Common misunderstandings B737
it's all about proper cockpit etiquette
"Riding" the controls no matter how lightly is not only unnecessary but intensely distracting for whoever is the pilot handling at the time
Agreed!
Last edited by Mikehotel152; 29th Oct 2011 at 12:18.
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people thinking "we have him on TCAS" is relevant.
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Plenty of Captains keep their feet on the rudder pedals during the take off roll even though the FO has the controls.
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Quote:
Plenty of Captains keep their feet on the rudder pedals during the take off roll even though the FO has the controls.
Yes because the captain must be ready to perform the RTO.
Plenty of Captains keep their feet on the rudder pedals during the take off roll even though the FO has the controls.
Yes because the captain must be ready to perform the RTO.
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Autobrakes arm...
On ground...
Wheel speed less than 60 knots at the time RTO is selected...
Speed 90 knots or greater for RTO to work when thrust levers brought to idle.
That said low speed abort accomplished by the skipper with manual braking.
On ground...
Wheel speed less than 60 knots at the time RTO is selected...
Speed 90 knots or greater for RTO to work when thrust levers brought to idle.
That said low speed abort accomplished by the skipper with manual braking.
people thinking they only have 12 minutes to reach 10 000 feet in an emergency descent
Are you suggesting a liesurely descent at normal profile after a decompression? If so I hope I don't fly with your airline.
My reading of emergency descent checklists from various manufacturers leaves me in no doubt that if an emergency descent is required, then it is an urgent response, not at your convenience. It is probably also the reason why, on most aircraft, an emergency descent is a recall item (no time to pull out the QRH).
It might also explain why manufacturers specify that an emergency descent be carried out at Vmo. Certainly in cases of suspected aircraft damage a lesser speed is suggested, however in such cases additional drag such as speedbrakes or landing gear are recommended to achieve the descent rate required to reach a safe altitude in minimum time.
It was in fact originally a certification requirement that a manufacturer had to demonstrate the ability to complete an emergency descent from highest certified altitude to FL140 within 4 minutes.
Yes, most oxygen generators will provide 12 minutes supply to the passenger, however that does not give one the option of conducting an emergency descent at normal profile.
Where did you get the idea (if I am understanding your post correctly) that an emergency descent could take as long as, or longer than, 12 minutes?
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Chimbu,
Its in the 737 Flight Planning and Performance Manal under the section Passenger Oxygen Requirements which sports a confusing and convoluted chart that may not satisfy national regulations on pax oxy requirements. You are correct in that the initial manouever must be completed as a rapid descent to achieve at least 17,000' within about 5 mins.
Its in the 737 Flight Planning and Performance Manal under the section Passenger Oxygen Requirements which sports a confusing and convoluted chart that may not satisfy national regulations on pax oxy requirements. You are correct in that the initial manouever must be completed as a rapid descent to achieve at least 17,000' within about 5 mins.
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Turbulence speed again:
Think about what severe turbulence implies. Airspeed variations of maybe 30 knots! I find it quite irrelevant to talk about a "target" airspeed in such a situation. One should be happy to see a speed in the normal range and react only to an unacceptable airspeed trend (note that it's not the "trend vector" indication that is being referred to, but the general meaning of the word, development/change). That would mean a trend were it would likely be predictable that it would take you outside the normal range.
So depending on altitude and what the trend is, I would say that both the number you mention may be acceptable.
For the record I never experienced severe turbulence in the Boeing. Neither did Boeing during the test flights:
"The maximum degree of turbulence encountered at the pilot’s station during certification flight tests was evaluated as moderate."
So you are pretty much on you own. Do what you have to do to survive (remember with severe turbulence, aircraft may be temporary out of control).
With climb and descent you have the luxury that you can trade altitude to absorb the speed variations, hence it makes sense to choose an airspeed that is in the approximately center of the speed band. In level flight you don't have that luxury, which Boeing acknowledges with their described technique in the FCOM1 and FCTM.
Anyway, again the point is that .76 is not a magical speed that will give you a smoother ride in level flight in light turbulence.
BOAC:
- err - those two don't quite join up! Is M.65 acceptable? M.82? As long as you have the right N1's of course......................
NB For youngsters - N1's do NOT provide buffet boundaries.
- err - those two don't quite join up! Is M.65 acceptable? M.82? As long as you have the right N1's of course......................
NB For youngsters - N1's do NOT provide buffet boundaries.
So depending on altitude and what the trend is, I would say that both the number you mention may be acceptable.
For the record I never experienced severe turbulence in the Boeing. Neither did Boeing during the test flights:
"The maximum degree of turbulence encountered at the pilot’s station during certification flight tests was evaluated as moderate."
So you are pretty much on you own. Do what you have to do to survive (remember with severe turbulence, aircraft may be temporary out of control).
With climb and descent you have the luxury that you can trade altitude to absorb the speed variations, hence it makes sense to choose an airspeed that is in the approximately center of the speed band. In level flight you don't have that luxury, which Boeing acknowledges with their described technique in the FCOM1 and FCTM.
Anyway, again the point is that .76 is not a magical speed that will give you a smoother ride in level flight in light turbulence.
Thread Starter
"Stuff that annoys your friendly checkie"
1/Start witches to Cont in light turbulence
2/ Using Auto Brake when it's not needed
3/ Not checking the cabin ROC indicator with the ATO cx's
4/ Quickly stowing the reversers at 60kts
5/ Using Sups for crossfeeding and No Bleed takeoff
6/Using too much aileron during roll during crosswinds departures
7/Relying blindly on the rotate call
8/Following through on thrust levers after TOGA pushed
9/Inability to resolve PIO's
10/ Thinking that hand flying is dangerous
11/Questioning every decision the Captain makes
12/ Relying 100% on TCAS instead of looking out
12/Reducing to M0.76 in the cruise due turbulence
13/Maintaining thrust until 10ft during flare
14/Not confirming the FMA(s)
15/Using checklists etc to cover the windows (sunlight)
16/Over controlling on the approach (PIO)
17/Slow rotation, not pulling correctly through the dead zone
18/ Changing frequencies then immediatley transmitting
19/- Putting the automatic temperature selector to full low (or even to manual) on a hot summer day
20/Doing the flight control check (rudder part) without holding the tiller
21/Disregarding a gentle suggestion by the FO not to climb to the max level when it is turbulent
22/Going overboard with superfluous confirming switch selections.
23/Pilots who have no idea of immediate actions in event of tail-pipe fire
24/Fuel cross feeding/balancing well before the IMBL caution is alive.
25/Pumping the elevators on rotation and flare
26/Failing to call rotate if the speeds drop out of the FMC.
27/not calling the FMA correctly. LVL CHG is the button you press on the MCP. MCP SPD is the pitch mode that is engaged.
28/flying in V/S when inappropriate
29/people thinking they only have 12 minutes to reach 10 000 feet in an emergency descent
30/people pushing TO/GA before engine are spooled up & around the same value.
31/people thinking "we have him on TCAS" is relevant.
32/..............
1/Start witches to Cont in light turbulence
2/ Using Auto Brake when it's not needed
3/ Not checking the cabin ROC indicator with the ATO cx's
4/ Quickly stowing the reversers at 60kts
5/ Using Sups for crossfeeding and No Bleed takeoff
6/Using too much aileron during roll during crosswinds departures
7/Relying blindly on the rotate call
8/Following through on thrust levers after TOGA pushed
9/Inability to resolve PIO's
10/ Thinking that hand flying is dangerous
11/Questioning every decision the Captain makes
12/ Relying 100% on TCAS instead of looking out
12/Reducing to M0.76 in the cruise due turbulence
13/Maintaining thrust until 10ft during flare
14/Not confirming the FMA(s)
15/Using checklists etc to cover the windows (sunlight)
16/Over controlling on the approach (PIO)
17/Slow rotation, not pulling correctly through the dead zone
18/ Changing frequencies then immediatley transmitting
19/- Putting the automatic temperature selector to full low (or even to manual) on a hot summer day
20/Doing the flight control check (rudder part) without holding the tiller
21/Disregarding a gentle suggestion by the FO not to climb to the max level when it is turbulent
22/Going overboard with superfluous confirming switch selections.
23/Pilots who have no idea of immediate actions in event of tail-pipe fire
24/Fuel cross feeding/balancing well before the IMBL caution is alive.
25/Pumping the elevators on rotation and flare
26/Failing to call rotate if the speeds drop out of the FMC.
27/not calling the FMA correctly. LVL CHG is the button you press on the MCP. MCP SPD is the pitch mode that is engaged.
28/flying in V/S when inappropriate
29/people thinking they only have 12 minutes to reach 10 000 feet in an emergency descent
30/people pushing TO/GA before engine are spooled up & around the same value.
31/people thinking "we have him on TCAS" is relevant.
32/..............
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Not using the checklists to cover up the sun.with the sun on the horizon and flying staight into it. If you don't put the checklists up your goin to go blind!! ther green slide on visors are useless. and blue tack to hold them on works wonders.
Thread Starter
Hmmmm Cosmo...... there seems to be quite a few learned pilots that disagree with you about the cruise speed issue. If a test pilot from boeing explained it to you in an undeniably logical fashion that the intent of M0.76 was to give you the largest margins to either high or low speed buffets would you change your thinking on it or is it set in stone?
there seems to be quite a few learned pilots that disagree with you about the cruise speed issue.
“Even when all the experts agree, they may well be mistaken.” - Bertrand Arthur William Russell
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Originally Posted by cosmo
With climb and descent you have the luxury that you can trade altitude to absorb the speed variations, hence it makes sense to choose an airspeed that is in the approximately center of the speed band. In level flight you don't have that luxury,
For the record I never experienced severe turbulence in the Boeing.
IF you have an EADI with buffet indicators on it, surely the best speed is half-way? 0.76 (NG) is a good ball park but not set in stone..
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Now you are nitpicking.
There is a difference between letting the altitude vary but sticking somewhat to around a certain flight level, and letting the aircraft pitch up and down to keep a constant speed with either full- or idle- thrust.
I am sure you know what I meant.
Good to hear that you are still with us, most people seems to confuse moderate turbulence with severe. And since your choice was to declare an emergency and descent, I am sure you would agree that it not really a realistic option to maintain .76 and cruise happily along whilst the aircraft is sometimes uncontrollable.
I'll agree as a compromise, to end the discussion 
But I will maintain that setting .76 accomplishes nothing in light turbulence.
There is a difference between letting the altitude vary but sticking somewhat to around a certain flight level, and letting the aircraft pitch up and down to keep a constant speed with either full- or idle- thrust.
I am sure you know what I meant.
Good to hear that you are still with us, most people seems to confuse moderate turbulence with severe. And since your choice was to declare an emergency and descent, I am sure you would agree that it not really a realistic option to maintain .76 and cruise happily along whilst the aircraft is sometimes uncontrollable.
..0.76 (NG) is a good ball park but not set in stone.
But I will maintain that setting .76 accomplishes nothing in light turbulence.
Last edited by cosmo kramer; 31st Oct 2011 at 15:14.
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Are you suggesting a liesurely descent at normal profile after a decompression? If so I hope I don't fly with your airline.
What I meant to highlight was that a lot of people try to do this in such a rush, forgetting items and thinking they have to be at 10.000' after 12 minutes. In some cases over the Alps it leads to "fun" situations in the simulator.
In fact in the B737 you have the following time:
5' descent till 17.000', then 5' level at 17,000 feet, descent to 14,000, 30 minutes at 14'000, then descent to 10,000.
That was what I was trying to highlight. Knowing this might give you some confidence in dealing with an emergency descent over higher terrain in stead of desperately trying to reach the 10,000 ASAP.
Of course the emergency descent should always be done as per QRH (MMO/VMO).
Hope you'll fly with my airline now
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As far as the autobrakes go, at my airline their use is mandatory unless the system is inop. Your checkie getting annoyed for their use beats mine busting you for not using them! 
Thread Starter
Hey where did this info come from?
I have never seen it before.
Ta.
In fact in the B737 you have the following time:
5' descent till 17.000', then 5' level at 17,000 feet, descent to 14,000, 30 minutes at 14'000, then descent to 10,000
5' descent till 17.000', then 5' level at 17,000 feet, descent to 14,000, 30 minutes at 14'000, then descent to 10,000
Ta.