speed control
More than just an ATCO
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throw in an expidite request and see what happens!
Controller then requests, "Use your speedbrakes."
Pilot answers,"They're for my mistakes, not yours."
Lon More
Here before Pontius was a Pilot or Mortus was a Rigger
Controller then requests, "Use your speedbrakes."
Pilot answers,"They're for my mistakes, not yours."
Lon More
Here before Pontius was a Pilot or Mortus was a Rigger
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so just to confirm, if both aircraft told to fly 250kts, the one at higher level is actually still faster than the one at a lower level?
minimum clean speed = no flaps, no speed brakes = minimum cruise speed?
minimum clean speed = no flaps, no speed brakes = minimum cruise speed?
More than just an ATCO
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so just to confirm, if both aircraft told to fly 250kts, the one at higher level is actually still faster than the one at a lower level?
Yes
minimum clean speed = no flaps, no speed brakes = minimum cruise speed?
Should be lower, can't remember off-hand as I don't think I ever used it; it should be laid down in the aircraft manual - Vmin.m? - if it's become this desperate, I'd want the stall horn blaring
Yes
minimum clean speed = no flaps, no speed brakes = minimum cruise speed?
Should be lower, can't remember off-hand as I don't think I ever used it; it should be laid down in the aircraft manual - Vmin.m? - if it's become this desperate, I'd want the stall horn blaring
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If all else fails, turn left, turn right etc usually works, and if we take 'em off the STAR, - please explain is required. An arriving plane usually slows down quicker when it is not pointing at the airport.
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I agree with "know your a/c" all modern day a/c can reduce speed if required but only to a certain limit before the use of flaps etc. Down under a/c are told to reduce speed by the flow controller many miles away from the destination for sequencing. I don't know if this is the same in the USA. In the UK in an area environment a/c can also be told to reduce speed at high levels but will only do so if the a/c can comply. In an approach environment a/c can reduce/increase speed if the speeds are within the envelope. Outside this the captain will not comply. It is really up to the controller to know what a/c can comply with any speed control which may be required. "Speedbird Concorde 1, reduce speed to 140kts", "Sorry cannot decrese below 210kts at this stage", "Roger", "Midland001, (F100), decrease speed to 140kts", "Roger wilco, can do 130kts if required". Its all up to knowing what the a/c performance is. Mainly aqquired from experience.
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ma again.
if an aircraft at FL370 which we want it to be fast and given descent speed 310+,and one at FL270 told to maintain descent speed 280kts.
am i correct in saying that the aircraft will only pick up speed (310 kts)when it starts descending and passes say FL290?
i was given the impression that an aircraft is quicker at higher level!
thank you
if an aircraft at FL370 which we want it to be fast and given descent speed 310+,and one at FL270 told to maintain descent speed 280kts.
am i correct in saying that the aircraft will only pick up speed (310 kts)when it starts descending and passes say FL290?
i was given the impression that an aircraft is quicker at higher level!
thank you
Van de Vart
Yes you are basically correct. You need to sit down with someone who is good at big sums to understand it properly but your best speed will be around FL290 to FL320. Below that your true speed will again decrease.
Yes you are basically correct. You need to sit down with someone who is good at big sums to understand it properly but your best speed will be around FL290 to FL320. Below that your true speed will again decrease.
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Van Der Vart:
Some good info so far, but you need to get clear in your head the relationship between Mach No, Indicated Airspeed and Ground Speed.
1) Ground speed: Self explanatory, and it is affected by headwinds/tailwinds and the airspeed of the aircraft.
2) Indicated airspeed: In the scenarios you are describing, it is the number of knots shown on the Air Speed indicator and is, in simple terms, the speed of the air past the aircraft. At lower levels (say FL280 and below) it is this that aircraft refer to and it is this which is the limiting reference.
3) Mach No: This is the speed of the aircraft in relation to the speed of sound. (Mach 1 being the speed of sound). At higher levels, it is the mach no which becomes the reference and the limiting factor. Because of the changes in air pressure and density at higher levels, the indicated airspeed in knots actually reduces for a constant mach no as an aircraft climbs. Therefore, and aircraft which is doing M0.84 at high level might have an IAS of only 250 kts or so but a True Airspeed of 490 kts and a groundspeed around that, depending upon winds. If you like, the reason the IAS is lower is that there are less molecules of air per second going past the aircraft for the instrument to measure, because the air is less dense.
Where all this becomes relevant to ATCOs is in the application of the theory. If you ask an aircraft to maintain an indicated airspeed all the way from FL350 to FL 180 you will find that his speed over the ground (ignoring wind) will reduce considerably. This is because he will by choice be using a MACH NO to, say, FL270 and then an indicated airspeed which is often the maximum permissible. For a 737 the mach no might be M0.74 which might equate to 250 kts IAS, but gradually as he descends into thicker air the IAS will rise towards 310kts, whilst the Mach no remains constant. Thus, if you limit him to 250 kts from high level you will find him doing 60 kts less than you might expect.
The easiest way to use speed control is to specify a mach no and then "When able, IAS of 300kts" (or whatever you want). As others have said, Speed control will not CREATE separation, but will MAINTAIN it.
Some good info so far, but you need to get clear in your head the relationship between Mach No, Indicated Airspeed and Ground Speed.
1) Ground speed: Self explanatory, and it is affected by headwinds/tailwinds and the airspeed of the aircraft.
2) Indicated airspeed: In the scenarios you are describing, it is the number of knots shown on the Air Speed indicator and is, in simple terms, the speed of the air past the aircraft. At lower levels (say FL280 and below) it is this that aircraft refer to and it is this which is the limiting reference.
3) Mach No: This is the speed of the aircraft in relation to the speed of sound. (Mach 1 being the speed of sound). At higher levels, it is the mach no which becomes the reference and the limiting factor. Because of the changes in air pressure and density at higher levels, the indicated airspeed in knots actually reduces for a constant mach no as an aircraft climbs. Therefore, and aircraft which is doing M0.84 at high level might have an IAS of only 250 kts or so but a True Airspeed of 490 kts and a groundspeed around that, depending upon winds. If you like, the reason the IAS is lower is that there are less molecules of air per second going past the aircraft for the instrument to measure, because the air is less dense.
Where all this becomes relevant to ATCOs is in the application of the theory. If you ask an aircraft to maintain an indicated airspeed all the way from FL350 to FL 180 you will find that his speed over the ground (ignoring wind) will reduce considerably. This is because he will by choice be using a MACH NO to, say, FL270 and then an indicated airspeed which is often the maximum permissible. For a 737 the mach no might be M0.74 which might equate to 250 kts IAS, but gradually as he descends into thicker air the IAS will rise towards 310kts, whilst the Mach no remains constant. Thus, if you limit him to 250 kts from high level you will find him doing 60 kts less than you might expect.
The easiest way to use speed control is to specify a mach no and then "When able, IAS of 300kts" (or whatever you want). As others have said, Speed control will not CREATE separation, but will MAINTAIN it.
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van der vart
Get yourself a decent flight simulator program and fly a couple of planes....pay particular attention to all the parameters that are the cause of your concerns!
