... and maintain
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... and maintain
Hi,
why use US ATCOs (and some others) the phrase e.g. "ABC123 climb and maintain FL270" whereas in other countries the ATCOs use (only) "ABC123 climb FL270"?
Is there any "history" of the phrase "... and maintain" ?
Omitting this "add-on" will save time regarding freq occupancy ... so what's the benefit of adding these two words - compared to the "condensed" version?
Regards,
Redfox
ATCO: "The number is 220 - either reduce to it or make it your heading"
why use US ATCOs (and some others) the phrase e.g. "ABC123 climb and maintain FL270" whereas in other countries the ATCOs use (only) "ABC123 climb FL270"?
Is there any "history" of the phrase "... and maintain" ?
Omitting this "add-on" will save time regarding freq occupancy ... so what's the benefit of adding these two words - compared to the "condensed" version?
Regards,
Redfox
ATCO: "The number is 220 - either reduce to it or make it your heading"
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Because some suit decided that it was going to be in our book <G>... Can't think of any other reason for it... Of course, we can also use the term maintain XXX when they are going up or down and we want them to stop... We like the word too, <G> we use it for speeds as in maintain 320 knots or greater, or on the other side of the coin, maintain 250 knots or less stand by for holding <G>...
regards
Scott
regards
Scott
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Redfox
I think you'll find that US controllers save RT time by missing out the words "climb" or "descend". An instruction to climb to FL340 would thus be "BAW123 maintain FL340".
It would also appear that "maintain" when relating to speeds does not necessarily mean "fly at this speed". See the thread entitled "Question for a US controller - 250kts <10".
Maintainingly yours
G W-H
I think you'll find that US controllers save RT time by missing out the words "climb" or "descend". An instruction to climb to FL340 would thus be "BAW123 maintain FL340".
It would also appear that "maintain" when relating to speeds does not necessarily mean "fly at this speed". See the thread entitled "Question for a US controller - 250kts <10".
Maintainingly yours
G W-H
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I fully appreciate that it's not your MATS Pt 1 standard but I do occasionally use it in the TMA, usually when I know the a/c will have to level as there's another chap descending to a 1000ft above. This is a precaution against the odd airline who assume they are going to receive continuous climb from departure and climb at 3000+ft/min till the last possible moment! Usually resulting in TCAS TA and occasionally RA's. I usually combine this with TI at the time of the clearance if I consider it appropriate.
If we consider an a/c is climbing or descending at such a rate that it will trigger an RA it is considered good practice to issue TI and if I know the RT is going to get rather busy I'd much rather get this out of the way early than face a TCAS TA at a time when I've hardly time to take a breath.
(And yes I also appreciate that adding 'and maintain' adds half a second to my transmission, but a TCAS RA and subsequent evasive manoeuvres take up a whole lot more and does nothing for my heart rate...)
If we consider an a/c is climbing or descending at such a rate that it will trigger an RA it is considered good practice to issue TI and if I know the RT is going to get rather busy I'd much rather get this out of the way early than face a TCAS TA at a time when I've hardly time to take a breath.
(And yes I also appreciate that adding 'and maintain' adds half a second to my transmission, but a TCAS RA and subsequent evasive manoeuvres take up a whole lot more and does nothing for my heart rate...)
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Cartman's Twin
that sounds very reasonable ...
I assume the "history" of this phrase has something to do with step climbs/descents - even at a pre-TCAS time ...
regards,
Redfox
that sounds very reasonable ...
I assume the "history" of this phrase has something to do with step climbs/descents - even at a pre-TCAS time ...
regards,
Redfox
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Quite possibly Redfox.
A number of our SIDS include stepped climbs to 3, 4 then 6000ft, so it could have a place when you clear an a/c to say 5000, cancelling the final level mentioned on the SID chart
A number of our SIDS include stepped climbs to 3, 4 then 6000ft, so it could have a place when you clear an a/c to say 5000, cancelling the final level mentioned on the SID chart
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Cartman's twin,
What a load of ****e. The phrase "and maintain" will not prevent a TCAS RA. The rate of climb/descent is what causes a TCAS RA. Version 7 of TCAS has since alleviated nearly all spurious RAs.
As for acft in a busy terminal environment being given intermediate levels, wouldn't it be better to give the PIC an estimate of how long before they can receive further climb/descent. Eg. QFA25 climb to F110, expect further climb in 3 minutes.
refplus20,
"To" should be used. Eg, "descend 5000 feet". Does this mean descend to 5000 feet or does it mean descend 5000 feet (ie. descend from F150 to A100).
A controller should also say eg. "descend to two thousand five hundred feet" and not descend to two five zero zero feet" as happened in one fatal crash.
Communication in air traffic control must be clear, concise and simple. Standard phraseology is set down and pretty standard throughout the world for a reason. Little add ons like "and maintain" do not aid good communication between ATC and the PIC.
What a load of ****e. The phrase "and maintain" will not prevent a TCAS RA. The rate of climb/descent is what causes a TCAS RA. Version 7 of TCAS has since alleviated nearly all spurious RAs.
As for acft in a busy terminal environment being given intermediate levels, wouldn't it be better to give the PIC an estimate of how long before they can receive further climb/descent. Eg. QFA25 climb to F110, expect further climb in 3 minutes.
refplus20,
"To" should be used. Eg, "descend 5000 feet". Does this mean descend to 5000 feet or does it mean descend 5000 feet (ie. descend from F150 to A100).
A controller should also say eg. "descend to two thousand five hundred feet" and not descend to two five zero zero feet" as happened in one fatal crash.
Communication in air traffic control must be clear, concise and simple. Standard phraseology is set down and pretty standard throughout the world for a reason. Little add ons like "and maintain" do not aid good communication between ATC and the PIC.
Last edited by DirtyPierre; 11th Jul 2005 at 21:26.
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"A controller should also say eg. "descend to two thousand five hundred feet" and not descend to two five zero zero feet" as happened in one fatal crash."
Sorry, did you say descend 22500 feet or to 2500 feet. I think we should be told.
Descend/climb and maintain avoids any confusion
Sorry, did you say descend 22500 feet or to 2500 feet. I think we should be told.
Descend/climb and maintain avoids any confusion
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Wouldn't bet next month's pay check on it, (Mrs Tug would kill me!), but believe ICAO rules may state the requirement for "climb/descend to and maintain...".
Some authorities/providers may be more strict in their interpretation/application of the ICAO RTF rules than others.
Rgds
T3
Some authorities/providers may be more strict in their interpretation/application of the ICAO RTF rules than others.
Rgds
T3
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As far as I can get it (see my location 
) the most commonly used phrases are
"climb/descend Flightlevel 230"
"climb/descend Altitude 5000ft"
No "maintain" and no "to" ... short and sweet ... even so (nearly) no chance for any misinterpretation ... (???)
My assumption is that the "history" of the phrase "climb/descend xxxx and maintain" has something to do with step climbs/descents associated with wrongly adopted continous climbs/descents ... ( ? )
I also assumed that there were some "incidents" caused by such misinterpreted climb/descent instructions ... like the phrase "ready for take off" was amended to "ready for departure".
... or something like that.
regards,
Redfox
) the most commonly used phrases are"climb/descend Flightlevel 230"
"climb/descend Altitude 5000ft"
No "maintain" and no "to" ... short and sweet
... even so (nearly) no chance for any misinterpretation ... (???) My assumption is that the "history" of the phrase "climb/descend xxxx and maintain" has something to do with step climbs/descents associated with wrongly adopted continous climbs/descents ... ( ? )
I also assumed that there were some "incidents" caused by such misinterpreted climb/descent instructions ... like the phrase "ready for take off" was amended to "ready for departure".
... or something like that.
regards,
Redfox
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Descend/climb and maintain avoids any confusion
What will the PIC do after he reaches the level he is instructed to climb/descend to........um, maintain. So why say maintain?
In Oz we say flight levels for 11000ft and above, and feet for 10000ft and below. Similar to what the Brits use (ie. altitude/height). So an instruction to descend to A070 would be, " Descend to seven thousand feet". Where is the confusion?
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The reason 'to' gets confusing is that some idiots chose to drop it. In my neck of the woods, the books say we must say 'to'. When there is variation between phrases confusion occurs.
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Dirty Pierre
'What a load of ****e'.....
I fully understand what causes TCAS RA's. No confusion here thanks very much.
I feel if you'd actually taken a moment to think about what I said you'd understand how it may reduce the chance of said RA.
If the a/c know that they will have to level off due to conflicting traffic they are LESS LIKELY to climb at max rate until the moment they're about to bust their level. It may be different in your neck of the woods but some airlines here have a habit of assuming they will be climbing continously. With the additional information the a/c usually reduce their ROC as they approach their cleared level and THEREFORE no RA. In theory..
Less Black and White, more shades of grey..... We're all human
I've tried the "Climb FL120, expect further climb in 10 miles". The a/c climbed to twelve, and then climbed further after 10 miles.....
'What a load of ****e'.....
I fully understand what causes TCAS RA's. No confusion here thanks very much.
I feel if you'd actually taken a moment to think about what I said you'd understand how it may reduce the chance of said RA.
If the a/c know that they will have to level off due to conflicting traffic they are LESS LIKELY to climb at max rate until the moment they're about to bust their level. It may be different in your neck of the woods but some airlines here have a habit of assuming they will be climbing continously. With the additional information the a/c usually reduce their ROC as they approach their cleared level and THEREFORE no RA. In theory..
Less Black and White, more shades of grey..... We're all human
I've tried the "Climb FL120, expect further climb in 10 miles". The a/c climbed to twelve, and then climbed further after 10 miles.....
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OK, for the differently abled, let's try again.
"In Oz we say flight levels for 11000ft and above, and feet for 10000ft and below. Similar to what the Brits use (ie. altitude/height). So an instruction to descend to A070 would be, " Descend to seven thousand feet". Where is the confusion?"
Sorry, did you say "descend to seven thousand feet" or "descend two seven thousand feet"
It seems pretty obvious that confusion might occur from time to time.
chump
"In Oz we say flight levels for 11000ft and above, and feet for 10000ft and below. Similar to what the Brits use (ie. altitude/height). So an instruction to descend to A070 would be, " Descend to seven thousand feet". Where is the confusion?"
Sorry, did you say "descend to seven thousand feet" or "descend two seven thousand feet"
It seems pretty obvious that confusion might occur from time to time.
chump
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Sorry, did you say "descend to seven thousand feet" or "descend two seven thousand feet"
Two seven thousand feet......Read the post again.
Flight levels for altitudes @ and above 11000ft. So 27 thousand feet would be transmitted as flight level two seven zero.
No confusion here in Oz.
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Another go,
Date: 19 FEB 1989
Time: 06:36
Type: Boeing 747-249F
Operator: Flying Tiger Line
Registration: N807FT
Msn / C/n: 21828/408
Year built: 1979
Total airframe hrs: 34000 hours
Cycles: 9000 cycles
Engines: 4 Pratt & Whitney JT9D-7Q
Crew: 4 fatalities / 4 on board
Passengers: 0 fatalities / 0 on board
Total: 4 fatalities / 4 on board
Airplane damage: Written off
Location: 12 km (7.5 mls) from Kuala Lumpur (Malaysia)
Phase: Approach (APR)
Nature: Cargo
Departure airport: Singapore
Destination airport: Kuala Lumpur-Subang Airport (KUL)
Flightnumber: 66
Narrative:
The Boeing, named "Thomas Haywood", was less than half loaded with textiles, computer software and mail when it departed Singapore. Approaching Kuala Lumpur, the crew were cleared to route direct to the Kayell (KL) beacon for a runway 33 approach. While on the NDB approach, the crew were cleared to "...descend two four zero zero..." which was interpreted by the crew as "...to 400...". The aircraft descended below minimum altitude and crashed into a hillside at 600 feet/180m msl just before reaching the Kayell NDB, where minimum descent height was 2400 feet. The Boeing hit treetops and started to break up until bursting into flames.
PROBABLE CAUSE: Non-standard phraseology was used by Kuala Lumpur ATC, causing the crew to misinterpret the instructions.
chump
Date: 19 FEB 1989
Time: 06:36
Type: Boeing 747-249F
Operator: Flying Tiger Line
Registration: N807FT
Msn / C/n: 21828/408
Year built: 1979
Total airframe hrs: 34000 hours
Cycles: 9000 cycles
Engines: 4 Pratt & Whitney JT9D-7Q
Crew: 4 fatalities / 4 on board
Passengers: 0 fatalities / 0 on board
Total: 4 fatalities / 4 on board
Airplane damage: Written off
Location: 12 km (7.5 mls) from Kuala Lumpur (Malaysia)
Phase: Approach (APR)
Nature: Cargo
Departure airport: Singapore
Destination airport: Kuala Lumpur-Subang Airport (KUL)
Flightnumber: 66
Narrative:
The Boeing, named "Thomas Haywood", was less than half loaded with textiles, computer software and mail when it departed Singapore. Approaching Kuala Lumpur, the crew were cleared to route direct to the Kayell (KL) beacon for a runway 33 approach. While on the NDB approach, the crew were cleared to "...descend two four zero zero..." which was interpreted by the crew as "...to 400...". The aircraft descended below minimum altitude and crashed into a hillside at 600 feet/180m msl just before reaching the Kayell NDB, where minimum descent height was 2400 feet. The Boeing hit treetops and started to break up until bursting into flames.
PROBABLE CAUSE: Non-standard phraseology was used by Kuala Lumpur ATC, causing the crew to misinterpret the instructions.
chump