Speed Control Phraseology

[kuwait340]

Hello...

couple of days ago....during the descent into the home-base...

the approach controller instuction was like this " (CallSign)...descend alt 10.000ft then reduce speed to 250kts.when reaching 250kts descend 5000ft" .

there after ..while passing 7000ft...he said "when reaching 5000ft reduce speed 220kts.when reaching 220kts descend 3000ft".

is this the correct way of doing it ?

in my opinion...i think it would have been better in the first clearence to say " (CallSign)...descend 5000ft .speed 250kts below 10.000ft" as simple as this .

in the second clearnce ...i think it is better to be like this "descend 3000 speed 220kts" .

because i know this controller...after landing i called him on his mobile phone to tell him that this is my first time to hear clearnces like this .

he said this is the standard way of doing it...i said...you sounded like you want us to level at 10.000ft..reduce to 250kts...THEN ...descend to 5000ft.

and he said...yes ..i want you to level off !!

then i said why you want us to level off...he said...to reduce speed ...better than reducing while descnding...i said...why do we have to level off to decelerate...we can do it on the descent...he said...i have to do it this way because i don't know this aircraft can decelerate while descending or not(he said ..i am not sure that everyone can reduce speed while in the decsent without leveling off).

he said also ...that this procedure is written down in his ATC manual.

is that true ?!

and is there any official manual where i can read the correct speed control phraseology ?

Thanks in advance.

[SM4 Pirate]

I wouldn't do that. I'd give you the descent and speed too.

In the first circumstance I'd say "make speed not above 250 knots below ten thousand feet, descend and maintain 5000 feet."

In the second, "make speed not above 220 knots below five thousand feet, descend and maintain 3000 feet".

If you choose to level off to get the reduction, that's your choice.

But I'd probably choose a distance base point; OM, joining final, fix on the route distance from touch etc.

Of course we understand that it's hard to wash off speed and descend; but it's you decision to comply or not, if not shout.

[CuitoCuanavale]

Kuwait340, to answer your question,…no, it is not written/stated anywhere that you must level off when descending to decelerate in any ATC manual that I am aware of.

Quite possibly you will find this sort of procedure in some parameter operating manual for various aircraft, but definitely not any ATC manual.

It sounds to me like this chap simply threw validations out there to sew his reasoning together as you placed very valid questions to him.

If an ATC wants you to level off at any FL or altitude, he/she will clearly state so. If they don’t and upon questioning there-of by the pilot re-affirm that that is what they expected you to do without instructing it………….well,….hate to say it, but that pretty much starts falling into the much taboo category of controlling that all ATC’s are warned against and that is “assumption”. Most ATC’s in their training, either at recognized training institutions or post Course training will definitely be told that by one of their in-field OJTI’s.

The reason is quite simple; assumption is the Mother of all F**k Ups!

There is an old tried and tested adage from the vestiges of training methodologies in ATC circles (and other corporate arena’s) that still holds very true today. It is called the K.I.S.S. principle. Keep It Safe & Simple.

Most good ATC’s stick almost religiously to this principle as it virtually (not completely) eliminates any form of assumption or misinterpretation/understanding.

As you correctly stated you can bleed that speed off while descending, no need to level off. The ambiguity window here is rather wide as I see it, because if this chap did as he says expect you to level of, what are the parameters in miles/distance that his current traffic pattern, sequencing/ATM can allow you to level off at any altitude before it starts to become a problem in that it can adversely affect his current plan??........and surely if no parameter is stated then this will allow every pilot he gives this instruction to depending on various elements, interpret this in their own way?

This instruction is normally given in the following manner, “ (Acft Reg)…descend 3000’, passing 10000’, reduce 250kts, reaching 3000’ reduce 220kts..”

It is a four part instruction and some pilots might even ask for it to be repeated, but there are no area’s open for assumption.

My experience has been that if a pilot deems it necessary to level off to reduce speed (does not happen that often), he will always advise me of this.

[pocpicadoor]

With the imminent (April 2008) strict interpretation of "Aviation English" requirements with its various categorisations of 1,2,3=unacceptable; and 4,5,6= acceptable with "stipulations" (4&5), will that ATC have a microphone in his hands post....??

ICAO phraseologies should take care of the situation: but knowledge of aircraft operational procedures/capabilities will continue lacking in ATCs "off the streets" instead of trained through a formalised recruitment, assessment and follow-through training system.

Ask training personnel from M.E. Aviation Colleges of the chaff they have to turn into wheat... in less than a season!!

IBN bin POC

[kuwait340]

Thank you Very Very much Gents...

is there any document that i can download to read the correct way of doing the speed control including the phraseology...

i really want to convince my freind and put him in the right track.

Once Again ....Thanks

[Say Again, Over!]

Kuwait340,

I don't use this method all the time nor exactly the way he did it but my reason for doing so is simple: I want you down first, then slow later.

On one of our runway ops, it seems that we always have a tailwind to 2,000 feet and then a slight headwind. You can imagine the shrinking effect this can have on spacing. So, often enough, I'll instruct a crew to descend with a good rate and when level to slow down.

I'd much rather have you in the same wind and slowing down than at the same IAS as the previous traffic but still with a 40 knot tailwind.

In my opinion, what your friend wanted was simple enough: He wanted the altitude first, to resolve a coming conflict, and the second part of his plan was to have you reduce to follow someone. But he needed you down first. If you end up reducing your rate of descent to slow down, you might ruin his plan...

Food for thought?

Felix

[Farrell]

That initial instruction is an accident waiting to happen in some circumstances.

The phraseology is all wrong.

The phrase "descend 5000ft" can very easily be misconstrued as some pilots will understand that as - reduce current altitude by 5000ft -

Thankfully at 10000ft, it made no difference which way you interpreted it as either way you were going to end up at 5000ft. However, had you been at, say for example, 8000ft.....then depending on how you responded to "descend 5000ft", you would either have ended up at 5000ft or 3000ft.

It is a problem that I deal with every day over here. And part of the battle is that my boys just don't see the difference. It's the preposition that's vital.

[trailblazer]

That initial instruction is an accident waiting to happen in some circumstances.
The phraseology is all wrong.
Have to agree with Farrell, this very unpresise. I remember being taught a
long time ago that every number has a name, whether it be altitude, flight level, heading or anything else involving numbers.
Unfortunately this seems to be lost on many people who happily throw about ambiguous clearances

[A Comfy Chair]

Farrell...

I'd like to think NO professional (or even private) pilot would ever interpret that clearence as "descend BY 5000ft". THAT is not a standard clearence.

Far more dangerous is if ATC ever start issuing clearances that ask you to "Descend (by) 5000ft".

Clearances are always to an altitude, and pilots respond accordingly. A request to "Descend 5000ft" should always be interpreted as Descend (to) 5000ft by a pilot... THAT is the standard part of the phraseology!

Although there should be the "to" in there, even if there isn't, as long as the ONLY requests pilots ever get is to descend is to something, not by something, then the system works.

[Jerricho]

Listen to you Mr Farrell........

We'll make a professional pilot out of you yet ;) :p

[CuitoCuanavale]

Hi Kuwait340, I think you have to see this for what it is. Based on your description of the controllers RTF, it appears he was instructing you how to arrange your decent profile in order to meet certain speed requirements….essentially he was telling you how to fly the acft.

As PIC of that flight, it is your decision how best to meet those speed requirements. If for whatever reason you felt you were unable to meet those speeds on a continuous decent or even meet certain speeds issued at certain altitudes or FL’s, then it is your responsibility to advise the ATC of this. This is the one area where ICAO is clear on certain issues….that being that irrespective of any ATC clearance the final responsibility of the safety of the flight and its passengers rests with the PIC of that flight, NOT the ATC.

It would appear that one of two scenarios’ is present;
1) Either the ATC concerned really just thumb-sucked his reasoning when questioned about it and fell back on what I have seen so many ATC’s do and say….”…..its in the manual….”. Most pilots, because of the very broad and somewhat detached world of ATC mechanics never really pursue it, believing that the controller knows of some existing and obscure document that in fact does say that….and invariably leave it at that.
2) This controller friend of yours either washed out or withdrew from flight training many years ago and it still haunts him to this day, manifesting itself particularly when his actions are questioned by a pilot…often digging his heals in on a scenario that he knows full well is groundless.

I obviously could be way off on both, but it has all the marking of what I have seen happen in the past so often and bizarrely enough, still happens today. What always amazes me is that pilots invariably accept the reasoning presented before them, despite the somewhat ominous odour of non-existence. I do however understand it as who wants to get involved in a to-and-fro over a somewhat obscure procedure, which ultimately never came close to narrowing any safety margin.

The clear cut written evidence that you are asking for is not that easy to produce. ICAO, despite the fact that its language now incorporates procedures relating to all forms of automation…..ADS, ADS-B, ADS-B TcasIIv7, Data Link (CPDLC), Mode S..etc,etc…..it is still a language that when read on the basics of ATC methodology and procedures smacks of post-war broad-brush language….meaning, that it is designed to cater for all levels of ATC service, in particularly those countries that still don’t have adequate VHF, HF and radar coverage. (Mostly in still largely underdeveloped or developing countries often referred to as Third World)

Therefore the exact and precise language you are searching for will cause you some trauma in finding….however, there are sections that do support you correct understanding of what should transpire and are worth a read; try Annex II– ICAO Pans-ATM Doc 4444 – Determination of level Occupancy, Use of Radar in ATS 7.11 and Adherence to a Flight Plan 3.6.2 to end of section.

If however this is an important issue to you I would simply try a different approach, ask the controller concerned to direct you to the document that he says it is in with such conviction.

I would however still like to congratulate you on the manner in which you handled your inquiry, that being …..waiting until you have landed and then phoning the concerned controller. I am, like most ATC’s, very pro being questioned either when it is not understood or when it is deemed counter to standard procedure………but more often than not, I have seen either overzealous pilots or controllers take a minor issue to ridiculous proportions on frequency………..very silly and highly unprofessional.

All the professional opinion, directions and advice aside, my personal opinion and advice to you is, if you really have to, satisfy your understanding on this issue and don’t pursue it with your friend.

It is a minor issue and the chances are very high that you are going to cause your friend a great deal of embarrassment, especially since he, already in a telephone call, seemed to cement his belief that he is right. An issue this minor doesn’t warrant the potential destruction of a friend-ship.

[Wojtus]

The phraseology is all wrong.

The phrase "descend 5000ft" can very easily be misconstrued as some pilots will understand that as - reduce current altitude by 5000ft

ATC never ever issue instructions/clearances with relative altitudes. If any pilot is to understand this as a relative value, his instructor shall burn in IMC-hell for ages. Anyway, to avoid such suicides I use british "descend altitude 5000ft" phrase.

Only relative alt transmissions may be traffic informations ("oposite 12 o'clock, 1000ft above").

[Farrell]

"I'd like to think NO professional (or even private) pilot would ever interpret that clearence as "descend BY 5000ft". THAT is not a standard clearence."

As an RT Safety Advisor, I can assure you that "descend 5000ft" is misconstrued by crews more times than you can imagine and even recently, has been responsible for multiple events of level busts and unfortunately, in some cases, CFIT incidents as well.
Reports of stuff like this ends up on my desk on a regular basis.

"ATC never ever issue instructions/clearances with relative altitudes."

Not true. It happens. A lot! Not necessarily where you are but if you travel round a bit, what you see and hear can be enlightening!

[Wojtus]

Not true. It happens. A lot! Not necessarily where you are but if you travel round a bit, what you see and hear can be enlightening!
I would say it's terrifying... Could you give any examples when ATC uses relative altitudes? I'm suprised, because using relative alt, ATCO don't know current a/c altitude (that may be reason for using relative alt), neither at what alt a/c will level off. One of primary ATC functions is to constantly know a/c positions and intentions...

Creating local, colloquial "phraseologies" may be funny at time, but there's deeper concern. Pilot's may get used to them and cause an incident on the other side of the Earth, when ATC is using proper phrases. The good example is omitting "2" in altimeter values in the USA - "altimeter 992" instead of "2992". It already caused some incidents in Europe: eg. "QNH 992" is said to pilot and he sets 2992 inches...

[kuwait340]

Hi CuitoCuanavale

you are right...it looks like it's hard to find the correct way of this kind of instuction unless reading the documents that you stated above.

and as for this controller(he is a very close freind) i called him recently...but i didn't mention anything about that day...neither he did.

i noticed that he is assertive that he is right....and he is not accepting me pointing his mistake.

-----------------------------------------------------------------------

once before...another controller (not a freind) gave me this instruction before he change me to the tower ..he said ...maintain speed 180kts till 6 miles then 160kts till 4 miles !!!.

later on....after leaving the aircraft and was going back to the dispatch office in the airport...i called the control tower and i asked the guy who answered that i need to speak to the approach controller.

i talked to him and i told him what you did is not right ...and he said... why ?

i said ...you can't give two speed restriction that are 2 miles apart...you either say maintain 180kts till 10 miles then 160kts till 4 miles..

or..

to say....maintain 180kts till 6 miles.

because most of the jet aircrafts ( airbuses & boeings ) needs about 1 mile to wash 10 kts off the speed scale "this is ofcourse while descending on the glide which is the worse case scenario"

so when we pass the 6 miles by 180kts...then we are going to reduce to the final approach speed...and we will pass the 4 miles around 160-150kts...

then he said.....Mmmmmm...thank you very very much...now i got it...and he said...this is a promise that i will not do it again.

by the end of the day...we are all human...and we all do mistakes...and the good part that we should learn from our mistakes and accept the others opinions.

Thanks Every One.:ok:

[JunkHole61]

Hi kuwait340.
I'm a controller in the US. I don't know what requirements controllers in your part of the world must abide by, but here our requirements for speed reduction and altitude change are pretty explicit: don't issue a simultaneous descent clearance and speed adjustment.
Here is a snippet from the manual US controllers use, the 7110.65: found at this link:
===============================
c. Simultaneous speed reduction and descent can be extremely difficult, particularly for turbojet aircraft. Specifying which action is to be accomplished first removes any doubt the pilot may have as to controller intent or priority. Specify which action is expected first when combining speed reduction with a descent clearance.
1. Speed reductions prior to descent.
PHRASEOLOGY-
REDUCE SPEED:
TO (specified speed),
or
(number of knots) KNOTS.
THEN, DESCEND AND MAINTAIN (altitude).
2. Speed reduction following descent.
PHRASEOLOGY-
DESCEND AND MAINTAIN (altitude).
THEN, REDUCE SPEED:
TO (specified speed in knots),
or
TO MACH (Mach number),
or
(number of knots) KNOTS.
NOTE-
When specifying descent prior to speed reduction, consider the maximum speed requirements specified in 14 CFR Section 91.117. It may be necessary for the pilot to level off temporarily and reduce speed prior to descending below 10,000 feet MSL.
===============================
Here's a link to the whole section on speed control phraseology and procedures adhered to by US ATC:
http://www.faa.gov/airports_airtraffic/air_traffic/publications/atpubs/ATC/Chp5/atc0507.html
My ATC brother at your home base may have similar requirements. Hope this helps. If I'm butting in where I don't belong, please excuse me.
Happy flying!

[kuwait340]

JunkHole61 Thank you very very much ....indeed that's what i am looking for.

in this case...my freind the controller here in my home base was right with what he instructed us to do.

may be he was mixing the two methods together (Speed reductions prior to descent. & Speed reduction following descent.).

i will pass this link to him...to clarify the procedure to him ( what a freind for :ok:)

thanks a million

[JunkHole61]

You're welcome! Glad I could help.
:)

[Jawspec77]

c. Simultaneous speed reduction and descent can be extremely difficult, particularly for turbojet aircraft. Specifying which action is to be accomplished first removes any doubt the pilot may have as to controller intent or priority. Specify which action is expected first when combining speed reduction with a descent clearance.
1. Speed reductions prior to descent.
PHRASEOLOGY-
REDUCE SPEED:

TO (specified speed),



(number of knots) KNOTS.

THEN, DESCEND AND MAINTAIN (altitude).
2. Speed reduction following descent.
PHRASEOLOGY-
DESCEND AND MAINTAIN (altitude).

THEN, REDUCE SPEED:

TO (specified speed in knots),

or


TO MACH (Mach number),

or

(number of knots) KNOTS.
NOTE-
When specifying descent prior to speed reduction, consider the maximum speed requirements specified in 14 CFR Section 91.117. It may be necessary for the pilot to level off temporarily and reduce speed prior to descending below 10,000 feet MSL.
d. Specify combined speed/altitude fix crossing restrictions.
PHRASEOLOGY-
CROSS (fix) AT AND MAINTAIN (altitude) AT (specified speed) KNOTS.
EXAMPLE-
“Cross Robinsville at and maintain six thousand at two three zero knots.”
REFERENCE-
FAAO JO 7110.65, Para 2-4-17 (http://www.faa.gov/air_traffic/publications/atpubs/atc/atc0204.html#VBJ21cJACK), Numbers Usage.
FAAO JO 7110.65, Para 4-5-7 (http://www.faa.gov/air_traffic/publications/atpubs/atc/atc0405.html#OAL118JACK), Altitude Information.
5-7-3. MINIMA
When assigning airspeeds, use the following recommended minima:
a. To aircraft operating between FL 280 and 10,000 feet, a speed not less than 250 knots or the equivalent Mach number.
NOTE-
1. On a standard day the Mach numbers equivalent to 250 knots CAS (subject to minor variations) are:
FL 240-0.6
FL 250-0.61
FL 260-0.62
FL 270-0.64
FL 280-0.65
FL 290-0.66.
2. If a pilot is unable to comply with the speed assignment, the pilot will advise.
b. When an operational advantage will be realized, speeds lower than the recommended minima may be applied.
c. To arrival aircraft operating below 10,000 feet:
1. Turbojet aircraft. A speed not less than 210 knots; except when the aircraft is within 20 flying miles of the runway threshold of the airport of intended landing, a speed not less than 170 knots.
2. Reciprocating engine and turboprop aircraft. A speed not less than 200 knots; except when the aircraft is within 20 flying miles of the runway threshold of the airport of intended landing, a speed not less than 150 knots.
d. Departures:
1. Turbojet aircraft. A speed not less than 230 knots.
2. Reciprocating engine and turboprop aircraft. A speed not less than 150 knots.
e. Helicopters. A speed not less than 60 knots.
REFERENCE-
FAAO JO 7110.65, Para 5-7-2 (http://www.faa.gov/air_traffic/publications/atpubs/atc/atc0507.html#qnI37aJACK), Methods.
5-7-4. TERMINATION
Advise aircraft when speed adjustment is no longer needed.
PHRASEOLOGY-
RESUME NORMAL SPEED.

[mxwbuaa]

as a controller ,when instructing an aircraft to exit a orbit or holding and vector it to a new heading, if i should use the phraseology: " xx, fly heading XXX"? in this case， i want to know how the pilot will turn to the new heading , in the shortest direction or in the oribit direction ?