Unclear Clearance

[Mitty]

OK, just to distract you guys from "IFR with a VFR GPS" ---

Flying into Grand Marais MN last week (KCKC) I was out maybe
30 miles at 7000 and got "Cleared for the approach, maintain
4000 until established. Contact advisory ... "

The reason for the early clearance was, I think, that I was
at the edge of Center's radar and comm coverage. (Grand
Marais is near the Canadian border on the north shore of
Lake Superior. There was nobody around.)

But I really didn't want to fly that last 30 miles at 4000
as there were clouds about there and maybe a little ice. I
wanted to stay at 7. So I queried: "Center, that 4000 was
pilot's discretion, right?" and got a "Right."

Did I need to ask? Should I have assumed pilot's
discretion? She did not tell me to descend, just gave me
the altitude limit.

[Peter R.]

Mitty > wrote:

<snip>
> Did I need to ask?

If you are unclear, then you were right to ask. However, if your example
were complete, then you were allowed to descend.

> Should I have assumed pilot's
> discretion? She did not tell me to descend, just gave me
> the altitude limit.

Assuming there was no other restriction ("upon reaching {IAF}" or "maintain
four thousand until established"), then you are cleared to descend as per
the approach plate when the controller states "cleared for the approach."


--
Peter
























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[Steven P. McNicoll]

"Mitty" > wrote in message
...
>
> Flying into Grand Marais MN last week (KCKC) I was out maybe 30 miles at
> 7000 and got "Cleared for the approach, maintain 4000 until established.
> Contact advisory ... "
>
> The reason for the early clearance was, I think, that I was at the edge of
> Center's radar and comm coverage. (Grand Marais is near the Canadian
> border on the north shore of Lake Superior. There was nobody around.)
>

I suspect it was solely due to communications. What was your assigned
route?

[Mitty]

On 11/15/2005 5:37 PM, Steven P. McNicoll wrote the following:
> "Mitty" > wrote in message
> ...
>
>>Flying into Grand Marais MN last week (KCKC) I was out maybe 30 miles at
>>7000 and got "Cleared for the approach, maintain 4000 until established.
>>Contact advisory ... "
>>
>>The reason for the early clearance was, I think, that I was at the edge of
>>Center's radar and comm coverage. (Grand Marais is near the Canadian
>>border on the north shore of Lake Superior. There was nobody around.)
>>
>
>
> I suspect it was solely due to communications. What was your assigned
> route?
>
Direct KCKC. And she was going to lose me, probably at
5000. Both comm and radar. But it was the altitude
assignment that was the question.

[Roy Smith]

In article >, Mitty >
wrote:

> OK, just to distract you guys from "IFR with a VFR GPS" ---
>
> Flying into Grand Marais MN last week (KCKC) I was out maybe
> 30 miles at 7000 and got "Cleared for the approach, maintain
> 4000 until established. Contact advisory ... "

As worded, you were required to vacate 7000. No need to rush down, but you
can't just hang out at 7000 for another 30 miles either.

> "Center, that 4000 was pilot's discretion, right?" and got a "Right."
>
> Did I need to ask?

Yup, you did. You did the right thing by asking.

> Should I have assumed pilot's discretion? She did not tell me to
> descend, just gave me the altitude limit.

If you're at 7000 and you're told you maintain 4000, descending is pretty
much the only way to comply. She didn't give you an "altitude limit", she
have you an "altitude". If she had said, "maintain at or above 4000 until
established", then you could have stayed at 7000 as long as you wanted.
Same with "descend at pilot's discretion and maintain 4000". Or, "Cruise
7000".

[Ron Rosenfeld]

On Tue, 15 Nov 2005 16:32:42 -0600, Mitty > wrote:

>Did I need to ask?

Yes.

>Should I have assumed pilot's discretion?

No.

> She did not tell me to descend, just gave me
>the altitude limit.

ATC gave you a new altitude to "maintain" until established. That is your
altitude assignment. In my part of the world, it is usually preceded by a
"climb" or "descend" but I don't know if that is required.

Since you were uncertain, and since the terminology seems somewhat
ambiguous, clearing it up with ATC seems prudent.

She could have said "maintain at *or above* 4000' until established", in
which case it would have been pilot's discretion as to when to descend to
4000' prior to becoming established, but she did not.

======================================
AIM 5-5-4 a.
3. Upon receipt of an approach clearance while on an unpublished
route or being radar vectored:
(a) ...
(b) Maintains the last assigned altitude until established on a
segment of a published route or IAP, at which time published altitudes
apply.
---------------------

Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Roy Smith]

Ron Rosenfeld > wrote:
> ATC gave you a new altitude to "maintain" until established. That is your
> altitude assignment. In my part of the world, it is usually preceded by a
> "climb" or "descend" but I don't know if that is required.

I'm reasonably sure that the "descend" is a required part of the
phrasology. But, the real point is that whether saying "descend" is
required or not, controllers are human, as are pilots. On both sides of
the mike, minor mistakes are made all the time. The key to making the
whole system work is to ask for clarification whenever you're not sure you
understood what the other person said or meant.

[Steven P. McNicoll]

"Mitty" > wrote in message
...
>
> Direct KCKC.
>

Direct KCKC from where?


>
> And she was going to lose me, probably at 5000. Both comm
> and radar.
>

That may be, but it is only the loss of communications that is reason to
issue the clearance and have you over to CTAF before it happens.


>
> But it was the altitude assignment that was the question.
>

It was bad phraseology, and possibly a bad clearance. It's not clear if the
controller meant for the descent to be discretionary or not.

[Jim Macklin]

You were clear for the approach because you were the only
IFR in the area and the minimum altitude for the area was
4,000 until you reached a part of the published approach.
You owned all altitudes from 7,000 feet on down, until you
reported 'out" of an altitude.
It never hurts to ask...The contact advisory meant you could
leave the Center and go to CTF. Cancel when you're on the
ground or landing assured, whichever you prefer.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm



"Mitty" > wrote in message
...
| OK, just to distract you guys from "IFR with a VFR
GPS" ---
|
| Flying into Grand Marais MN last week (KCKC) I was out
maybe
| 30 miles at 7000 and got "Cleared for the approach,
maintain
| 4000 until established. Contact advisory ... "
|
| The reason for the early clearance was, I think, that I
was
| at the edge of Center's radar and comm coverage. (Grand
| Marais is near the Canadian border on the north shore of
| Lake Superior. There was nobody around.)
|
| But I really didn't want to fly that last 30 miles at 4000
| as there were clouds about there and maybe a little ice.
I
| wanted to stay at 7. So I queried: "Center, that 4000
was
| pilot's discretion, right?" and got a "Right."
|
| Did I need to ask? Should I have assumed pilot's
| discretion? She did not tell me to descend, just gave me
| the altitude limit.

[Steven P. McNicoll]

"Jim Macklin" > wrote in message
news:B%wef.3438$QW2.1494@dukeread08...
>
> You were clear for the approach because you were the only
> IFR in the area and the minimum altitude for the area was
> 4,000 until you reached a part of the published approach.
> You owned all altitudes from 7,000 feet on down, until you
> reported 'out" of an altitude.
>

What do you base that on?

[Jim Macklin]

8,000 hours experience
"Steven P. McNicoll" > wrote in
message
k.net...
|
| "Jim Macklin" > wrote
in message
| news:B%wef.3438$QW2.1494@dukeread08...
| >
| > You were clear for the approach because you were the
only
| > IFR in the area and the minimum altitude for the area
was
| > 4,000 until you reached a part of the published
approach.
| > You owned all altitudes from 7,000 feet on down, until
you
| > reported 'out" of an altitude.
| >
|
| What do you base that on?
|
|

[Ron Rosenfeld]

On Tue, 15 Nov 2005 21:03:35 -0500, Roy Smith > wrote:

>Ron Rosenfeld > wrote:
>> ATC gave you a new altitude to "maintain" until established. That is your
>> altitude assignment. In my part of the world, it is usually preceded by a
>> "climb" or "descend" but I don't know if that is required.
>
>I'm reasonably sure that the "descend" is a required part of the
>phrasology. But, the real point is that whether saying "descend" is
>required or not, controllers are human, as are pilots. On both sides of
>the mike, minor mistakes are made all the time. The key to making the
>whole system work is to ask for clarification whenever you're not sure you
>understood what the other person said or meant.

As both of us pointed out, asking ATC was the proper procedure.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Steven P. McNicoll]

"Jim Macklin" > wrote in message
news:JHxef.3469$QW2.1475@dukeread08...
>
> 8,000 hours experience
>

A misconception heavily reinforced.

[Jim Macklin]

Clear for approach to an uncontrolled airport, only issued
when there is no other IFR [conflicting] traffic in the
system.
No instructions to "descend and maintain" means you can
remain at your altitude after the IFR approach clearance is
issued, the maintain 4,000 is required by FAA procedure
since the airline 727 descended to IAP and hit a mountain
near DC about 30 years ago.
A Cruise clearance allows you to fly any legal and safe
altitude at pilots discretion, climbing back to altitude if
desired, as long as the pilot has not reported leaving the
altitude.
A clearance limit to the airport implies "clear for the
approach at arrival" but if comm. has not been lost, you
should get a specific clearance. If cleared to a fix, you
can expect to make an approach at ETA or EAC as cleared.
Unless cleared for a particular approach, the pilot may
select any published approach or even a contact approach,
but it is recommended the pilot advise ATC of which approach
will be flown.
It is important at non-towered airports for the PIC under
IFR to cancel IFR when on the ground or in good VFR, when
landing is assured so the next aircraft can be cleared for
take-off or landing. Most airports with IFR approaches will
have some freq. that can reach ATC while on the ground, but
you can have another airplane relay.
The goal is to not hit other airplanes or the terrain, in
general all ATC cares about is other airplanes.




"Steven P. McNicoll" > wrote in
message
.net...
|
| "Jim Macklin" > wrote
in message
| news:JHxef.3469$QW2.1475@dukeread08...
| >
| > 8,000 hours experience
| >
|
| A misconception heavily reinforced.
|
|

[Steven P. McNicoll]

"Jim Macklin" > wrote in message
news:XWyef.3487$QW2.1662@dukeread08...
>
> No instructions to "descend and maintain" means you can
> remain at your altitude after the IFR approach clearance is
> issued, the maintain 4,000 is required by FAA procedure
> since the airline 727 descended to IAP and hit a mountain
> near DC about 30 years ago.
>

The aircraft was instructed to "maintain 4000".


>
> A Cruise clearance allows you to fly any legal and safe
> altitude at pilots discretion, climbing back to altitude if
> desired, as long as the pilot has not reported leaving the
> altitude.
>

A cruise clearance was not issued.


>
> A clearance limit to the airport implies "clear for the
> approach at arrival" but if comm. has not been lost, you
> should get a specific clearance.
>

An airport clearance limit does not imply an approach clearance.

[BillJ]

Mitty wrote:
> OK, just to distract you guys from "IFR with a VFR GPS" ---
>
> Flying into Grand Marais MN last week (KCKC) I was out maybe 30 miles at
> 7000 and got "Cleared for the approach, maintain 4000 until established.
> Contact advisory ... "
>
> The reason for the early clearance was, I think, that I was at the edge
> of Center's radar and comm coverage. (Grand Marais is near the Canadian
> border on the north shore of Lake Superior. There was nobody around.)
>
> But I really didn't want to fly that last 30 miles at 4000 as there were
> clouds about there and maybe a little ice. I wanted to stay at 7. So I
> queried: "Center, that 4000 was pilot's discretion, right?" and got a
> "Right."
>
> Did I need to ask? Should I have assumed pilot's discretion? She did
> not tell me to descend, just gave me the altitude limit.
In a situation like that, I sometimes get a "Cruise 4000" clearance.
That is usually the last I hear from them, cancel on the phone.

[Dave Butler]

Steven P. McNicoll wrote:

> It was bad phraseology, and possibly a bad clearance. It's not clear if the
> controller meant for the descent to be discretionary or not.

What was unclear about it? I'd never infer discretionary descent unless it was
explicitly stated by the controller. I'd say the clearance unambiguously
required vacating 7000 (before amendment).

Dave

[Jose]

> If she had said, "maintain at or above 4000 until
> established", then you could have stayed at 7000 as long as you wanted.

Could he climb above 7000 with such a clearance?

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[Newps]

Jose wrote:
>> If she had said, "maintain at or above 4000 until established", then
>> you could have stayed at 7000 as long as you wanted.
>
>
> Could he climb above 7000 with such a clearance?

No.

[three-eight-hotel]

Have you considered making a phone call to the controlling facility and
getting there feedback on this clearance and any expectations they
might have had?

I'm a relatively new IFR pilot and don't get as much practice as I
would like. It's a frustrating feeling, to have been given a
clearance, and try decipher all that you can and cannot do because the
clearance was a little vague. You definitely did the right thing,
asking for clarification.

The part I'm a little unclear on is: "Center, that 4000 was pilot's
discretion, right?" ...... "Right."

How is that different from a cruise clearance? Is it because you are
cleared to decend to 4000 at your discretion, but once you leave the
altitude you can't go back, unless cleared to climb again?

These groups are great for getting clarification on things we encounter
in the air, but they aren't of much use when you are at 7000 feet and
concerned about picking up a little ice... ;-)

Best Regards,
Todd

[Steven P. McNicoll]

"Dave Butler" > wrote in message
news:1132150865.836980@sj-nntpcache-5...
>
> What was unclear about it?
>

Well, the controller thought it was discretionary. That you and she
disagree tends to indicate it's not clear.


>
> I'd never infer discretionary descent unless it was explicitly stated by
> the controller.
>

The controller does not have to state "descend at pilot's discretion" in
order for the descent to be discretionary. A descent clearance with a
crossing restriction is a discretionary descent. A cruise clearance to an
airport without an IAP is a discretionary descent.


>
> I'd say the clearance
> unambiguously required vacating 7000 (before amendment).
>

What amendment? The pilot asked the controller to verify that the descent
was at pilot's discretion and the controller responded in the affirmative.

[Mitty]

On 11/16/2005 10:57 AM, three-eight-hotel wrote the following:
> Have you considered making a phone call to the controlling facility and
> getting there feedback on this clearance and any expectations they
> might have had?
>

Actually, it wasn't that big a deal. I just thought I'd
throw a little meat to the wolves. I was and am tired of
all the bickering under "IFR with a VFR GPS." :-) So ...
something new.

> I'm a relatively new IFR pilot and don't get as much practice as I
> would like. It's a frustrating feeling, to have been given a
> clearance, and try decipher all that you can and cannot do because the
> clearance was a little vague. You definitely did the right thing,
> asking for clarification.
>
> The part I'm a little unclear on is: "Center, that 4000 was pilot's
> discretion, right?" ...... "Right."
>
> How is that different from a cruise clearance? Is it because you are
> cleared to decend to 4000 at your discretion, but once you leave the
> altitude you can't go back, unless cleared to climb again?
>
Yes, I think so. But as a practical matter she was about to
lose me both on radar and on comm, so I think she was
effectively giving me the airspace below 7 until she
received my cancellation. I'm sure she didn't have any IFR
aircraft anywhere near me and didn't have any departures
coming out of KCKC.

> These groups are great for getting clarification on things we encounter
> in the air, but they aren't of much use when you are at 7000 feet and
> concerned about picking up a little ice... ;-)

I was in the clear and the deck was thin. No real concern,
but that's why I asked for clarification.

[Dave Butler]

Steven P. McNicoll wrote:
> "Dave Butler" > wrote in message
> news:1132150865.836980@sj-nntpcache-5...
>
>>What was unclear about it?
>>
>
>
> Well, the controller thought it was discretionary. That you and she
> disagree tends to indicate it's not clear.

OK.

>
>
>
>>I'd never infer discretionary descent unless it was explicitly stated by
>>the controller.
>>
>
>
> The controller does not have to state "descend at pilot's discretion" in
> order for the descent to be discretionary. A descent clearance with a
> crossing restriction is a discretionary descent. A cruise clearance to an
> airport without an IAP is a discretionary descent.

OK, agreed. I'd call those clearances explicitly discretionary.

>
>
>
>>I'd say the clearance
>>unambiguously required vacating 7000 (before amendment).
>>
>
>
> What amendment? The pilot asked the controller to verify that the descent
> was at pilot's discretion and the controller responded in the affirmative.

Yes, exactly. The clearance as originally stated was not for a discretionary
descent. By responding "right" to the pilots question, the controller amended
the clearance and simultaneously demonstrated lack of understanding of the way
clearances are stated. But OK, I see your point.

[Daniel Roesen]

* Steven P. McNicoll >:
> The controller does not have to state "descend at pilot's discretion" in
> order for the descent to be discretionary. A descent clearance with a
> crossing restriction is a discretionary descent.

Hm. I'm lacking any real world experience, but in our little wannabe Sim
world (VATSIM) I'm used to crossing restrictions like "XYZ, descend FL120
(to be) level(ed) at FIX" which is to be interpreted as "start descent
now with at least 1000fpm and be at FL120 latest at FIX". This is for
Europe and confirmed to be real-world compatible by several real-world
ATC controllers here. Now I happen to like "flying" in US airspace, where
instructions like "XYZ, cross CEDES at 11000ft" are used. Is that to be
taken analogue to European interpretation to start descending to 11000ft
_now_, or to be taken as "descend 11000ft at own discretion"? If the
latter, does ATC expect a report like "leaving FL240 for 11000" if not
explicitly requested? What is the US equivalent of the European
clearance to "descend now to X with 1000fpm or more, to be level at
FIX"? Is there any at all (short of a full "descend and maintain 11000ft,
1000fpm or more, cross CEDES at level")?

The European expectation of immediate descent with at least 1000fpm v/s
might mean that I do reach 11000ft earlier than CEDES - some folks
argued that "cross X at Y" means that I should carry out my descend so
that I reach the target altitude no later AND NO EARLIER than the fix.
Which would mean that if ATC gives the instruction too early, I would
have to descend with considerably less than 1000fpm, in case the
"cross X at Y" is to be interpreted in this way.

Comments? Insights?


Best regards,
Daniel

[Andrew Sarangan]

While flying at 3000 ft, I get a clearance that says "maintain 3000
until established on the localizer, cleared ILS...." If I am already
at 3000, what exactly is the purpose of "maintain 3000"?

The purpose of the "maintain 3000" is to caution the pilot that the
approach clearance does not imply that he can start descending right
away.

In this context, I take the "maintain 3000 until established" to mean
"maintain at least 3000 until establshed".

If it were an instruction to descend, it would have been issued as
"descend and maintain".

[Jose]

> While flying at 3000 ft, I get a clearance that says "maintain 3000
> until established on the localizer, cleared ILS...." If I am already
> at 3000, what exactly is the purpose of "maintain 3000"?
>
> The purpose of the "maintain 3000" is to caution the pilot that the
> approach clearance does not imply that he can start descending right
> away.
>
> In this context, I take the "maintain 3000 until established" to mean
> "maintain at least 3000 until establshed".
>
> If it were an instruction to descend, it would have been issued as
> "descend and maintain".

"Maintain" means "don't go higher or lower. There may be terrain lower.
There may be traffic higher.

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[Roger]

On 24 Nov 2005 07:19:39 -0800, "Andrew Sarangan" >
wrote:

>While flying at 3000 ft, I get a clearance that says "maintain 3000
>until established on the localizer, cleared ILS...." If I am already
>at 3000, what exactly is the purpose of "maintain 3000"?
>
>The purpose of the "maintain 3000" is to caution the pilot that the
>approach clearance does not imply that he can start descending right
>away.
>
>In this context, I take the "maintain 3000 until established" to mean
>"maintain at least 3000 until establshed".
>
>If it were an instruction to descend, it would have been issued as
>"descend and maintain".

Another way of thinking of about it would be a clearance that says,
"Descend to and maintain 3000 until established, cleared for the
approach."

Maintain 3000 until established is what you get when you are alread at
the altitude ATC wans.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

[Andrew Sarangan]

Actually, "maintain 3000 until established" is what you get even if
you are at a different altitude. This is the cause of the confusion, as
the original poster to this thread mentioned.

[Ron Rosenfeld]

On Wed, 23 Nov 2005 03:52:46 +0000 (UTC), Daniel Roesen > wrote:

>* Steven P. McNicoll >:
>> The controller does not have to state "descend at pilot's discretion" in
>> order for the descent to be discretionary. A descent clearance with a
>> crossing restriction is a discretionary descent.
>
>Hm. I'm lacking any real world experience, but in our little wannabe Sim
>world (VATSIM) I'm used to crossing restrictions like "XYZ, descend FL120
>(to be) level(ed) at FIX" which is to be interpreted as "start descent
>now with at least 1000fpm and be at FL120 latest at FIX". This is for
>Europe and confirmed to be real-world compatible by several real-world
>ATC controllers here. Now I happen to like "flying" in US airspace, where
>instructions like "XYZ, cross CEDES at 11000ft" are used. Is that to be
>taken analogue to European interpretation to start descending to 11000ft
>_now_, or to be taken as "descend 11000ft at own discretion"? If the
>latter, does ATC expect a report like "leaving FL240 for 11000" if not
>explicitly requested? What is the US equivalent of the European
>clearance to "descend now to X with 1000fpm or more, to be level at
>FIX"? Is there any at all (short of a full "descend and maintain 11000ft,
>1000fpm or more, cross CEDES at level")?
>
>The European expectation of immediate descent with at least 1000fpm v/s
>might mean that I do reach 11000ft earlier than CEDES - some folks
>argued that "cross X at Y" means that I should carry out my descend so
>that I reach the target altitude no later AND NO EARLIER than the fix.
>Which would mean that if ATC gives the instruction too early, I would
>have to descend with considerably less than 1000fpm, in case the
>"cross X at Y" is to be interpreted in this way.
>
>Comments? Insights?



From the (US) AIM:

e. If the altitude information of an ATC DESCENT clearance includes a
provision to "CROSS (fix) AT" or "AT OR ABOVE/BELOW (altitude)," the manner
in which the descent is executed to comply with the crossing altitude is at
the pilot's discretion. This authorization to descend at pilot's discretion
is only applicable to that portion of the flight to which the crossing
altitude restriction applies, and the pilot is expected to comply with the
crossing altitude as a provision of the clearance. Any other clearance in
which pilot execution is optional will so state "AT PILOT'S DISCRETION."

Here are three examples, also from the AIM, which I believe cover the
various nuances:

-----------------------------------
EXAMPLE-
3. "United Four Seventeen, cross Lakeview V-O-R at or above Flight
Level two zero zero, descend and maintain six thousand."

NOTE-
3. The pilot is authorized to conduct descent at pilot's discretion
until reaching Lakeview VOR and must comply with the clearance provision to
cross the Lakeview VOR at or above FL 200. After passing Lakeview VOR, the
pilot is expected to descend at the suggested rates until reaching the
assigned altitude of 6,000 feet.
------------------------------------
EXAMPLE-
4. "United Four Seventeen, cross Lakeview V-O-R at six thousand,
maintain six thousand."

NOTE-
4. The pilot is authorized to conduct descent at pilot's discretion,
however, must comply with the clearance provision to cross the Lakeview VOR
at 6,000 feet.
--------------------------------------
EXAMPLE-
5. "United Four Seventeen, descend now to Flight Level two seven zero,
cross Lakeview V-O-R at or below one zero thousand, descend and maintain
six thousand."

NOTE-
5. The pilot is expected to promptly execute and complete descent to FL
270 upon receipt of the clearance. After reaching FL 270 the pilot is
authorized to descend "at pilot's discretion" until reaching Lakeview VOR.
The pilot must comply with the clearance provision to cross Lakeview VOR at
or below 10,000 feet. After Lakeview VOR the pilot is expected to descend
at the suggested rates until reaching 6,000 feet.
-----------------------------------------

Also, so far as the "proper" rate of descent or climb is concerned:

---------------------
Descend or climb at an optimum rate consistent with the operating
characteristics of the aircraft to 1,000 feet above or below the assigned
altitude, and then attempt to descend or climb at a rate of between 500 and
1,500 fpm until the assigned altitude is reached.
-----------------------------------------

Hope this helps.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Daniel Roesen]

* Ron Rosenfeld >:
> From the (US) AIM:

Thank you very much for citing the relevant regs. Is this stuff available
online for future reference?

> e. If the altitude information of an ATC DESCENT clearance includes a
> provision to "CROSS (fix) AT" or "AT OR ABOVE/BELOW (altitude)," the manner
> in which the descent is executed to comply with the crossing altitude is at
> the pilot's discretion. This authorization to descend at pilot's discretion
> is only applicable to that portion of the flight to which the crossing
> altitude restriction applies, and the pilot is expected to comply with the
> crossing altitude as a provision of the clearance. Any other clearance in
> which pilot execution is optional will so state "AT PILOT'S DISCRETION."

OK, that's clear.

> Here are three examples, also from the AIM, which I believe cover the
> various nuances:

Yep, covered my questions. Thanks.

> 5. "United Four Seventeen, descend now to Flight Level two seven zero,
> cross Lakeview V-O-R at or below one zero thousand, descend and maintain
> six thousand."
>
> NOTE-
> 5. The pilot is expected to promptly execute and complete descent to FL
> 270 upon receipt of the clearance. After reaching FL 270 the pilot is
> authorized to descend "at pilot's discretion" until reaching Lakeview VOR.
> The pilot must comply with the clearance provision to cross Lakeview VOR at
> or below 10,000 feet. After Lakeview VOR the pilot is expected to descend
> at the suggested rates until reaching 6,000 feet.
> -----------------------------------------
>
> Also, so far as the "proper" rate of descent or climb is concerned:
>
> ---------------------
> Descend or climb at an optimum rate consistent with the operating
> characteristics of the aircraft to 1,000 feet above or below the assigned
> altitude, and then attempt to descend or climb at a rate of between 500 and
> 1,500 fpm until the assigned altitude is reached.
> -----------------------------------------

Hm... interesting. "optimum rate consistent with the operating
characteristics of the aircraft". This is fuzzy.

The most economically way to descend a jet is at near idle thrust,
tactically. But strategically, that's only true if I'm on my computed
economic descent path. So if ATC orders me earlier than reaching my ToD
to "descend now FL270", at what rate do I descend? "optimum rate"
would be very shallow and be not quick enough for the controller who
wants to get me out of the way of something. Should I descend at near
idle thrust? But that would bring me down much quicker than strategically
economic, as I have to fly a longer distance on a suboptimal low flight
level.

I guess this is why in Europe a descent/climb instruction implies
(unwritten rule) "1000fpm or more" - and actually the FMS of a 737NG
seems to do exactly that (at least in the simulation that I have) when
you initiate a VNAV descent earlier than ToD via the "DES NOW"
function. It descends with 1000fpm until it either reaches the target
altitude dialed in the MCP, or it crosses the computed optimum vertical
descent path at which point it raises the rate of descend and lowers
the thrust, in order to maintain the optimum descent path.


Best regards,
Daniel

[Ron Rosenfeld]

On Mon, 28 Nov 2005 03:30:59 +0000 (UTC), Daniel Roesen > wrote:

>Hm... interesting. "optimum rate consistent with the operating
>characteristics of the aircraft". This is fuzzy.

Nothing wrong with giving the pilot discretion over the rate of descent.
However, there is a requirement to notify ATC if climb/descent rates will
be less than 500 fpm.

>
>The most economically way to descend a jet is at near idle thrust,
>tactically. But strategically, that's only true if I'm on my computed
>economic descent path. So if ATC orders me earlier than reaching my ToD
>to "descend now FL270", at what rate do I descend? "optimum rate"
>would be very shallow and be not quick enough for the controller who
>wants to get me out of the way of something. Should I descend at near
>idle thrust? But that would bring me down much quicker than strategically
>economic, as I have to fly a longer distance on a suboptimal low flight
>level.

You seem to be defining "optimum" as equivalent to "economic". I see no
such implication in the US.

>
>I guess this is why in Europe a descent/climb instruction implies
>(unwritten rule) "1000fpm or more" - and actually the FMS of a 737NG
>seems to do exactly that (at least in the simulation that I have) when
>you initiate a VNAV descent earlier than ToD via the "DES NOW"
>function. It descends with 1000fpm until it either reaches the target
>altitude dialed in the MCP, or it crosses the computed optimum vertical
>descent path at which point it raises the rate of descend and lowers
>the thrust, in order to maintain the optimum descent path.

Well, Europe has to handle a lot fewer aircraft than does US ATC. So maybe
that's why they need more regulations. But wait, you stated that this is
an "unwritten rule". So it's not a regulation, but merely an expectation.

I would expect that if ATC clears a jet a/c to "descend now" that they
would expect prompt execution and completion of the descent (as stated in
the AIM) and that the rate of descent and so forth would be set out in the
training manuals and possibly the ops specs of the carrier involved.
Again, if it will be less than 500 fpm, the pilot should notify ATC.

The AIM is available on line. Look at www.faa.gov for the publications.
It is not regulatory, but its procedures are generally followed.




Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Daniel Roesen]

* Ron Rosenfeld >:
>>Hm... interesting. "optimum rate consistent with the operating
>>characteristics of the aircraft". This is fuzzy.
>
> Nothing wrong with giving the pilot discretion over the rate of descent.
> However, there is a requirement to notify ATC if climb/descent rates will
> be less than 500 fpm.

OK, that makes sense. Never heard of that requirement yet, thanks for
that. Will check our regulations here about comparable requirements.

> You seem to be defining "optimum" as equivalent to "economic". I see no
> such implication in the US.

Well, what other interpretations of "optimum rate of descend" would
you have in mind? If they didn't have anything specific in mind, they
could have written "any rate consistent with the operating
characteristics". Which would be kinda superfluous as you should never
climb/descend with a rate not being consistent with the operating
characteristics.

My definition of "optimum rate of descend" without further reference to
the parameters for determination of optimality would be something along
the lines of "the minimum rate of descend required to reach a destination
altitude complying to all altitude and speed restrictions as well as
maintaining target speed". This rate is of course a function of time,
with the result being roughly what FMS computes for VNAV as well. :-)

> Well, Europe has to handle a lot fewer aircraft than does US ATC. So
> maybe hat's why they need more regulations. But wait, you stated that
> this is an "unwritten rule". So it's not a regulation, but merely an
> expectation.

Yep. But compliance with that is quite universally as far as I'm told by
controllers. :-)

> The AIM is available on line. Look at www.faa.gov for the publications.
> It is not regulatory, but its procedures are generally followed.

Thanks!


Best regards,
Daniel

[Roger]

On Mon, 28 Nov 2005 06:35:53 +0000 (UTC), Daniel Roesen >
wrote:

>* Ron Rosenfeld >:
>>>Hm... interesting. "optimum rate consistent with the operating
>>>characteristics of the aircraft". This is fuzzy.
>>
>> Nothing wrong with giving the pilot discretion over the rate of descent.
>> However, there is a requirement to notify ATC if climb/descent rates will
>> be less than 500 fpm.
>
>OK, that makes sense. Never heard of that requirement yet, thanks for
>that. Will check our regulations here about comparable requirements.
>
>> You seem to be defining "optimum" as equivalent to "economic". I see no
>> such implication in the US.
>
>Well, what other interpretations of "optimum rate of descend" would
>you have in mind? If they didn't have anything specific in mind, they
>could have written "any rate consistent with the operating
>characteristics". Which would be kinda superfluous as you should never
>climb/descend with a rate not being consistent with the operating
>characteristics.
>

I typically climb in the neighborhood of a 1000 fpm and descend
between 800 and 1200 fpm.

If I have a descent to and cross at, I'll adjust the rate of descent
to get me down within a mile or two of the crossing point.
However if I'm kept "up there" too long, I'm not going to blow my, or
my passengers ear drums with too fast a descent.

If I'm at cruise, backing off on the throttle 5" will give me 500 fpm
while the speed stays constant. If need be I can slow down a *bit*
which will give me a steeper descent yet.

However I prefer to keep the descent to about 800 and calculate how
far out I need to start down. If I'm within a minute or two of my
limits I'll call ATC and request to start down.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>My definition of "optimum rate of descend" without further reference to
>the parameters for determination of optimality would be something along
>the lines of "the minimum rate of descend required to reach a destination
>altitude complying to all altitude and speed restrictions as well as
>maintaining target speed". This rate is of course a function of time,
>with the result being roughly what FMS computes for VNAV as well. :-)
>
>> Well, Europe has to handle a lot fewer aircraft than does US ATC. So
>> maybe hat's why they need more regulations. But wait, you stated that
>> this is an "unwritten rule". So it's not a regulation, but merely an
>> expectation.
>
>Yep. But compliance with that is quite universally as far as I'm told by
>controllers. :-)
>
>> The AIM is available on line. Look at www.faa.gov for the publications.
>> It is not regulatory, but its procedures are generally followed.
>
>Thanks!
>
>
>Best regards,
>Daniel

[Ron Rosenfeld]

On Mon, 28 Nov 2005 06:35:53 +0000 (UTC), Daniel Roesen > wrote:

>Well, what other interpretations of "optimum rate of descend" would
>you have in mind? I

I would take it to mean that you take into account all the factors
involved, not just how much money you're going to spend/save. That would
include, but not be limited to, operating characteristics of the aircraft,
passenger comfort, ATC expectations, expense, visibility at the required
angle of attack, etc.

For example, in my Mooney, I would typically use a cruise climb of 115-120
KIAS rather than a best rate of climb of about 90 KIAS because of improved
forward visibility at the lower AOA (unless ATC requested "best rate").




Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

[Jose]

> Well, what other interpretations of "optimum rate of descend" would
> you have in mind?

Depends what one is trying to optimize. Money, turbulence, time
enroute, arrival time (to coincide with an open gate), dive currency,
there are many things that one can attempt to "optimize", though I'd
agree that ATC is not likely to think of them all. :)

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

[Mitty]

On 11/27/2005 9:30 PM, Daniel Roesen wrote the following:
> * Ron Rosenfeld >:
>
>>From the (US) AIM:
>
>
> Thank you very much for citing the relevant regs. Is this stuff available
> online for future reference?
>

Some of that stuff is hard to find but virtually everything
the FAA publishes is available on line. Here is a links
page that has a lot of it:

http://www.clubcherokee.com/links/

Look towards the lower left for the FAA stuff. I find the
searchable FAR database at risingup.com to be particularly
handy.

[Steven P. McNicoll]

"Dave Butler" > wrote in message
news:1132165254.489969@sj-nntpcache-3...
>
> OK, agreed. I'd call those clearances explicitly discretionary.
>

I'd call those clearances implicitly discretionary. I'd call a clearance
that included "descend at pilot's discretion" explicitly discretionary.


>
> Yes, exactly. The clearance as originally stated was not for a
> discretionary descent. By responding "right" to the pilots question, the
> controller amended the clearance and simultaneously demonstrated lack of
> understanding of the way clearances are stated. But OK, I see your point.
>

The controller didn't amend the clearance, she just verified that descent
was at pilot's discretion.

[Steven P. McNicoll]

"Daniel Roesen" > wrote in message
...
>
> Hm. I'm lacking any real world experience, but in our little wannabe Sim
> world (VATSIM) I'm used to crossing restrictions like "XYZ, descend FL120
> (to be) level(ed) at FIX" which is to be interpreted as "start descent
> now with at least 1000fpm and be at FL120 latest at FIX". This is for
> Europe and confirmed to be real-world compatible by several real-world
> ATC controllers here. Now I happen to like "flying" in US airspace, where
> instructions like "XYZ, cross CEDES at 11000ft" are used. Is that to be
> taken analogue to European interpretation to start descending to 11000ft
> _now_, or to be taken as "descend 11000ft at own discretion"?
>

It means the pilot can begin descent at the time of his choosing and use the
descent rate of his choosing so long as he reaches 11,000 feet not later
than CEDES.


>
> If the latter, does ATC expect a report like "leaving FL240 for 11000" if
> not
> explicitly requested?
>

No.


>
> What is the US equivalent of the European
> clearance to "descend now to X with 1000fpm or more, to be level at
> FIX"? Is there any at all (short of a full "descend and maintain 11000ft,
> 1000fpm or more, cross CEDES at level")?
>

There is no equivalent standard US phraseology.

[Steven P. McNicoll]

"Andrew Sarangan" > wrote in message
oups.com...
>
> While flying at 3000 ft, I get a clearance that says "maintain 3000
> until established on the localizer, cleared ILS...." If I am already
> at 3000, what exactly is the purpose of "maintain 3000"?
>

To ensure you do not descend below 3000 before you intercept the localizer.


>
> The purpose of the "maintain 3000" is to caution the pilot that the
> approach clearance does not imply that he can start descending right
> away.
>
> In this context, I take the "maintain 3000 until established" to mean
> "maintain at least 3000 until establshed".
>

So you can climb above 3000? Nope, it means just what it says, 3000 until
established, no more and no less.

[Steven P. McNicoll]

"Daniel Roesen" > wrote in message
...
>
> Thank you very much for citing the relevant regs. Is this stuff available
> online for future reference?
>

The AIM can be found online at:

http://www.faa.gov/atpubs/AIM/index.htm


>
> Hm... interesting. "optimum rate consistent with the operating
> characteristics of the aircraft". This is fuzzy.
>
> The most economically way to descend a jet is at near idle thrust,
> tactically. But strategically, that's only true if I'm on my computed
> economic descent path. So if ATC orders me earlier than reaching my ToD
> to "descend now FL270", at what rate do I descend? "optimum rate"
> would be very shallow and be not quick enough for the controller who
> wants to get me out of the way of something. Should I descend at near
> idle thrust? But that would bring me down much quicker than strategically
> economic, as I have to fly a longer distance on a suboptimal low flight
> level.
>

When the descent is to avoid other traffic, as it is whenever "descend now"
is used, quicker is better than slower.

[Dave Butler]

Steven P. McNicoll wrote:
> "Dave Butler" > wrote in message
> news:1132165254.489969@sj-nntpcache-3...
>
>>OK, agreed. I'd call those clearances explicitly discretionary.
>>
>
>
> I'd call those clearances implicitly discretionary. I'd call a clearance
> that included "descend at pilot's discretion" explicitly discretionary.

OK, suit yourself.

>>Yes, exactly. The clearance as originally stated was not for a
>>discretionary descent. By responding "right" to the pilots question, the
>>controller amended the clearance and simultaneously demonstrated lack of
>>understanding of the way clearances are stated. But OK, I see your point.
>>
>
>
> The controller didn't amend the clearance, she just verified that descent
> was at pilot's discretion.

The clearance as originally stated was not for a discretionary descent. It's not
what's in the controller's head that counts, it's what she says. When she
"verified" that that the descent was to be discretionary, she was in effect
changing the clearance. That may not have been the controller's intention, but
that's what a pilot receiving the clearance should infer.

Dave, out.

[Steven P. McNicoll]

"Dave Butler" > wrote in message
news:1133385648.868087@sj-nntpcache-3...
>
> OK, suit yourself.
>

No, you suit yourself, I'll adhere to the established definitions.


>
> The clearance as originally stated was not for a discretionary descent.
> It's not what's in the controller's head that counts, it's what she says.
> When she "verified" that that the descent was to be discretionary, she was
> in effect changing the clearance. That may not have been the controller's
> intention, but that's what a pilot receiving the clearance should infer.
>

As I said previously, the controller used nonstandard phraseology. The
controller from the start intended for the descent to be at pilot's
discretion, she verified that it was when the pilot asked for clarification.
The clearance was not amended.

[Jose]

> As I said previously, the controller used nonstandard phraseology. The
> controller from the start intended for the descent to be at pilot's
> discretion, she verified that it was when the pilot asked for clarification.
> The clearance was not amended.

IF the controller intends to say "turn heading 270 intercept the
localizer" but instead actually says "turn heading 170 intercept the
localizer" and the pilot, sensing that 170 is not an approprite heading
and that 270 is probably what was intended, asks "confirm heading 270,
straight west" and the controller says "affermative, heading 270
intercept the localizer", was the clearance amended?

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

[Mike Teague]

"Daniel Roesen" > wrote in message
...
> * Ron Rosenfeld >:
> >>Hm... interesting. "optimum rate consistent with the operating
> >>characteristics of the aircraft". This is fuzzy.
> >
> > Nothing wrong with giving the pilot discretion over the rate of descent.
> > However, there is a requirement to notify ATC if climb/descent rates
will
> > be less than 500 fpm.
>
> OK, that makes sense. Never heard of that requirement yet, thanks for
> that. Will check our regulations here about comparable requirements.
>
> > You seem to be defining "optimum" as equivalent to "economic". I see no
> > such implication in the US.
>
> Well, what other interpretations of "optimum rate of descend" would
> you have in mind? If they didn't have anything specific in mind, they
> could have written "any rate consistent with the operating
> characteristics". Which would be kinda superfluous as you should never
> climb/descend with a rate not being consistent with the operating
> characteristics.

I believe FAAO 7110.183 has all the performance expectations for various
aircraft from ATC's perspective. Good luck finding it.. I have a 6 year old
version and cant find it online right now.




--
Mike Teague - Vancouver WA, USA
-- Opie and Anthony - XM202 - O&A Party Rock!
-- Phil Hendrie = Radio Genius

[Mike Teague]

"Mike Teague" > wrote in message
...
> "Daniel Roesen" > wrote in message
> ...
> > * Ron Rosenfeld >:
> > >>Hm... interesting. "optimum rate consistent with the operating
> > >>characteristics of the aircraft". This is fuzzy.
> > >
> > > Nothing wrong with giving the pilot discretion over the rate of
descent.
> > > However, there is a requirement to notify ATC if climb/descent rates
> will
> > > be less than 500 fpm.
> >
> > OK, that makes sense. Never heard of that requirement yet, thanks for
> > that. Will check our regulations here about comparable requirements.
> >
> > > You seem to be defining "optimum" as equivalent to "economic". I see
no
> > > such implication in the US.
> >
> > Well, what other interpretations of "optimum rate of descend" would
> > you have in mind? If they didn't have anything specific in mind, they
> > could have written "any rate consistent with the operating
> > characteristics". Which would be kinda superfluous as you should never
> > climb/descend with a rate not being consistent with the operating
> > characteristics.
>
> I believe FAAO 7110.183 has all the performance expectations for various
> aircraft from ATC's perspective. Good luck finding it.. I have a 6 year
old
> version and cant find it online right now.
>
>

Ahh, I found it, sorry, it's now appendix A in the 7110.65.

--
Mike Teague - Vancouver WA, USA
-- Opie and Anthony - XM202 - O&A Party Rock!
-- Phil Hendrie = Radio Genius

[Herb Sewell]

Mike Teague wrote:
> "Mike Teague" > wrote in message
> ...
> > "Daniel Roesen" > wrote in message
> > ...
> > > * Ron Rosenfeld >:
> > > >>Hm... interesting. "optimum rate consistent with the operating
> > > >>characteristics of the aircraft". This is fuzzy.
> > > >
> > > > Nothing wrong with giving the pilot discretion over the rate of
> descent.
> > > > However, there is a requirement to notify ATC if climb/descent rates
> > will
> > > > be less than 500 fpm.
> > >
> > > OK, that makes sense. Never heard of that requirement yet, thanks for
> > > that. Will check our regulations here about comparable requirements.
> > >
> > > > You seem to be defining "optimum" as equivalent to "economic". I see
> no
> > > > such implication in the US.
> > >
> > > Well, what other interpretations of "optimum rate of descend" would
> > > you have in mind? If they didn't have anything specific in mind, they
> > > could have written "any rate consistent with the operating
> > > characteristics". Which would be kinda superfluous as you should never
> > > climb/descend with a rate not being consistent with the operating
> > > characteristics.
> >
> > I believe FAAO 7110.183 has all the performance expectations for various
> > aircraft from ATC's perspective. Good luck finding it.. I have a 6 year
> old
> > version and cant find it online right now.
> >
> >
>
> Ahh, I found it, sorry, it's now appendix A in the 7110.65.
>
> --
> Mike Teague - Vancouver WA, USA
> -- Opie and Anthony - XM202 - O&A Party Rock!
> -- Phil Hendrie = Radio Genius
You like Phil Hendrie too?

[Mike Teague]

"Herb Sewell" > wrote in message
oups.com...
>
>> You like Phil Hendrie too?
>
>

obviously.. heard from walter bellhaven lately? I hear he is doing lectures
on botany in the day-room these days ;)


--
Mike Teague - Vancouver WA, USA
-- Opie and Anthony - XM202 - O&A Party Rock!
-- Phil Hendrie = Radio Genius

[Steven P. McNicoll]

"Jose" > wrote in message
t...
>
> IF the controller intends to say "turn heading 270 intercept the
> localizer" but instead actually says "turn heading 170 intercept the
> localizer" and the pilot, sensing that 170 is not an approprite heading
> and that 270 is probably what was intended, asks "confirm heading 270,
> straight west" and the controller says "affermative, heading 270 intercept
> the localizer", was the clearance amended?
>

Yes.

[Jose]

>> IF the controller intends to say "turn heading 270 intercept the
>> localizer" but instead actually says "turn heading 170 intercept the
>> localizer" and the pilot, sensing that 170 is not an approprite heading
>> and that 270 is probably what was intended, asks "confirm heading 270,
>> straight west" and the controller says "affermative, heading 270 intercept
>> the localizer", was the clearance amended?
>
> Yes.

It is in that sense that the OP (I think - it's an old thread I'm not
going to dig up) had used the word "amended", and you claimed that it
did not count as an amended clearance. The two situations are quite
parallel.

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

[Steven P. McNicoll]

"Jose" > wrote in message
. ..
>
> It is in that sense that the OP (I think - it's an old thread I'm not
> going to dig up) had used the word "amended", and you claimed that it did
> not count as an amended clearance. The two situations are quite parallel.
>

There is no similarity.

[Jose]

> There is no similarity.

Yes there is.

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

[Steven P. McNicoll]

"Jose" > wrote in message
...
>
> Yes there is.
>

What is the similarity?

[Jose]

> What is the similarity?

In both cases the controller uttered something that did not match what
he intended to mean. In both cases clarification was called for. In
both cases the controller then uttered something that did match what he
originally intended to mean.

In both cases the controller's intent did not change, but the clearance
the pilot received did.

I call that an amended clearance. Inadvertently amended perhaps, but
amended nonetheless.

But at this point I don't care either way what you call it.

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

[Steven P. McNicoll]

"Jose" > wrote in message
t...
>
> In both cases the controller uttered something that did not match what he
> intended to mean. In both cases clarification was called for. In both
> cases the controller then uttered something that did match what he
> originally intended to mean.
>

What did the controller utter that did match what he originally intended to
mean in the first case?


>
> In both cases the controller's intent did not change, but the clearance
> the pilot received did.
>
> I call that an amended clearance.
>

I call it an amended clearance when the clearance is changed.


>
> Inadvertently amended perhaps, but amended nonetheless.
>

Inadvertently? You don't think the controller intended to assign a
different heading after the request for clarification?

>
> But at this point I don't care either way what you call it.
>

Then you won't respond to this message.