Slowing at/by 10K

[Hold West]

Quote:
Originally Posted by Say Again Over
Well the AIM isn't the "how to operate book" it's more of a book of guidelines, I feel that a majority of new guys will now leave this thread thinking it's perfectly normal to come streaking in at 340 KTS to 10K and stop there while they bleed off speed, WRONG, that is not how to operate (reference xTWA conversations with ATC), and that is not what the AIM is advocating.


>Wow, that's a pretty bold statement! I guess that myself and the several
> other hundreds of pilots that I have flown with over the last 20 some
> years need to go back to school.

Well, from my perspective and what the FAA teaches controllers is that AIM is essentially that, guidelines in how to apply the FARs and other documents that actually regulate aviation.

In fact, the preface to AIM itself says:

"This publication, while not regulatory, provides information which reflects examples of operating techniques and procedures which may be requirements in other federal publications or regulations. It is made available solely to assist pilots in executing their responsibilities required by other publications."

Emphasis added by me.

Just like at work, I'm always going to look for the underlying regulation before going off what the AIM says, and quote that instead.

 

[Say Again Over]

Thanks for bailing me out.

 

[Say Again Over]

HS125, don't get me wrong, I have used that procedure also, the last thing I need is a violation from exceeding the speed limit below 10K, normally it's something that happens due to ATC interference, if traffic is not a factor I and others I fly with will simply dial in 250 around 12K and presto, going through 10 it happens. If you like waiting til 10K it looks like that is your prerogative depending on what part of the AIM you look at.

 

[Vector4fun]

I don't know why a controller wouldn't anticipate a short level-off, at least half the crews or more do it. It's also mentioned in the Controller's Handbook.

See Note at end of section:


FAA 7110.65, 5-7-1 (c)

c. Simultaneous speed reduction and descent can be extremely difficult, particularly for turbojet aircraft. Specifying which action is to be accomplished first removes any doubt the pilot may have as to controller intent or priority[SIZE=-2]. [/SIZE]Specify which action is expected first when combining speed reduction with a descent clearance.
1. Speed reductions prior to descent.
PHRASEOLOGY-
REDUCE SPEED:

TO (specified speed),

or

(number of knots) KNOTS.

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

THEN, REDUCE SPEED:

TO (specified speed in knots),

or


TO MACH (Mach number),

or

(number of knots) KNOTS.


NOTE-
When specifying descent prior to speed reduction, consider the maximum speed requirements specified in 14 CFR Section 91.117. It may be necessary for the pilot to level off temporarily and reduce speed prior to descending below 10,000 feet MSL. ​

 

[Gorilla]

Nothing wrong with any of the techniques listed, but all I'm saying is the "fun" technique is to try and minimize pitch changes. I like to descend using V/S, then at the appropriate point, say 12K, roll the speed window back but leave the V/S where it's at. Done properly, the airspeed will slowly bleed to 250 right when you pass 10K. At 250, you may need to increase the V/S slightly, or select LVL CHANGE / CLAMP; hopefully the nose won't need to drop much to maintain the 250.

I just think it's uncomfortable to many pax to do an idle descent, then, as you approach 10K at 2500 fpm, abruptly jack the nose up to slow. Kind of like an MD-80 departing cruise, when the guy selects CLMP and drags the throttles back. WHOOOM, down goes the nose and everyone gets a bit light in the seat, followed by increased G as the bad MD-80 A/P corrects its pitch.

I guess I'm easily amused, and doing things like making a smooth transition at 10K adds a tiny bit of fun or challenge. VNAV is boring.

 

[HS125]

Quote:
In fact, the preface to AIM itself says:

"This publication, while not regulatory, provides information which reflects examples of operating techniques and procedures which may be requirements in other federal publications or regulations. It is made available solely to assist pilots in executing their responsibilities required by other publications."

Emphasis added by me.

Just like at work, I'm always going to look for the underlying regulation before going off what the AIM says, and quote that instead.

While the AIM is not regulatory in nature, much of the information within is compiled from other sources that may not be readily available to pilots without a fair amount of research that is regulatory in nature .

 

[HS125]

Nothing wrong with any of the techniques listed, but all I'm saying is the "fun" technique is to try and minimize pitch changes. I like to descend using V/S, then at the appropriate point, say 12K, roll the speed window back but leave the V/S where it's at. Done properly, the airspeed will slowly bleed to 250 right when you pass 10K. At 250, you may need to increase the V/S slightly, or select LVL CHANGE / CLAMP; hopefully the nose won't need to drop much to maintain the 250.

I just think it's uncomfortable to many pax to do an idle descent, then, as you approach 10K at 2500 fpm, abruptly jack the nose up to slow. Kind of like an MD-80 departing cruise, when the guy selects CLMP and drags the throttles back. WHOOOM, down goes the nose and everyone gets a bit light in the seat, followed by increased G as the bad MD-80 A/P corrects its pitch.

I guess I'm easily amused, and doing things like making a smooth transition at 10K adds a tiny bit of fun or challenge. VNAV is boring.

Anyone who leaves it up to the machine to do the work is just lazy. If you are leaving it to VNAV to do the job for you, you are obvioulsy not interested in giving the pax a good ride. You fly the airplane, the airplane doesn't fly you.

 

[HS125]

HS125, don't get me wrong, I have used that procedure also, the last thing I need is a violation from exceeding the speed limit below 10K, normally it's something that happens due to ATC interference, if traffic is not a factor I and others I fly with will simply dial in 250 around 12K and presto, going through 10 it happens. If you like waiting til 10K it looks like that is your prerogative depending on what part of the AIM you look at.

Agreed, it's all a matter of technique. However, in your previous post, you said that leveling off at 10,000 to slow to 250 was wrong and it is not. ATC expects it and (as Hold West and Vector4fun have pointed out) prepared for it. If ATC needs something different they will tell you. If you blow through 10,000 going faster than 250, its been my experience, the pilot flying isn't minding his/her business.

I personally use both techniques. Which one I use depends on what airport I am flying into and how my decent planning is working out. When the descent is left up to me, I try to plan my descents so that I can come out of altitude at Idle thrust and not touch the throttles until I need to spool up to stabilize the approach around 1,000' AGL. All the while trying to give my PAX the smoothest ride possible.

If I need to bring the throttles up to make it to the runway or use the speed brakes or any special maneuvering to get down, then I didn't do my descent planning propperly.

 

[AdlerDriver]

..........If I need to bring the throttles up to make it to the runway or use the speed brakes or any special maneuvering to get down, then I didn't do my descent planning propperly.

I was with you until this last part.

"Bring the throttles up to make the runway"??

Most companies that have stabilized approach criteria including "Engines spooled" for a good reason.

If you're attempting to stay at idle all the way to the runway, I think you're setting yourself up for a situation where you might need some more power and it won't be there. Maybe I'm misunderstanding your comment.

Idle to the marker or gear down perhaps is a nice goal for style points. Depends on how accomodating ATC is that day.

 

[FL420]

I like to descend using V/S, then at the appropriate point, say 12K, roll the speed window back but leave the V/S where it's at. Done properly, the airspeed will slowly bleed to 250 right when you pass 10K. At 250, you may need to increase the V/S slightly, or select LVL CHANGE / CLAMP; hopefully the nose won't need to drop much to maintain the 250.

Gorilla,

When I first read this I thought you were saying you liked to maintain a constant rate-of-descent as selected on the MCP as you slowed to 250KIAS between 12K and 10K. The only way I could see this happening is if you were descending with power set well above idle which would be very fuel inefficient.

If already at idle the only way to slow to 250KIAS would be to decrease the rate-of-descent below that selected on the MCP by raising the nose until the selected speed is reached. When the selected speed is attained the nose will pitch down again to attempt to regain the selected V/S. Is that your technique?

A lot of check airmen I have encountered really don't like pilots to use V/S, especially below 10K, not only because of the lack of speed protection in V/S but more importantly because you can fly away from an altitude selected on the MCP in V/S. I believe there have been some accidents where pilots inadvertently flew into the ground using V/S with a higher altitude selected on the MCP.

 

[HS125]

I was with you until this last part.

"Bring the throttles up to make the runway"??

Most companies that have stabilized approach criteria including "Engines spooled" for a good reason.

If you're attempting to stay at idle all the way to the runway, I think you're setting yourself up for a situation where you might need some more power and it won't be there. Maybe I'm misunderstanding your comment. I've never done that and I never would intentionally. I've flown with pilots that do it and I don't like it and I don't hesitate to let them know how I feel about it.

Idle to the marker or gear down perhaps is a nice goal for style points. Depends on how accomodating ATC is that day.

Go back an reread my original post! In the paragraph before the one you quote, I said that I stabilize the approach by 1,000 AGL. If I have to bring the throttles up at any point before 1,000 AGL to make it to the runway, or do unusual maneuvering to get to 1,000 AGL and stabilized, then I didn't plan the descent propperly. It's all energy management.

Not only is it for style points, it's the most fuel efficient.

 

[Stifler's Mom]

Not sure what the previous three pages have said, but in ASA's POH it states.... Unless otherwise requested by ATC, deceleration should be accomplished in level flight. (4-22)

 

[AdlerDriver]

Go back an reread my original post! In the paragraph before the one you quote, I said that I stabilize the approach by 1,000 AGL. If I have to bring the throttles up at any point before 1,000 AGL to make it to the runway, or do unusual maneuvering to get to 1,000 AGL and stabilized, then I didn't plan the descent propperly. It's all energy management.

Not only is it for style points, it's the most fuel efficient.

Got it. I figured I didn't read it right - I was in a hurry.

The micro-manage control of ATC when flying in to most major airports seems like it would preclude you from accomplishing this very often. Probably doable at smaller, less controlled fields.

 

[HS125]

Got it. I figured I didn't read it right - I was in a hurry.

The micro-manage control of ATC when flying in to most major airports seems like it would preclude you from accomplishing this very often. Probably doable at smaller, less controlled fields.

ATC requirements make it difficult at most airports, but when you get to do it it's a lot of fun and challenging. However, when you go to some airports on a regular basis and learn the local ATC practices, you can modify your procedures to accomplish some of the same principles.

 

[pilot error]

so much easier in countries that say things like, "descend and maintain fl40, maintain 310 kts as long as practical".

 

[JFReservist]

along these lines...

Hold West - or anyone else
I was out your way a few days ago and coming in on the Opaca arrival. We were cleared below 10000 and there was some discussion as to the lack of speed restriction outside 12 miles from the coast line. Does anyone know offhand where can I find the rule about the no-250 speed restriction? By the way, do you ever clear military aircraft for the 'channel visual' to 8L?

Mahalo

 

[Hold West]

Hold West - or anyone else
I was out your way a few days ago and coming in on the Opaca arrival. We were cleared below 10000 and there was some discussion as to the lack of speed restriction outside 12 miles from the coast line. Does anyone know offhand where can I find the rule about the no-250 speed restriction? By the way, do you ever clear military aircraft for the 'channel visual' to 8L?

Mahalo

I'm at work now, I'll dig up the logic on >250 below 10,000 when I have a few minutes later.

I don't work HNL approach proper, but I was on a team a while back that worked on several things, amongst them was a proposed charted procedure for the channel visual. It never went anywhere for various reasons. Essentially the only ones that get cleared for the channel visual are local operators of non-heavy aircraft. Personally I think it would help everyone to chart it and let everyone that wants to play, since it's a big timesaver, and a noise saver as well. But that's just me....

 

[cheater1239]

this makes ecceding 250 below ten o.k.



Section 91.1: Applicability.

(a) Except as provided in paragraphs (b) and (c) of this section and §§91.701 and 91.703, this part prescribes rules governing the operation of aircraft (other than moored balloons, kites, unmanned rockets, and unmanned free balloons, which are governed by part 101 of this chapter, and ultralight vehicles operated in accordance with part 103 of this chapter) within the United States, including the waters within 3 nautical miles of the U.S. coast.
(b) Each person operating an aircraft in the airspace overlying the waters between 3 and 12 nautical miles from the coast of the United States must comply with §§91.1 through 91.21; §§91.101 through 91.143; §§91.151 through 91.159; §§91.167 through 91.193; §91.203; §91.205; §§91.209 through 91.217; §91.221; §§91.303 through 91.319; §§91.323 through 91.327; §91.605; §91.609; §§91.703 through 91.715; and §91.903.

 

[Hold West]

this makes ecceding 250 below ten o.k.

Thanks, Cheater!

 

[Gorilla]

Gorilla,

When I first read this I thought you were saying you liked to maintain a constant rate-of-descent as selected on the MCP as you slowed to 250KIAS between 12K and 10K. The only way I could see this happening is if you were descending with power set well above idle which would be very fuel inefficient.

If already at idle the only way to slow to 250KIAS would be to decrease the rate-of-descent below that selected on the MCP by raising the nose until the selected speed is reached. When the selected speed is attained the nose will pitch down again to attempt to regain the selected V/S. Is that your technique?

A lot of check airmen I have encountered really don't like pilots to use V/S, especially below 10K, not only because of the lack of speed protection in V/S but more importantly because you can fly away from an altitude selected on the MCP in V/S. I believe there have been some accidents where pilots inadvertently flew into the ground using V/S with a higher altitude selected on the MCP.

You are correct, the profile I describe by definition cannot be an idle descent, and is not as fuel efficient as it could be. Sometimes we're forced to start down early, sometimes we choose to do it. All I was saying is that if it's possible, I like to keep pitch changes small and slow.

At least in a 737-800, ~2600 fpm V/S, idle power, will produce a steadily increasing airspeed up to about 320 knots at 14,000'. With the speed dialed back, which brings the throttles to idle, and the V/S set, it's still pretty efficient. The pitch is relatively fixed. At 14,000, I like to slowly bring the nose up, real slowly, and at maybe 1,000 fpm the A/S will bleed off nicely to 250.

It's just a stupid way I entertain myself. Going level change at 40,000' (VNAV idle descent isn't much better) imitates a submarine pretty well, prompting "AH OOOOOH GAH!" catcalls from the other seet. I just think V/S is smoother and I feel more in control of where the aircraft is going vertically.