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crappy situation, advise needed A320

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crappy situation, advise needed A320

Old 31st Aug 2012, 19:41
  #41 (permalink)  
 
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Please take a moment to enjoy this observation flight with this Handling the Big Jets -trained Flight Crew--as this is the way to 'do it' of course exact SOP vary.... It was hard to find this video but I think it's good to see
Aviation Video: BAE Systems One Eleven - Bath Travel

'there you are" BTW does anyone else notice that they painted the Ramp Centerline wrong...

The Bible of fundemental learning wrt jets HTBJ

The Airplane's Bible is the Flight Manual

and The Word is the Training Manual...


Last edited by Pugilistic Animus; 1st Sep 2012 at 03:06.
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Old 31st Aug 2012, 21:47
  #42 (permalink)  
 
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2000' above profile(path), at FL340, is nothing.

Idle, full speedbrakes, redline, from FL370 to configured, that's high.
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Old 31st Aug 2012, 21:59
  #43 (permalink)  
 
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There's much excellent advice from plenty of experienced 'hairy asses'- yes even the lady pilots......and 'grey beards' on CRM, ATC and Energy management and such ...

But since you're on the Bus,

While I have no experience with Airbuses but as an aerodynamicist I do understand their FBW control logic pretty well...if I may refer you to this thread regarding some factors that maybe helpful for an Airbus pilot in general

http://www.pprune.org/questions/4941...ment-scan.html


Last edited by Pugilistic Animus; 31st Aug 2012 at 22:01.
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Old 1st Sep 2012, 02:38
  #44 (permalink)  
 
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Hi,

A couple of thoughts probably already expressed.

1) ATC should have probably instructed you to start descending a little earlier. They know planes' descent capability is less at flaps up, or green dot speeds, so the first one goes to them.

2) If ATC "screws up" by having you slow down while too high, at some point they´ll realize AND they´ll fix it with a 360° turn, a vector...etc..

3) You can always inform ATC that your rate of descent at low speeds will be low AND/OR use a few more kts to stay away from augmented VLS due to spdbk, and extend it.

Now all that being said, this situations happen often and if this guy yells at their right seating colleagues for being cautious like you were, then he needs to do something else besides flying. If you had increased your speed a few knots to use full spdbk he would have probably yelled at you saying "ATC said slowest speed you "%$&!"%($"#%".

As a first officer, it´s hard to guess what each captain you fly with wants you to in these situations.

I am a left seating ignorant, but what I do is I politely tell them what I want and spare them the guessing, when these things happen and I realize the other guy is in doubt.

If there is more than one correct or acceptable course of action (99% of the time) you can just check with your captain which one he prefers.

Enjoy your flying and disregard this .

Last edited by sudden Winds; 1st Sep 2012 at 16:57.
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Old 1st Sep 2012, 06:36
  #45 (permalink)  
 
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But i never really studied what happens if you wack it full with VLS shooting up. Anyway, VLS shot up and speed kept increasing to remain above it. At this point i was blur as hell, i wasnt too sure what was happening. Is it ok to do that? what the captain asked me to? and can someone explain to me...what was happening please? thank you in advance
To answer your original question:

You had GD bugged, in Open Des. When the speed brakes deployed, Vls increased above GD. The autoflight system now considers Vls the target airspeed since it is above the bugged speed. To maintain that higher speed with the thrust fixed at idle (THR IDLE in the autothrust column of the FMA), the system pitched down. Had you been in SPEED mode (say, SPEED, V/S) the system would have increased thrust to maintain Vls.

Is it OK to do that? Well, the system kept you safe, but it is piss poor airmanship.

With several thousand hours in both the left and right seat of the A320, I am still learning. This forum is an excellent source of info. Good luck in your career.
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Old 1st Sep 2012, 08:29
  #46 (permalink)  
 
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......if you are 2000' high on normal profile at FL340.... is really not a problem......hmm i'm really surprised to hear the other guy on your left is worried.....
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Old 1st Sep 2012, 08:58
  #47 (permalink)  
 
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1) ATC should have probably instructed you to start descending a little earlier. They know planes' descent capability is less at flaps up, or green dot speeds, so the first one goes to them.

2) If ATC "screws up" by having you slow down while too high, at some point they´ll realize AND they´ll fix it with a 360° turn, a vector...etc..
Sudden winds, although ATC may be that proactive in some parts of the world, in many parts they are not. In fact, in some parts they are not even proficient in the basics of controlling let alone what you describe. A few weeks back I was inbound to a SE Asain country and the airport closed due to the movement of a VIP aircraft. It was NOTAM´d and expected, however, ATC struggled to organise the five or six inbound aircraft into holding patterns and after a few minutes simply stopped talking and we pilots broadcast our intentions to each other in order to remain separated. Fifteen minutes later when the VIP movement had finished ATC came back on air and started controlling like nothing had happened.
Personally I find it best to assume that ATC will drop the ball and that way I am caught out less often. There is no point (in my opinion) of thinking about how ATC dropped the ball because the final responsibility lies with the crew. That responsibility cannot be transferred to a controller.
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Old 1st Sep 2012, 16:48
  #48 (permalink)  
 
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Framer,

I knew this "crew responsibility" thing would come eventually.

In the situation described, ATC seemed to be knowing what they were doing. I am not suggesting letting them flying you into a volcano, what I am saying is that you cannot always discredit their instructions and think that they are a bunch of clueless public employees sitting behind a video game. If they want you to slow down, there is a reason for that, that is their first priority, now...if that leaves you a bit high you can always inform them before your excess altitude becomes a problem. Keep in mind that whatever you do to lose that altitude will need to be coordinated with them, unless you just lose it by increasing rod without increasing speed.

Trust me, it´s not always that bad an idea to let them do their job, while monitoring what they are doing for safety and logic.

Hope I made myself clear(er).

A few months ago someone posted a comment asking who determined runway in use and approach to be flown. I said that ATC will normally inform of a rwy and app in use, based on winds, wx conditions, NOTAMS, etc and it was up to PIC to make sure rwy and app were ok for the airplane. Well, my english must be terrible because I received a pvt message saying that I was wrong, that it was my responsibility bla bla blah. Well, offreakingcourse it´s my responsibility!!! the minute I step inside the airplane I am responsible, I simply can´t just tell everyone else how to do their job. Oh well...never mind.

Last edited by sudden Winds; 1st Sep 2012 at 16:56.
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Old 1st Sep 2012, 19:59
  #49 (permalink)  
 
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just request atc for more track miles simple or to hold to lose height. like many of the great captains here have mentioned. don't put yourself in a worse situation. as for now keep it simple : ). peace.
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Old 1st Sep 2012, 22:36
  #50 (permalink)  
 
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I´d really like to fly with this captain. A true team.

IBERIA A340-300 - YouTube

Wish you the best Airmen25
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Old 2nd Sep 2012, 01:12
  #51 (permalink)  
 
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2000' 'high' at FL340 is nothing. Today, descending through about FL230-240, we were 2400'+ above path with a 250/12000 restriction ahead of us.

FLCH(Airbus open descent??), idle, increased IAS from 280 to 320-325, and the increased drag from 320-325 vs. 280 KIAS used up the 2400'+ of vertical track error(above VNAV PATH).

If you were 2000' high at FL340 and the Captain demanded full speedbrakes he's pretty insecure about his ability to manage the airplane's energy.
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Old 2nd Sep 2012, 09:52
  #52 (permalink)  
 
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Airmen25,

Welcome to the forum, and indeed the industry. As has been pointed out, if you can cut through the BS on here, there are some really great guys contributing on here, and it's always a good place to come for constructive conversation and letting off steam.

Myself, I am currently operating the DH8, but I have spent 2 years on Embraer RJ's.

One great piece of advice I was given has stood me well. As a cadet of a major European charter company, I was told in the early days that they wanted more confident, assertive First Officers on the line. They were finding new FO's being too docile, and not standing up to Captains even when they themselves were blatantly wrong.

So how does this translate to the real world? I guess, for you right now; hit the FCOM and your Operations Manuals. Absorb all that you can and leverage your other company crews for advice, "what would you do if..." etc. Armed with job knowledge and a little experience, your confidence will grow naturally.

Share your mental model. Possibly (my opinion, possibly wrong) your hesitation meant the Captain felt he had to do something. When he suggested using Speedbrake too close to VLS, that was the opportunity to explain you were not comfortable doing that. Always let the other guy know what your thinking, or planning.

Don't over complicate matters either. Energy management, especially in a slippery jet is an art form. Getting high and fast is an issue and will happen to you again. You can recover slight deviation by either killing the speed, or the height, and some line experience will tell you how much is possible.

In your example, would an extra 5 miles have solved the problem? 5 miles is what, 2 mins airborne? Surely the better outcome than forcing the matter and having to go around because your above the profile. There is no shame in this!

Lastly, debrief! A quick chat with the other guys, even Capt. Frontbottom, with a "what would you have done in that situation" could result in some interesting answers. In the early days, take notes of these Golden Nuggets, or keep a training diary and you'll find yourself up to speed in no time.

The early days can go past in a blur, don't get hung up on one guy being unfairly harsh, and try and enjoy it!
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Old 3rd Sep 2012, 01:54
  #53 (permalink)  
 
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We can certainly all learn a thing or two from Charlie Culp...make no mistake...please don't let me distract you gentlemen...Yes it's absulte true...Speed Breaks Airplanes...
nice Airbus Flight...

Saw him live at Calabro field Twice Quite a Show in real life...
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Old 4th Sep 2012, 04:11
  #54 (permalink)  
 
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I fly the B737 but I imagine the speedbrakes on the A320 have approximately the same performance. i.e. they reduce the lift/drag ratio by about 30% when fully extended.

Some observations that I have made over the years that have served me well...

Whatever your descent speed is whether it be 210 kt, 250 kt, 280 kt, 300 kt, or 320 kt, when you extend the speed brakes, the descent angle will increase by 1 degree.

e.g. At 210 kt IAS your descent gradient will increase from say 2.8 degrees to 3.8 degrees.

At 250 kt IAS your descent gradient will increase from 2.9 deg to 3.9 deg.

At 280 kt IAS your descent gradient will increase from 3.0 deg to 4.0 deg.

At 300 kt IAS your descent gradient will increase from 3.2 deg to 4.2 deg.

At 320 kt IAS your descent gradient will increase from 3.6 deg to 4.6 deg.

If you use the 1 in 60 rule, 1 degree = 1 nm per 60 nm
1 nm = 6000 ft (actually it's 6080 ft)
therefore = 6000 ft per 60 nm = 1000 ft per 10 nm.

In other words, at virtually all speeds, full speed brakes will increase your descent profile by 1000 ft for every 10 nm.

So if you are 2500 ft high on profile, if you remain at the speed programmed in the FMC, it will take you 25 nm to get back on profile. (Give or take for the effects of wind. More distance with tailwind, less distance with a headwind).

Now you could keep thrust at idle, increase airspeed, and the aircraft will zoom down to a lower profile, but the total energy will remain the same. You will simply be converting potential energy into kinetic energy. Your descent angle will increase a little once the airspeed has stabilised at the higher value, from say 3.0 deg to 3.6 deg but you will have to slow down again at some stage and this will convert your increased kinetic energy back into potential energy.

You will hear people say that speedbrakes are not effective at 210 kt but this is not true. It's just that because you are flying at such a relatively slow speed, the effects seem slow too. But I bet you if you were on final approach at 20 nm and you were 1000 feet high, speed brakes alone would have you back on glide slope at 10 nm to touchdown. (i.e. 1000 ft per 10 nm) It's just that it would take around 3 minutes to do so which would seem to take for ever! But don't forget you're only travelling at around 3.5 - 4 nm per minute!



P.S. The descent gradients given above are not absolutely correct in that they depend on the actual gross weight at the time. As weight increases, the best L/D airspeed increases, therefore those gradients for a given airspeed would vary a little from flight to flight as the gross weight varies from flight to flight. But the extra 1 degree descent gradient is pretty consistent give or take 0.1 degree.

Last edited by Blip; 4th Sep 2012 at 05:49.
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Old 4th Sep 2012, 07:55
  #55 (permalink)  
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The back of the Jepp CR2 computer gives rough descent rates from groundspeed...set the TAS index at the groundspeed, find the 3deg mark (for a nominal 3deg descent path), on the inner scale and read the rate of descent on the outer. 250kts GS = 1300fpm. If you don't have a Jepp CR2 computer, you should.

Quick method...GS/2 x 10 = descent rate for a 3deg path.

PJ2
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Old 4th Sep 2012, 12:31
  #56 (permalink)  
 
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Did anyone consider the fact that ATC may already had planned more track miles, then what the "magenta" displayed?

Don't be so reliant on a computer. Just go with the traffic flow. 2000' high is nothing above FL200. Just descend normally and watch the trend, both in terms of further deviation from planned profile, but not least what ATC is doing with the other traffic. Situational awareness is the key, stay calm, wait, assess and you may end up realizing that you are not 2000' high, rather 2000' low according to what ATC has planned out.

Some said don't let ATC fly the aircraft, I'd rather say: don't let the computer fly the aircraft!
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Old 5th Sep 2012, 00:29
  #57 (permalink)  
 
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hey gents !

maybe some of you noticed that the thread opener requested several days ago this :

and if possible i would like to put a full stop to this thread.
cheers
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Old 5th Sep 2012, 02:56
  #58 (permalink)  
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maybe some of you noticed that the thread opener requested several days ago this :

: and if possible i would like to put a full stop to this thread.
cheers
You're trying to herd cats... ;-)

Last edited by PJ2; 5th Sep 2012 at 02:57.
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Old 5th Sep 2012, 03:42
  #59 (permalink)  
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True.

Generally, except for the AF thread series (which looks like going on forever), threads tend to be self-limiting when everyone loses interest in the particular topic.
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