't know if the Air Force ever got anything like it.

In reading your posts about the 111, it is obvious that they really clamped down on the program after I left it. I didn't think we lost THAT many planes! I found the A to be one of the easiest to fly I had in the service. Extremely stable weapons platform. Your D should have been the same airframe with different avionics. Yes? I also wanted to ask if they ever got away from the requirement to grease the wing pivots after every 5 cycles?

 

[poadeleted20]

In reading your posts about the 111, it is obvious that they really clamped down on the program after I left it. I didn't think we lost THAT many planes! I found the A to be one of the easiest to fly I had in the service. Extremely stable weapons platform. Your D should have been the same airframe with different avionics. Yes?

Not quite -- different (bigger) engines and different inlet system (translating cowls out, blow-in doors in).

I also wanted to ask if they ever got away from the requirement to grease the wing pivots after every 5 cycles?

Never heard of that one, but I didn't work in maintenance.

 

[Ted]

Thanks for the explanations, I have certainly learned something new!

What's even more incredible to me, Ray, is the 0/0 landings completely via onboard avionics. That's just beyond cool. Here at IPT, that would be nice. As my CFII was explaining to me yesterday, frequently the problem with instrument landings is the visibility, not just the ceiling.

 

[dmccormack]

Thanks for the explanations, I have certainly learned something new!

What's even more incredible to me, Ray, is the 0/0 landings completely via onboard avionics. That's just beyond cool. Here at IPT, that would be nice. As my CFII was explaining to me yesterday, frequently the problem with instrument landings is the visibility, not just the ceiling.

Look up Cat III C ILS...

Special crew, special equipment and 0/0

 

[jesse]

Look up Cat III C ILS...

Special crew, special equipment and 0/0

I'm sure Ted knows about that. The difference is that this is with ALL onboard avionics--nothing special at the airport like a ILS.

 

[poadeleted20]

I flew ARA's from 1974 to 1988, and I never heard of the Navy or Air Force authorizing them to zero-zero conditions. Ray's experience predates mine, so perhaps they were legal that way at one time, but having flown the same system he did (the avionics in the F-111A was identical to that in the F-111E's I flew), I cannot imagine it being done in that jet to zero-zero other than in a flat-out emergency.

The only zero-zero system I know in a fighter-type aircraft is the Automatic Carrier Landing System, which is a two-way datalink system relying on 3D radar on the ship with a transponder on the aircraft and a computer on the ship feeding corrections to the autopilot. ACLS was authorized all the way to the deck only in the full auto "hands-off" mode -- IIRC, the lesser modes were only authorized to 200 feet.

Finally, while Cat IIIc ILS is technically authorized in zero-zero, nobody does it. The lowest mins I know of are those at United, which won't go with less than 300 feet RVR. After all, you need some vis just to taxi off the runway and to the gate! Most other airlines only go Cat IIIb, which requires 600 feet RVR.

 

[2256Q]

Never heard of that one, but I didn't work in maintenance.

We were required to keep a log of every time we cycled the wings. If you never heard of it, then obviously that requirement became unnecessary.

 

[2256Q]

I flew ARA's from 1974 to 1988, and I never heard of the Navy or Air Force authorizing them to zero-zero conditions. Ray's experience predates mine, so perhaps they were legal that way at one time, but having flown the same system he did (the avionics in the F-111A was identical to that in the F-111E's I flew), I cannot imagine it being done in that jet to zero-zero other than in a flat-out emergency.

When the plane first came into the inventory, it was necessary to find out where its limits were. That we did. In time of war, the safeties are not quite as hard-wired as in peace time. I suspect we did several things with the plane that were later changed without the urgency of combat being involved. Discoveries were also a constant challenge. Remember the little 'polarize' toggle on the TFR? And the little fiberglass dome on the TFR antenna? The original models didn't have the switch or the dome. Flying in SEA showed the TFR would give a hard failure in rain over there. I never quite believed it, but according to the engineers the raindrops in SEA are shaped differently than those in the states and caused the TFR to fail. Where I was completely comfortable with the 111, I seem to sense you didn't much care for it. Admittedly, it was a lot of airplane and some pilots were less than enthusiastic about flying it.

 

[poadeleted20]

Where I was completely comfortable with the 111, I seem to sense you didn't much care for it.

You couldn't be farther from the truth. I loved the 'Vark, and if I were going into combat in one of the jets I flew (A-6, RF-4, F-111), it would be my hands-down first choice every time.

But I still wouldn't do an ARA in zero-zero if I had any other choice.

 

[dmccormack]

Finally, while Cat IIIc ILS is technically authorized in zero-zero, nobody does it. The lowest mins I know of are those at United, which won't go with less than 300 feet RVR. After all, you need some vis just to taxi off the runway and to the gate! Most other airlines only go Cat IIIb, which requires 600 feet RVR.

Hmmm..

I've been on Southwest when they landed at BWI while nobody else was moving.

Maybe they are more liberal with RVR?

 

[2256Q]

You couldn't be farther from the truth. I loved the 'Vark, and if I were going into combat in one of the jets I flew (A-6, RF-4, F-111), it would be my hands-down first choice every time.

But I still wouldn't do an ARA in zero-zero if I had any other choice.

Great! I loved that silly old airplane and enjoy being around other (I'll use your phrase) 'Vark drivers who feel the same way.

To be perfectly honest, the 0-0 ARA was never the most fun thing in the world for me, either, but remember we were grooming a new weapons platform for war. It was that early 'push the envelope' phase. I was already 27 years old when I made that first flight, so I was beginning to get a glimmering that maybe I wasn't bullet-proof after all.

 

[2256Q]

Who is going to be able to find the airplane on the runway, hook it up an then tow it to the gate in 0/0?

I would submit that 0-0 for a pilot landing an aircraft is not necessarily 0-0 for a tug driver. Coming down the chute at 120 kts is a bit different, vis wise, than driving along at 5 mph.

 

[dmccormack]

I submit it won't happen because there are no US Air Carriers approved for Cat III c so the discussion is really mute.

And how many discussion here are not -- in some way -- moot?

 

[poadeleted20]

Great! I loved that silly old airplane and enjoy being around other (I'll use your phrase) 'Vark drivers who feel the same way.

Not my phrase -- "Aardvark" is the official USAF name of the aircraft, as finally, officially announced by Maj. Gen. Lee Downer (you may remember him as a captain or so) at its retirement ceremony in 1996.

 

[poadeleted20]

Do a quick search of Ops Spec's and name one carrier authorized for Cat IIIc.

I know United is, because Greg's talked about it. However...

Who is going to be able to find the airplane on the runway, hook it up an then tow it to the gate in 0/0?

...the company limit is 300 RVR for just that reason.

 

[poadeleted20]

I would submit that 0-0 for a pilot landing an aircraft is not necessarily 0-0 for a tug driver.

There's an old story about that...

Back in the 60's, when the British (who invented ILS in the first place) invented the Cat III autoland system, they put it on the Trident (kind of a British-built slightly shrunken 727). Nobody got to use it for real at first, until one day the weather at Berlin was 0/0. After Air France and PanAm turned around and went back out the corridor to the FRG, BOAC rather snootily announced they'd continue and land, Cat IIIc, and they did.

As they rolled to a stop, they announced to Tower that they were on the ground, and were cleared to taxi to the terminal. "Ahh, Speedbird 742 has a slight problem with that -- we can't see the runway." "Keine problem, Speedbird, you are ze only aircraft moving, so traffic iss not a problem." "Sorry, old boy, I don't think you understand -- we can't see the runway from the cockpit -- not even straight down." "Ach, zat iss a problem -- shtand by."

Well, they sent out Hans and Fritz to retrieve the airplane -- Hans driving the tug, and Fritz walking ahead with a flashlight -- the flashlight being aimed back at Hans so he could keep sight of Fritz walking bent over to see the taxiway centerline stripe. The found the Trident when Fritz bumped into it. After they hooked up the tug, Fritz took the lead with the flashlight, followed by Hans on the tug, followed by the Trident. It took like two-and-a-half hours from touchdown to debarkation. Since then, nobody's used the 0/0 option in commercial flying.

 

[2256Q]

There's an old story about that...

Back in the 60's, when the British (who invented ILS in the first place) invented the Cat III autoland system, they put it on the Trident (kind of a British-built slightly shrunken 727). Nobody got to use it for real at first, until one day the weather at Berlin was 0/0. After Air France and PanAm turned around and went back out the corridor to the FRG, BOAC rather snootily announced they'd continue and land, Cat IIIc, and they did.

As they rolled to a stop, they announced to Tower that they were on the ground, and were cleared to taxi to the terminal. "Ahh, Speedbird 742 has a slight problem with that -- we can't see the runway." "Keine problem, Speedbird, you are ze only aircraft moving, so traffic iss not a problem." "Sorry, old boy, I don't think you understand -- we can't see the runway from the cockpit -- not even straight down." "Ach, zat iss a problem -- shtand by."

Well, they sent out Hans and Fritz to retrieve the airplane -- Hans driving the tug, and Fritz walking ahead with a flashlight -- the flashlight being aimed back at Hans so he could keep sight of Fritz walking bent over to see the taxiway centerline stripe. The found the Trident when Fritz bumped into it. After they hooked up the tug, Fritz took the lead with the flashlight, followed by Hans on the tug, followed by the Trident. It took like two-and-a-half hours from touchdown to debarkation. Since then, nobody's used the 0/0 option in commercial flying.

 

[2256Q]

Well, if Greg said so, I stand corrected. I will make sure IOPSS is updated. Tell me why a company that went through the hassle to gain approval for something but decides not to use it but still be held to that standard?

Barney, I most certainly don't mean to offend you, but may we know your background on all this? Controller, FAA, that sort of thing?

 

[bbchien]

Even category 1 taxi can be a problem. Five years ago I made a perfectly legal RIGHT TO MINS ILS 13 at PIA, and as I moved down the runway, had to shut down. There was nobody else flying. RVR was right at 6000 measured at the APPROACH END, but now I was mid runway (10,000 foot runway).

They sent a minivan with two guys to find us....on foot.

 

[poadeleted20]

They sent a minivan with two guys to find us....on foot.

Were their names Hans and Fritz?

 

[nosehair]

328-1/2 200 (200-1/2).

I'm so glad someone has asked this question.

It is a very basic piece of information on the approach chart that all civilians should know about.

It is the minimum weather requirement for a military aircraft in IFR to file for that destination.

The wx must be forcasted to be at or above that minimum ceiling and vis to expect to break out and see the runway at published mins.

In the above example, the published 328 MSL DH would be 200 ft AGL which is the required ceiling.

The reason it is good knowledge for civilian part 91 pilots is for in-flight divirsion or deciding on possible alternates when going on an unplanned missed approach.

"How's the wx at XYX?"

"XYZ is showing 300 and 3/4 now."

A quick glance at those numbers in parenthasis will give you instant information about the possibility of making the approach.

Not regulatory, but practical.

 

[drizzt76]

This is how we use it in the Army. The reg AR 95-1 and where is says "weather planning minimum" the numbers you use are the (200 1/2) for example.....my wx minimum would be 600 1-1/4. If its lower than that I need an alternate which must meet the requirements in para. f. Some might be thinking why 1/4....earlier in the reg. it states that if in a helicoper you can divide the vis. by 1/2. I don't know how other parts of the military use it but that is how I am required to use it. Sorry for the odd print.​

e. Alternate airfield planning.

An alternate airfield is required when filing IFR to a destination under any of the following conditions:​

(1) Radar is required to execute the approach procedure to be flown.​

(2) The instrument approach navigational aids to be used are unmonitored.


(3) The predominant weather at the destination is forecast at ETA through 1 hour after ETA to be less than—​

(a) Ceiling 400 feet above the weather planning minimum required for the approach to be flown.

(b) Visibility 1 mile (or metric equivalent) greater than the planning minimum required for the approach to be flown.​

(4) An alternate is not required if descent from en route minimum altitude for IFR operation, approach, and landing can be made in VFR conditions.

f. Alternate airfield selection.

(1) An airfield may be selected as an alternate when the worst weather condition for that airfield is forecast for ETA
through 1 hour after ETA to be equal to or greater than—​

(a) Ceiling 400 feet above the weather planning minimum required for the approach to be flown and visibility 1 mile (or metric equivalent) greater than the weather planning minimum required for the approach to be flown; or​

(b) VFR minimums and descent from en route minimum altitude for IFR operation, approach, and landing can be made in VFR conditions.

(2) An airfield will not be selected as an alternate except per f(1)(b) above—
​

(a) If the approach procedure to be used at the alternate is shown not authorized (NA) in FLIP.​

(b) If radar is required for the approach procedure to be used at the alternate.​

28 AR 95–1 • 3 February 2006​