windshear/TOGA
Join Date: Aug 2013
Location: chicago
Posts: 359
Likes: 0
Received 0 Likes
on
0 Posts
I've flown planes without autothrottles
and with modern boeing autothrottles.
it was just so, so hard to move two big levers (or four for that matter) forward and back to control the engines.
go= forward
go for all you are worth, forward till you bend throttles over mechanical stops.
or
go...engage autothrottles to pre programmed thrust setting, watch and feel thrust levers move by themselves
but be sure clutching mechanism works properly and moves them together and make sure the thrust setting is correct
soon, there will be automatically tying shoe laces!
and with modern boeing autothrottles.
it was just so, so hard to move two big levers (or four for that matter) forward and back to control the engines.
go= forward
go for all you are worth, forward till you bend throttles over mechanical stops.
or
go...engage autothrottles to pre programmed thrust setting, watch and feel thrust levers move by themselves
but be sure clutching mechanism works properly and moves them together and make sure the thrust setting is correct
soon, there will be automatically tying shoe laces!
Thread Starter
Join Date: Apr 2008
Location: nowhere
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Maybe I am getting caught up in words here, I'm just not sure what Maximum Available Thrust is with THR REF indicated. Max takeoff, max continuous, full climb thrust, CLB 1, CLB 2. Maybe I'll just try a second TO/GA push in the sim.
Thread Starter
Join Date: Apr 2008
Location: nowhere
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
In 'classic' (non-FADEC etc) aircraft, levers all the way forward = maximum fuel flow and something heading towards maximum thrust that the physical installation can deliver; probably lots more that it's rated at in many cases. Catastrophic failure may not be far away, and lasting damage is very possible.
Join Date: Feb 2008
Location: somewhere
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
I should now the asnwer to this already but I want to make sure. You are in a modern Boeing doing a derated thrust takeoff. After selecting TOGA, you see THR REF displayed on your FMA. Soon after liftoff you encounter a windshear and desire maximum available thrust to escape the windshear. To achieve this, you can press TOGA again and now you will have full rated takeoff thrust.
quoting initial "jazmmedstab" post and I'll be giving B 777 description.
If aircraft is detecting windshear with associated warnings ,you MUST press TOGA switches so as to activate windshear followup by flight director.
Thrust status will change from THR REF to THR .
As someone said THR REF is just the reference thrust commanded by FMS ( D-TO, CLB etc)
Per exemple in approach , as flaps are non 0 ang glide slope captured thrust reference changes to G/A ( indicated top left of EICAS) and you autothrottle in SPEED mode on your FMA .
If you then press TOGA switches to make a go around, you will have a FMA change to THR REF wich means your airplane in is go around mode , THR REF meaning in this case: engine thrust is just thrust to acheive 2000 ft/mn rate of climb (if just one click on TOGA switch) . If you press a second time on toga switches , you then have your reference thrust changed to full goaround engine thrust .
Regarding thrust situation awareness , my eyes scan goes from FMA of course ,to EICAS green thrust indication . This particuraly on engine failure until CON is selected
pause !
Refering to some post speaking of TOGA control law :
Whatever take off or goaround mode, indeed, when altitude rate is greater than 1200 ft/mn, elevator controls pitch to keep selected speed.
When altitude rate becommes negative, aircraft is controlledby pitch.
When rate is between 0 and 1200 ft/mn, there is a combination of speed control and pitch control. Kind of small difference if autopilot used 600 ft/mn replacing 1200 value to be simple !
Happy new year.
quoting initial "jazmmedstab" post and I'll be giving B 777 description.
If aircraft is detecting windshear with associated warnings ,you MUST press TOGA switches so as to activate windshear followup by flight director.
Thrust status will change from THR REF to THR .
As someone said THR REF is just the reference thrust commanded by FMS ( D-TO, CLB etc)
Per exemple in approach , as flaps are non 0 ang glide slope captured thrust reference changes to G/A ( indicated top left of EICAS) and you autothrottle in SPEED mode on your FMA .
If you then press TOGA switches to make a go around, you will have a FMA change to THR REF wich means your airplane in is go around mode , THR REF meaning in this case: engine thrust is just thrust to acheive 2000 ft/mn rate of climb (if just one click on TOGA switch) . If you press a second time on toga switches , you then have your reference thrust changed to full goaround engine thrust .
Regarding thrust situation awareness , my eyes scan goes from FMA of course ,to EICAS green thrust indication . This particuraly on engine failure until CON is selected
pause !
Refering to some post speaking of TOGA control law :
Whatever take off or goaround mode, indeed, when altitude rate is greater than 1200 ft/mn, elevator controls pitch to keep selected speed.
When altitude rate becommes negative, aircraft is controlledby pitch.
When rate is between 0 and 1200 ft/mn, there is a combination of speed control and pitch control. Kind of small difference if autopilot used 600 ft/mn replacing 1200 value to be simple !
Happy new year.
Last edited by VNAV PATH; 31st Dec 2013 at 08:07.
Join Date: Apr 2005
Location: Southeast USA
Posts: 801
Likes: 0
Received 0 Likes
on
0 Posts
I'm just not sure what Maximum Available Thrust is with THR REF indicated … Max takeoff, max continuous, full climb thrust, CLB 1, CLB 2.
…there is an automatic windshear recovery system for the aircraft allowing the FD to command appropriate pitch and can be followed by the autopilot
Maybe I'll just try a second TO/GA push in the sim.
In that case you will overthrust the engine.(if you go more than the N 1 limit)
And ... I, too, hope that each of you and each of your families' enjoy a peaceful, prosperous, and SAFE New Year!!
Last edited by AirRabbit; 31st Dec 2013 at 22:39.
Thread Starter
Join Date: Apr 2008
Location: nowhere
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
…there is an automatic windshear recovery system for the aircraft allowing the FD to command appropriate pitch and can be followed by the autopilot
No, you are to believe that Boeing says that this is a procedure which I repeated. Nothing more and nothing less. I don't think it is reasonable to expect the designer to accompany every flight that has windshear potential so no point bringing the subject up as it is not the basis for whether or not to be aware of manufacturers procedures and recommendations.
Maybe I'll just try a second TO/GA push in the sim.
It is quite possible that the sim could be different than the aircraft but I still think that useful information could be gained. Which of course is why we use the simulator. If a certain procedure does apply to the simulator, I should think that there is a high probability that it will apply in the aircraft as well. But as you suggest, no guarantees.
As earlier stated, the procedure is to manually advance thrust levers so this is more of a learning a bit more exercise.
…so, are we to believe that you would be perfectly confident in the airplane systems to the degree that you would allow the airplane to safely fly itself out of a windshear encounter? I think that doing so is very likely a result of either “over confidence” in the airplane systems or “under confidence” in the pilot flying … who do you know better … YOU … or the guy(s) who designed, developed, constructed, and installed that system … and how come he isn’t there with you when you have to make that decision?
Maybe I'll just try a second TO/GA push in the sim.
Before you make any potentially life-altering decision on how to operate your AIRPLANE based on what you see, hear, and/or feel in a SIMULATOR, I would strongly suggest that you find out what kind of information was used to program that particular simulator for the specific conditions you desire to examine. The fact is that the simulator will do what it is programmed to do … and ONLY what it is programmed to do. Good input = good output … Bad input = bad output … and No input = potentially deadly output.
As earlier stated, the procedure is to manually advance thrust levers so this is more of a learning a bit more exercise.
Last edited by JammedStab; 1st Jan 2014 at 02:20.
Join Date: Jul 2001
Location: East of West and North of South
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
…so, are we to believe that you would be perfectly confident in the airplane systems to the degree that you would allow the airplane to safely fly itself out of a windshear encounter? I think that doing so is very likely a result of either “over confidence” in the airplane systems or “under confidence” in the pilot flying … who do you know better … YOU … or the guy(s) who designed, developed, constructed, and installed that system … and how come he isn’t there with you when you have to make that decision?
I would have disengaged the autopilot, opened the throttles and pulled to the shaker.
Thank god times have changed.
Join Date: May 2001
Location: A few degrees South
Posts: 809
Likes: 0
Received 0 Likes
on
0 Posts
Cosmo, I am afraid this time you are not correct.
If 15 degrees NU still results in a negative VS, all you can do to avoid ground contact, is to pull up more. Up to the stick-shaker, if necessary.
This is common on all aircraft, I believe, after the DC10 accident in DFW.
If 15 degrees NU still results in a negative VS, all you can do to avoid ground contact, is to pull up more. Up to the stick-shaker, if necessary.
This is common on all aircraft, I believe, after the DC10 accident in DFW.
Join Date: Jul 2001
Location: East of West and North of South
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
If 15 degrees NU still results in a negative VS, all you can do to avoid ground contact, is to pull up more. Up to the stick-shaker, if necessary.
Wind sheer escape maneuver does NOT call for raising pitch to stick shaker, but as you wrote 15 deg ANU. Even if this results in negative V/S, you hold 15 deg (or what ever value applicable to you aircraft), as long as ground contact is NOT a factor.
If ground contact becomes a factor, you are no longer flying a "wind sheer escape maneuver", and the wind sheer is no longer the priority. Because it's obviously far worse to risk a crash. Hence, the wind sheer escape transitions over to "terrain avoidance maneuver", which calls for raising the nose to intermittent stick shaker.
However, in e.g. 1500 feet during approach or takeoff, and getting into wind sheer, it makes no sense what so ever to raise the nose to stick shaker and risk going into a stall. In addition to not making sense, it is not correct procedure either.
Join Date: Jul 2001
Location: East of West and North of South
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
737 Windshear Escape Maneuver
Manual flight:
• Disconnect autopilot.
• Press either TO/GA switch.
• Aggressively apply maximum*
thrust.
• Disconnect autothrottle.
• Simultaneously roll wings level and
rotate toward an initial pitch attitude of 15 °.
• Retract speedbrakes.
• Follow flight director TO/GA
guidance (if available).
Automatic flight:
• Press either TO/GA switch**.
• Verify TO/GA mode annunciation.
• Verify thrust advances to GA
power.
• Retract speedbrakes.
• Monitor system performance***.
GPWS Warning
• Disconnect autopilot.
• Disconnect autothrottle.
• Aggressively apply maximum* thrust.
• Simultaneously roll wings level and rotate to an initial pitch attitude of 20°.
• Retract speedbrakes.
• If terrain remains a threat, continue rotation up to the pitch limit indicator (if available) or stick shaker or initial buffet.
Manual flight:
• Disconnect autopilot.
• Press either TO/GA switch.
• Aggressively apply maximum*
thrust.
• Disconnect autothrottle.
• Simultaneously roll wings level and
rotate toward an initial pitch attitude of 15 °.
• Retract speedbrakes.
• Follow flight director TO/GA
guidance (if available).
Automatic flight:
• Press either TO/GA switch**.
• Verify TO/GA mode annunciation.
• Verify thrust advances to GA
power.
• Retract speedbrakes.
• Monitor system performance***.
GPWS Warning
• Disconnect autopilot.
• Disconnect autothrottle.
• Aggressively apply maximum* thrust.
• Simultaneously roll wings level and rotate to an initial pitch attitude of 20°.
• Retract speedbrakes.
• If terrain remains a threat, continue rotation up to the pitch limit indicator (if available) or stick shaker or initial buffet.
Join Date: May 2001
Location: A few degrees South
Posts: 809
Likes: 0
Received 0 Likes
on
0 Posts
Cosmo, I see your point clearly. And it would indeed result in the same.
However, In my QRH, Maneuvers 11.1, pulling up to the stick shaker, is part of the "wind-shear escape maneuver".
However, In my QRH, Maneuvers 11.1, pulling up to the stick shaker, is part of the "wind-shear escape maneuver".
Join Date: Jul 2001
Location: East of West and North of South
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
I would be interested to see that quoted in full. The above is quoted from Boeing standard QRH, and is written as such in all the QRH I have from the previous companies where I worked.
Intermittent stick shaker is mentioned in the notes, as the upper pitch limit, i.e. it may necessary to lower the nose, below 15 degs ANU. Which of course makes sense if 15 degs would result in a stall.
...still the point is that there is no reason to "blindly" raise the nose to intermittent stick shaker for every wind sheer warning, as John Farley suggest.
Intermittent stick shaker is mentioned in the notes, as the upper pitch limit, i.e. it may necessary to lower the nose, below 15 degs ANU. Which of course makes sense if 15 degs would result in a stall.
...still the point is that there is no reason to "blindly" raise the nose to intermittent stick shaker for every wind sheer warning, as John Farley suggest.
Join Date: May 2001
Location: A few degrees South
Posts: 809
Likes: 0
Received 0 Likes
on
0 Posts
Cosmo:
Trying to cut and paste, to no avail.
So, extract from QRH B737 rev.17, 17_07 dec12:
Man. 1.11
action, dot nr 5, "simultaneous roll the wings level and rotate towards an INITIAL pitch attitude of 15 degrees.
And then in the first note, the devil is always in the tail:
"Flight at intermediate stick shaker may be required to obtain a positive terrain clearance.. "
I do not think I have to refer to a different manoeuvre, while, in my opinion, this covers the exercise.
Of course, there is no reason to go to SS at the initial notation of windshear.
Trying to cut and paste, to no avail.
So, extract from QRH B737 rev.17, 17_07 dec12:
Man. 1.11
action, dot nr 5, "simultaneous roll the wings level and rotate towards an INITIAL pitch attitude of 15 degrees.
And then in the first note, the devil is always in the tail:
"Flight at intermediate stick shaker may be required to obtain a positive terrain clearance.. "
I do not think I have to refer to a different manoeuvre, while, in my opinion, this covers the exercise.
Of course, there is no reason to go to SS at the initial notation of windshear.
Join Date: Apr 2005
Location: Southeast USA
Posts: 801
Likes: 0
Received 0 Likes
on
0 Posts
WHAT?
Originally Posted by JammedStab
No, you are to believe that Boeing says that this is a procedure which I repeated. Nothing more and nothing less.
Originally Posted by JammedStab
I don't think it is reasonable to expect the designer to accompany every flight that has windshear potential so no point bringing the subject up as it is not the basis for whether or not to be aware of manufacturers procedures and recommendations.
Originally Posted by JammedStab
It is quite possible that the sim could be different than the aircraft but I still think that useful information could be gained.
Originally Posted by JammedStab
If a certain procedure does apply to the simulator, I should think that there is a high probability that it will apply in the aircraft as well. But as you suggest, no guarantees.
Join Date: Mar 2006
Location: Ormond Beach
Age: 49
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by AirRabbit
I’m not sure how you can say that … no guarantees, but go ahead anyway? Please, re-read my response, above … and if that doesn’t do anything for you … I’d recommend reviewing the ABX DC-8 accident in Narrows, Va in December, 1996 … and if that doesn’t impress you, I’d recommend a vocation change.
On a related note, I'm not altogether clear on what windshear escape procedures (in a simulator or otherwise) have to do with the crash you mentioned, but then I don't have three decades of writing FARs under my belt.