Use of V/S at high levels in A320
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Use of V/S at high levels in A320
Here you have my question guys:
Above FL250 use of EXP CLB mode is not recommended.
Normally, if we are very heavy is more evident, the CLB and OP CLB modes (using managed speed) have the tendency to Level off, gain some speed, and continue climbing every now and again.
That is why I was taught to use either V/S and slight increment of speed (using selected, in order to keep speed as high as possible and Thrust) or just select slower speed to increase angle of attack.
I have been in different companies and I have seen both techniques, although in the company I am now, V/S + selected speed increment is not considered.
Disregarding reasons that come from experienced guys, such as V/S is not used at high levels in climb due to incidents that happened to conventional planes where the crew selected V/S at high FL, forgetting about it later on and leading to a stall, I would like to know if it is permitted the use of this technique as we have protections, is more accurate (constant V/S) and is a tool of the aircraft.
I was kindly asked by one of the captains in the airline to show him where it says we can use this technique, and although in FCOM´s and Training Manuals use of V/S, CLB and OP CLB is defined and considered I could not find any reference of interrelation between the use of this modes and selected speed.
As I did my TR under Standard Airbus Procedures and Line Training under supervision of Airbus approved TRI´s I do not think they are wrong in the use of this technique but I would appreciate anyone who can help me to know if V/S and Selected speed (near Vmax) is a forbidden or not recommendable procedure by AIRBUS.
Thanx chaps!
Above FL250 use of EXP CLB mode is not recommended.
Normally, if we are very heavy is more evident, the CLB and OP CLB modes (using managed speed) have the tendency to Level off, gain some speed, and continue climbing every now and again.
That is why I was taught to use either V/S and slight increment of speed (using selected, in order to keep speed as high as possible and Thrust) or just select slower speed to increase angle of attack.
I have been in different companies and I have seen both techniques, although in the company I am now, V/S + selected speed increment is not considered.
Disregarding reasons that come from experienced guys, such as V/S is not used at high levels in climb due to incidents that happened to conventional planes where the crew selected V/S at high FL, forgetting about it later on and leading to a stall, I would like to know if it is permitted the use of this technique as we have protections, is more accurate (constant V/S) and is a tool of the aircraft.
I was kindly asked by one of the captains in the airline to show him where it says we can use this technique, and although in FCOM´s and Training Manuals use of V/S, CLB and OP CLB is defined and considered I could not find any reference of interrelation between the use of this modes and selected speed.
As I did my TR under Standard Airbus Procedures and Line Training under supervision of Airbus approved TRI´s I do not think they are wrong in the use of this technique but I would appreciate anyone who can help me to know if V/S and Selected speed (near Vmax) is a forbidden or not recommendable procedure by AIRBUS.
Thanx chaps!
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I was on my 6 week, wine with lunch, 320 course in Toulouse in 1993. I was taught Airbus Philosophy and one of their standard climb modes is v/s. I think it is because the 320 was designed to be economical, the designers accepted that at higher levels, the thrust would be adequate as opposed to excessive !
So, here I am in 2006, I still use v/s as a standard higher level mode, but with a sensible brief to the F/O or other Capt because the 320/321 uses it's energy far more effeciently in v/s than in managed climb or in open climb.
You have high and low speed protections, the aeroplane will not stall and it will not exceed it's vmo/mmo. Understand Airbus Philosophy and fly the aeroplane how it was designed to be flown
So, here I am in 2006, I still use v/s as a standard higher level mode, but with a sensible brief to the F/O or other Capt because the 320/321 uses it's energy far more effeciently in v/s than in managed climb or in open climb.
You have high and low speed protections, the aeroplane will not stall and it will not exceed it's vmo/mmo. Understand Airbus Philosophy and fly the aeroplane how it was designed to be flown
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Airbus V/S Issue
Gentlemen,
Please accept my humble opinion...and it is only that...my opinion.
First, your airline's SOP takes precedence....assuming your airline's SOP addresses this issue. If the SOP does not specifically, explicitly prescribe the procedure, you might consider discussing this with someone in the Flight Standards and Training Department of your carrier (or similar office). This will give you guidance with regard as to how your company wants things done. Also, you might kindly suggest that the issue be addressed in the SOP through future document revisions.
My old airline's SOP very clearly described the procedure to be used; it was 'their' way of doing things. And, this is what we followed.
My current airline mandates what the Airbus SOP and Flight Crew Training Manual prescribe.
The Airbus SOP states with respect to climb: "The normal vertical mode is CLB or OP CLB with managed speed active." (FCOM 3.03.14 P1)
The Flight Crew Training Manual describes the philosophy in great detail...too much to quote here. (FCTM 02.060 Page 1) But, having a copy of the FCTM has been very helpful to me. If you don't have a copy, try to obtain one through your airline.
I will say, however, that the problem of vertical speed rates and RVSM (TCAS RAs) are a consideration. Again, at my old airline, this procedure was specific and very explicit. With my present employer, it's left to 'technique'.
Thus, during the last 1000 feet of climb or descent, I make it a habit to limit the rate to less than 1500 FPM, but (if possible) at least 500 FPM. (If not possible to do at least 500 FPM, it would be wise to notify ATC.) Limiting your vertical speed during the last 1000 feet of climb/descent precludes the need to change underpants after encountering a high-altitude RA.
I hope what I've written provides some help and guidance for you with regard to this topic. Again, it's only my opinion.
Tom
Please accept my humble opinion...and it is only that...my opinion.
First, your airline's SOP takes precedence....assuming your airline's SOP addresses this issue. If the SOP does not specifically, explicitly prescribe the procedure, you might consider discussing this with someone in the Flight Standards and Training Department of your carrier (or similar office). This will give you guidance with regard as to how your company wants things done. Also, you might kindly suggest that the issue be addressed in the SOP through future document revisions.
My old airline's SOP very clearly described the procedure to be used; it was 'their' way of doing things. And, this is what we followed.
My current airline mandates what the Airbus SOP and Flight Crew Training Manual prescribe.
The Airbus SOP states with respect to climb: "The normal vertical mode is CLB or OP CLB with managed speed active." (FCOM 3.03.14 P1)
The Flight Crew Training Manual describes the philosophy in great detail...too much to quote here. (FCTM 02.060 Page 1) But, having a copy of the FCTM has been very helpful to me. If you don't have a copy, try to obtain one through your airline.
I will say, however, that the problem of vertical speed rates and RVSM (TCAS RAs) are a consideration. Again, at my old airline, this procedure was specific and very explicit. With my present employer, it's left to 'technique'.
Thus, during the last 1000 feet of climb or descent, I make it a habit to limit the rate to less than 1500 FPM, but (if possible) at least 500 FPM. (If not possible to do at least 500 FPM, it would be wise to notify ATC.) Limiting your vertical speed during the last 1000 feet of climb/descent precludes the need to change underpants after encountering a high-altitude RA.
I hope what I've written provides some help and guidance for you with regard to this topic. Again, it's only my opinion.
Tom
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Originally Posted by Rayoflight
I was kindly asked by one of the captains in the airline to show him where it says we can use this technique,
In my airline we use this high altitude V/S climb as well. It's not described in our SOP's, but it's a procedure being taught during linetraining by all my company's TRI's. It appears to me to be the best way to do heavy weight, high alt climbs in the bus. (Just have to keep an eye on the IAS to avoid a mode reversion, and if you don't, oh well, the "stupid" protections will keep you out of trouble)
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Thanx for the information provided.
It is quite clear to me I should apply the company SOP's. But the question is if it is specifically not recommended by Airbus.
My opinion is that V/S + selected speed is a technique available to the pilot, whitout the need to be described in an SOP's.... Shortly, we will need SOP's about how to breath in the flightdeck.
Keep it up
It is quite clear to me I should apply the company SOP's. But the question is if it is specifically not recommended by Airbus.
My opinion is that V/S + selected speed is a technique available to the pilot, whitout the need to be described in an SOP's.... Shortly, we will need SOP's about how to breath in the flightdeck.
Keep it up
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A couple of years ago a 321 crew used too high a v/s at altitude and ended up in Alpha Prot. The a/c continued to climb at avery high rate and they ended up some 2,500' above their cleared altitude. I would use v/s with some caution at altitude!
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Don't take the protections you have for granted,it may happen that right when you need them they won't work.
I know of one instance when,after remaining with an unnoticed high Vs (due to autochange during alt aquire while setting a higher altitude) ,the plane slowed to stall speed,and protection didn't work.Fortunately there was no turn on ongoing flight path,and pilots managed to realise the extremely slow speed,due to unusual quiet cockpit,and accelerated the plane.If I remember corectly the speed was around 150-160 kts at Fl 270 (but I may be wrong)
So,don't use Vs just reliyng on auto-protections,or you'll find yourself in trouble someday.
I'm using managed speed mode (VNAV on the 737) and at 1000' to LVL off,I select 1000'/min Vs,also for TCAS reasons.
I know of one instance when,after remaining with an unnoticed high Vs (due to autochange during alt aquire while setting a higher altitude) ,the plane slowed to stall speed,and protection didn't work.Fortunately there was no turn on ongoing flight path,and pilots managed to realise the extremely slow speed,due to unusual quiet cockpit,and accelerated the plane.If I remember corectly the speed was around 150-160 kts at Fl 270 (but I may be wrong)
So,don't use Vs just reliyng on auto-protections,or you'll find yourself in trouble someday.
I'm using managed speed mode (VNAV on the 737) and at 1000' to LVL off,I select 1000'/min Vs,also for TCAS reasons.
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I believe there was a 'directive' from Toulouse in the early millineun not to 'use' V/S above FL300-for the reasons mentioned-Is this still in the yellow pages??
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Originally Posted by Rayoflight
Thanx for the information provided.
It is quite clear to me I should apply the company SOP's. But the question is if it is specifically not recommended by Airbus.
My opinion is that V/S + selected speed is a technique available to the pilot, whitout the need to be described in an SOP's.... Shortly, we will need SOP's about how to breath in the flightdeck.
Keep it up
It is quite clear to me I should apply the company SOP's. But the question is if it is specifically not recommended by Airbus.
My opinion is that V/S + selected speed is a technique available to the pilot, whitout the need to be described in an SOP's.... Shortly, we will need SOP's about how to breath in the flightdeck.
Keep it up
The Airbus SOP states with respect to climb: "The normal vertical mode is CLB or OP CLB with managed speed active." (FCOM 3.03.14 P1)
High Altitude V/S climbs are not recommended, and can lead to several problems including Alpha-Prot, TOGA Lock, etc. Or worse, the protections fail, and you fly the aircraft into a high altitude stall.
Originally Posted by Rayoflight
My opinion is that V/S + selected speed is a technique available to the pilot, whitout the need to be described in an SOP's
Originally Posted by Rayoflight
Shortly, we will need SOP's about how to breath
