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Author Topic: ATC message - At your discression??  (Read 34351 times)

Offline flight level 350

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ATC message - At your discression??
« on: September 06, 2009, 07:25:44 AM »
Recently when listening to ATC transmissions, i keep hearing the ATC telling the pilots to "land/takeoff/taxi at there discression", and was wandering if someone could give me some information on what the term means.

Thanks
Danny



Offline Casper87

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Re: ATC message - At your discression??
« Reply #1 on: September 06, 2009, 07:59:50 AM »
'At your own risk'or'when you consider it safe to do so'

Which frequency are you listening to when you've heard 'at your discretion'?

Offline atcman23

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Re: ATC message - At your discression??
« Reply #2 on: September 06, 2009, 10:15:40 AM »
It depends on the type of aircraft the pilot was flying.  You'll usually hear this phrase with helicopters.  Since they can take off and land pretty much anywhere, ATC can grant a request to land on a non-movement area (a part of the airport not under control by ATC) at the pilot's request.  Since they are taking off/landing in the non-movement area, the takeoff/landing is at the pilot's discretion and if they cannot be seen by the tower controller, the takeoff/landing is at the pilot's own risk since ATC cannot see or determine if anything in the path of the helicopter may be ha hazard to the aircraft.  Also, since ATC does not have control authority in a non-movement area, ATC cannot issue a formal cleared for takeoff/cleared to land command.

If you know you are listening to aircraft and not helicopters, then I'm not exactly sure why ATC would be using this phraseology unless they know there is a problem with the runway/taxiway but are unsure what the problem is.  I can't say that I've heard the command "taxi at your discretion" or even "takeoff/land at your discretion."  Basically, you're either "cleared" to do so or advised otherwise since runways and taxiways are movement areas controlled by ATC, they typically know their conditions at all times.

Offline flight level 350

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Re: ATC message - At your discression??
« Reply #3 on: September 06, 2009, 01:26:08 PM »
I heard the "land at your discression" when a plane was making an emergency landing...

djmodifyd

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Re: ATC message - At your discression??
« Reply #4 on: September 06, 2009, 04:38:17 PM »
I sometimes tell guys to taxi to the ramp at their discretion...

i think the only situation i do this is when they are holding waiting for a gate...and their company pushes and starts taxii...i just say taxi to the ramp at your discretion.  since the gate isn't clear yet..and an aircraft is in their way.

Offline atcman23

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Re: ATC message - At your discression??
« Reply #5 on: September 07, 2009, 10:31:31 AM »
I sometimes tell guys to taxi to the ramp at their discretion...

i think the only situation i do this is when they are holding waiting for a gate...and their company pushes and starts taxii...i just say taxi to the ramp at your discretion.  since the gate isn't clear yet..and an aircraft is in their way.

That makes sense.

Offline darry2385

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Re: ATC message - At your discression??
« Reply #6 on: September 07, 2009, 06:49:22 PM »
the ramp at SYR is uncontrolled.  i always hear pilots calling ground to push and the controller always tells them that the ramp is uncontrolled and to push at pilot's discretion.

Offline atcman23

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Re: ATC message - At your discression??
« Reply #7 on: September 08, 2009, 01:20:10 PM »
Almost all major airports' ramps are not controlled by ATC.  They are either uncontrolled (like SYR) or are controlled by the airline that has the largest presence at that airport.

Offline glencar

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Re: ATC message - At your discression??
« Reply #8 on: September 10, 2009, 07:29:20 AM »
En route aircraft can also do things at their discretion. Turn, climb, descend.

Offline JMM

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Re: ATC message - At your discression??
« Reply #9 on: September 10, 2009, 11:38:27 AM »
On my New York Oceanic feed, each & every every aircraft inbound for landing is always given something similar to the following: "Descend pilot's discretion 5000".  That clearance gives the pilot clearance to start descending, whenever the pilot would like to, down to 5000 feet.  Some aircraft would start descending immediately, while others delay their descent, hence the "pilot's discretion" part.

Similarly, transiting aircraft often need to deviate slightly from their route due to weather.  In cases like that, they're given a clearance simalar to: "Deviate left or right of track 10 degrees at pilot's discretion; direct DASER (or whatever waypoint they were initially heading to) when able".

There's of course other instances too, just that the above are heard all the time on my feeds.

Regards,
John

Offline klkm

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Re: ATC message - At your discression??
« Reply #10 on: September 10, 2009, 06:06:57 PM »
On my New York Oceanic feed, each & every every aircraft inbound for landing is always given something similar to the following: "Descend pilot's discretion 5000".  That clearance gives the pilot clearance to start descending, whenever the pilot would like to, down to 5000 feet.  Some aircraft would start descending immediately, while others delay their descent, hence the "pilot's discretion" part.

Similarly, transiting aircraft often need to deviate slightly from their route due to weather.  In cases like that, they're given a clearance simalar to: "Deviate left or right of track 10 degrees at pilot's discretion; direct DASER (or whatever waypoint they were initially heading to) when able".

There's of course other instances too, just that the above are heard all the time on my feeds.

Regards,
John


Yes we like to use the descend pilots discretion at Bermuda, we give 5,000 because the MEA/MVA outside of 50 miles in 5000ft, even though no one will ever be down below 5,000ft at that point that is the most legal way of giving the descent.  Others like to just give them PD to 3,000 and watch to ensure they wont go below 5,000.  Once within 50 miles 1500 is the MEA/MVA so typically we will just give a straight descent to 1,500 or 1700 or 3,000 depending on the approach once within 50 miles.  RNAV to runway 12 at the IF is 1700 IAF is 3000 and to runway 30 the IF is 1500 IAF 3000.  Typically we do visuals so 1500 is used the majority of the time. 

Past 10pm EST the tower is closed and if there is an arrival/departure you may hear "tower is closed, landing at your discretion, radar services terminated, report cancellation of IFR on this freq"  or "released, takeoff at your discretion, clearance void at XXXX"  very rarely are there flights in or out past the tower being closed.  Typically they are lifeguard flights or GA flights who are coming in late. 

We enjoy the feed you provide at work, keep it up.  If you have any questions about what we do there let me know.

- Controller ZNY Oceanic

Offline joeyb747

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Re: ATC message - At your discression??
« Reply #11 on: September 10, 2009, 09:12:08 PM »
I've also heard "Speed, your discretion"...below ten thousand speed is restricted to below 250KIAS.
My guess is, as far as that goes,  fly what feels good... :-D

Offline JMM

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Re: ATC message - At your discression??
« Reply #12 on: September 10, 2009, 09:18:27 PM »
Wow, KLKM, happy to meet you on here :-).  And thanks for your input on here.  I never bothered to think about why it was 5000, or such things as how far out they were given that descent.  But you've answered a lot of questions here, and is greatly appreciated.

I do have one question though, and glad you're on here to answer this.  I sometimes (rarely, actually) hear you folks asking someone to come up on 133.5, and I believe there's at least one other one like that - possibly 132.something.  What are those freqs?  I have 133.5 in your feed scanner, but no idea how often it's activated, or even if there's been any comms on it since I entered it :-D.  Just curious.

Offline JMM

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Re: ATC message - At your discression??
« Reply #13 on: September 10, 2009, 09:21:17 PM »
I've also heard "Speed, your discretion"...below ten thousand speed is restricted to below 250KIAS.
My guess is, as far as that goes,  fly what feels good... :-D
Fly what feels good, huh?  Well, my Mach 2+ days used to feel REAL good, especially when flying down low level :-D.  Ahhhh, those were the days .... oh so long ago, unfortunately.

Offline sykocus

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Re: ATC message - At your discression??
« Reply #14 on: September 11, 2009, 02:02:40 AM »
I've also heard "Speed, your discretion"...below ten thousand speed is restricted to below 250KIAS.
My guess is, as far as that goes,  fly what feels good... :-D

I use this one a lot. As you mentioned there is a restriction to fly less then 250 kts below 10k feet. Many times pilots will ask for for that restriction to be lifted. As a controller I don't have the power to do so, but if it won't screw up my sequence (which is most of the time) I don't care. Also the speed restriction doesn't apply more then 12nm off shore. Most pilots don't seem to be aware of that part of the rule. So instead of explaining all of that every time, it's easier to say "speed at your discretion."

Offline glencar

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Re: ATC message - At your discression??
« Reply #15 on: September 11, 2009, 10:55:40 AM »
Just curious where you work that it won't screw up your sequence?

Offline sykocus

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Re: ATC message - At your discression??
« Reply #16 on: September 11, 2009, 04:03:32 PM »
Guam Center...we have a low plane to airspace ratio. :(

Offline joeyb747

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Re: ATC message - At your discression??
« Reply #17 on: September 11, 2009, 08:32:05 PM »
I've also heard "Speed, your discretion"...below ten thousand speed is restricted to below 250KIAS.
My guess is, as far as that goes,  fly what feels good... :-D
Fly what feels good, huh?  Well, my Mach 2+ days used to feel REAL good, especially when flying down low level :-D.  Ahhhh, those were the days .... oh so long ago, unfortunately.

Ex-Military I assume...what did you fly if I may ask?   8-)

Offline glencar

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Re: ATC message - At your discression??
« Reply #18 on: September 11, 2009, 08:40:07 PM »
Guam Center...we have a low plane to airspace ratio. :(
Come to NY!

Offline sykocus

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Re: ATC message - At your discression??
« Reply #19 on: September 11, 2009, 09:08:02 PM »
Sure. I've always wanted to visit the east coast.

Offline atcman23

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Re: ATC message - At your discression??
« Reply #20 on: September 11, 2009, 11:16:29 PM »
Guam Center...we have a low plane to airspace ratio. :(
Come to NY!

NY - Where you have a low airspace to plane ratio.

Offline klkm

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Re: ATC message - At your discression??
« Reply #21 on: September 12, 2009, 02:10:29 AM »
Wow, KLKM, happy to meet you on here :-).  And thanks for your input on here.  I never bothered to think about why it was 5000, or such things as how far out they were given that descent.  But you've answered a lot of questions here, and is greatly appreciated.

I do have one question though, and glad you're on here to answer this.  I sometimes (rarely, actually) hear you folks asking someone to come up on 133.5, and I believe there's at least one other one like that - possibly 132.something.  What are those freqs?  I have 133.5 in your feed scanner, but no idea how often it's activated, or even if there's been any comms on it since I entered it :-D.  Just curious.

133.5 is the Atlantic Sector, it is to our right, but about 300 miles or so north of Bermuda.  Not sure in what reference you hear this request, but sometimes, if there is a plane that is flying low level, or does not have HF for some reason we will tell them the contact point for the next sector on 133.5, or to the northwest is 126.025.  We do this in case the aircraft cannot get a hold of ARINC on HF's they will at the minimum contact our next radar sector.  But either way you wouldn't hear any comms on that frequency from Bermuda, so you can probably remove it from the scanner. 

Offline martgenia

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Re: ATC message - At your discression??
« Reply #22 on: October 18, 2009, 01:12:10 PM »
So a pilot can fly over 250 speed when under 10k attitude? then if plane hits say a duck, who´s fault is it, pilot or ATCO? because its all monitored I would say ATCO say fly at 200 and whatever and if pilot still hits a seagull noting happens...agree?

Offline Pilot3033

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Re: ATC message - At your discression??
« Reply #23 on: October 18, 2009, 09:32:54 PM »
So a pilot can fly over 250 speed when under 10k attitude? then if plane hits say a duck, who´s fault is it, pilot or ATCO? because its all monitored I would say ATCO say fly at 200 and whatever and if pilot still hits a seagull noting happens...agree?

The speed restrictions has nothing to do with fowl and everything to do with playing nice the smaller and slower traffic (and to an extent: noise abatement). If a plane hits a bird, it's not really anyone's fault.

As far as exceeding the restriction, a controller can issue an exemption. Certain heavy aircraft, for example, prefer to climb out at a higher rate of speed, and the regulations (in the US at least) guiding the speed restrictions have an exemption that allows aircraft to operate at their minimum safe speed, even if it is greater than the restriction.

Quote from: FAA FAR § 91.117
§ 91.117   Aircraft speed.

(a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).

(b) Unless otherwise authorized or required by ATC, no person may operate an aircraft at or below 2,500 feet above the surface within 4 nautical miles of the primary airport of a Class C or Class D airspace area at an indicated airspeed of more than 200 knots (230 mph.). This paragraph (b) does not apply to any operations within a Class B airspace area. Such operations shall comply with paragraph (a) of this section.

(c) No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport or in a VFR corridor designated through such a Class B airspace area, at an indicated airspeed of more than 200 knots (230 mph).

(d) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

Emphasis mine.
« Last Edit: October 18, 2009, 09:34:26 PM by Pilot3033 »

Offline sykocus

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Re: ATC message - At your discression??
« Reply #24 on: October 19, 2009, 02:19:26 AM »
As far as exceeding the restriction, a controller can issue an exemption. Certain heavy aircraft, for example, prefer to climb out at a higher rate of speed, and the regulations (in the US at least) guiding the speed restrictions have an exemption that allows aircraft to operate at their minimum safe speed, even if it is greater than the restriction.

Quote from: FAA FAR § 91.117
§ 91.117   Aircraft speed.

(a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).

...

(d) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

Emphasis mine.

I think you misunderstand that section of the FAR. It says the administrator can authorize exemption from the 250kt rule not controllers. Aircraft who's minimum safe airspeed is higher then 250kts are allowed to go faster then 250 by the section of the far, not controllers.
« Last Edit: October 19, 2009, 07:16:59 AM by sykocus »