Pierre Garneau Posted July 10, 2003 Share Posted July 10, 2003 This happened a few months ago. The aircraft (A321) arriving in St. John's, NF for Cat II approach, runway 29. The RVR was holding at 1000' (A & and the ATIS was 1/4 sm visibility. Now, under these circumstances the approach to a landing is fair game, but 10 miles back the controller offers the tower vis as 'variable 1/8-1/2 sm (600-2600)'..whooops...are you still legal? Prior to reaching the OM the RVR from the tower is given as 1200' (A & , and we landed and called it a night. Does the 'ad lib' from the tower as to below and above visibility affect the legalities to land. OVER. Regards. Pierre Garneau Link to comment Share on other sites More sharing options...
Guest rance Posted July 10, 2003 Share Posted July 10, 2003 No, tower vis is irrelevant with a functioning rvr.Approach bans are governed by rvr values. You would be fine.Where they giving you a hastle?? Link to comment Share on other sites More sharing options...
Pierre Garneau Posted July 10, 2003 Author Share Posted July 10, 2003 No hassles from ATC, just a discussion between ourselves with yours truly, as the conservative opinion. When the ban originally came out as #555, one of the examples was actually pretty much this scenario. As I recall, a few pilots got into "discussions' with MOT and check pilots over interpretations of the new Air Reg. Basically are you ok with the landing with a 20 minute old ATIS giving 1/4 sm vis and a current RVR below 1200', assumed to be local phenomenon? Pierre Link to comment Share on other sites More sharing options...
Guest rance Posted July 10, 2003 Share Posted July 10, 2003 HI Pierre: I would still say you would be legal.If the rvr is fluctuating and vis. is reported as 1/4 mile. An even more confusing situation is when the rvr goes u/s and the tower says vis. is 1/8th of a mile. From what I remember you can still do the approach because approach bans are governed by rvr values. Correct me if i'm wrong. All confusing especially when your 3 miles back from the outer marker. Intresting discussion. Cheers. Link to comment Share on other sites More sharing options...
Moon The Loon Posted July 10, 2003 Share Posted July 10, 2003 ATIS information is irrelevant in the example at the beginning of the thread. Also, if the RVR is 1000 but the tower controller reports fluctuating values as described, being an "accredited observer", the requirements of "fluctuating" can be applied. Regardless, in the example given, the last reported RVR prior to the FAF was 1200 so the question became moot. But it "used to be" that if the tower gave a snap visibility that differed from the RVR, one could continue the approach to a landing. In recent years however, TC may have revised their way of seeing things. There is still a huge move afoot in Ottawa to raise the approach ban limits to coincide with ICAO standards. At present, Canada is one of the only nations that has a variance to this convention. Link to comment Share on other sites More sharing options...
Don Hudson Posted July 10, 2003 Share Posted July 10, 2003 Hi Pierre; Were you legal to continue the approach? Good question. The only definitive answer would have come if you'd had an incident. Then everyone else has months to come up with the answer that we have to in about a minute, if the visibility changes or if ATC (quite properly) introduces new information during the approach. The regs are obviously less clear on this than we would like, as per your question and this thread. They are unclear first, to provide some flexibility to aircraft commanders. But they are also unclear because we don't know how the various terms and bits of information (ATIS info vs an "accredited" observer's vs the legal meaning of the term "fluctuating" etc) will be ultimately interpreted and presented should there be any incident or "infraction". Obtaining a legal interpretation of all those terms and guidelines is impossible until there is an interest involved such as establishing blame, etc. Until then, any interpretation is just that. Thus, each commander has to interpret the law and the regs as best s/he can with the experience and training s/he has. Ninety-nine-point-nine percent of the time its done correctly and nothing happens and we never have a definitive answer as to whether we interpreted correctly or not. "Correct" is only relevant when it comes to establishing culpability, not do-ability. That's not the same as "carte-blanche" and doing just what one can get away with either! But the flexibility built into the regulations partly by design but mostly by default, serves both masters...the Commander, and the Regulator. To relate to another discourse below, that is one of the reasons why airline pilots are paid the way they are. They are paid to make those decisions according to the law and according to their experience and training that their employer provides. (In my opinion, Air Canada's work in this area is second-to-none). By the statistics, especially over the last decade, it looks as though the job of interpretation and execution is getting done pretty well. Great question, as the discussion is all part of the experience of learning how others interpret the data. Another question arose when we were doing CAT III's here in VR last December. Another carrier asked if VR was conducting CAT III "a's" or "b's", as they could do CATIIIa but not b. (For those who don't know, the difference is RVR visibility). Vancouver responded by saying they were doing Category 3 approaches period and that they didn't know what "a" or "b" meant. The carrier diverted. We carried on. I based my decision on the notion that "a" or "b" is an aircraft-relevant requirement and not an ATC "restriction", and as long as the RVR (and obviously all other ground and aircraft equipment) was sufficent for "CAT III", we could do what the aircraft was capable of and what we were trained and had qualifications for. The RVR was just above 600 feet, (we entered the fog at around 80' from a brilliant sunshiny day), landed and followed the green centreline lights to the ramp, at about 8kts! An important meaning to the term "Category" when used to describe approaches is that there is backup power standing by and that the approach area is clear as per the taxiway markings. Otherwise, I don't think ATC or Transport cares what the visibility is or what the individual carrier's capabilities or crew qualifications are as long as the requirements of the carrier's OC and Ops-Specs are adhered to. They only care after there's an incident and that's when we'd get our "legal" interpretion. Cheers, Don Link to comment Share on other sites More sharing options...
Guest CabinDweller Posted July 10, 2003 Share Posted July 10, 2003 “ …after there's an incident, that's when we'd get our 'legal' interpretion.” Hello CD, As someone who’s always appreciated your posts, do you have a front-end colleague that can offer a legal opinion/interpretation? CD (the original ) Link to comment Share on other sites More sharing options...
Don Hudson Posted July 10, 2003 Share Posted July 10, 2003 Hello OCD... Do we have anyone who can offer a legal opinion on these terms? Absolutely. We have many lawyers who are pilots, we have ACPA Legal and ACPA Labour Relations who are well-versed on the process of defining what is "legal". The commander of an aircraft won't be consulting lawyers before s/he does an approach of course, but that wasn't the point of my post... Don donandfran_hudson@telus.net Link to comment Share on other sites More sharing options...
Steam Driven Posted July 10, 2003 Share Posted July 10, 2003 Otherwise, I don't think ATC or Transport cares what the visibility is or what the individual carrier's capabilities or crew qualifications are as long as the requirements of the carrier's OC and Ops-Specs are adhered to. Experience tells me otherwise Don. We at WestJet had several 737's bound for YVR remain on the ground in YYC. They were told we could not attempt the approach a while back in fog similar to what you describe. The question was asked - "Are you Cat II? No, then your clearance will be denied. Only Cat II aircraft are being allowed into YVR airspace." Several hasty and hot phone calls later from our operations dept. finally got our Aircraft Airbourne. In this example, Nav Canada certainly cares what the individual carrier's capabilities are. The question begs to be asked are they exceeding their perview to deny airspace to aircraft because of what weather may be like an hour and a half after an aircraft takes to the air? Our ops manual states that we are able to do an ILS approach to 1200 RVR, but because we were not CAT II we were not allowed to even attempt the approach. Cheers. Link to comment Share on other sites More sharing options...
handyman Posted July 10, 2003 Share Posted July 10, 2003 Was he legal to continue the approach? Sure he was because as stated by others the ban is predicated on RVR. Was he legal to land? This is the question and he may have to answer some from TC if they were watching. It’s very hard to bust someone on approach without documented information about the weather conditions on the approach end of the runway. RVR is obviously the primary method but if it’s down and the weather limits are close to the actual your going to get away with it. As for CAT 3A and 3B I would like to ad a few additional points. CAT 3A can be flown without autothrottles or thrust control where CAT 3B cannot. CAT 3B’s can have a DH (15’-22’ minima with our airline at some airports) or no DH (which we have at most 3B airports. Visual reference is not required until after the nosewheel touch’s down on a 3B no DH approach. Minimum RVR on CAT 3B allows sufficient vis to taxi the aircraft clear of the runway and onto the ramp. I believe Gatwick has what they used to call a CAT 3C which would allow taxi guidance to the gate. I was also told that a airport must be certified for 3B vs 3A as localizer tolerance is different due to dependence on rollout. Our airline is certified for 3B approaches but only 3A in YVR which leads me to believe this is true. Our regs also state that ATC regs require greater aircraft spacing on CAT 3 approaches vs CAT 2 Cheers. CPDude Link to comment Share on other sites More sharing options...
handyman Posted July 10, 2003 Share Posted July 10, 2003 I am curious why you are certified for 1200 RVR but not CAT 2. To get that close to the runway at 200' would look like a Stuka approach. Link to comment Share on other sites More sharing options...
Steam Driven Posted July 10, 2003 Share Posted July 10, 2003 Our -700's are Cat II equiped and the Pilot's qualified. The -200's are not. Why would it look like a "Stuka" approach? Normal 3 degree glide path and landing for the runway. You see the runway environment at MDA or you don't. Cheers Link to comment Share on other sites More sharing options...
handyman Posted July 10, 2003 Share Posted July 10, 2003 I was just having a chuckle what a 200'/1200RVR approach would have to look like. It was a joke man! Link to comment Share on other sites More sharing options...
Steam Driven Posted July 10, 2003 Share Posted July 10, 2003 No sweat, received as intended. ( It'll be nice to get on the -700 and back on some glass. The -200 is a nice machine but it needs help where IT NEEDS HELP! Link to comment Share on other sites More sharing options...
Guest Avcat Posted July 10, 2003 Share Posted July 10, 2003 I say "Land 3 Landing!" Cheers, Avcat Link to comment Share on other sites More sharing options...
Don Hudson Posted July 11, 2003 Share Posted July 11, 2003 Thanks CPDude...nice additions. AC charts show "3B" for Airbus products in VR with an Alert Height concept of 100' but no decision height. No visual references are required to land and the same requirements obtain for rollout/taxi. I'm not sure what the differences would be between our operations in VR but I would think that when an airport is conducting CATIII approaches, it doesn't advertise whether it is only for "A" or "B" but that the approach plates reflect the Ops-Specs of each carrier. Our own plates show VR available as "B". We don't do "C" in any of our operations, primarily because of the costs of maintaining the authority balanced against the cost-savings of not missing the very rare "C" airport. Our 3B DH (actually an AH) is "none", so on the Airbus we type "NO" in the FMC DH box rather than a RadAlt. The AH concept means an autocall (made by the aircraft) at 100' and if everything is working we land without external references (as you know). Great discussion. Refreshing change... Don Link to comment Share on other sites More sharing options...
Don Hudson Posted July 11, 2003 Share Posted July 11, 2003 Steam... Re "Nav Canada certainly cares what the individual carrier's capabilities are." I think we're on the same page. Such restrictions are not at all unusual in Europe, nor are they here. It has nothing to do with a carrier's OpSpecs or the legality of the approach. It has everything to do with needlessly tying up the ATC, airport and likely close-by alternate airport resources by aircraft which are almost certain to miss. I can't see such a ground hold being issued if the RVR were hovering around 1200 because the approach can be taken right to the FAF and your OpSpecs allow the approach to begin. But the RVR in the circumstances under discussion was nowhere near that. I have had the same restrictions applied in the past on less qualified aircraft too, especially going to the US. Perhaps an ATC type might join in and enlighten us as to what their own operational restrictions and definitions are. Worthwhile thread... Don Link to comment Share on other sites More sharing options...
Pierre Garneau Posted July 11, 2003 Author Share Posted July 11, 2003 This thread was apt to bring some varied responses, and so far it's a good read. Given the thread opener, what if 1) the ATIS gave 1/4 sm visibility, 2) the RVRs for runway 29 remained at 1000' (A & , and 3) the controller had offered the same tower visibility observation ie. variable 1/8 - 1/2 sm. You are outside the marker.......can you continue beyond the marker for a Cat II approach and landing, or for that matter any approach? I've posted the Air Regs for your consideration. Note: the 'smilies' and the beers on the text Approach Ban below were not inserted by me, and appeared both times that I copied the text from the TC site...what happened? Approach Ban - General 602.129 (1) With respect to an aeroplane, for the purposes of subsection (3), the RVR is below the minimum RVR if (a) where both RVR "A" and RVR "B" are measured, RVR "A" is less than 1,200 feet and RVR "B" is less than 600 feet; or ( where only one of RVR "A" or RVR "B" is measured, the RVR is below 1,200 feet. (2) With respect to a helicopter, for the purposes of subsection (3), the RVR is below the minimum RVR if (a) where both RVR "A" and RVR "B" are measured, RVR "A" is less than 1,200 feet; or ( where only one of RVR "A" or RVR "B" is measured, the RVR is below 1,200 feet. (3) Where the RVR is reported to be below the minimum RVR as described in subsection (1) or (2), as applicable, the pilot-in-command of an IFR aircraft conducting an instrument approach shall discontinue the approach unless (a) when the RVR report is received, the aircraft (i) has passed the outer marker or the fix that serves as the outer marker, and (ii) is in descent to the runway; ( the aircraft is on a training flight where a landing is not intended, and the appropriate air traffic control unit is informed that a missed approach procedure will be initiated at or above the decision height or the minimum descent altitude, as appropriate; © the RVR is fluctuating above and below the minimum RVR and the ground visibility of the aerodrome where the runway is located is reported to be at least one-quarter mile; or (d) the pilot-in-command of the aircraft is conducting a precision approach to CAT III minima. Approach Ban - CAT III 602.130 No pilot-in-command of an IFR aircraft conducting a CAT III precision approach shall continue the approach beyond the outer marker or the fix that serves as the outer marker unless the RVR is at or above the minimum approach RVR specified by the Minister in the Canada Air Pilot. Link to comment Share on other sites More sharing options...
Fester Posted July 11, 2003 Share Posted July 11, 2003 From an approach controller point of view, over the years we have taken the attitude of "it's your call". Police we are not, nor do we want to be. We know the published minima for each and every approach, however, we also are very tuned in to the fact that different carriers, even different crews at the same carrier, have different limitations. When we inquire whether the approach will be say Cat2 or Cat1, we just want to know, because our spacing minima change. Everyone doing a Cat2 needs to be five miles behind the previous guy. To sidetrack, many US carriers are not allowed to conduct NDB approaches, even BC Loc approaches are verboten on several types of aircraft. To get back to spacing, on Cat2 approaches with aircraft departing the same runway, the rule says that the departure has to be past the localizer antenna when the arrival is 5nm final. Often, the loc antenna is at the opposite end of the runwaym making a minimum spacing of 12 -15 nm necessary between arrivals. So you can see how quickly we run out of room. Another point, ATIS info is worthless in terms of legality of conducting an approach or landing, simply because it can be up to one hour old. Good thread for a change. Link to comment Share on other sites More sharing options...
Don Hudson Posted July 11, 2003 Share Posted July 11, 2003 Thanks for the info, Fester. As I suspected, NavCan isn't interested in legalities as such, and allows the OpSpec of each carrier determine legality. I know for certain that interference with ILS signals can be a serious problem on a category approach, so the distance between a/c is important. That adds information to the question regarding why non-CatII aircraft as well as others shooting non-ILS approaches are not allowed into the area. So you don't care whether its an CAT III "A", "B" or "Z", do you? Yeah, nice change. dh Link to comment Share on other sites More sharing options...
Don Hudson Posted July 11, 2003 Share Posted July 11, 2003 Thanks Pierre, On the smilies, put a space between the letter and the bracket. Otherwise, its telling the site to insert the beer glass when bracketing the 'b'. Not that that's a bad idea... :[ Link to comment Share on other sites More sharing options...
Don Hudson Posted July 11, 2003 Share Posted July 11, 2003 Thanks Pierre, On the smilies, put a space between the letter and the bracket. (bad) = (bad ) (toy) = (toy ) (a) = (a ) (boo, er, well you get the idea. Otherwise, its telling the site to insert the beer glass when bracketing the 'b'. Not that that's a bad idea... Link to comment Share on other sites More sharing options...
handyman Posted July 11, 2003 Share Posted July 11, 2003 I believe the regs are fairly clear on this one. Since RVR is available and by your example not fluctuating, the ban stands. If you heard two or three different RVR values then you could call it fluctuating and use the airport vis. As for other approaches, if you’re certified and the airport is conducting LWMO, then you could fly a CAT3 approach. Link to comment Share on other sites More sharing options...
Moon The Loon Posted July 11, 2003 Share Posted July 11, 2003 Not any more you don't! ( Link to comment Share on other sites More sharing options...
Moon The Loon Posted July 11, 2003 Share Posted July 11, 2003 It's a "Canadian" thing - Cat I's can be carried out and completed as low as RVR1200. History has demonstrated it to be an extremely safe allowance amongst regional and national carriers in Canada. Link to comment Share on other sites More sharing options...
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