B777 single engine go around and TOGA switches

[Cropduster]

Question for the group. My apologies, I couldn’t find the answer in our manuals and am not near a simulator to find out for myself.

When initiating an airborne go around single engine, can you push either TOGA switch or do you have to push the one for the operating engine. In other words, does shutting down an engine inhibit the associated TOGA switch?

Thanks.

[iceman50]

Why would you take your hand off the operating engine's thrust lever to operate the TOGA switch on the thrust lever that is at idle?

[stilton]

Why not just answer the question ?

[perantau]

Iirc, pressing either TOGA switch will do the trick.

[iceman50]

Stilton

If you cannot see why it did not need answering, Airmanship is dead..

[aviator1970]

He asked a doubt, you’re going an about airmanship. Sarcasm breeds contempt. 🤦🏽‍♂️ I guess you had to answer, whilst not knowing what to write. QED

[mattyj]

I think from memory you can press the little CON button on the Autothrottle section of glareshield display select panel..that gives you max continuous on whatever is working

[Uplinker]

"iceman50; If you cannot see why it did not need answering, Airmanship is dead.."

I can think of two possible airmanship reasons to use the dead engine's TOGA switch. Let's keep an open mind - we might learn something useful.

[Wirbelsturm]

Either will work to give you TOGA.

A question is a question, why not answer it.

[BuzzBox]

mattyj

Please don't tell me you'd select CON thrust during a one-engine inoperative go-around (before flap retraction)...:=

[EDML]

Well, if you are sitting on the left hand side and engine one failed the TOGA button on the RH throttle is not easily reachable as your thumb is on the wrong side.

[BuzzBox]

Why do you need your thumb? The TOGA switches are on the forward side of the thrust levers.

[FullWings]

It can be quite a reach to get to the TO/GA switch if the thrust lever is already well advanced, especially if you’re going over the top of the retarded one. Also easy to think you’ve pressed it but the FMA says no, so try again. Whatever works and distracts you less from the task of flying the aeroplane...

[Cropduster]

Perantau, Wirbelsturm, thank you for your answers. Full wings, you are on the right track as to what prompted the question.

Recently a student in the sim attempted a single engine G/A but the thrust did not come up. He was adamant that he pushed the TOGA switch and I was wondering if he may have pushed a de-activated one. Now I am fairly certain that he touched the switch but didn’t actually push it hard enough to engage it.

[Uplinker]

There you go, Iceman50, (and others), every day is a learning day :ok:

[Vessbot]

Cropduster

Much less pushing the thrust lever...

[Lookleft]

I like the Airbus method, just push the bloody things forward!

[maui]

Could I suggest that : If you can't reach the TOGA sw on the advanced thrust lever, you should better consider your seating position when you set up your cockpit.

[TukwillaFlyboy]

Iceman might have been a bit snarky but surely the point he was making is valid. The inoperative engines thrust lever should be at idle. Why would you even think of touching it ?

[320busboy]

Lookleft

Exactly. Why even need a toga switch. 🤷🏼‍♂️

[TukwillaFlyboy]

There was an incident in Australia a few years ago where an A320 crew attempted to go around from the minima when not visual. Except they didn’t push the thrust levers through the gate. Very exciting moments accelerating toward the runway until they figured out what was happening.
TOGA works just fine.

[Avinthenews]

Other considerations

Both thrust levers could easily be at idle

One TOGA switch could be inoperative

It’s not unheard of for crew to grab the incorrect lever.

[Pugilistic Animus]

​​​​​A Go around is not a good place to be when you don't have OEI protections that are provided by the approach climb criteria... here in the US we have an approach climb protection for both OEI or AEO.
​​​​Landing climb is predicated on AEO. Just a friendly reminder
​​​​

[mattyj]

BuzzBox

can’t remember, I think there was a time on the missed approach or engine failure after V1 where CLB CON was called for..wish I still had my 777 to fly, that was a hell of a machine

[max alt]

I could never understand the move from the rear of the thrust lever G/A switches as on the 757/767 to the front of the thrust levers as in the 777.A great number of pilots would graduate from the former to the latter which may confuse at a critical phase of flight.If if aint broke don't fix it springs to mind.
Just an observation.

[allaru]

For your benefit and not mine....

Either TOGA switch. But note that if SE the live engine will likely be positioned forward and thats the one you will have your hand on, the dead engine lever will be at idle and difficult to access unless you can somehow reach back with your extra long fingers to reach the switch, and why would you do that anyway. If the live engine TOGA switch fails, (which I think is why you are asking) the other one I guess would work but its position may be an issue.

Re position..TOGA switches are paddles in front of and below the thrust levers and are activated using your fingers by reaching over the thrust knobs, the switches on the side of the thrust levers are AT switches on the 777 not GA switches as in some other types......often confused by those who came off AC with that configuration. Attempted GA by disconnecting the AT instead of activating TOGA is an interesting concept.

ALWAYS follow through with thrust levers as TOGA switches may fail (so press both anyway if you have both engines operating) AND be aware that TOGA mode is not available on the ground if you have touched down already. (ie 777 accident in Dubai). If TOGA is not available for whatever reason then the AP/FD will remain in whatever mode it was in, ie LOC/GS or VNAV/LNAV and will not increase thrust or command the pitch attitude required for GA. The only option therefore is to disconnect the AP, and apply thrust manually, pitch up manually against the FD then turn FDs off to avoid distraction. (easier said than done, and especially difficult at low level if on one engine in IMC). Note that if the AP remains engaged and you just manually apply thrust the aircraft will accelerate down the runway without climbing as it is attempting to land but cannot due to the higher speed.

Re performance the SE and 2 ENG cases are checked to meet regulatory requirements but this does not guarantee terrain clearance at your particular airport. The LANDING CLIMB LIMIT WEIGHT table in the QRH checks both SE and 2 ENG cases ie a minimum climb gradient of 2.1% S.ENG/F20/GR UP and 3.2% 2 ENG/F25-30/GR DN.

SE case is always the most limiting. The table is based on F20 so depending on configuration you may have F5 for a SE GA in which case you may get slightly better performance. However the 2.1% that it checks does not give obstacle clearance as 2.5% is required for PANOPs and 3.3% for TERPS charts plus another 0.6 if turns are involved.

To check if you have sufficient performance for the airport you are flying into can be done by entering the required gradient into the OPT and it will tell you if it can be achieved or not. If it cannot be achieved you can still do the approach by opting to fly the engine out escape maneuver OR commit to land.

Re previous post about CON, CON power is less than TOGA and probably wont cut it on one engine, and in any case is not correct. CON would be selected after the GA has been completed.

And for :mad: sake enough of the bitching...you're like a bunch of sheila's !

[vilas]

TukwillaFlyboy

That is due to wrong habits maybe from earlier aircraft. Also due arbitrary change of SOP by the airline not to immediately check FMA but only after gear up, which they reverted back after the incident. In Airbus you don't nurse thrust levers to TOGA you just hit the stop. It's FADEC controlled and FBW levers. Same procedure even after touchdown unlike Boeing. No confusion

[alf5071h]

Can the 777 auto throttle be used single engine ?

If so, then with habit of not following-up with hands-on, the reach for TOGA switch would be unusual; quick hand movement anticipating two hands on the wheel for manual GA.

Slight similarities with prior 777 accident - no GA due to low rad alt (design), weakness in checking annunciation, and poor feel - feedback from TOGA switch if not used very often.

[allaru]

'Can the 777 auto throttle be used single engine' - yes and would normally be used if available.

[flightleader]

This is where call-outs become important. After pressing TOGA switch in a go-around, FMA change to TOGA and should be sighted and callout by pilot.

[Check Airman]

No 777 experience, but there’s a lot of talk about failure of the TOGA switch, mode confusion etc.

I’ve only flown one plane with an Autothrust motor. My technique was either:

- push the levers forward, then click the TOGA switch

- push the levers forward while clicking the TOGA switches

I probably exercised that second option more often. The point being, I flew the plane first. Aviate, navigate, communicate, automate.

[stilton]

Anyone have any idea why the TOGA switches were relocated?

[maui]

alf5071h

Alf. Why would you need two hands on the control wheel. A practice fraught with danger. Even with an active or inactive auto throttle there is only one place for the second hand, unless operating some other AFCS switch or knob, On the bloody thrust lever.

In the OEI situation, the retarded thrust lever makes a good rest for your wrist or hand while your fingers guard the live thrust lever. Unless you have infant sized hands.

[BuzzBox]

mattyj

CON thrust shouldn't be selected until after the aircraft has reached the acceleration altitude and the flaps have been retracted to the desired setting for the continued climb.

[alf5071h]

“Why would you need two hands on the control wheel. A practice fraught with danger.” … quite so …
I don't know, … not 777 rated.

Perhaps Ppruners, without fear of fault or ridicule, could answer this based on their experience, together with ‘because’, explaining why this is-is/not done, supporting opinion.

Everyone get two answers; that which is trained for; and that which is done … and why.

[BuzzBox]

1. One hand on the control column, the other on the thrust levers.
2. See above.

Why? Because it's good airmanship; no pilot should ever blindly rely upon the automation. Having your hand on the thrust levers might just save your bacon if the automation doesn't do what's expected.

[TukwillaFlyboy]

Is there any Boeing pilot out there has not been taught from day 1 not to follow up the thrust levers ?
Its Boeing one-o-one.
Its not that hard people.
FTFA

[Vessbot]

Agreed. Left stick to turn left, push the thrust levers to climb, push the stick forward to get away from stall... stuff like that. The basic basics. Lot of other stuff built on top that eases life and increases efficiency, but if you pull out the foundation then the whole pile collapses. Don't lose the plot, folks.

[allaru]

Re the TOGA switch failure it’s the sort of unlikely BS failure that smart arse sim instructors come up with to :mad: you about and waste 30min of checking (previously called training) time rather than emphasising the basics.

Re basics ....that sort of stuff went out years ago it’s all about being able to regurgitate the latest change to the SOPs and have hands, feet and mouth going in all directions in an attempt to comply to avoid being whacked over the knuckles with a huge stick.

We would be much much much safer if we were left to fly the aircraft without worrying about all that crap.

[tdracer]

TukwillaFlyboy

I've done countless flight tests on Boeing aircraft - and observed many simulator sessions. The PF always has one hand on the thrust levers during the final approach/landing phases.
It's that sort of basic piloting skill that would have saved the Asiana 777 at SFO. I remain convinced that a major contributory factor in that accident was that the PF had recently crossed over from flying Airbus, without sufficient difference training (such as hammering in the need for follow the thrust levers during final approach/landing).
With the notable exception of the 787, the autothrottle system on Boeing aircraft is not designed or certified as 'flight critical' - but I bet they don't teach the pilots that part...

[FlightDetent]

The thing is, Airbus pilots are trained to have a hand on the thrust levers. Not to mention it's kind of complex to have both on the stick given the location, thus the TLs become a natural resting place.

[tdracer]

But the Airbus thrust levers are not back driven, so simply having your hand on the lever doesn't tell you much. On Boeing, if you have your hand on the lever and it's all the way back at idle and not moving - while your speed is getting dangerously low - a competent pilot should make the connection (at least if he'd been trained to)...
Reportedly, due to the way the Boeing back drives the yoke on the 777, as Asiana was approaching stall the pilot was having to pull back on the yoke with something approaching 100 lbs. force. Not many people could have done that with one hand on the thrust levers...

[FlightDetent]

The idea that a hand on non-moving levers (stuck at idle) tells you more than a hand on non-moving levers (placed in CL detent) is illogical.

And likewise is the implied suggestion the crew would had received vital information from those non-moving thrustlevers if they had a hand on them and would have reacted, the same crew who could not react to the low speed situation unfolding right in-front of them on the PFDs because it has never occured to them that low speed is no good.

Let's face it, there are real-pilots (Boeing), half-pilots (Airbus) and non-pilots. All of them make mistakes, but the outcome differs accordingly. An Airbus half-pilot does not need to have his hand on the TLs to know what the engines are doing (as you well explained already it's non-moving and the placement is not corelated to thrust under A/THR ops) since he's vitally trained by necessity to watch the N1/EPRs.

Thus an Airbus half-pilot moving to B will have no need of touching the TLs to derive information (yet again, those were not moving anyway in the Asiana case) but would know what the engines are doing or not by looking at EIS. Still, he would have the hand there anyway, a fact showing even the last sentece of the post above is incoherent.

Now, take a non-pilot from Airbus to Boeing and there's your dish as ordered. Served on a plate of autothrottle logic that apparently has more downgrading mode reversions than the Airbus FBW itself (hyperbole).

[Check Airman]

With the notable exception of the 787, the autothrottle system on Boeing aircraft is not designed or certified as 'flight critical' - but I bet they don't teach the pilots that part...

Can you elaborate on this bit please tdracer ?

[Check Airman]

FlightDetent

Never understood why Airbus wants us to fly with a hand on the levers if the AT is on. It always feels pretty useless to me. If I'm that worried about the wind, I probably have the AT off anyway.

[Roj approved]

@FlightDetent

I can see your post is full of humour, which might be missed by a few, but it is also some valid points re: "feedback" via the back driven thrust levers.

When I began flying, it was taught, actually, drummed into us. One hand on the "lever" at all times.

In the following 30 years, this has worked out well across all types, SE Pistons, Twin Pistons, Twin Turbine, and 4 different Jet types. (3 Real-Pilot types (WW24, Jet, B787), and 1 Half-Pilot type, (A320)) The first Jet type didn't have any form of "Auto Throttle/Thrust" or even "Glass". No idea how I survived??!!

Having back driven thrust levers on a modern Glass cockpit really doesn't make any difference to my life. I went from being a Half-Pilot to a Real-Pilot then back to being a Half-Pilot, A320->B787->A320. There is so much information directly in-front of you on the PFD, and the Engine instruments are a great back up.

Having all this Automation makes me very "Lazy".

Recently in the SIM, during a manual thrust exercise, the Instructor was talking about manual handling of the speed and the best reference for Thrust setting on approach. We have IAE which have EPR as the primary reference, fairly useless, but the N1 works well. We discussed the expected pitch/thrust for the approach. We all managed to regurgitate the "numbers" ie: 2.5º N/U with Thrust = GW-10%.

His next question was an eye opener. "How are you going to set the Thrust from then on?"

At this point I needed to re tie my shoelaces, and my mate had something important in his flight bag that needed to be repacked.

"THE BEST REFERENCE FOR THRUST SETTING IN A MODERN A/C IS THE AIRSPEED TREND VECTOR"

This is true for the Boeing, Embraer or the Airbus, regardless of the back driven Thrust Levers.

As far as the Airbus v Boeing thrust lever debate, I vote for the Table and Sidestick. ;-)

[Check Airman]

Agree with your instructor 100%. Get it in the ballpark, then do the rest with the ASI. If your instrument scan is good, you'll only occasionally need to glance at the N1, and mostly to make sure they are synched.

[TukwillaFlyboy]

Or get a HUD :)

[vilas]

tdracer

On final Approach hands should be on Thrust levers that's because pilots may not have to search for them when they are desparately needed and not because of anything else.That's not the cause of SFO. Any approach in any aircraft is doomed if no one is going to look at the speed at all. In Bangalore A320 was the same problem. Every few seconds the eyes must glance at the speed. That's what must be drilled and not so much the hand position. In a fully serviceable aircraft in VMC, flying 26kts(Bangalore) or 31kts below Vapp(SFO) is simply unacceptable. The pilots had lost the basic scan. In both the cases they didn't even check ATHR modes. How can You trust automation without even checking that it's in appropriate mode? The systems worked as designed but the pilots didn't fly as they were supposed to.

[FlightDetent]

Combine symbology change with unusual attitude presented to a non-trained, fatigued crew right on the wrong side of WOCL: the mix has killed before ("B" Rostov). Could happen on any type. Just like speedtape confusion mixed with stomagravic illusion ("A" Sochi).

Thanks gentlemen. I went from a novice real-pilot to half-pilot 16 years ago. The transition was not a problem as I was trained on the 737 to watch my N1s. 1) Set the target, 2) check your V/S + speed and move the levers accordingly, 3) review and memorize the new N1 value. Noting extreme, scan the "T" once and then peak at the EIS, rinse & repeat.

Speed vector turned me to a lazy engine scanner over time, significant drop there once the EPR models came by. Eyes never learned to pick the N1 from the new location, I guess. My personal feelings about AB non-moving is beyond the scope of the thread.

Back to the scheduled programming, now that the obligatory hijack of a BA thread by AB semi-pilots is done, shall we? ;)Before we do: The suggestion that Asiana disaster was majorly contributed by the training on an advanced previous model is absurd, moreover because that training (if done) actually reinforces the vital skills that were missing on the accident day. I threw in the pandora's box because the opinion re-occurs - how airbus experience unteaches the skills needed to survive boeing - while the exact opposite is true. Yes, there are organs that atrophy naturally and weathervane on the 'bus, airspeed control is not one of them, same as where your hands go.

[Uplinker]

Judging by how many pilots of other types cannot seem to understand how the Airbus FBW and A/THR works, there is nothing "half" about being an Airbus pilot. :)

Why do some pilots find it so hard to simply look at N1/EPR gauges, instead of the position of the thrust levers? Both tell you exactly what the A/THR is doing, but moving thrust levers can become a proxy for the engine gauges, so the pilot's scan of their engine instruments gets forgotten. The levers are the input, not the engine output, so the engine gauges in any type need to be looked at anyway; witness Centaurus's SIM test where he failed a Boeing thrust lever and the crew did not notice, ending in a 'crash'.

Never mind which type one flies: one hand should be on the thrust levers during approach in case a go-around is required, or if the A/THR does not react correctly and/or manual thrust control is required. A turbulent day and an approach where manual thrust or TOGA becomes necessary is not the time to start trying to put your hand on the levers, it should be there already.

As regards only one hand on the (conventional) yoke: Is there any situation in which both hands on the yoke would be helpful? I can think of a few. Would there ever be a situation in which PF would ask PM for TOGA while he, PF, put both hands on the yoke to ensure correct pitch and bank and not overshoot?
For example, I always found it much easier and more accurate to do 60° banked level turns* if I had both hands on the yoke rather than one. Both hands also means both sides of the brain are used, and gives finer control.

* obviously a SIM exercise, not part of normal flying !

[Pugilistic Animus]

"Reportedly, due to the way the Boeing back drives the yoke on the 777, as Asiana was approaching stall the pilot was having to pull back on the yoke with something approaching 100 lbs. force. Not many people could have done that with one hand on the thrust levers..."

Tdracer, why were they pulling on the yoke while approaching the stall anyway?

[Vessbot]

Most people's intuitive concept of what the yoke does, has little to nothing to do with its effect on AOA and/or airspeed. It's considered simply for pointing the nose, and in turn, for pointing the flight path.

[Pugilistic Animus]

Indeed Vessbot... what you say is true about untrained people but these guys were pilots they should know about stall recovery.

[tdracer]

Check Airman

Apologies for diverting this into another 'Boeing moving throttles vs. Airbus non-moving throttles debate' - that wasn't my intent. Rather I was trying to point out that I believe the differences training the Asiana PF received was inadequate - something I didn't see in the final report... The Boeing and Airbus design philosophies are considerably different - not saying one is better - but they are very different. That needs to be thoroughly accounted for in the training when switching between.
To understand the Boeing design philosophy for the autothrottle systems, you need to go back in time a bit. The original A/T installed on the 747 (FFRATS - Full Flight Regime Auto Throttle System) was an analog device and quite crude. It was simply intended to relieve crew work load on long haul flights, not to completely take over the task. Move on to the 757/767 A/T - which was digital and far more sophisticated than FFRATS, but had numerous potential failure modes (slipping lever clutches being a common one due to down-stream cable loads), and it was a single servo so could not control the levers independently. The software was only developed to DAL C (essential) - not flight critical - which was consistent with the rest of the system design. When we went to FADEC on the 767 and 747-400, the basic system didn't change that much from the original - getting rid of the throttle cables helped a lot (simple friction devices where added to the thrust levers to give 'feel' and prevent uncommanded movement since the force to move the thrust lever resolvers was minimal), and a 'trimmer' function was added to the A/T software that sent small adjustments to the commanded EPR/N1 of each engine to align EPR/N1 across the wing (to account for pilot induced throttle stagger or small rigging errors). But it was still single thread, with a single servo drive, and the s/w was DAL C. In short it was still viewed as an 'aid' and the pilot was still expected to monitor what it was doing.
The 777 got a completely new A/T relative to what was used in the 747-400/757 (tel:747-400/757)/767 - dual servo so independent control of both engines, s/w was DAL B, but it still wasn't certified as a 'flight critical' function. On the engine side, we always had to assume 'worst case' - that the A/T could be lying and so we still needed provisions to disable it and ignore all inputs. We complained mightily that the A/T should be considered flight critical - that the pilots were starting to treat that way, but got nowhere.
My understanding - based on conversations with my cohorts who worked on the 787 - is that they finally designed the 787 autothrottle as a flight critical system. But I don't know details.

[tdracer]

Pugilistic Animus

I don't think they realized they were about to stall until it was too late. The pilot kept pulling back because he was headed for the seawall. Four pilots on that flight deck, and only one noticed that airspeed was getting critically low and he didn't voice it strongly.

[Check Airman]

tdracer

Thanks as usual for your insight. I learned something new today.

[Check Airman]

tdracer

We'll agree to disagree on the number of pilots in the cockpit that day.

[stilton]

trace

Interesting chronology thanks for that,

Still curious as to why the Toga and AT disconnect switches changed positions after the 757 / 67 ?

[tdracer]

That I don't know - I was involved in the thrust lever design aspects - but only on the engine side, not the A/T side.

[roundsounds]

matty

The CLB/CON switch only changes the Reference Thrust, it won’t change the thrust lever position. Pressing either TOGA switch will activate the TOGA mode, which not only increases thrust, but changes lateral and vertical AFDS modes and inserts the MCP Alt into the VNAV cruise page.

[WhatShortage]

iceman50

Yep, CRM is also dead for you.

[tcasblue]

I always wondered why they halved the number of engines on the 777 versus 747 but doubled the number of auto throttle switches

[Pugilistic Animus]

For finals, HOST.....Hands on Stick and Throttle during manual flying, the only time you don't follow that recommendation is at V1 when both hands are placed on the on the yoke

[vilas]

Investigators said the flight’s three veteran pilots made 20 to 30 different errors, some minor and others significant, during the landing approach on July 6, 2013.
This is about Asiana SFO. So let's put t bed the theory that throttles had anything to do with it. I think they would've crashed any aircraft.

[Pugilistic Animus]

Just thinking, where do you Airbus pilots put your hand at V1? :}

[vilas]

Are you serious? They just remove the hand away from thrust levers, can keep even in the lap.. The other hand uses the stick to fly.

[Pugilistic Animus]

Vilas it's called sarcasm

[Pugilistic Animus]

TDracer excellent description of the history of Boeing AT

I think that we, on pprune, know you're one of the heaviest!

[vilas]

It's not sarcasm but real. You can't keep it on thrust levers so got to keep somewhere.

[Pugilistic Animus]

I don't think that you were sarcastic I was the one being sarcastic .

Don't worry John, I will only post relevant materials in this thread from here on:)