Not even when the clearance includes a SID with a speed limit?

 

As it's stated in the SID, it is not reiterated in a clearance.  It's implicit in the SID.  In fact, many of the SIDs over here are around simply to cut down on frequency congestion.

 

...but again, you'd be hard-pressed to find a SID with a speed restriction on it at an airport where heavies utilizing the 91.117d exemption are operating.

All the London airports (Heathrow, City, Gatwick, Luton and Stansted) all have procedure limit of 250KIAS below FL100 as do  Amsterdam - Schiphol (EHAM) add Paris - CDG (LFPG).

 

Singapore - Changi (WSSS) SIDs have 220KIAS until passing 4000ft and 250KIAS until passing 10000ft. All Hong Kong - Lantau SIDS have speed limits of 220K or 230IAS until established on track to intermediate waypoints.

 

Anyway, surely limits in  91.117d are "trumped" by procedure speed limits by  91.123a - "When an ATC clearance has been obtained, no pilot in command may deviate from that clearance unless an amended clearance is obtained, an emergency exists, or the deviation is in response to a traffic alert and collision avoidance system resolution advisory." The pilot may not deviate from any speed limits.

 

 

All the London airports (Heathrow, City, Gatwick, Luton and Stansted) all have procedure limit of 250KIAS below FL100 as do  Amsterdam - Schiphol (EHAM) add Paris - CDG (LFPG).
 
Singapore - Changi (WSSS) SIDs have 220KIAS until passing 4000ft and 250KIAS until passing 10000ft. All Hong Kong - Lantau SIDS have speed limits of 220K or 230IAS until established on track to intermediate waypoints.

 

As all of my posts have been related to the US regulations, and the ATC procedures thereof, pointing out foreign procedure is of little use in this discussion.  I do not have the knowledge of the regs over there to challenge this in that arena, and even so, it is not part of the point I'm trying to make.

 

 

 

Anyway, surely limits in  91.117d are "trumped" by procedure speed limits by  91.123a - "When an ATC clearance has been obtained, no pilot in command may deviate from that clearance unless an amended clearance is obtained, an emergency exists, or the deviation is in response to a traffic alert and collision avoidance system resolution advisory." The pilot may not deviate from any speed limits.

 

This is correct, but only in a somewhat shortsighted manner.  Yes, you are correct that if ATC says "maintain 220 knots or less [until]" then this trumps and higher restrictions set by the other regs, in compliance with 91.123a.  Where the logic shows shortsightedness, however, is its lack of credence given to "unless an amended clearance is received."  This, along with the provisions of 91.3 (PIC Authority), applied as outlined in AIM 4-4-1b, allow for the pilot to decline any direction provided by ATC, though he or she must request an amended clearance (utilized here more in the "instruction" manner, rather than "route clearance" manner - the latter would involve "you are re-cleared to [location], via [route], maintain [altitude]," and so on).

 

So, contrary to what you've written, the pilot may well deviate from ATC procedural limits legally.  The only limitation is that the pilot must inform ATC of this, provided he or she is utilizing the 91.3 authority only to decline the procedural limit and remain within the other provisions of 91.117.

One can say that there is a "general" restriction of 250kts below 10,000ft. However, a specific SID or STAR restriction is often published. for example at LIMZ the KUK6Q departure is limited to 210kts below 1,800ft agl.

 

And, have a look at this typical BAW departure from LIMF:-

;ADEU Card #1 for LIMF to EGKK
1 N 45*15.2 E 007*39.1   ; MF401
2 N 45*15.3 E 007*44.7   ; MF402
3 N 45*11.1 E 007*49.7   ; MF403
4 N 44*55.5 E 007*51.7   ; TOP
5 N 44*56.6 E 007*40.2   ; KODOK
6 N 45*06.5 E 007*41.9   ; BARBY
7 N 45*18.6 E 007*38.1   ; D338Y
8 N 45*23.2 E 007*35.4   ; MATOG
9 N 45*44.7 E 007*20.3   ; SCS

 

There is no way you can go above 250kts without sticking the a/c on its wingtip!

If ATC waive any speed restriction it's all down to your airmanship to decide whether or not one can go directly to climb speed e.g. 290kts. or as in the above departure stay at or below 250kts to ensure that the turns are executed precisely.

pointing out foreign procedure is of little use in this discussion.

This thread began as a general discussion of this rule. The first country mentioned was the UK in post #10 followed by Sweden in Post #11. The USA (FARs) were not mentioned until Post #16. This is an international forum after all.

 

So, contrary to what you've written, the pilot may well deviate from ATC procedural limits legally. The only limitation is that the pilot must inform ATC of this, provided he or she is utilizing the 91.3 authority only to decline the procedural limit and remain within the other provisions of 91.117.

 

A pilot can't decline a clearance once it's obtained - it's too late then and 91.123a prevents him from deviating from it except in an emergency etc.

 

Similarly, 91.3 doesn't permit a pilot to deviate from it either except in an emergency because 91.3( B) reads

 

( B) In an in-flight emergency requiring immediate action, the pilot in command may deviate from any rule of this part to the extent required to meet that emergency.

 

[Note that this part is Part 91.]

 

Once a pilot has obtained an clearance he may not legally deviate from it without ATC permission.

 

 

This thread began as a general discussion of this rule. The first country mentioned was the UK in post #10 followed by Sweden in Post #11. The USA (FARs) were not mentioned until Post #16. This is an international forum after all.

 

I agree.  I did, however, add in that the United States has a different rule where certain aircraft may exceed 250 under 10 and people picked (to include yourself) at it, so I'm addressing those comments.

 

 

A pilot can't decline a clearance once it's obtained - it's too late then and 91.123a prevents him from deviating from it except in an emergency etc.

 

A pilot can most certainly decline a clearance.  In the United States, the benefit of the doubt really always goes to the pilot when it comes to the operation of the aircraft (based on proper action according to the AFM).

 

If a controller issues a vector that would conflict with terrain, or weather, I can certainly decline that, and that is not an emergency.

If ATC assigns a speed that is slower than comfortable, I can certainly decline that, and that is not an emergency.

If ATC assigns a runway that it beyond my own (or company) crosswind or tailwind limits, I can certainly decline that, and that is not an emergency.

 

 

 

[Note that this part is Part 91.]
 
Once a pilot has obtained an clearance he may not legally deviate from it without ATC permission.

 

Saying Part 91 is quite the broad reference, but luckily I know you're cutting from Part 91.3.  Your interpretation of it, however, couldn't be further from the truth.

 

Part 91.3 is written permissively.  That is to say that Part 91.3 is written to give the pilot all necessary powers to ensure the safe operation of the aircraft.  As I mentioned above, the pilot has been assigned the role of supreme authority to the safety of the flight.  Part 91.3 gives the pilot all power necessary to ensure that any potential compromise to that safety is mitigated.  It goes further to say, in b, that "all bets are off" when it comes to an in-flight emergency.  All rules within Part 91 are null and void to get the aircraft on the ground safely.

 

Nowhere in Part 91.3 or 91.123 does it say that the pilot may not deviate without permission.  Furthermore, it is not stated that the pilot need to wait for permission to be granted in cases where safety is marginalized.

 

In fact, the FAA's interpretations of 91.123 and 91.3 as written in AIM 4-4-1 a and b (which you seemed to have ignored) state:

 

 

a. A clearance issued by ATC is predicated on known traffic and known physical airport conditions. An ATC clearance means an authorization by ATC, for the purpose of preventing collision between known aircraft, for an aircraft to proceed under specified conditions within controlled airspace. IT IS NOT AUTHORIZATION FOR A PILOT TO DEVIATE FROM ANY RULE, REGULATION, OR MINIMUM ALTITUDE NOR TO CONDUCT UNSAFE OPERATION OF THE AIRCRAFT.

(bold type NOT mine - that's all the FAA - I only highlighted with color)

 

Note how it specifically exempts unsafe operation of the aircraft, and not just emergencies.  Furthermore, this lines up with the 91.117d exemption for minimum safe airspeed.

 

Furthermore - and here's the big hitter of FAA interpretation of the regs:

 

 

 

b. 14 CFR Section 91.3(a) states: “The pilot-in-command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.” If ATC issues a clearance that would cause a pilot to deviate from a rule or regulation, or in the pilot's opinion, would place the aircraft in jeopardy, IT IS THE PILOT'S RESPONSIBILITY TO REQUEST AN AMENDED CLEARANCE. Similarly, if a pilot prefers to follow a different course of action, such as make a 360 degree turn for spacing to follow traffic when established in a landing or approach sequence, land on a different runway, takeoff from a different intersection, takeoff from the threshold instead of an intersection, or delay operation, THE PILOT IS EXPECTED TO INFORM ATC ACCORDINGLY. When the pilot requests a different course of action, however, the pilot is expected to cooperate so as to preclude disruption of traffic flow or creation of conflicting patterns. The pilot is also expected to use the appropriate aircraft call sign to acknowledge all ATC clearances, frequency changes, or advisory information.

(bold type NOT mine - that's all the FAA)

 

Pay particular attention to the bold type.  The first instance refers to the pilot responsibility to request an amended clearance in cases of aircraft jeopardy (an unsafe airspeed would qualify).  If ATC says "maintain [speed slower than min safe]," then the pilot may request an amended clearance.  The second instance refers to pilot preference (note the term "preference" and not only something responding to an aircraft emergency) and a pilot being able to inform ATC of said preference.  Again, this is not limited to emergencies, though they do note that the pilot is expected not to act in a way to cause disruption of traffic flow.  The speed issue would be more related to the first mention, however, and simply stating unable is acceptable enough.  ATC doesn't really argue with speeds when a pilot says "unable," as the pilot is the one with the knowledge of the aircraft.

 

So, in the case a pilot of a heavy said "unable 250 at [fix on SID]" this would be perfectly acceptable and ATC would know to just say "okay" and ensure that separation is not lost.  Done.

Again, USA controllers are familiar with the aircraft types(flight plan) they are controlling. I currently fly in the same airspace(North East coast) that I flew DC10s. I was never requested to limit my speed on departure in the DC10. Now days I depart from the same airports in the G5/550 and I'm routinely asked to limit my speed to 200kts. Sometimes i'm told no higher than 250 as i pass 10,000. Funny thing is that they often forget the restriction from controller to controller so we often query them on check in.

 

 

Funny thing is that they often forget the restriction from controller to controller so we often query them on check in.

 

Some facilities aren't as big on passing strips around, or utilize the scratchpad for other information (haven't given D to FIX yet, or what SID you're on, etc), so speed restrictions sometimes get lost in the mix.

 

Smart to ask, because unless they say it's for metering (highly unlikely on departure in a TRACON), chances are, it was just to keep separation within the one controller's airspace.  They're supposed to communicate it within the facility, however.

Saying Part 91 is quite the broad reference, but luckily I know you're cutting from Part 91.3. Your interpretation of it, however, couldn't be further from the truth.

 

 

I'm cutting from 91.123 which couldn't be more unambiguous. Here the full text.

 

 

§ 91.123   Compliance with ATC clearances and instructions.

 

(a) When an ATC clearance has been obtained, no pilot in command may deviate from that clearance unless an amended clearance is obtained, an emergency exists, or the deviation is in response to a traffic alert and collision avoidance system resolution advisory. However, except in Class A airspace, a pilot may cancel an IFR flight plan if the operation is being conducted in VFR weather conditions. When a pilot is uncertain of an ATC clearance, that pilot shall immediately request clarification from ATC.

 

( B) Except in an emergency, no person may operate an aircraft contrary to an ATC instruction in an area in which air traffic control is exercised.

 

© Each pilot in command who, in an emergency, or in response to a traffic alert and collision avoidance system resolution advisory, deviates from an ATC clearance or instruction shall notify ATC of that deviation as soon as possible.

 

(d) Each pilot in command who (though not deviating from a rule of this subpart) is given priority by ATC in an emergency, shall submit a detailed report of that emergency within 48 hours to the manager of that ATC facility, if requested by ATC.

 

(e) Unless otherwise authorized by ATC, no person operating an aircraft may operate that aircraft according to any clearance or instruction that has been issued to the pilot of another aircraft for radar air traffic control purposes.

 

 

 

This discussion has been about deviating from a obtained clearance and not about  an offered clearance which is totally different.

 

Further, there's no question about a pilot being expected to fly unsafely  - but is a heavy aircraft  unable "unable" to fly at 250KIAS and would doing so be unsafe or is it just inconvenient?

 

Similarly, if a pilot prefers to follow a different course of action, such as make a 360 degree turn for spacing to follow traffic when established in a landing or approach sequence, land on a different runway, takeoff from a different intersection, takeoff from the threshold instead of an intersection, or delay operation,

 

 

Does that really mean that a pilot who's cleared to land on one runway can simply chose to land on another runway regardless of any emergency without getting a revised clearance?

 

 

I'm cutting from 91.123 which couldn't be more unambiguous. Here the full text.

 

True.  Look at your earlier post, though, which just states "[Note that this part is Part 91.]"

 

That was ambiguous.  I was saying your reference to the reg (in that case an entire part of the regs) was ambiguous.  Not the reg itself.  You may have mis-typed, but all it said was Part 91.  That is ambiguous.

 

 

 

This discussion has been about deviating from a obtained clearance and not about  an offered clearance which is totally different.

 

No, it really hasn't been about deviating from an obtained clearance.  An obtained clearance would be an explicit statement by a controller (or listed on a SID - again, SID because that's where heavies would need the 91.117d exemption) stating a specific speed to be followed.

 

The initial post referred to the "hard limit" of 250/10, where people then jumped in and noted that this is not, in fact, a hard limit.  This 250/10 limit is never stated by a controller - ever.  You will never hear a controller say "descending through 10,000, comply with the restrictions of 91.117."  Ergo, the topic of discussion at hand is the implied 91.117 rule and, related to the MD11, the 91.117d (or similar, in applicable foreign cases) exemption.

 

You were the one (though there may have been others) who took it to stated clearances, supposedly in an effort to combat the arguments myself and others have made.  Even then, we've provided evidence to the contrary, yet the discussion somehow continues.

 

I have stated numerous times - in agreement, mind you - that an explicit statement by a controller is handled separately from the generic 91.117 language (as you correctly noted with 91.123).  However, this can then be trumped by 91.3 (as properly clarified by AIM 4-4-1 a and b).  Discussion below.

 

 

Further, there's no question about a pilot being expected to fly unsafely  - but is a heavy aircraft  unable "unable" to fly at 250KIAS and would doing so be unsafe or is it just inconvenient?

 

It is actually unsafe in many circumstances.  As Rick has pointed out several times, the climb profile of aircraft is determined in a set config (normally clean).  That config is used to ensure climb profile clearance from obstacles, and ATC climb gradients.  Holding onto 250 knots through using flaps/slats will change your climb profile.

 

Hitting obstacles because the profile was calculated off clean performance, but flown dirty at 250 has the potential to get you (and several of your passengers) killed.

-I'd consider that a safety issue.

 

Hitting another plane because you couldn't climb on the proper gradient because the profile was calculated off clean performance, but flown dirty at 250 and hit a crossing stream of aircraft has the potential to get you (and several of your passengers) killed.

-I'd consider that a safety issue.

 

Holding onto 250 in a clean state in an attempt to follow a false interpretation of the rule, while trying to follow the clean state listed in the AFM raises the AoA, putting you closer to a stall.  Stalling a heavy aircraft could be a very ugly situation (they don't stall nicely like your average small trainer).  This has the potential to get you (and several of your passengers) killed.

-I'd consider that a safety issue. 

 

So yes, despite it only appearing to be a "minor inconvenience" on its face, it is actually a safety issue.

 

A conversation that would never happen, but if it did, this would be it:

ATC: "Airline 13 heavy, say indicated airspeed."

AIR13: "272 knots, Airline 13 Heavy."

ATC: "Airline 13 Heavy, maintain 250 knots or less until 10,000."

AIR13: "Unable for minimum safe speed, Airline 13 Heavy."

 

Done.

 

...and it wouldn't have even gotten that far because - again - controllers here are taught to know of the 91.117d exemption exercised by most heavies from time to time.  As such, they apply the necessary separations as second nature.  It's not some crazy new concept every time they talk to an 747/MD11/DC10/etc.

 

 

 

Does that really mean that a pilot who's cleared to land on one runway can simply chose to land on another runway regardless of any emergency without getting a revised clearance?

 

Technically?  Yes, but remember the clarification:

"When the pilot requests a different course of action, however, the pilot is expected to cooperate so as to preclude disruption of traffic flow or creation of conflicting patterns."

 

The pilot may reject the instruction, but that does not mean that he or she will maintain his or her current priority in the queue, or current route.  In the landing case, the pilot may be required to hold until the requested runway is available.  In the speed case, the pilot may not be able to join his or her route until the controller vectors the flight around another, slower aircraft.  It's a give and take.

 

In reality, though, the landing situation would never really happen as the pilot would have listened to the ATIS, would have likely gotten a "expect visual Runway #[L/C/R]," and would have had ample time to request the another runway before the controller said "Runway #[L/C/R], cleared to land."

 

So, while the pilot has the end say in how the aircraft is operated, he or she must also cooperate with ATC to avoid disruption of the rest of the aircraft.

 

 

 

 

To all:

 

This is getting to be a little ridiculous, to be honest.

I'm all for a hearty debate, but when it gets to ignoring citations of the regs, the explanation of the regs from the regulatory agency that created them, and the testimony - although anecdotal - of several people who have flown aircraft in a manner that reflects the regs and agency clarification...at that point, we're getting into so much willing suspension of belief that I'm wondering if we're still discussing the real world here.

 

Generic Disclaimer:

Yes, I know we're discussing Flight Sim, which is not the real world, but let's be honest:

It's meant to simulate real planes, out of real airports, with real metrics of altitude, weight, and weather phenomena.  Additionally, the whole discussion stemmed from questioning if the MD11 is following a rule from the real world.  So, yes, despite being the sim, we're discussing its ties to the real world.

 

The lawyer-like choice of words and covering every possible angle due to everyone here seeming the believe that they've somehow stumbled upon some new interpretation of the regs that hasn't already been hashed out hundreds of times.  Stump the chump might be fun for getting the better of your average simmer, but I'm not your average simmer, and neither are the other two known heavy drivers who have weighed in here.

 

I know people do not like to resolve cognitive dissonance*, particularly when found to believe a falsehood, but it's time to grow up, learn and move on.

 

*Essentially, "the art of lying to oneself."

Kyle, honestly mate, never wrestle a pig, you get dirty and the pig enjoys it.....

Kyle, honestly mate, never wrestle a pig, you get dirty and the pig enjoys it.....

 

Haha - good point, Rob.  Then again, I'm clearly not above some mud.

It's getting ridiculous, but at the same time, there's a certain masochistic side that curious as to what remaining straw will be grasped at next.

 

...then again, part of me feels like the guy with the hose:

 

BE CLEAN, PEOPLE!

In fact, the FAA's interpretations of 91.123 and 91.3 as written in AIM 4-4-1 a and b (which you seemed to have ignored) state:

 

 If you'd read that document further you'd have found this, which makes my point for me. (I've emphasised the relevant words):

 

4-4-10. Adherence to Clearance

 

a. When air traffic clearance has been obtained under either visual or instrument flight rules, the pilot-in-command of the aircraft must not deviate from the provisions thereof unless an amended clearance is obtained. When ATC issues a clearance or instruction, pilots are expected to execute its provisions upon receipt. ATC, in certain situations, will include the word “IMMEDIATELY” in a clearance or instruction to impress urgency of an imminent situation and expeditious compliance by the pilot is expected and necessary for safety. The addition of a VFR or other restriction; i.e., climb or descent point or time, crossing altitude, etc., does not authorize a pilot to deviate from the route of flight or any other provision of the ATC clearance.

 

 

 If you'd read that document further you'd have found this, which makes my point for me. (I've emphasised the relevant words):

 

Sure, but what point are you trying to prove with this?  It's essentially clarification of 91.123.

1. An ATC route clearance will not explicitly state any speeds unless absolutely necessary (and even then, you'd be hard pressed to find one).  As such, speeds are limited only by 91.117, implicitly, which allows operation above 250 for the MD11 where it is necessary.
2. SIDs rarely have speed restrictions in the United States.  If assigned a SID with a speed restriction that could not be met, 4-4-10 requires an amended clearance, but a speed that creates an unsafe condition would fall under 4-4-1, where the pilot would simply notify ATC who would then have to amend/cancel the instruction.
3. Controllers rarely issue speed restrictions on departure.  Again, the 7110.65 severely frowns upon the practice.  More specifically it recommends assigning no less than 230 knots for turbojet departures.  Despite being a recommendation, this is what controllers are taught to.  You can very easily see how the practice is frowned upon from that, alone.  Even if one were issued, you would be correct in that 91.123/4-4-10 would require an amended clearance, but a speed that creates an unsafe condition would fall under 4-4-10, where the pilot would simply notify ATC who would then have to amend/cancel the instruction.

You may think that the 4-4-1 and 4-4-10 interaction would require pilots to wait for the amended clearance, but if you think about it, that discourse could be too long to wait.  While speeds probably wouldn't be as jeopardizing, think of it this way:

A controller instructs me to fly a heading of 270, directly at a mountain, but it is a good 30nm away.  I'm not in any immediate danger, currently.  If the controller forgets about me and I'm straying into an area of higher terrain, I do not need to wait to ask a controller for a new vector.  Once I determine that I'm getting too close for my own comfort to that terrain, I may initiate a turn or climb to place the aircraft back in a safe situation.  4-4-1 would require that I notify the controller of the action.  That controller would then provide an amended clearance.  In this case "maintain present heading," or a new heading.

 

4-4-10 isn't anything new.  It simply contains the same information as 91.123 that I've already addressed.

 

Next?

 

 

but what point are you trying to prove with this?

 

Simply that when an ATC clearance with a speed restriction  has been obtained, no pilot in command may deviate from that clearance unless an amended clearance is obtained, an emergency exists, or the deviation is in response to a traffic alert and collision avoidance system resolution advisory. FAR (§ 91.123 ) and that FAR §  91.117d doesn't change that.