What's the deal with the AP "TOGA"

[gums]

I understand the aero and the various engine configurations that may or may not induce a positive pitch moment. BFD.

What I have a problem with is hitting a button, once or twice, and expecting the plane to actually "go around" without reaching absurd pitch and then rapidly bleeding off speed and increasing AoA more than a human could do by simply advancing throttle and triming forward or holding forward pressure/movement as you increase altitude until at safe altitude or published altitude for a missed approach. I am thinking about the Russian accident/prang. Also, some posts have mentioned similar pitch changes and such using the AP and the magic "TOGA" button.

I ask for opinions and such from the heavy pilots here.

[de facto]

What's the deal with the AP "TOGA"


Whats your question?

I ask for opinions and such from the heavy pilots here.

83 kgs,do i qualify?:p

[172_driver]

I am not sure what horror stories you've been told, but pressing TOGA is not really a big thing and guides you through a nice controlled go around. On the B737 TOGA it is a pitch mode, i.e. the flight directors gives you a pitch guidance through through the flap retraction. If auto throttle is armed, it will also set the appropriate go around thrust. If not, you have to set it yourself. Extending your arm fully gives sufficient thrust. Yes, you have to trim a little but nothing a competent pilot cannot do.

[greybeard]

TOGA selected with the Autopilot engaged is a thing of beauty to watch and gets the aircraft up and away from the minima to go/return for another approach.

On the A-310 if manually flying and selecting TOGA, you had to get onto the trim fast and positive, a little forward pressure to assist until all sorted.

Failure to positively trim and the pitch up was quite spectacular, I seem to recall over 45 nose up with very low if not a stall airspeed. The recovery was to FIRST close the thrust levers to assist in pitch reduction, trim, trim, trim, let the aircraft get a LONG WAY nose down, achieve some positive airspeed and recover.

Emirates?? had a real one and cycled through the event a couple of times until all was sorted. Mine were thankfully in the Simulator, looking at 20R filling the windscreen at SIN, going down, speed low and waiting for speed to build for recovery was "interesting" to say the least.

Hope that helps.
:ok:

[Denti]

What I have a problem with is hitting a button, once or twice, and expecting the plane to actually "go around" without reaching absurd pitch and then rapidly bleeding off speed and increasing AoA more than a human could do

Why? That is exactly how an automatic go around works. Click the button, watch all the parameters and see the plane going around on itself. Works like a charm. In manual flight one has to keep control oneself of course, which amounts to some (light) forward pressure and trimming. Nothing serious. Not to mention that one gets automatic FD guidance if below 2000ft RA or flaps deployed (on the 737 that is).

Personally if i see that a go around might be a likely outcome i keep the autopilots in and therefore have the automatic go around capability available if i want it. Not because i can't fly it manually, simply because i'm lazy.

[Centaurus]

Personally if i see that a go around might be a likely outcome i keep the autopilots in and therefore have the automatic go around capability available if i want it. Not because i can't fly it manually, simply because i'm lazy.

Nice to see an honest reason ie too lazy.:ok: On the other hand, there are those pilots that are quite apprehensive of conducting a manual go-around possibly because things happen fast with flap selection, thrust lever manipulation, and pitch up requiring speedy stab trimming - and we haven't even discussed basic instrument flying skills if an IMC go-around. Are you sure you are not a closet too frightened to fly manually pilot, disguising this fault as "too lazy?":=

[SOPS]

A 777 autopilot go around is lovely. What more can I say.

[latetonite]

So why is it that, in the simulator of the 737, I witness so many funny combinations of flaps, trust, gear, and flight director?

What makes pilots think TOGA means / includes 'go around thrust'?

Why do experienced pilots fly perfect healthy aircraft into the ground during a Go-around?

It does not seem to be an obvious maneuver among the industry.

[Denti]

Are you sure you are not a closet too frightened to fly manually pilot, disguising this fault as "too lazy?"

Well, if you check out my other posts you might see that i'm quite in favor of manual flight, and to the slack jawed surprise of latetonite i fly quite a few of my departures and approaches manually without FD. Of the three go arounds i did last year one wasn't expected and therefore flown manually, not an issue at all. But then, did you have anything useful to add to this thread or only personal slights?

[de facto]

So why is it that, in the simulator of the 737, I witness so many funny combinations of flaps, trust, gear, and flight director?

Reflection of general training in your airline?

What makes pilots think TOGA means / includes 'go around thrust'?

Maybe because GA is shown on the TMA after pressing TOGA?

Why do experienced pilots fly perfect healthy aircraft into the ground during a Go-around?

It does not seem to be an obvious maneuver among the industry.

Again,,training/checking issues added to complacency during one whole career?

But then, did you have anything useful to add to this thread or only personal slights?

Dont worry i have no doubt the CRM patrol (framer,kramer) will put Centaurus back in place of the manual flying PPRUNE master .At least he hasnt mentioned you to have a read at the FCOM:E,he would then be in real trouble...

[Natstrackalpha]

Quote "Are you sure you are not a closet too frightened to fly manually pilot, disguising this fault as "too lazy?":= " unquote


ARE YOU SURE YOU ARE NOT A CLOSET CONSPIRACY THEORIST JEALOUS OF A PILOT SO ADEPT AT FLYING THAT HE IS QUALIFIED TO BE LAZY WHILST, IF HE CHOSE TO DO SO COULD FLY THE MANUAL APPROACH WHILST PEELING AN ORANGE IN HIS BACK POCKET WITH BOXING GLOVES ON THE WRONG HANDS.


TOO FRIGHTENED MY **S!

[Natstrackalpha]

Excuse my confusion maybe somebody can help me see the light.


Lets just say if all the F-PLAN was plugged into the FMGC and also the Approach to runway XX at WherEver International.


Not on the APP page, but where is the Go Around Trk in Nav on the flight plan/MCDU and which page was it inserted to, or, was it (the go around) built in there by the pilot, please?


From the database, on the runway list we can select runway, after that we can select Star or No star as applicable to the flight. Where is the Go around portion of the flight derived from or, I ask again, is it created by the pilot using whatever:- PBDs, PB-PBs, whatever . . ?


Thank you for your time.

[Denti]

On my tiny 737 the missed approach is part of the instrument approach procedure and with the selection of the approach it is put into the flightplan. Pretty straight forward actually. And yes, therefore it comes from the database. The missed approach remains inactive (dashed blue line) until the RWYxxL/R/C waypoint is passed.

LNAV remains in arm (white) during the approach and will be activated automatically once above 400ft AGL (dual channel) or 50ft AGL (single channel, non precision). The only time LNAV arm will vanish is during a single engine dual channel approach as automatic switching to LNAV would also disable the rudder servo which could create massive amounts of yaw. However LNAV can of course be selected manually.

[Natstrackalpha]

Quote: "And yes, therefore it comes from the database. The missed approach remains inactive (dashed blue line) until the RWYxxL/R/C waypoint is passed" Unquote.

Ah, thank you, I`ll revise my MCDU manual and look for it.

[EMIT]

Hello Gums,

An answer to your question about the (Take-Off) / Go Around mode.

As you state correctly, for a Go Around you push up the power, raise the nose and fly the missed approach track. In big lumbering aircraft it works exactly the same as in the small agile ones.
Because sometimes the approach is flown on autopilot, that box too has to know how to fly a go around. All such boxes can execute that maneuver beautifully.
If you fly manually, you can also use the flight director, it gives pitch and roll commands, that will produce the same path that the autopilot would have flown, if it had been in command, but to that end you have to follow those FD commands.
The TOGA button (name may differ, according to manufacturer) is a handy, one button action that changes the whole autoflight setup to go around mode.

What does that mean in practice?
During the approach, Autothrottle (AT) is in speed mode, it adjusts thrust to maintain speed; Autopilot (AP) pitch mode follows a vertical path (either the ILS glideslope or an FCC generated path), or a pilot selected vertical speed; the AP roll mode follows the ILS localizer, or an FCC generated track to the runway (possibly with GPS precision).
For the GA, the AT goes to a thrust mode, the responsibility for speed goes to the AP pitch mode. As AT increases thrust, the result will be that the AP raises the nose. AP roll mode abandons the previous tracking mode and strives to maintain ground track as it was at the moment of GA selection.
Selection of flaps and gear remains a manual pilot task.

Because this all has to be initiated at low altitude (DH during a Cat3B ILS can be as low as 15 ft), the manufacturers have placed the TOGA button in a handy place, not on the glareshield panel where you find the rest of the AP buttons. The GA buttons can be an actual button on the thrust levers (hands are on stick and throttles, no kiddin’), or in the case of Airbus, pushing the thrust levers to the forward stop is the signal for a go around.

What can go wrong in such a perfect setup? Be surprised, the cunning human being is able to wreak havoc always and ever.
Thinking that you initiate the GA, but not actually hitting the button is one (yeah, it happens).
Always, on the top line of your Primary Flight Display (PFD), above the artificial horizon, are the AT and AP mode annunciations (FMA).
Whenever there is a change in an AP or AT mode, the new mode is highlighted with a box drawn around the change for some 10 seconds.
It is of paramount importance to always check that the active modes are the modes that YOU desire! If you make some kind of wrong selection, you should notice that by checking your FMA. This is the point where you see matters go sour. People miss a button, and do not notice that the AP just keeps trucking down the ILS while speed increases because they did push the throttles forward but pushed the AT disconnect button instead of the GA button. Similarly in an Airbus, pushed the throttles forward, but not quite to the forward stop.
It is all right in front of their eyes, the flight guidance system is telling the what it is doing, but the people just ASSUME that they did the correct thing (push a button), so the aircraft should be doing by now what they wanted it to do – they do not actually CHECK that it is also happening.

Failures
When there is an AT failure while on an ILS, you will notice that an AP is just a dumb limited machine – its task is to maintain the aircraft on the ILS LOC and G/S and so it does – the speed is the responsibility of the AT.
If you don’t notice the result (speed dropping below command speed), the AP keeps trimming all the way into the stall. If you then initiate a GA at a late stage, the very aft trimmed state plus the pitch up effect of the engine thrust may overpower the capabilities of the AP. Pitch may increase quickly to abnormally high values. If control is taken over manually, pilots may be surprised by the unusual amount of forward stick that is necessary, due to daily habit of small control forces they may be hesitant to forcefully put the controls where they belong and may forget to trim simultaneously.


Magic?
No, the automatics do a nice job, but the pilot always has to monitor that the machine sticks to HIS (the pilot's) plan. If it doesn't, act upon that situation, don't just sit there and let yourself be surprised .


I could go on for a while, for instance, explain why there is a TO in a GA (as in TOGA button), but what I have stated above should be enough to take the magic out of the story.

[gums]

Thanks, EMIT.

This paragraph is what I was interested in:

Failures
When there is an AT failure while on an ILS, you will notice that an AP is just a dumb limited machine – its task is to maintain the aircraft on the ILS LOC and G/S and so it does – the speed is the responsibility of the AT.
If you don’t notice the result (speed dropping below command speed), the AP keeps trimming all the way into the stall. If you then initiate a GA at a late stage, the very aft trimmed state plus the pitch up effect of the engine thrust may overpower the capabilities of the AP. Pitch may increase quickly to abnormally high values. If control is taken over manually, pilots may be surprised by the unusual amount of forward stick that is necessary, due to daily habit of small control forces they may be hesitant to forcefully put the controls where they belong and may forget to trim simultaneously.

As I was interested in the Aiana and the Russian accident, your reply satisfies my curiosity and helps me to understand all the mosed and connections between the systems.

Although I flew several high-tech lites, including the first FBW jet besides Concorde, we had very limited AP functions for the most part. Being a single-seater, I was a big proponent of the AP to reduce workload when there was a "change in plans" requiring an alternate or a different approach. The second thing was that we had very responsive controls, so controlling pitch on a GA was no big deal. However, the only jet I was familiar with that used the AP for tactical stuff was the F-111 and its terrain following system. The rest required us to manually control pitch and heading by follwing a steering dot when using the TFR system ( A-7D). Gotta tellya, it was a life saver down low in crappy WX, and was like a cosmic enhanced GPWS, so we could get an up command way early when a granite cloud was a few miles ahead.

Thanks, man.

[A37575]

Thinking that you initiate the GA, but not actually hitting the button is one (yeah, it happens).

Often seen in the simulator. Presses TOGA and for some technical reason the thrust levers don't move and rapid loss of airspeed usually occurs due slow reaction by pilot. For a GA it is prudent to first manually advance the thrust levers to high power position then followed by pressing TOGA. That way you are covered.

Similar thing seen on rejected take off. The pilot presses the AT disconnect button on the thrust levers first and then closes them. That one second delay in closing the thrust levers can cost you 200 feet - more on wet runway. Best close the thrust levers as initial action and at your leisure click off the AT button. Mind you, the above recommendations may depend on aircraft type.

[Field In Sight]

A37575, maybe Airbus has got it right in this respect.

To initiate the go-around you slam them forward to get TOGA thrust and also get the correct modes.

To set idle thrust and disconnect the A/Thr, you just move the thrust levers to idle.

Also, I like the sidestick, just wished they where connected.

[Lord Spandex Masher]

For a GA it is prudent to first manually advance the thrust levers to high power position then followed by pressing TOGA. That way you are covered.



Erm, also seen this happen in real life when the FO mistakenly didn't press TOGA but shoved on a handful of power at CAT II DH and all that happened initially was a pretty good acceleration down the GS below 100' agl in cloud.

Not pleasant or recommended.

[Trackdiamond]

TO-GA=TakeOff then GoAround=Pitch then Go Around Power.Yes the two have to be done simultaneously but the most important is to get the right amount of pitch to kil the vertical downward momentum and translate it(with the appropraite GoAround Power doing the job of producing upward momentum)..not too much pitch..and not too much power.Folow FD for pitch if manually(remember S.E. GA demands less pitch accordin to Flap setings) and GA thrust/power should be armed or if manually bugged and set.
(Ref report on AF471 incident regarding the importance of pitch management)

Drag management is paramount to get this vertical translation of momentum from downward to a healthy upward and forward.Flap retract to the recomendd G.A. setting..usually high end take off setting..important that PM doesn't kaka this one up when close to the ground..as.a "thud"/Balked landing might result. Once positively climbing LG is rtracted..and normal climb resumed at the right minimal acceleration height.This drag management is particularly important when in high density altitude conditions.
GA is a high workload sequence demanding swift and precise coordination to achieve the target flight condition..a job best left to the AP and AT if available..but even more acute vigilance demanded by BOTH PF and PM and standard calls annunciated via the FMA and after the scheduled actions of drag configuration completed..don't forget to comunicate your GA on Tower frequency.

[gums]

Thank you, Spandex.

Closing in on my concerns about the AP modes and the AT modes and all that stuff.

If the AP is trying to maintain a flight path, then I can understand an increase in speed if the pilot crams the throttles forward before disconnecting the AP.

Only AP approaches I ever flew required manual throttle, so for GA, hit the paddle switch below stick grip to disconnect AP and move throttles forward. Jet tries to maintain trimmed speed/AoA and descent rate changes. Kinda like the "Navy" approaches, where AoA was primary, not a calculated speed, and descent rate controlled by power and not by nose position. Establish a "standard" attitude then, and use throttle for speed climbing back up.

From my peanut gallery seat, it all comes back to the level of automation and what happens in this mode or the other or the sub-mode and the beat goes on. Would seem to me that the pilots and engineers designing the system could come up with something that resembles, closely resembles, what a human pilot would do, ya think?

I thank all here flying the heavies and using all the automation on a regular basis. Am learning a lot, and also seeing a lot of philosophy. Except for 400 hours with an AP that could be used for a precision approach, my other 3500 hours were all manual. I still had to deal with configuration changes and such for a missed approach, but knew exactly what was gonna happen. Lest you think I never flew much in weather, my first two years were in a lot of WX, and I was cleared for field minimums even as a nugget.

[F-16GUY]

Gums,

Mind you that the dweebs with the thick glasses who designed the lovely Viper you used to fly, actually did a good job regarding pilot friendliness. The entire way the aircraft is built is oriented towards making it very simple and easy to fly, so that the green, self propelled stick actuator can concentrate on the tactical stuff. And not only that. The stuff that is automated, is very simple and easy to figure out.

The leading edge flaps manages themselves. The trailing edge flaps are hooked to the gear handle. The gear limit is 300 KTS, the flap (if you for some reason elect to extend them manually without the gear) have an even higher limit. The engine reacts almost instantaneously and the stick does not take a lot of strength to manipulate.

Only thing I used to find challenging when first exposed with this wonderful aircraft, was getting used to the 1 g trim and the lack of feedback from the stick (as opposed to a conventional flight control system), and the lack of sound change (noise) with the change in speed. It takes a good instrument crosscheck to fly it well in the weather, especially if flying heads down. In the MLU, the HUD is not certified as a primary flight instrument/display and we therefore have to be able to fly on the round dials.

Also, the weather here in northern Europe kind-of sucks, so we are often exposed to real IMC conditions, which in turn helps the jocks to hone their skills. Apparently all this automation in the liners, along with some companies policy that demand it is to be used to the max extent possible, results in the fact that the crews lose their most important skills. Being able to hand fly their aircraft by use of stick (joke) and throttle. Scary !! The old American Airlines video, "Children of the Magenta", shows that it is a known issue, and that it has been known for a while now.

Maybe the designers at Boeing and Airbus should rethink the concept of pilot friendliness and how tho reduce pilot workload, and maybe the airline companies should focus their training a bit more on basic pilot skills.

[gums]

Nice, F-16.

Off-topic: Don't know who the pilots were that helped design the Viper, but they sure as hell knew how to keep the basics simple. Just wish we had a better autopilot like I was used to in two other jets.

Secondly, I was a HUD pilot due to being far-sighted, but always cross-checked the steam gauges per the official policy.


I still like to hear from the heavies here about the GA/TOGA stuff. I am gaining an appreciation about the automation and the procedures and such.

Seems most of the high time folks here are very comfortable with a manual GA and such. A mental picture of the missed approach course and altitudes and such must really help to ensure otto is doing his job.. Then cleaning up the jet as I never had to do except raising the gear handle and in four others, the flaps. BFD.

The 777 folks seemed to have a lotta pilots in the design process, and I thot the 'bus folks did too. The latter may have been a poor opinion on my part, as evidenced by a few accidents/incidents.

[Chris Scott]

Salute Gums,

Airbus radically changed the pilot actions to initiate a go-around when they/we introduced the A320 into airline service in 1988.

Their previous type, the A310 (and the A300, for that matter), had thrust levers that the auto-throttle / auto-thrust could drive forwards and backwards when it needed to change the thrust setting - just like most other 1970s and 1980s big jets, including the DC10 and B747. I call that a "driven" thrust lever. Of course the pilot - if he must - can override the A/THR temporarily, without disengaging it, simply by overpowering the clutch that connects the levers to the mechanism that drives them.

To initiate a take-off or go-around on an A310, the PF presses a small "go-lever" on each thrust lever (just below the hand grip). if the A/THR is armed or active, it will advance the thrust levers and the thrust to TOGA thrust (unless, only in the case of take-off, the crew has pre-set Flexible Thrust on the Thrust-Rating Panel).

But the "go-levers" have a second, crucial function, which is to re-jig the auto-flight system for the flight director (assuming it's in use) and AP (likewise) to provide suitable pitch and roll commands for a T/O or G/A. So, if the PF is using manual thrust, (s)he must still remember to operate the go-levers.

Boeing stuck with a similar philosophy for the B777, although they probably have a different name and form for the go-levers (buttons or switches, perhaps). To see what can happen if the PF forgets to operate the B777 equivalent of the A310's go levers, see the PPRuNe thread here (http://www.pprune.org/rumours-news/533229-af471-nov-16th-2011-final-report.html#post8297355), and the BEA report (http://www.bea.aero/docspa/2011/f-pp111116.en/pdf/f-pp111116.en.pdf) on the same serious incident.

So what did Airbus change on the A320, and the Airbuses that followed? Well, as you know, the thrust ("throttle") levers are no longer "driven" by the A/THR (although they work conventionally for manual thrust). Their position provides a thrust LIMIT only. On T/O or G/A, the PF pushes the thrust levers forwards manually. That single, instinctive action commands the thrust increase AND re-configures the AFS for flight-director/AP.

Hope this helps?