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How about a pilot request to maintain high speed to lose some height. Also an occasional request from ATC to maintain high speed for the sequence both of which are often heard on the approaches to EIDW Dublin.

Rustydog wrote:

How about a pilot request to maintain high speed to lose some height. Also an occasional request from ATC to maintain high speed for the sequence both of which are often heard on the approaches to EIDW Dublin.

I think here you may talking about a late clearance to descend. Normally ATC will give you clearance to descend from cruise in good time. In a fpl from Sanya to Kai Tak I was given clearance from cruise FL240 to FL160 at RAGSO. The next wypt being CHALI about 100nm distant. So I am able to descend slowly at high airspeed. I am wondering if you might be confused with the meaning. I would say that it would be vary rare and indeed extremely dangerous for ATC to clear you to descend at a high "airspeed" within the TMA. So at what point does EIDW Approach actually give this clearance? High speed descent does not necessarily mean descend at high airspeed. And in fact if you were in the TMA descending at close to your cruise airspeed you would most likely overshoot your target.
Another example aircraft flying into LIMF from the North West have to descend very rapidly because LIMF (Torino) is literally just after having crossed the Alps. Here the a/c effectively turn themselves into bricks with wings. You literally "drop" out of the sky. But the airspeed itself is low. Italian ATC just give them the required altitude at the next waypoint.
Oh and btw EIDW have to post their charts on Eurocontrol. So the most up to date EIDW charts say this:-

Quote:

2. ARRIVAL
SPEED RESTRICTIONS
MAX 250 KT below FL100.
MAX 210 KT between holding fix and IF.
MAX 180 KT between IF and FAP.
MAX 160 KT between FAP and 4NM to THR.
Speed as performance requires between 4NM to THR and THR.
ATC may request specific speeds for accurate spacing.
Comply with speed adjustments as promptly as feasible within operational constraints.
If unable to comply with the above, advise ATC as soon as possible.

So I think it is most unlikely that ATC would give clearance to descend at a high airspeed.
If you are thinking of " "Expedite" your descent" then yes that would be nice but it would mean re recording all the voice sets as Expedite doesn't exist unfortunately.

Somehow related, here is an interesting story of a "too high, too fast and too close" approach:
http://www.skybrary.aero/index.php/Non- ... GHFA_SE%29

In the real world it is unlikely that ATC would issue a late clearance as the pilot would request lower. Which incidentally I often do, but that is probably my bad flight planning. As to what point they are issued to increase or maintain speed I am unsure but now it becomes relevant I will take more notice. But aircraft that have entered Dublin controlled airspace are often requested to increase or maintain 300-310kts for spacing (and this can be as low as 3000ft) and are asked to inform when they need to slow. Pilots also frequently ask to maintain high airspeed or to increase airspeed to lose altitude more quickly. I suspect this is because approach often give the aircraft shortcuts to the localiser which results in them being high. A normal approach can be very convoluted. see charts. ATC also when asking if the pilot would like a shortcut tell them they can increase speed to lose height if they need to. I am not a real pilot and so don't understand the physics I just observe what is said. I listen to Dublin most nights as it is legal in Ireland to listen in.

Rustydog wrote:

In the real world it is unlikely that ATC would issue a late clearance as the pilot would request lower. Which incidentally I often do, but that is probably my bad flight planning. As to what point they are issued to increase or maintain speed I am unsure but now it becomes relevant I will take more notice. But aircraft that have entered Dublin controlled airspace are often requested to increase or maintain 300-310kts for spacing (and this can be as low as 3000ft) and are asked to inform when they need to slow. Pilots also frequently ask to maintain high airspeed or to increase airspeed to lose altitude more quickly. I suspect this is because approach often give the aircraft shortcuts to the localiser which results in them being high. A normal approach can be very convoluted. see charts. ATC also when asking if the pilot would like a shortcut tell them they can increase speed to lose height if they need to. I am not a real pilot and so don't understand the physics I just observe what is said. I listen to Dublin most nights as it is legal in Ireland to listen in.

Starting with your last point. It's illegal to transmit without an RT licence. Nor is it illegal to own an airband radio receiver. You can always plead to the court that you overheard a transmission! Many many Moons ago I was once stopped on top of terminal 3 car park at Heathrow by a police officer because I was listening. I produced my various licences including my RT licence and he had to walk away. I was actually more qualified to listen than he was!
I do find it unusual for an ATC unit to regularly practise something that they have published must not be done. i.e. they have published speed restrictions. To fly at speeds of 300-310 kts as low as 3,000ft is extremely dangerous for everyone concerned to put it mildly. It takes a good 3 miles plus to slow down to a safe manouevering speed from 310kts even with full on speed brakes, possible reduction to idle thust (which at that low altitude is also a high risk) So ATC are asking for trouble in that the number of airmisses would be very high.
You wouldn't be asked to "increase airspeed" in order to loose altitude more quickly. That's a highly dangerous manoeuvre. It means diving! The correct way to loose altitude quickly is to slow down to just above flaps 1 speed say 210kts and then full speed brake. The a/c will drop like a stone.
In the VC10 flying at 310kts at 3,000ft I am only 20kts below Vno. And the 10 is a high performance aircraft!
Here is something you can practise in the sim. An emergency dive. Fly to cruise altitude and simulate a depressurisation failure. Correct recovery in most a/c is: mask on, throttle closed, speed brakes full up, wing over at least 60 deg in the direction of your escape route. As FL240 approaches start bringing the nose up to avoid busting Vne. If you go over Vne you risk the a/c breaking up. There have been a number of potentially unexplained crashes where the a/c initially dived out of the sky and crashed in pieces. A depressurisation failure has been put forward in those cases as a hypothesis where the crew failed to recover the a/c from the initial dive.
Winging over in this context prevents negative G and consequently avoids passenger vomit down the back of your neck!

Another point regarding high speeds at low altitude. If what you say is corrct then you'd better not be in a 757 if you're flying into Dublin!

Quote:

The B757-200 however has a VMO below 10,000 ft of just 250 knots because the windshield isn't certified to withstand birdstrike above 313 knots. Above 10,000 ft the 757 is VMO limited to 350 knots.

[quote="vololiberista"]
Starting with your last point. It's illegal to transmit without an RT licence. Nor is it illegal to own an airband radio receiver. You can always plead to the court that you overheard a transmission! [quote]

I listen in via the internet which as stated, in Ireland is quite legal. If it was legal at EGBB I would listen there but hey ho.
If you doubt me then you could always listen in yourself. I would post the link to the site but I think that is against forum rules, but not certain.
I have read many times where people including pilots have said it is dangerous to keep high speed below 10000ft but as I said it happens regularly at EIDW.

Rustydog wrote:

vololiberista wrote:

Starting with your last point. It's illegal to transmit without an RT licence. Nor is it illegal to own an airband radio receiver. You can always plead to the court that you overheard a transmission!

Quote:

I listen in via the internet which as stated, in Ireland is quite legal. If it was legal at EGBB I would listen there but hey ho.
If you doubt me then you could always listen in yourself. I would post the link to the site but I think that is against forum rules, but not certain.
I have read many times where people including pilots have said it is dangerous to keep high speed below 10000ft but as I said it happens regularly at EIDW.

I'm surprised that pilots of a/c flying into EIDW comply with such requests. On Moday I'll have a chat with one of my colleagues to ensure that none of those ATC controllers can find work here!

I just listened to http://www.liveatc.net/flisten.php?mount=eidw3 for a short while and I may have misheard it, but I think approach issued a speed restriction and a short while later the pilot asked "do you still need this fancy restriction?" and the reply was negative

Edit: I still hear "fancy restriction" ... listen to it at http://archive-server.liveatc.net/eidw/ ... -1630Z.mp3 (starting at 26:30)

I'm guessing he may be saying Vatry but fancy sounds more fun.