London City when it's busy - just what landing/takeoff separation minima is possible?

[throw a dyce]

Rule 3,
No it was my Chinese landlady who said that when I tried to get the rent lowered.Mind you I've had a few hot dinners in down town Lockhart Road.
Yeah CAD would suspend you for trying to shift traffic.What was perfectly legal and safe at home was a real there.If the CAD could see what we do with helis in ISZ,they would spit out their congee.

[slip and turn]

What would have been the MDH? Did I read somewhere it was as high as 400 feet at London City ? Chilli's daylight under the departing aircraft's wheels tells me the ATCO requirement. Finally then, how about the piloting requirement for an aircraft with no landing clearance at 400 feet ? Can someone pin that one down too, please ?

[Gonzo]

S&T, sometimes you don't even need 'daylight'. We can use something called a 'Land after...' instruction, which as long as the following pilot is happy, he can land with the one ahead still on the runway.

Similarly, at specified airports,. we can give an 'After the landed, cleared to land' and/or 'After the departing....cleared to land' clearance, subject to certain conditions (met and otherwise), again the first a/c can still be on the runway.

Decision Height/Alt. is the height on a precision approach at, or above which, the inbound crew must have visual reference with the runway. It is nothing to do with the runway still being occupied or being cleared to land.

The same thing on a non-precision approach is called minimum descent height/alt.

[slip and turn]

Thanks Gonzo.

I see HD mentioned the land after variant in the other thread and I had got the (wrong) impression that it might have been an earlier practice that perhaps wasn't used so much anymore.

I must admit I'd got a more reserved (wrong again?) idea of what the "decision" actually is at MDH, MDA, DH, DA or whatever. Is it then just "Can I see the runway? If so continue, if not go around ..." ? i.e. no decision about whether the runway is occupied/obstructed?

I find it surprising that in the absence of any further rules, an almost simultaneous rotation and flare is permitted so long as the controller gets in some kind of clearance (be it land after..." or the normal kind...) before touchdown! Is that really the case?

[eyeinthesky]

A clearance to land (in the UK at least) is approval by an air traffic controller for a pilot to decide to do so. Ultimately the decision rests with the crew, and they may decide to go around. If the crews in this case were kept in the picture by ATC (did you have an airband radio so you know what was said?), then the crew can decide to continue the approach visually for as long as they like, provided they assess that a safe landing will ensue. ATC can issue whatever clearances they are allowed to to permit this (land after, expect late landing clearance etc). Job done.

I can't understand why S&T is still harping on with the same question when the answer was given in the first few posts.

MDA/MDH etc are complete red herrings and are to do with the requirement to achieve visual reference for landing when approaching in IMC, as Gonzo has eloquently explained.

[slip and turn]

Nope I wasn't listening in, just watching. My view was from about 200m abeam the threshold. Remember this wasn't just a two aircraft potential conflict ... initially it was three because the backtracker was slow to exit. I guess that's either because instructions were awaited or they hesitated as they verified their stand visually. Arriving traffic exiting the runway/entering an almost saturated tiny apron has to make a simultaneous decision to turn left or right to their stand or risk boxing themselves in or having to go round the roundabout described earlier! So the two on the ground were effectively grid-locked for a few moments ...

I am sorry if some of you think it is 'harping on', but as London City is a special case where an apron extension has already been planned as a sorely needed thing, where taxiways are roundabouts, where STOL operations are being conducted, where heavy landings / heavy braking are perhaps more frequent than elsewhere, and where room for excursions is limited, I just thought it was worth analysing a bit further...

[Taffy1]

Slip and Turn

Without meaning to sound condacening - to an outsider the picture you see ay eglc may seem like chaos, to those in the know i.e atc etc, they are aware of whats going on and how it works. and if it isn't working do something about it (may be a go around).

I dont think eglc is unique, as to any outsider then all airports are a maze of mov, it's just that eglc is on a smaller scale and tight on areas to move aircraft on the ground. Makes it fun

[Gonzo]

S and T,

I find it surprising that in the absence of any further rules, an almost simultaneous rotation and flare is permitted so long as the controller gets in some kind of clearance (be it land after..." or the normal kind...) before touchdown! Is that really the case?

Yes. In the past I have given a landing clearance to an inbound aircraft, only for the readback of the instruction to be delayed by a few seconds as the aircraft touched down. As long as you keep the crews in the picture, then it can be that tight. Of course, we don't aim for it to be that tight, but sometimes due to other factors, it is.

Arriving traffic exiting the runway/entering an almost saturated tiny apron has to make a simultaneous decision to turn left or right to their stand or risk boxing themselves in or having to go round the roundabout described earlier! So the two on the ground were effectively grid-locked for a few moments ...

Anyone from EGLC forgive me (I don't know that much about your ops!), but S and T, I can virtually guarantee you that the ATCO working the traffic told the a/c which way to turn. With such a small apron, the taxi instructions would be planned to the nth degree, a few minutes, at the very least, in advance. Not wishing to resurrect the old thread(!), but one of the hardest skills to master as a Tower ATCO is planning sufficiently far in advance, whilst also reacting to any changes or unplanned for events (crews getting disorientated, mistakes etc). To fight this we often have a handful of 'plans' running concurrently in our heads at any one time, each one initiated by a different, possible occurrence....a/c can't park on stand and thus blocks the taxiway, a/c takes an unexpected exit off the runway, etc etc.

Using taxiways as roundabouts is a great tactic, although sometimes it takes some explaining to the crews to understand what you want them to do.

[slip and turn]

Thanks again Gonzo ... it's a pity I'm too old for your game ... I reckon I'd enjoy it tremendously

PS Do you reckon they sometimes go both ways around the roundabout? I reckon they sometimes do ... maybe that's why Helicopters are banned ... captains sit on the wrong side and aren't trained on roundabouts

[Skipness One Echo]

Technically safe as it is I don't believe it is desirable to be exiting Runway 28 to hold on the taxiway behind traffic waiting to backtrack and then re-entering the main runway to turn west and exit again nearer the jet centre to re-enter the apron. I saw three aircraft do this last Wednesday due congestion on the apron.

Hence the active runway is the roundabout and it is very busy at peak periods.