Old 28th Mar 2019, 12:27
  #23 (permalink)  
Lantirn
 
Join Date: May 2007
Location: FL390
Age: 33
Posts: 169
First of all thanks for your participation in this discussion.

Originally Posted by aterpster View Post
What about this approach which has zero offset and no straight-in minimums?
I dont fly TERPS but in PANS OPS when a procedure doesnt satisfy for a straight in minimums, they publish circling minimums usually due to offset, steep angles, or protruding obstacles nearby. This doesnt mean that you cant fly a straight in approach, but: Always respecting circling minimums.

Originally Posted by oggers View Post
There is no general prohibition against circling back.



For me it is not black and white. I don't see why with 20 - 25° bank you cannot maintain line of sight to the runway environment. To my mind it is legal to circle back. It may not be wise. There is an example in this article at Fig 4.
Very nice input. Althought TERPS thats something that i was searching for. Also there are some other maneuvers to make you stay with the runway is sight at all times but it would require to offset in the beginning, then parallel the landing runway and then make a turn when passing the opposite threshold to join downwind.

Originally Posted by sabenaboy View Post
According to ICAO and EU ops, It is not a requirement to have the runway environment in sight at all times.

Don't confuse a visual approach during an IFR flight with a standard visual circuit in VFR!
For EU ops a minimum RVR of 800 m is required.
Sabena boy, well said about the visual approach. Although that was a new chapter popping in the thread, it wasnt my intention to merge also a visual approach for the sake of conversation because when ATC grants a visual approach you can fly as you want.

Originally Posted by sabenaboy View Post
I would think it is legal to do so. I don't consider not being able to see the runway behind you while turning onto downwind as 'losing visual reference'.
I think this is the cone of confusion for the law. If losing visual reference due to "airplane structures" is permissible, and for how long. Losing the runway for a second due to wings roll movement could be acceptable but could be different than losing the runway below when overflying the runway for many seconds untill turning downwind.

Originally Posted by Small cog View Post
Lantirn
if you have had an approach and cannot get the required visual reference at DA/DH for r/w 16 (1.1nm from the threshold), then I think you are unlikely to achieve anything by trying to circle (or visual approach either). There circling procedures that specify that the circling starts at or after passing the r/w threshold. However, those I have flown also require that visual contact with specific landmarks be maintained while turning ‘downwind’ and up until r/w threshold becomes visible again.
Of course you can achieve and you can see it with mathematics. The straight in minimums calculating for the VDP require more than 4000m in many NPA's. (disregard the approach lights for simplicity). Although you are legal to start the approach, you can expect that unless the lighting system is very long and powerfull, you will see nothing there. Approaching from above at circling minimums (1000ft minimums = 328m < 4000m visibility), although higher, at some point you will see the runway but you will be too high to land, so you will have to plan for a circling approach. And this is the basis of this thread.

Originally Posted by Small cog View Post
Sabenaboy
Your not familiar with OLBA are you? Steep rising ground to the east and south that you don’t want to take liberties with. The OP posed the question that what if the r/w wasn’t seen until starting the go around; vis must be bad eh? Aside the no-no of thinking “it’s a good idea to stop the missed approach and position visually down wind”, just how far will your turn downwind take you from the airfield? If the OP has failed to see the r/w at 788 ft & 1.1 nm, what chance have YOU got by flying a visual circuit. And how would you plan you position your aircraft for base/final? You don’t want to be flying through the c/l at OLBA.

The circling approach is perhaps the most challenging manoeuvre the pilot is asked to fly. Some airlines have even prohibited their crews from flying them. They need to be well planned and brief, not a last minute decision. In the case in question, the usual procedure would be for the right hand seat pilot fly and maintain visual contact. Is your RHS pilot up to speed on flying circling approaches/ visual circuits in poor visibility?

As for scraping around low level in poor visibility over the sea without surface features to aid you to getting where you want to go ... that’s just unprofessional and asking for trouble.
The conversation was for the sake of legality. I didnt say that i would change plan over the minimums and execute another type of approach.
I said that after a missed approach on the straight in, you comeback for a circling approach and briefed.
This was to discuss the legality of this type of circling and not the quality of the decision making, its obvious that its a very very risky approach.

Originally Posted by sonicbum View Post
Exactly... OP forget about asking the legality of turning a straight in into a circling or a visual approach because of weather, it's just a way to understand if You can legally try the EGPWS.
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Sonicbum,
As i wrote in my opening post, you will find out that I agree with this. I dont think its legal since the beggining. But thats what we are discussing here, to let others justify and get something. What i believe is that you are not allowed and if i was 100% sure i wouldnt be discussing here.
I say again, the amount of responses i get by professionals outside vary alot...and thats scary guys.

Originally Posted by sabenaboy View Post
Small cog
The OP poster did not ask if it was wise to fly the scenario he was describing, he was asking about legality:

And I had already said:
So, I think it's pretty obvious that the OP and myself are well aware of the risks involved in circling or visual approaches in low vis conditions. We are talking about legality here, not airmanship. Why do you find it necessary to start lecturing us about that?
I just reacted to you correcting me for saying that it's not a legal requirement to have the rwy in sight at all times during a visual approach in EASA rules.
I provided proof of what I claimed and you were wrong about that.
Sabenaboy, well said again regarding my legal-bound focus.

Originally Posted by Small cog View Post
No. Having been cleared to fly the procedure, unless otherwise cleared, if not visual by the MAP, you are required to fly the missed approach procedure so as to ensure terrain clearance.
Small cog I agree with you when flying OLBA. But I already mentioned OLBA was a bad example by me. There is no point in finding out another approach plate, they are dozen out there.
1)Assume you are cleared for a circling approach same runway.
2)Assume MAP is over the runway.
3)Disregard all circling sector prohibitions limitations


Originally Posted by custardpsc View Post
Not sure if I have missed the point here but I see that in the OLBA example, the viz required for circle to land off VOR DME 16 is 4800m ( and the 1070ft minima you mention) . So, no. , not legal IFR in your declared conditions of 4000m viz. (assuming cat C/D aircraft)
Really? My minimums for this plate on circling are 2.4V. Lido provider. Strange.

Originally Posted by custardpsc View Post
But, circling minima are higher in general than approach minima for obvious reasons, so its likely that in the general case of a marginal approach viz circling wouldn't be an option.
Well, look in this post above for further explanation why you would benefit with visual cues.
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