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-   -   when is a late landing clearance TOO late? (https://www.pprune.org/tech-log/9258-when-late-landing-clearance-too-late.html)

get'em to heaven & back 24th Oct 2000 04:46

when is a late landing clearance TOO late?
 
given reasonable weather, how far are you happy to continue- provided you have been given a clear picture of what's going on ahead?

Fuzzy 24th Oct 2000 05:53

touch down. they will get over it.

COWPAT 24th Oct 2000 07:53

Depends what I,m flying, what I,m following and what the weather, specifically wind is.

An average flight into LHR in the last few months seems to be clearance at about 300-400 feet, but those guys are good.

BHX 24th Oct 2000 12:02

Before you close the taps!!!!

PaulDeGearup 24th Oct 2000 13:16

ILS minimum seems reasonable unless you have been warned to expect a late landing clearance. But then at CDG you know when the "Listen very carefully I will same this only once - minimum approach speed" at 4 miles is announced you could be on for a go around. http://www.pprune.org/ubb/NonCGI/frown.gif

Jetdriver 24th Oct 2000 22:25

......When you have landed !

cossack 25th Oct 2000 02:01

At MAN (and LGW) in mixed mode ops it is permissable to use the "land after the departing" procedure. In this case it is possible for both arriving and departing aircraft to be on the runway at the same time providing that when the arrival crosses the start of the runway (not threshold) the departing aircraft is 2400m (MAN figure, assume LGW same)or more down the runway.

I would say that very late landing clearances are more common in mixed rather than segregated mode.

Prepares to be contradicted...

WOK 25th Oct 2000 02:27

Happy to continue to the flare in the circumstances you describe if it is due to an unforeseen situation eg preceding a/c slow to clear.

In decent wx I don't think anyone would complain about ldg clearance below cat1 DA if it's to let another a/c cross or depart or allow a runway inspection and i don't think anyone would be upset with a very late clearance (<100') if it was due to circumstances outside the ATCO's control as described above.

I think that PLANNING to offer ldg clearance below cat1 DA is pushing it a bit.

My own experience of late clearances at LHR and LGW relate to crossing and departing a/c respectively and have always been handled in an exemplary manner.

cossack 25th Oct 2000 14:20

These days airport operators are looking for more flights per hour on their runways, 50+ @ LGW and MAN. There are a few ways of achieving this.

Aircraft closer together on final approach - 2.5 miles @ LHR already done, but segregated mode used most of the time. Delays are huge when single runway mixed mode in use.

Reducing vortex wake separation minima - already done @ the big 3, light behind heavy and lower medium reduced to 7 and 5 miles respectively

Reducing departure vortex wake minima - can't do that...yet

Increasing speed on final approach - pilots not happy with that

In mixed mode ops, reduce the spacing on final approach to 5 miles (or less in a good headwind) vortex wake permitting - done regularly, results in a smaller time gap for the departure which takes the same time as it always has, therefore, later landing clearances.

Its a fact of life, at busy airports landing clearance at more than a mile from touchdown is becoming rarer. If you want landing clearance earlier you can either fly somewhere quieter or spend longer in the hold. Neither are options today I'm afraid.

The phrase "expect late landing clearance" is a bit superfluous at busy times. It is now the standard.



Reimers 28th Oct 2000 00:01

After touchdown would propably be a bit late, of course there always is a slim chance that you will not get that landing clearance, and after touchdown it is company procedure to unlock the reversers (making a go-around impossible). Also, we are not allowed to extend the flare, no long landings, only long roll out (fear of tailstrikes).
Only in really tiny places where you can see the entire runway surroundings are clear of in case of a bad emergency would I accept an unauthorised landing from my captain or do it myself (yes, at Lufthansa, the first officer can command a go-around to be flown when deemed nessecary and the aircraft is below 500 feet).

Ignition Override 30th Oct 2000 10:16

Several years ago, we were flying a Cat 2 approach into (PHL)Philadelphia, and because a jet took a while to clear the runway in front of us, we did not get the landing clearance until about 100' above Decision Height! That was after asking tower at least twice for it. Luckily the RVR was about 1600 or so, versus 1200 for our minimum allowed.

Slasher 31st Oct 2000 12:55

Dont confuse what sounds good to do or what commonsense tells you to do but instead concentrate on what you are required to do.
The landing manouver starts at the threshold (typicaly 50 feet). So a clearance must be obtained at or prior to this position. If no landing clearance has been obtained by then, a go-around must be executed. Continuing in CAT 11 conditions or worse without a landing clearance would be downright deadly!
To land anytime without a clearance is putting your licence on the line. Its just not worth it. If there was ANY mishap (even an unrelated one) the first thing the Board will ask you, captain sir, is "why did you proceed to land without a landing clearance from ATC?"

PS The old Oz AIP used to say DME arrival procedures clear an aircraft down the steps right to the THRESHOLD of the runway. A landing clearance was then required at or prior to that point.

HugMonster 31st Oct 2000 16:40

I reckon the threshold is too late. Clearance should be by MDA (Cat I/II) whichever is applicable. If Cat III operations, then by Cat II MDA and no later. By 50' you're probably going to touch down briefly anyway, which is a breach of your clearance even if you've already commenced a go-around.

Slasher 1st Nov 2000 10:46

Yeh Hugs you and I both know a landing clearance at or very close to the threshold is rediculusly bloodey late in practicality but I was speaking from the licence-busting legal aspect.
I believe the runway threshold (or 50' RA if you will) is the cutoff point for a landing clearance issue and I use the DME arrival procedure (mentioned above) as my reference as well as the legal definition of the landing manouver. Again this is only legaly speaking. In practical application you determine your own cutoff point or the Companys policy on the subject (if any).
Also Hugs Im not rated CAT III or lower but doesnt a go-around from 20 odd feet RA result in a brief touchdown anyway?

CaptainSquelch 1st Nov 2000 17:32

Slash,

A G/A at 20' hardly ever results in a touchdown because the A/P is already flaring at this time. Since an approach at Cat III minima is supposed to be made on A/P the G/A will also be automatic. The very moment you touch the TOGA switches the nose comes up from the already flared attitude and the thust is increased immediately. This happens much faster than this lazy @ss can do it personally.

Besides what is wrong with a nice G/A if the clearance is a little late? It is good practice to do one every now and than in real life in stead of the sim.

U R NumberOne 1st Nov 2000 18:45

I had to send a 737 around the other day from about a half mile final 'cos the one ahead was too slow to vacate (it was night = no land afters). What amazed me was the fact one of the punters must have come straight off the plane and phoned the local paper (and told them the plane was 50 feet above the ground - b****cks!) as the press office were looking for details a couple of hours later following the paper's enquiry. This was then blown out of proportion in the paper the following morning.

Have some people really got nothing better to do? :mad:

SID the STAR 2nd Nov 2000 01:18

CaptainSquelch,

A g/a in my 767 at 20 feet with autopilot does result in a touchdown (maingear only)followed by 3 to 4 seconds of rolling before we are airborne again.

I do agree that more g/a's should be carried out in real life.

Cmdr Data 5th Nov 2000 17:56

SID the STAR, My 767?

addinfurnightem 5th Nov 2000 18:21

In recent months I have had to do three or more missed approaches in a B747-400, each cost me about 4.6 tons of fuel. Just so long as I have it on board then no problem. If I have already burnt it due to unfavourable levels and speeds all the way from the Far East to Europe then I am in a bad position and anything below top of descent is not good.
From a performance point of view, anywhere before reverse thrust is selected will do.

alt sel 7th Nov 2000 01:29

For those of us without auto pilot go around capabilities.... :)
(As soon as we hit the GA button - the A/P disconnects!)

Minimum height for us would probably be 50'. - I very much doubt if we would touch the runway from that height - we do not have nearly so much inertia as you heavy guys!! - not unless we were really slow in pitching up/adding power!!


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