Auto Throttles.
 

Auto Throttles.

In the thread on the Turkish Airlines accident, there is a lot of discussion on auto throttles during the approach phase. I've never flown an aircraft with auto throttles, but have ridden in the back when they've been used. How do I know? The engines were forever 'hunting' to maintain speed. Most annoying. I could tell it made many passengers nervous.

When you guys/gals have the auto throttles engaged, what do you do with your right/left hand? Seems to me, without having your hand on the throttles, attention could be drawn away from your airspeed and just what the engines are doing. Seems like there's just too much reliance on auto throttles to perform the task that pilots have done themselves since the Wright Brothers.

But, I imagine all aircraft produced now-a-days come 'standard' with auto throttles. Is that right? I just think it's sad that more and more tasks are being taken away from the pilot leading to more and more problems. Next step is the drone for passenger carrying aircraft. Don't laugh.

OK.....let's hear how "ancient" my thoughts on this are.

hold on to the auto throttle, while wondering what it's going to do next....

And no there's nothing subtle about it.

GC

edit: yes they move (luckily)

On the last approach of a 4 sector day in gusty conditions, when you are told to "turn right heading 110degrees to establish on the localiser and intercept glideslope from above maintain 170kts to 5DME contact tower on 118.425 expect late landing clearence due to departing aircraft." You will be thankful for Auto Thrust, especially if you are a relatively inexperienced pilot like me.

On the note of system competence. I've only flown the A320 series, and unless its seriously gusty, it performs the job well. I don't think you can really judge how well the A/T is working by "sitting in the back". On approach, with A/T is engaged, it's SOP to keep your hand (left hand for me) on the Levers.

Unlike the Boeing, when the A320 is in A/T, the levers don't actually move, I found this quite strange at first, but quicky adapted. N1 is displayed on the upper ECAM, and airspeed on the PFD. The levers don't directly control the airpeed, so I'm not quite sure of the benifit of having your hands on moving levers and that being related to knowing your airspeed. You can "feel" and "hear" the aircraft engine power, which is an added bonus, but really, all of the information you need is provided to you in an efficient scan.

I don't think it's being "taken away", as on many days I enjoy a manual thrust approach, it's my choice. At the end of the day I must judge how much mental capacity I have, and if it is safe to take a particular course of action.

EpsilonVaz

When the A/T is engaged, never touch them! It is only when you fly with u/s A/T you realise what a boon it is. Always setting correct climb power for you, backing off power when you level, setting cruise power and maintaining it. When they are u/s, it actually becomes hazardous because you are varying between near clacker and near min buffet! You do lose continual situational awareness as you rely on it so much. Flying such a 747 back from BKK to LHR was very hard work! Are they worth it? Yes, a million times over! Takes away a very tedious task.

On approach, you can get hands on thrust levers, disconnect A/P and then do whatever your company does to the A/T. Safe, better monitoring and control of speed by the automatics, with warnings of speed discrepancy- what can be wrong with them? While they work!

EpsilonVaz -
I don't much like THAT idea at all; engines changing power and the throttles NOT moving. Guess I'm just too old fashined.

On the airbus it's easiest to just think of the thrust levers as thrust limiters (with A/T engaged of course). Typically the thrust levers will be in the CLB detent from thrust reduction altitude until the flare. Obviously the thrust will vary throughout the flight but the levers will be stationary.
In manual thrust they work the same as any other aircraft.

I think some of the smaller Embraer aircraft do not have auto thrust installed but don't take that as gospel!

Why, out of interest? The gauges tell you what the engines are doing... you don't need a great big lever constantly moving backwards and forwards to confirm that.

I personally find it to be a great system.

Quite.

:ugh:

I fly the B717, my first type with auto throttle.

For approach, say from 1500' AAL or thereabouts, when configuring for landing is usually complete, my hand is on the throttles moving with it, and if it wants to reduce power due to low level wind effects and I don't want it to, I resist the movement.

On take off, once the auto pilot is engaged my hand comes off the throttle, and sits on my knee, ready to intervene if necessary.

In my observation the hunting is caused more by technique than "it's got auto throttle".

I believe that if the pilot was not flying with auto throttle, they would manage the approach so that as constant a power as possible was held whilst progressively configuring for landing, to minimise power/pitch couple changes. However, with auto throttle and auto pilot engaged, Bloggs doesn't have to worry about it, and some let the automatics take care of it.

I find that on the 717, reducing from 250 kias (with some descent power on) to 210 kias (Co. min clean), and then configuring as the desired speed is progressively reduced, keeps the power at idle until configured, and then there is one increase to maintain Vapp, not an increase as the machine captures the 4 speed targets with configuring.

Well at least on your 717, it sounds like the throttles MOVE with power changes. Apparently, on the Airbus they don't.

And, yes..."Quite"...I am old fashioned. Piston-powered aircraft, and 'steam-powered' jet aircraft served me well for thirty years. I only hope all this new stuff gives you all the same results.

Thanks for the input.

Fair enough, DC-ATE...

...but you still haven't answered my question. What is it exactly about the non-moving thrust lever autothrust systems you don't like? Why is it? And what are these "more and more problems" to which you allude in your initial post? You haven't actually specified any, and there's no evidence yet that the 737 A/T system had anything to do with the Turkish crash.

I'm not having a go - just curious.

DC-ATE,
As you can see, most of us like our auto throttles. I agree with what you say about more automation reducing handling skills but it also frees up a few neurons for other tasks. You were probably a better handling pilot than many of us these days but we probably have more traffic to dodge than you had so need to keep an eye on the TCAS. The A/T on th 733 is prety good and is said to be able to recognise wind shear earlier than a human but it doesn't always look that way. Getting back to the left/right hand, most pilots in my company guard the thrust levers at level off as sometimes one side can malfunction and cause a large split. The 73 will roll abruptly if this is not corrected as you will remember.

bjkeates -
I just don't like the idea of engines changing settings without the throttles moving. Doesn't make sense...seems a little sppoky if you will. As someone has said the B-717 A/Ts move while engaged. I MIGHT be able to live with that.

And, I guess to say I don't like the idea isn't totally fair being as how I've never used them. All I can say is the idea does not appeal to me.

I guess I'm just one of those that wants to "be in control" all the time.:8

You're right, we don't know.....yet.....if auto throttles have played a part in recent accidents or not.
-------------------------
CHfour -
I can see by the replies that "most" of you like your auto throttles. But, I'm affraid that you could put any airplane equipped in any manner in front of many pilots and they'd fly it anyway. That's another reason why pay scales keep going down, but that's another topic!

As to your....."sometimes one side can malfunction and cause a large split."

Ah ha.....you admit something can and does go wrong with them. See, I told ya so!:}


OK.....again folks, thanks for the feed back. You all be careful out there.

The moving throttles give you a sensory input through your hand on what is happening with the power setting and keeps you more in the loop.

Let me add one more thing if I may.

The following link applies to automation in general (not just auto throttles) in today's cockpits.

While I realize automation is here to stay, it doesn't necessarily mean it is safer than what we had before.

Phase 1 Report - Flight Deck Automation Issues

Quite...and well worthwhile, IMO.
The autothrust on the 'ole L1011 is the same, and very accurate, without excessive throttle 'hunting'.
A superb arrangement...and oddly enough, I have never had it fail to function as advertised.
Combined with DLC, an unbeatable combination.

DC-ATE,

If 411A is saying something "modern" in terms of an Autothrottle is good, it must be pretty damn good!

I find Airbus' decision to not have the thrust levers move an odd one, but plenty of people around the world fly them and have no issues.

The 767 has moving thrust levers and does a pretty good job, esp as a speed protection function. Its a little more agracultural than some would like, but when all said and done it does a pretty good job!

DC-ATE

Well I beg to differ on that, if you compare the accident rate 20 to 30 years ago verse the last 10 years. Also remeber the number of jet transport aircraft has almost doubled since 1990 yet the accident rate has still dropped.

I cut my first 15 years flying out on very basic B732 (no auto thrust, no FMC, no Alt Cap on the A/P, no thrust computer) and F27 aircraft. The last 10 on a B733 with everything and I feel my management of flight is far superior than the good old days of "stick and rudder". I make better decisions and use less fuel with help from the automatics. Understanding what the aircraft is capable of and how to best manage the autoflight to achieve that is the key.

Yup, would agree.
When the FMS made its appearance on the TriStar, it was a huge improvement in flight management.
Full LNAV/VNAV and full time engine thrust management in a neat package.
Even today, it still works as advertised.

"Without belaboring a point, which is probably obvious to the reader, there are two features of the B-757/767 aircraft (and shared, of course, the B-747 and the B-777) which enable these airplanes to achieve the greatest benefit from the fuel-efficient engines and aerodynamic efficiencies These are (1) a computer which is able to perform complex cruise calculations and (2) an autoflight system, including autothrottle, which is able to translate the cruise calculations precisely.
The first-generation of turbojet transports such as the DC-8 and B-707 did not have autothrottles. If a pilot attempted to operate at maximum range cruise, it would be counter-productive due to the inherent instability at these speeds and the constant attention demanded of the pilot to thrust manage- ment. As a result, the "practical" minimum speed for these airplanes was Long Range Cruise (defined as 99% best economy). The fact is that flight manuals didn't even publish data for speeds less than LRC.

Second generation airplanes, such as the B-747, while incorporating an autothrottle system, were still unable to operate at maximum range cruise due to inherent inefficiencies of the autothrottle system. The automatic system operated the fuel controller though the same linkage used by the throttle levers in the cockpit. The system was difficult to maintain and thrust overshoots and undershoots were common. Much of the time at cruise was spent manually aligning the throttles. The practical minimum speed remained LRC.
The767-200 and the RB211 version of the 757 permit the fuel controller to change engine thrust through a pre-determined range without back driving the throttles. Although the system is still hydro-mechanical, more precise control of cruise is possible. Finally, with the advent of the true fly-by-wire system found on the B-747-400, 777, 767-300 and the Pratt & Whitney version of the 757, almost flawless control of the engines is possible. Speeds from Max Lift/Drag to the Vmo are fully usable."

Not on our E145s, though it is an option I understand

fc101
E145

OK.....again, thank you for your replies.

As I said in a post somewhere....."You boys stick with your new fangled toys and I'll stick with my needle/ball and airspeed and hopefully, we'll all get to wherever it is we're going!"

I'll add to that: My manual throttles and 'steam-powered' gauges too!

Gee...you don't think I'm a little stubborn and close-minded, do you?!:}

DC-ATE,
Not sure I follow the bit about pay. More automation lessens piloting skills which surely lessens the appeal of the job. The less interesting the job becomes, the less people will offer to do it for next to nothing (or even pay for the RH seat). Add to that the fact that passengers want to fly for nothing these days..........................

CHfour -

Well, you know as well as I do that there are thousands of "pilots" out there who would almost fly for nothing just to fly. And to get with an airline, they'll even PAY to do it. "Kids" coming along now days probably DO find it interesting and appealing mainly because all it is now is a computer game. They really don't have to know much about anything except how to program the computer to get them from point A to point B. Sad.....

I Blame GPS
 

I was too old to fly the line when I sorted out my career love. I'm one of those who would fly for free, just to fly. I draw the line at paying to fly, that's too needy. I stay away from the B vs. AB threads, way too ignorant other than my prehistoric skills and prejudices. I admit to being partisan, though, and DC-ATE has my vote. Training to fly a digital Beast neglects Some of Wolfgang's dogma?, a loss, in my opinion. I like DME with its built in altitude gotcha, because it makes one think and reason. Not to say that the little stick isn't a valid alternative, just a different, and very sophisticated platform. The Trend is toward complete machine dependence, the Drone is approaching. Along the way is a forever lost Spatial awareness/dependence; I listen to my Butt cheeks in a turn; rather than read digits. Just sayin'.

AF

airfoilmod

Thank you for your support!

Speaking of B vs AB:

You know...it's funny: I "flew by cable" for thirty years. I've been retired for almost twenty years. In that time, I've "flown by wire" only. That is to say, on a Flight Sim with joystick and keyboard. So, while I don't have as many hours on the sim as in real aircraft, I do have a little "feel" for FBW. Fortunately though, if there's a power outage or computer problem, myself and my "passengers" are not in jeopardy!

I'm 24 and fly the Airbus for a living - does that make me one of the 'kids' to whom you refer? I find that post a little condescending to be honest. Why did I bother spending 2 1/2 years training - and still learning from my experiences all the time - when I could have just used Flight Sim to teach me to programme a box? Wish I'd thought of that...

Are you seriously suggesting that spending a few hours on FS gives you the feel for FBW, or even comes close to replicating the handling characteristics of the real aeroplane?!

bjkeates -

I'm sorry if I seemed a little harsh. It was not directed at any one person. It was a generalization from what I've seen, heard, and read. Obviously, it can't and doesn't apply to everyone. The same as "my generation" was not always infallible either. As I have often said, sadly, probably well over 80% of all aircraft accidents can be traced to "pilot error" in one way or another.

If you will note...I put the word "feel" in quotes talking about the Flight Sim. There has to be a little similarity there however.

I do wish you well in your career. Just don't let that computer always tell you what to do. Stay in the loop. I flew the 737-300 briefly with its 'glass cockpit' and have seen what it does to some. They become too dependent on the computer to solve their problems.

Carry lots of fuel, avoid TRWs at all costs, and add a minimum of ten knots to everything and you'll do just fine!

Not necessarily, DC. Extra fuel isn't tolerated these days without a good reason and the extra 10 kts minimum might attract a call from your company OPTIC man (or woman).
BTW what are TRWs?

CHfour

With all due respect, Sir, if you don't know what TRWs are, then perhaps you shouldn't be flying airplanes, if you do.

As to the extra fuel, there are countless reasons and if you're a pilot then you know what they are. I have never worried about being called into the office on my 'conservative' approach to flying airplanes. I think I know what I'm talking about.....do you?

Thanks for your good wishes. I don't think, however, that my company's FDM team will take "some bloke on PPrune told me to do it" as an excuse for repeatedly busting stable approach parameters, nor do I like to modify the target speeds just for the hell of it! Those millions of pounds worth of computers have done their job just fine so far!

bjkeates

You're welcome.....and, I meant it!

Like everything else related to flying, you must have a reason for doing what you do. I always had a reason for my extra fuel and knots. It wasn't arbitrary. As you gain experience, you'll find out. I only hope it isn't too late. And, you can't worry about what someone else might say.....IF you think you're doing the right thing.

A good example of an extra ten knots would be the AA 191 accident in O'Hare. Had the Captain not REDUCED to V2+10 (or whatever their engine-out speed was supposed to be) they most likely would have been able to return and land. That wasn't the only thing that went wrong though.

Anyway, we digress.

Enjoy!

Just adding 10 knots to everything will not only get the companies safety department on your behind very fast indeed (in fact, you will bust your line release check), but the authority as well as it can and will breach the certified performance for a plane.

And quite a lot of extra every single flight will in some companies get you fired very soon and in others get you into another week of fuel saving training nowadays. Remember, FOQA catches everything you do on board and all the rest is put into computers as well and will be noticed.

And by the way, what is TRW?

DC-ATE,
Dont bother trying to explain.These new guys are a totally different breed.Computer junkies who would ground the aircraft without an FMC or AT.Not only can they not fly a damn without the AFDS,they're pretty cocky too(this pseudo-CRM bs)...2 1/2 years on the scarebus and think they know it all.TRW?Look it up sonny..you never know you may learn something.

I can imagine myself getting grounded very quickly if I just decide to add 10kts on to everything the computer has quite competently calculated. Also, as mentioned before, company flightplans generally add alot of extra, if you have a reason to take extra fuel, no problem, but you can't just add more for the hell of it.

By the way, what's a TRW?

I have over 20000 hrs , FBC and FBW, and I dont know what TWRs are?

Been flying a commercial jet before i could legally buy a beer.And about the same time as I could drive a car!
A decent ILS or CANPA approach flown 'manually' ie without an A/P or A/T is probably the most economical approach,besides being a very comfortable one( both for the PM and the invaluable passenger,who pays for the bread on out tables ).When i say 'flown manually',I of course mean flown manually by a competent pilot with average flying skills.My first airplane as PIC was the 732.And I think I have still to experience a similar joy of flying.Never spilt a drop off of the full coffee mug we sipped during our landings.And then,ever since its been the 733,734,735,320,321,738,739,739ER,300-600R,744 and now the 777(all versions).All as PIC.And most as a trainer.DC-ATE said he felt uncomfortable due to the constant hunting of the engines.SURE,he's damn right.I FOR ONE feel the same...!! He must be sitting in a 777! Whilst I can confidently say that the 777 IS god's gift to the pilot,it does have its quirks.The 734 had 22k engines,320-24k,738-26k,744-53k.But the 777 has 115K GIANTS for engines my friend! Imagine a less than perfect pilot flying a manual(no A/P but WITH A/T) ILS in less than perfect conditions in a 733/4.And then imagine the same in a 777.Engine respone to his imperfections in terms of pitch adjustments and/or speed loss and gain would be far far quicker in the 733 than in the 777.Mass of airplane AND engine bypass ratio and therby engine response/spool up time alone will dictate that agility of the A/T system in correcting the anomaly,therby minimising the need to constantly 'hunt' for the desired speed/pitch.
Now,couple the same A/T with the A/P on both airplanes.You will notice a WORLD of a difference.No hunting,no lagging.Cause the same computers that give the input to the A/P to follow an ILS for example,give the same input to both the A/T's via the EEC's within the same nano second!No discrepancy,no lag,and no hunt.....!! Net result pax comfort and a PM with lower BP after touchdown.
Wanna do a great job of smoothening out your slight imperfections on the ILS?? Fly the manual approach WITHOUT the A/T.Use manual thrust instead.You'll notice a marked improvement.But as soon as you go automatic,use FULL automatics and revert to your role as 'Manager'. Leave the 'Pilot' at home.
That's the trick I try and use as often as I can.Unfortunately my company SOP's dictate the use of the 777 A/T system.And I shan't argue with that ever! Follow the SOP's to the T and you shall live to be the cliched 'Old,bold pilot'.....Now THAT'S my mantra for you guys out there.
And watch those BRT's for bird ingestion(s)......!! ;) ...

Attitude, Human
 

Nothing personal, but the a/c in question possesses many of the Traits disdained by the twenty-somethings "flying it". Arrogant, Proven, Brook no deviations, No questions (My computers are quite competent, thank you.)
"I have three ways to fly, get right with that, etc." It is that regimen that irks those who flew before the digital age. Not having experienced that, youngsters compare seasoned flyers with their a/c, one approvingly, one disdainfully? If I were to fly with a Captain possessed of the (human) traits the Bus displays, I would not be comfortable, see?

AF

I am utterly amazed that we have several pilots (supposedly) that do not know what a TRW is. Apperently they never check the weather before they take off into the unknown.

Denti

re. the +10: read what I wrote.

If you don't know what a TRW is, then I suspect you don't fly airplanes, or if you do, you don't check the weather.