Descent cross over speed
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Join Date: Jul 2002
Location: uk
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Descent cross over speed
A question for radar controllers.
We encourage our pilots to fly 'managed' speed on very low cost index figures, due to the ever increasing fuel prices. These managed speeds during the descent could mean an economy cross over speed of around M.76/255 kts.
Just asking for your comments regarding these slow speeds when descending into the UK from the South? to say LGW/BHX/MAN?
Many thanks in advance.
We encourage our pilots to fly 'managed' speed on very low cost index figures, due to the ever increasing fuel prices. These managed speeds during the descent could mean an economy cross over speed of around M.76/255 kts.
Just asking for your comments regarding these slow speeds when descending into the UK from the South? to say LGW/BHX/MAN?
Many thanks in advance.
Join Date: Jul 2001
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Can't speak for the UK, but if you find yourself over here, just don't make it a surprise. If you want to fly slow, let us know. If we can accomadate it we will, if not we will assign a speed that will work... Surprises are NEVER good in aviation...
regards
Scott
regards
Scott
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I agree with Scott, over here in Oz, the big local (starting with Q) is econning everywhere, bit of a shock when they first started doing it, also different types had different speeds and implementation dates for econ speeds; so it was rather difficult; 737-400s still go fast (normal)...
Now we are constantly checking for intended speed; cause even with the econ philosophy some aircraft will go fast as the crew index is more important than the fuel, ie running very late and crew running out of duty time.
Where the econ speed will mean missing slots or cause undue delay to others we nominate speeds to fly, everyone knows that it should be accommodated where possible, so we do where possible.
Just make sure that you communicate your intent to ATCs on the job, not just company execs... Also good idea to tell the crew to nominate intended speed to ATC prior to top of descent, reduces the shock value that Scott mentioned; particularly where you have put number two 10NM behind thinking you'll be right.
265K-285K +/-10 seems to be the norm on econ speeds for the big Q; even it's low cost spin off (J*) are doing econ now.
Now we are constantly checking for intended speed; cause even with the econ philosophy some aircraft will go fast as the crew index is more important than the fuel, ie running very late and crew running out of duty time.
Where the econ speed will mean missing slots or cause undue delay to others we nominate speeds to fly, everyone knows that it should be accommodated where possible, so we do where possible.
Just make sure that you communicate your intent to ATCs on the job, not just company execs... Also good idea to tell the crew to nominate intended speed to ATC prior to top of descent, reduces the shock value that Scott mentioned; particularly where you have put number two 10NM behind thinking you'll be right.
265K-285K +/-10 seems to be the norm on econ speeds for the big Q; even it's low cost spin off (J*) are doing econ now.
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Again I can't speak for the UK but here in the Middle East and particularly into Dubai, just like Scott said, if you are going to fly economical speeds then tell us on first contact. If you surprise us then we will probably surprise you back, ie. you will be moved back in the sequence. Do us and yourselves a favour and advise the ATC'ers of your intended speed if it is something unexpected for the aircraft you are flying (for a modern jet anything from 270 kts or less). In this part of the world at least the usual speed we expect is 280kts and upwards until STAR speed restrictions take effect. If you give us less than that without asking and we don't have time to have a friendly chat with you about your speed, you may find that that economical speed won't be so economical as you get given a radar vectored tour of the Gulf or in some cases, you can fly an even more economical speed going round in the hold.
Bottom line, let us know early so we can either plan to accomodate you, or tell you no and make you speed up.
Bottom line, let us know early so we can either plan to accomodate you, or tell you no and make you speed up.
Join Date: Feb 2001
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Most controllers have a rule of thumb for the speeds that certain aircraft will naturally do and, in the absence of other information, will use those to make a plan. If you decide to fly your 747 at 250KIAS instead of the 285+ we would usually expect, then at the very least you will catch us out...
As others have said, if you're going slow for a reason, TELL US!
As others have said, if you're going slow for a reason, TELL US!
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into the UK from the south, you are more than likely on an ATC speed restriction anyways to stream you as there are so many inbounds - esp to the TMA. If you cannot fly that speed iinstruction, you MUST tell ATC.
If ATC do not put you on a speed restriction (which can be a fly greater or less than restriction), then technically you are free to do what speed you want, as long as you meet the 'level by' restrictions.
It would be nice to be told if economical speeds are being used, although it is a RADAR environment, so a controller should notice!!
If ATC do not put you on a speed restriction (which can be a fly greater or less than restriction), then technically you are free to do what speed you want, as long as you meet the 'level by' restrictions.
It would be nice to be told if economical speeds are being used, although it is a RADAR environment, so a controller should notice!!
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Question for Pilots
Dear Guys,
What do you prefer, if we (ATCOs) need to delay you due to sequencing or due to traffic congestion, to enter a holding pattern, to be given long vectors or to reduce to minimum clean speed. I never asked pilots about it and your answer will be highly appreciated.
Thanks
What do you prefer, if we (ATCOs) need to delay you due to sequencing or due to traffic congestion, to enter a holding pattern, to be given long vectors or to reduce to minimum clean speed. I never asked pilots about it and your answer will be highly appreciated.
Thanks
Per Ardua ad Astraeus
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Atco - we had a thread about this way back and I will try to locate it. The concensus was, I believe (and my preference), the hold, as we can compute required fuel to touchdown more easily from there than with 'indeterminate' track miles from vectors.
Found it: http://www.pprune.org/forums/showthread.php?t=3437
Found it: http://www.pprune.org/forums/showthread.php?t=3437
Join Date: Jun 2001
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OBK!
Not unusual to get this during early morning rush off the ocean.....for instance arriving during night curfew and wanting to lose some time. The regulars will usually ask if a "250 knot descent" is OK.
Never a problem if we know; remember that ATC sometimes use reasonable expected performance to separate traffic.......please mention any significant variation from normal operating practice.......hardly ever a problem....but we need to know.
If this is a fleet-wide practice, and is significantly different to the way that other operators fly the same equipment, write to ATC ops who will notify all controllers to expect it.
As an example we've just been given a set of performance figures for the new Embraer...very handy.
Not unusual to get this during early morning rush off the ocean.....for instance arriving during night curfew and wanting to lose some time. The regulars will usually ask if a "250 knot descent" is OK.
Never a problem if we know; remember that ATC sometimes use reasonable expected performance to separate traffic.......please mention any significant variation from normal operating practice.......hardly ever a problem....but we need to know.
If this is a fleet-wide practice, and is significantly different to the way that other operators fly the same equipment, write to ATC ops who will notify all controllers to expect it.
As an example we've just been given a set of performance figures for the new Embraer...very handy.
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055166k - not seen those Embraer stats, are they on the intranet or on a piece of paper circling the ops room or have I been caught out not reading my briefings today? 
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I know there is a requirement to report a change of speed to ATC when the change is bigger than .... kts (something; Alzheimer knows 
)
Same goes when an aircraft is locked om Mach number and he needs to change the speed with M0.01 or greater.
However if the speed is published within the Flightplan there is no need to report it as, in a way, it is already reported.
However in any case if the performance of an aircraft is altered beyound the expectations for that aircraft, although published in a flight plan, a head's up to ATC is more then appreciated.
)Same goes when an aircraft is locked om Mach number and he needs to change the speed with M0.01 or greater.
However if the speed is published within the Flightplan there is no need to report it as, in a way, it is already reported.
However in any case if the performance of an aircraft is altered beyound the expectations for that aircraft, although published in a flight plan, a head's up to ATC is more then appreciated.
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5Mb.......
On the EBS 'ol friend.... not sure quite how accurate they'll turn out to be, but it's a start 
Rgds BEX
not seen those Embraer stats, are they on the intranet or on a piece of paper circling the ops room or have I been caught out not reading my briefings today?
Rgds BEX
