737 Questions
Thread Starter
Join Date: Dec 2008
Location: Birmingham
Age: 39
Posts: 181
Likes: 0
Received 0 Likes
on
0 Posts
737 Questions
Hey friends,
talking about a 737 classic.
1.)In case of dual generator failure. Starting APU and you should connect the GEN 2 first to charge the battery through the TR3. Why? Don´t understand because GEN 2 powers the mainbus and the battery charger is then supplied? Where´s my fault?
2.) How long can the speedbrake be deployed. I mean with which flap setting? up to flaps 15?
3.)Where in the MEL can I find wether i have to have the athr engaged during the CAT III or not?
4.) Imagine ATHR is okay during CATIII approach and it does not retard. Can i retard the thrust levers on my own? So disconnect the autothrottle and pull them back?
5.) Is a cat III II landing in contaminated runway allowed? Which penalty must be applied?
6.) When the ATHR is in HLD during takeoff till 400ft AGL and i get a windshear in 200 ft AGL and pressing the TOGA buttons, nothing will happen right?
talking about a 737 classic.
1.)In case of dual generator failure. Starting APU and you should connect the GEN 2 first to charge the battery through the TR3. Why? Don´t understand because GEN 2 powers the mainbus and the battery charger is then supplied? Where´s my fault?
2.) How long can the speedbrake be deployed. I mean with which flap setting? up to flaps 15?
3.)Where in the MEL can I find wether i have to have the athr engaged during the CAT III or not?
4.) Imagine ATHR is okay during CATIII approach and it does not retard. Can i retard the thrust levers on my own? So disconnect the autothrottle and pull them back?
5.) Is a cat III II landing in contaminated runway allowed? Which penalty must be applied?
6.) When the ATHR is in HLD during takeoff till 400ft AGL and i get a windshear in 200 ft AGL and pressing the TOGA buttons, nothing will happen right?
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes
on
0 Posts
I'll have a crack:
1.)In case of dual generator failure. Starting APU and you should connect the GEN 2 first to charge the battery through the TR3. Why? Don´t understand because GEN 2 powers the mainbus and the battery charger is then supplied? Where´s my fault?
What else does TR3 do?
2.) How long can the speedbrake be deployed. I mean with which flap setting? up to flaps 15?
No limit but best not more than F5 due to tailplane buffet - don't want it falling off, do we?
3.)Where in the MEL can I find wether i have to have the athr engaged during the CAT III or not?
Not in MEL - in your AWOPS limitations section - A/T mandatory IF AVALABLE.
4.) Imagine ATHR is okay during CATIII approach and it does not retard. Can i retard the thrust levers on my own? So disconnect the autothrottle and pull them back?
Yes, (or just close them) just do not press TOGA
5.) Is a cat III II landing in contaminated runway allowed? Which penalty must be applied?
LDA check plus what are your AWOPS crosswind limits in your OM?
6.) When the ATHR is in HLD during takeoff till 400ft AGL and i get a windshear in 200 ft AGL and pressing the TOGA buttons, nothing will happen right?
Are you not at TOGA already? What does QRH say you should do?
1.)In case of dual generator failure. Starting APU and you should connect the GEN 2 first to charge the battery through the TR3. Why? Don´t understand because GEN 2 powers the mainbus and the battery charger is then supplied? Where´s my fault?
What else does TR3 do?
2.) How long can the speedbrake be deployed. I mean with which flap setting? up to flaps 15?
No limit but best not more than F5 due to tailplane buffet - don't want it falling off, do we?
3.)Where in the MEL can I find wether i have to have the athr engaged during the CAT III or not?
Not in MEL - in your AWOPS limitations section - A/T mandatory IF AVALABLE.
4.) Imagine ATHR is okay during CATIII approach and it does not retard. Can i retard the thrust levers on my own? So disconnect the autothrottle and pull them back?
Yes, (or just close them) just do not press TOGA
5.) Is a cat III II landing in contaminated runway allowed? Which penalty must be applied?
LDA check plus what are your AWOPS crosswind limits in your OM?
6.) When the ATHR is in HLD during takeoff till 400ft AGL and i get a windshear in 200 ft AGL and pressing the TOGA buttons, nothing will happen right?
Are you not at TOGA already? What does QRH say you should do?
1.)In case of dual generator failure. Starting APU and you should connect the GEN 2 first to charge the battery through the TR3. Why? Don´t understand because GEN 2 powers the mainbus and the battery charger is then supplied? Where´s my fault?
What else does TR3 do?
737 Electrics
2.) How long can the speedbrake be deployed. I mean with which flap setting? up to flaps 15?
No limit but best not more than F5 due to tailplane buffet - don't want it falling off, do we?
Not recommended more than flap five due increased roll sensitivity.
3.)Where in the MEL can I find wether i have to have the athr engaged during the CAT III or not?
Not in MEL - in your AWOPS limitations section - A/T mandatory IF AVALABLE.
Under the MEL for the autothrottle, I would think. Autoland with manual throttle permitted in my company.
4.) Imagine ATHR is okay during CATIII approach and it does not retard. Can i retard the thrust levers on my own? So disconnect the autothrottle and pull them back?
Yes, (or just close them) just do not press TOGA
5.) Is a cat III II landing in contaminated runway allowed? Which penalty must be applied?
LDA check plus what are your AWOPS crosswind limits in your OM?
My company has a requirement for edge and/or centre lighting to be visible on any contaminated landing. More restrictive crosswind limits apply. Other than that, there are no specific restrictions.
6.) When the ATHR is in HLD during takeoff till 400ft AGL and i get a windshear in 200 ft AGL and pressing the TOGA buttons, nothing will happen right?
Are you not at TOGA already? What does QRH say you should do?
TOGA is a Flight Director and autopilot mode. The autothrottle will be in THR HLD. If you're in performing a reduced thrust take-off with the N1 bugs in Auto, the calculated reduced thrust will be bugged on the N1 gauges. Pressing the TOGA button below 800feet will change the thrust limit mode to GA, and the GA thrust limit will bug on the N1 (to give you something to aim at should you have pressed the TOGA due to a need to increase thrust) - you have to manually increase thrust. Above 800 feet the autothrottle will advance to GA thrust (as it exits THR HLD to N1 mode automatically at 800').
What else does TR3 do?
737 Electrics
2.) How long can the speedbrake be deployed. I mean with which flap setting? up to flaps 15?
No limit but best not more than F5 due to tailplane buffet - don't want it falling off, do we?
Not recommended more than flap five due increased roll sensitivity.
3.)Where in the MEL can I find wether i have to have the athr engaged during the CAT III or not?
Not in MEL - in your AWOPS limitations section - A/T mandatory IF AVALABLE.
Under the MEL for the autothrottle, I would think. Autoland with manual throttle permitted in my company.
4.) Imagine ATHR is okay during CATIII approach and it does not retard. Can i retard the thrust levers on my own? So disconnect the autothrottle and pull them back?
Yes, (or just close them) just do not press TOGA
5.) Is a cat III II landing in contaminated runway allowed? Which penalty must be applied?
LDA check plus what are your AWOPS crosswind limits in your OM?
My company has a requirement for edge and/or centre lighting to be visible on any contaminated landing. More restrictive crosswind limits apply. Other than that, there are no specific restrictions.
6.) When the ATHR is in HLD during takeoff till 400ft AGL and i get a windshear in 200 ft AGL and pressing the TOGA buttons, nothing will happen right?
Are you not at TOGA already? What does QRH say you should do?
TOGA is a Flight Director and autopilot mode. The autothrottle will be in THR HLD. If you're in performing a reduced thrust take-off with the N1 bugs in Auto, the calculated reduced thrust will be bugged on the N1 gauges. Pressing the TOGA button below 800feet will change the thrust limit mode to GA, and the GA thrust limit will bug on the N1 (to give you something to aim at should you have pressed the TOGA due to a need to increase thrust) - you have to manually increase thrust. Above 800 feet the autothrottle will advance to GA thrust (as it exits THR HLD to N1 mode automatically at 800').
Last edited by Checkboard; 26th Jun 2010 at 21:00.
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes
on
0 Posts
What else does TR3 do?
2.) How long can the speedbrake be deployed. I mean with which flap setting? up to flaps 15?
No limit but best not more than F5 due to tailplane buffet - don't want it falling off, do we?
Not recommended more than flap five due increased roll sensitivity.
No limit but best not more than F5 due to tailplane buffet - don't want it falling off, do we?
Not recommended more than flap five due increased roll sensitivity.
3.)Where in the MEL can I find wether i have to have the athr engaged during the CAT III or not?
Not in MEL - in your AWOPS limitations section - A/T mandatory IF AVALABLE.
Under the MEL for the autothrottle, I would think. Autoland with manual throttle permitted in my company.
Not in MEL - in your AWOPS limitations section - A/T mandatory IF AVALABLE.
Under the MEL for the autothrottle, I would think. Autoland with manual throttle permitted in my company.
can you start apu at any alt? bear in mind start and have allready running apu`s are very different things
most apu`s that i know can be run in the air but not started in the air
its all down to windmilling you know
gs
most apu`s that i know can be run in the air but not started in the air
its all down to windmilling you know
gs
not in any MEL I have seen.
quote from my company's Ops Man:
INFLIGHT CAT 2/3 EQUIPMENT REQUIREMENTS CHECKLIST
Review the autoland status in the Technical Log.
Both engines must be operating.
The Autopilot system is capable of automatic approach and landing for CAT II/IIIA fail passive operations with the following systems operative and FLARE armed annunciated:
System..............................No. Required
Autopilot..............................................2
Radio Altimeter.....................................2
DH Display...........................................2
Digital Air Data Computer Sytem.............2
Windshield Wipers ................................2
ILS receiver and display..........................2
Flight Mode Annunciator (FMA)..................2
IRS in NAV mode ...................................2
Hydraulic Systems ...............................A and B
Electrical Power Sorce (APU may be used)..2
Review the autoland status in the Technical Log.
Both engines must be operating.
The Autopilot system is capable of automatic approach and landing for CAT II/IIIA fail passive operations with the following systems operative and FLARE armed annunciated:
System..............................No. Required
Autopilot..............................................2
Radio Altimeter.....................................2
DH Display...........................................2
Digital Air Data Computer Sytem.............2
Windshield Wipers ................................2
ILS receiver and display..........................2
Flight Mode Annunciator (FMA)..................2
IRS in NAV mode ...................................2
Hydraulic Systems ...............................A and B
Electrical Power Sorce (APU may be used)..2
)
Join Date: Oct 2006
Location: Ankh Morpork, DW
Posts: 652
Likes: 0
Received 0 Likes
on
0 Posts
4. APU procedure is to put APU on busses and wait for 1 minute before using as a bleed source - understand that fine, but what if we are on stand for 30mins in a hot destination and just want to use for A/C with ground power connected? Is there anything stopping using APU for bleed air but not electricity - I would assume it will burn less fuel without providing electric than with electric and air?
Join Date: Oct 2006
Location: Ankh Morpork, DW
Posts: 652
Likes: 0
Received 0 Likes
on
0 Posts
can you start apu at any alt? bear in mind start and have allready running apu`s are very different things most apu`s that i know can be run in the air but not started in the air
its all down to windmilling you know
its all down to windmilling you know
Per Ardua ad Astraeus
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes
on
0 Posts
Bally - I know that 'cabin service' is an archaic notion, but in the days when that fine airline DanAir ran a superb business class cabin service we found that whilst the 'econ' LGW-CDG sector showed FL300+ for a light 737 (with about 1 min at cruise), stopping at FL240 gave a much easier ride for the c/c for heaving trolleys up and down the mountain. Fuel burns were little affected and there were sometimes routing benefits too in the lower sector.
APU-wise
1) Boeing (737) 'recommend' starting below 250 for better start reliability but as IC says, no limit there.
2) DanAir (because of the way our APU maintenance was costed) found the improvement in 'life' by leaving it running LGW-CDG outweighed the fuel costs by eliminating rapid hot-cycling.
APU-wise
1) Boeing (737) 'recommend' starting below 250 for better start reliability but as IC says, no limit there.
2) DanAir (because of the way our APU maintenance was costed) found the improvement in 'life' by leaving it running LGW-CDG outweighed the fuel costs by eliminating rapid hot-cycling.
Join Date: Apr 2005
Location: Australia
Posts: 1,414
Likes: 0
Received 0 Likes
on
0 Posts
gave a much easier ride for the c/c for heaving trolleys up and down the mountain.
Join Date: Dec 2009
Location: Reality
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
DUAL GENERATOR FAILURE
Classic: Select Gen #2 first to be back on-line.
Why? Well Gen #1 cannot provide power to TR3.
While Gen #2 can provide power to ALL TR's.
You might not get a second chance otherwise.
Why? Well Gen #1 cannot provide power to TR3.
While Gen #2 can provide power to ALL TR's.
You might not get a second chance otherwise.
Join Date: Oct 2002
Location: In my seat
Posts: 822
Likes: 0
Received 0 Likes
on
0 Posts
Regarding APU on the classic: either the Garret or the Sunstrandt has a operational ceiling of 35000ft. Beware as the aircraft certified ceiling is Fl 370...So there is a limitation. On NG, all APU versions work untill aircraft certified ceiling.
Join Date: Apr 2004
Location: near EDDF
Posts: 775
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by despegue
...On NG, all APU versions work untill aircraft certified ceiling.
You get the full 90 KVA until FL 320.
Bleed is only available until FL 170.
Bleed and electrical load until FL100.
Join Date: Apr 2012
Location: Above the clouds where the sun is always shining
Age: 33
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
and before you can use it you have to start it which is better to do below FL250
above it's possible to start but a bigger chance it won't start
above it's possible to start but a bigger chance it won't start
Join Date: Jan 2006
Location: toulouse
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
I talking about 737 NG
APU can be started at all level, the only problem is in case of no AC power available ( loss of both EDG), the fuel boost pumps are not powered.
The Fuel supply to the APU will be by feeding line only which reduce the chance of a succesful start.
And you are only on battery power, any unsuccessful start will affect your battery endurance by 7 min i heard
So for me any reference not to start APU above FL 250 is only applicable to this specific scenario and has to do with fuel boost pumps not powered anymore
APU can be started at all level, the only problem is in case of no AC power available ( loss of both EDG), the fuel boost pumps are not powered.
The Fuel supply to the APU will be by feeding line only which reduce the chance of a succesful start.
And you are only on battery power, any unsuccessful start will affect your battery endurance by 7 min i heard
So for me any reference not to start APU above FL 250 is only applicable to this specific scenario and has to do with fuel boost pumps not powered anymore
Last edited by tony montana; 10th Jul 2012 at 07:49.
Join Date: Apr 2004
Location: near EDDF
Posts: 775
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by tony montana
... the only problem is in case of no AC power available ( loss of both EDG), the fuel boost pumps are not powered. ...
It will run with tank 1 (FWD&AFT) boost pump relays OFF and APU SW in ON.
Join Date: Apr 2012
Location: Above the clouds where the sun is always shining
Age: 33
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
So for me any reference not to start APU above FL 250 is only applicable to this specific scenario and has to do with fuel boost pumps not powered anymore
i don't have that much experience yet but i can't think of anything else as you can't use bleed above 170
i looked it up in my manuals and couldn't find it as a limit anymore
it was probably somewhere during the ground course they told us
Join Date: Apr 2012
Location: Above the clouds where the sun is always shining
Age: 33
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
missing windows
I have another question about the -800
I've noticed that on the right hand side there is 1 "missing" window around the engine. I'm thinking it's extra protection in case of an uncontained engine failure but if you look to the left of the aircraft it has also a window missing in the same row AND a 2 rows more to the front.
Does anyone know the reason for this?
I've noticed that on the right hand side there is 1 "missing" window around the engine. I'm thinking it's extra protection in case of an uncontained engine failure but if you look to the left of the aircraft it has also a window missing in the same row AND a 2 rows more to the front.
Does anyone know the reason for this?
Join Date: Oct 2006
Location: Ankh Morpork, DW
Posts: 652
Likes: 0
Received 0 Likes
on
0 Posts
I've noticed that on the right hand side there is 1 "missing" window around the engine. I'm thinking it's extra protection in case of an uncontained engine failure but if you look to the left of the aircraft it has also a window missing in the same row AND a 2 rows more to the front.
Does anyone know the reason for this?
Does anyone know the reason for this?