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-   -   If you have a choice at your airline - Airbus or Boeing? (https://www.pprune.org/tech-log/450776-if-you-have-choice-your-airline-airbus-boeing.html)

nitpicker330 17th May 2011 01:53

Sorry bud there have been incidents caused by "dual input" errors and other events such as heavy landings ( requiring main gear changes ) that occurred on the AB that probably would not have on a conventional aircraft where the Captain could have simply assisted on the yoke as required.
Sure I accept that on a conventional Aircraft the two Pilots can mistakenly work against each other effecting a safe outcome.
Nothing is perfect but I sure know which system I prefer.

DozyWannabe 17th May 2011 11:19

I'm talking about the B777 though, which is not a "conventional aircraft" as much as it is a computer simulation of one that happens to be built into an airframe.

Anyway - you don't *need* to "feel" what the other pilot is doing outside of a light trainer (though it's a nice to have for some).

There's no doubt that the envelope protections in the newer FBW aircraft have saved both airframes and lives over the years, and IMO that's far more important than appeasing the dinosaurs...

Tankengine 17th May 2011 13:42

At my airline Airbus pilots get paid more than Boeing.:hmm:
Not my decision, just the way our contract works.
Good enough reason for me! :ok:

Graybeard 17th May 2011 13:46

Visual Cues
 
A yoke moving in response to the other pilot's action, or autopilot action, is detected in peripheral vision, unlike a display screen that must be focused on. Same goes for throttle arm movements not initiated by your own hand.

GB

DozyWannabe 17th May 2011 20:01

Graybeard - true, but there's nothing stopping a pilot simply adding the sidestick/throttle position indicator to the scan - in fact the positioning of those gauges is designed to make it easy.

Let me make it clear again if I haven't already - I'm cool with the idea of some preferring one way over the other. It's when the old-fashioned way is put forward as superior and sacrosanct that I get a bee in my bonnet.

nitpicker330 18th May 2011 02:43

Mate the Sidestick indicator disappears during rotation, not only that it's a little display on the PFD, hardly big enough to "put into your normal scan" during the most important phases of flight ( Vr and the last 200 feet down to touchdown, where you should be eyes up as much as possible, not heads down trying to see where your mate has moved his stick to !! )

I recall a certain A340 incident in JNB where at Vr the PF simply placed the indicator where he thought the Elevator should be!! That little error nearly led to disaster but for the grace of.......
I can categorically state that this has never happened on a conventional Aircraft.

The Airbus is probably ok for those that have very little "flying" experience" but anyone who's ever flown a normal Aircraft will miss this subtle but none the less very important feedback loop.

AB were trying to make a safer Aircraft using these Sidesticks and non moving Throttles but, in my opinion, unfortunately they have in some situations done just the opposite. You need to keep the Pilot in the loop at all times using what he's used to seeing and FEELING as a Pilot.

Now don't get me wrong here, I still enjoy flying the Bus. I actually like the concept of the SS and the Table etc. I just think that they could have easily made it more "natural"

stilton 18th May 2011 03:22

Sorry but Airbus is simply out of touch here, their Aircraft were not designed with pilots in mind.


If it's 'old fashioned' to know what your Aircraft is doing through through every possible cue then I guess Boeing is guilty, I also think it should be mandatory.


Ab is not 'more clever' they just wanted to be different, such a shame they co**ed it up.

Sciolistes 18th May 2011 05:31

As far as the thrusties are concerned, this "backdrive" thing is a bit irrelevant. I'm talking 737 Classic, the A/T is often a nuisance and manual thrust usually results in much less fuss.

Also, I can't tell just by feel if the throttles are in 45% position or 65% position on final, I have to look at the N1s. One usually needs to keep N1 in the scan because of asymmetry, nearly always one lever needs an extra tug or nudge to get it within 10% of the other one. One should keep the N1s in the scan anyway, they pretty much validate the wind arrow and warn you of any likely required thrust changes further down the slope.

Therefore, non-moving thrusties on an Airbus are probably less hassle providing the flying Citroen has a competent A/T system

However, the control wheel backdrive can be a boon. Having experienced large thrust lever splits with A/T in the past, the most visible can be the control wheel, it lends itself to an apriori recognition of the situation in the way that data scans generally don't.

However, if you have an FBW system that limits yaw, then I guess that argument is potentially null and void.

nitpicker330 18th May 2011 06:03

Sorry mate but I respectfully suggest you're wrong.

I can easily see in my peripheral vision the location of the Thrust Levers on a Boeing to know what gives. Also i can ( and have ) easily push them up a bit or pull them back a bit whilst the A/T remains active and achieve a very smooth safe result where needed.

On the Bus it's a bit more complicated unfortunately, you cannot always just take em out of the detent to fix a slow system response. In fact if you push it forward out of the CLB detent below 100' to fix a sudden speed decay and then mistakenly put it back you keep TOGA.!! And around you go....

On a Boeing you simply push the TOGA buttons on T/O and hey presto it sets the desired thrust, on the Bus you must remember to put it in either Flex or Toga, get it wrong with a brain fart and "TO Thrust not set" pops up at 30 odd knots and maybe an embarrassing RTO!!! I know, you should always know what you are doing and where to put the levers but it's just one more thing this AB can lead you up the garden path!!


These things are known to all AB Pilots and we work around the issues but the point is that these issues shouldn't be there in the first place.

Denti 18th May 2011 07:57

On the classic you are right, there is sometimes a thrust lever split. However there shouldn't be with competent maintenance, so if you observe itwrite it up and let them correct it. Once you switch to the NG, thrust lever split is a thing of the past during normal flying.

Of course you can fly without a moving thrust levers, many airbus pilots do that every day. It just is bad design as we only have so many input channels and the visual tends to close down pretty rapidly during non normal situations (tunnel vision) where the tactile channel might still have capacity. Airbus took that one needlessly out of the equation putting even more stress on the already overstressed visual input channel. However that is only one part of a pretty big puzzle.

Sciolistes 18th May 2011 09:15

Denti,

so if you observe itwrite it up and let them correct it
Agreed, but if you would like to take my place and enter this particular infinite loop be my guest :ugh:


we only have so many input channels and the visual tends to close down pretty rapidly during non normal situations (tunnel vision) where the tactile channel might still have capacity.
An excellent point that I had not really considered fully. Is there a study available for perusal? I understand that already the eyes along provide more data than the brain can process, with a similar imbalance for the other senses too. Could the additional channels lead to overload and fixation or do they encourage maintaining a bigger picture?

Young Paul 18th May 2011 11:25

There are 4600 A320 series aircraft that have been built since they were introduced in the late 80s. There are 6600 B737s that have been built, in around 20 years longer.

To be honest, for all the opinions that have been voiced, if either had major character flaws, they wouldn't have been so successful. The early hull losses on the A320 were due to "pilots" who had ceased to be a part of the flying of the aircraft, and were forgetting things like ... you shouldn't be setting up vertical speeds of over 2000 fpm near the ground ... high bypass engines take time to spool up. And in these cases, Airbus have systems available that could have protected the pilots, which were either not installed or had been disabled (by the pilots, who perhaps didn't like being told how to fly their aircraft by the manufacturer?). If we want to talk about aircraft oddities, did Boeing ever get to the bottom of the rudder hardover mystery which means that the manoeuvre speeds for the 737 are now 10 knots higher than they were originally designed to be? IAMFI - I note that the BA 737s still ask for 170 to 5 miles ....

Two FBW Airbuses have made deadstick landings in which everyone has survived, due to external issues (fuel leak, birds); 737s have as well (birds).

If you are going to fly an Airbus, learn to fly it like an Airbus. The information, and more, is in front of you: learn to use it. If you flew it and didn't like it, 4600 built and largely still operating says that the problem is probably yours. If you are criticising it without having flown it, the word we use for that is "prejudice".

The objective of airline operations is the safe, reliable and efficient carriage of passengers from place to place. Both do the job admirably.

Sciolistes 18th May 2011 12:11


did Boeing ever get to the bottom of the rudder hardover mystery which means that the manoeuvre speeds for the 737 are now 10 knots higher than they were originally designed to be?
Before my time, but recent changes to the manuals have removed all references to unmodified 737s, only the lower speeds published and the associated non-normal checklist has been rewritten accordingly too.


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