Approach ban and circling
 

METAR EXXX 052120Z 00000KT 9999 R01/P1500U R19/0400 BCFG BKN012 15/14 Q1018=

EXXX has an instrument approach procedure (Cat 1 ILS) on runway 19 only. Can I legally make an approach to runway 19 to circling MDA followed by circling to land on runway 01?

If it's allowed, circling minima will be quoted on the approach plate for 19

An interesting question. I think that you can,PROVIDED you have the required visual reference(Rwy01) by-and do not continue below- the ILS approach ban point OR your circling minima whichever is the HIGHER. Assuming,the visual references are aquired by the higher of the two,you can continue at(or descend to)circling minima but must keep the runway or its' environment in sight at all times throughout the circling manouvre.You cannot descend from your circling MDA unless you have visual contact with the landing runway itself.

Circling is a demanding exercise and should be approached with meticulous planning - there's very little room for error that close to the ground.

1.My first thought was why would you want to make a circling approach to an airfield that MUST be in LVP's (RVR <600m)? The airfield probably wouldn't allow it.

2. What's the circling minima? You cannot go below 1000' ARTE as the RVR is below minima for the instrument runway in use (Approach BAN- automatic go-around?). You cannot leave circling minima until the landing threshold/touchdown area is visually acquired and maintained. With RVR at 1500m (approx 1 nm) it's unlikely your going to see it AND maintain it as you descend. YOU are responsible for obstacle clearance so be extremely careful about descening on base leg.

3. Remember PAN OPS circling for Cat C requires you to remain with 4.2nm of threshold/abeam. Taking into account you turn radius, at 1000' agl you will be at just about the limit of that to establish on a 3 mile final.

Those are my thoughts - I'm going to think about it some more :) Legally, I think you can. If the fog split was threshold 19 foggy, runway 01 9999's then it would probably be ok. Anything else becomes an Airmanship/Command decision.

I'll try to find the legal bits.

A4

Silly question, but how do you have 10km viz IN ALL DIRECTIONS with fog patches 400m RVR at one end?

Because prevailing vis is not measured at ground level. And RVR is a specific measurement along the runway. It's not an uncommon report.

I believe the definition changed a year or so ago to at least 50%,rather than ALL DIRECTIONS. A4-in Bookworm's initial posting,the R01 RVR is given as P1500(1e it could be anything greater than that, the max measurable). I doubt circling minima for ANY a/c category would permit a circle to land at an actual value of 1500m repoted RVR.As an aside,you can fly a VISUAL approach down to 800m,presumably by going visual off an instrument approach.HOWEVER,you can't try to buck the system by converting a circling approach to a "visual approach".Got that??!!

Why would you circle?? You need to be visual to start your circling, so simply continue your ILS to land if you are visual!

Sara,

You are not allowed to continue your approach because the RVR is below CAT 1 minima........ I've been in the hold with a clear view of the runway - but the RVR's were 400m! This would only become apparent as your slant view dimished in short final / flare.

A4

Bush - I think I got it. :}

very nice question, had to take my ops manual to check, and my answer would be: YES you can, because for ils cat2/3 rvr report is mandatory, for cat1 and non precision approach rvr is still the costraining report (but if not avaiable gen visibility is acceptable, eventually converted in rvr!!), but for circling approach the costraining met report is ONLY GEN VIS+CLOUD CEILING!!!

I'd vote for a 'yes' as long as you can persuade ATC:) - the only 'crippler' is as A4 says, if you NEED to descend below 1000'ARTE on the ILS for circling you are 'technically' illegal, but who is watching..........?:cool:

This comes from Cap 768 Guidance to operators.
Spitoon - I have encountered that many times but it is reported as MIFG.

Could you please elaborate bral?

A4

Yes bral, but you are allowed to make an approach irrespective of RVR's provided you do not go below 1,000' ARTE/4d/OM or equivelent if they are still below your minima. Of course, it's a valid question as to why you would want to commence an approach with 300m RVR when you need 550m....unless you plan to circle.

So if Circ minima is 1,100 agl (highish for circling) you could theoretically commence an approach, level off before the approach ban altitude and circle.
Legal? - theoretically yes. Sensible? Open to debate depending upon numerous other factors.

A4

I'm sure that in the conditions quoted the whole airfield would be visible. I also have sat in the MAY hold with 08 in use at LGW, Cat I a/c and 300m RVR, and the whole of the east end of LGW visible and RVRs in excess of 1500 on 26, but it could not be changed. Finished up at Manston:)

The answer is yes - you can make the approach provided it is a circling to the other end.

Why?

The "Approach Ban" prevents one from continuing an approach beyond the OM or equivalent position if the reported vis/rvr is less than the applicable minimums

In the case described, the applicable minimums are the Circling minima which are in terms of visibility.

The ILS minima is not of interest once it has been decided to circle.

Breaking visual and landing straight-in could bring up an interesting question in that the weather is below the straight - in minima and thus the approach ban would have been broken.

Very intresting situation.

From a practical point of view, I would want 2 alternates and if we went missed from the circling at any stage, would not be hopefull of an improvement in the weather which could justify hanging round to have another go.

Regards,

DFC

A4
If ATC are expected to inform the CAA of anyone continuing with RVR below minima, quite what do they use as the cutoff given JAR OPS says pretty much what's above & ANO says 1000' aal? In the context of a commercial operator with G reg aircraft of course :E

Well if the Operator is JAR approved in a JAR state and the Ops Man has been derived from JAR-OPS 1 then I'd do what the JAR's say.

Our Ops Manual (JAR(UK)) has the OM or equivalent quote but it also says

....The 'Equivalent Position' can be established by means of:

i) DME distance,
ii) a suitably located NDB or VOR, SRE or PAR fix,
iii) or any other suitable fix that independently establishes the position of
the aircraft.

Additionally:

......Where no outer marker or 'Equivalent Position' exists, the Pilot-in command shall make the decision to continue or abandon the approach before
descending below 1,000ft above the airport on the final approach segment.

which I suppose ties up the ANO bit.

As most runways have a check alt or marker at 4D (about 1300'agl) trying to get down to Circling altitude might be a bit difficult.

I think we are going round in circles now no-pun intended :) so I think it's probably legal but I'm not sure ATC would be happy with it. I think you'd struggle to get down to Circ minima due 4D/OM issues. That then places you right on the edge of the 4.2 nm obstacle protection limit when turning base/final. Finally, it's probably not the smartest thing to do in an airliner full of people due to the additional visibility factors.

A4

Interesting answers, thank you.

The ceiling was originally chosen to attempt to exclude the possibility of a visual approach to 01. And thanks for the safety tips -- strikes me that the biggest real-world challenge is avoiding the stream of VFR arrivals for 01. ;) But this is solely about legality.

Let me modify the question slightly then:

METAR EXXX 052120Z 00000KT 9999 R01/P1500U R19/0400 BCFG BKN009 15/14 Q1018=

Circling MDH is 600 ft for my category of aircraft. At 1000 ft aal (or the OM, depending on your particular flavour of approach ban) I'm in solid cloud with no visual reference. Can I continue the approach?

uh.... no.