For those of you who, like my, mainly fly the 737NGX using the information from the tutorial #1 as some sort of checklist for other flights, I have a little tip regarding when to enable Cmd B for an autoland. After completing the tutorial a few times, I 'translated' it to some sort of checklist (see http://forum.avsim.n...ost__p__2058394 or http://forum.avsim.n...ost__p__2060376 for an updated version) to use on flights from and to other airports. Everything worked fine apart from the autoland. Well, to be more precise: apart from turning on Cmd B in order to autoland. Even though I followed the tutorial (when to do what) as strictly as possible, I always got into trouble when the tutorial says to engage Cmd B. You should do that after pressing APP. But everytime I did that, pressing Cmd B resulted in Cmd A turning off... and vice versa. This usually led to some frantic buttonpressing until suddenly things seemed to stick... and the autoland (usually) went well, despite all. After some time I found out that you should wait with turning on Cmd B until you can enter Vref+5 in the speed window! So engage VOR/LOC, when LOC is intercepted engage APP but do NOT yet turn on Cmd B after that! Simply proceed as you should, lowering flaps at the right moment, lowering gear, etc. until you see you can actually enter Vref+5 in the Speed window on the MCP (which btw might only happen quite close to landing already, but that doesn't seem to matter)! As soon as you can do that, you can also engage Cmd B and both A and B will stay on at that moment and the autoland will be completed without any need for panic. This probably is old news for veteran pilots but 'discovering' this made my appraoches a lot more relaxed. ;) Obviously you have to adapt everything from the tutorial to your current flight: the order in which I have to lower flaps, engage VOR/LOC, etc. usually is a bit (or a lot) different from the tutorial flight (because for instance you often approach the airport at a different height, angle, speed, etc. etc.). It just never occured to me that enabling Cmd B for autoland isn't something that has to follow enabling APP directly! The tutorial led me to believe this was sort of 'one step', but it's not. So if you are also having problems with enabling Cmd B and Cmd A turning off, wait until you can enter Vref and all should be fine.

Thanks for the post!

Also if you are enabling Fail Operational mode,CMD will only come on and allow LAND 3 if you select the Flaps 35 VREF+5(not FLAPS 40) in the CDU and apply that speed to the MCP. Alex Chung

For those of you who, like my, mainly fly the 737NGX using the information from the tutorial #1 as some sort of checklist for other flights, I have a little tip regarding when to enable Cmd B for an autoland. After completing the tutorial a few times, I 'translated' it to some sort of checklist (see http://forum.avsim.n...ost__p__2058394 or http://forum.avsim.n...ost__p__2060376 for an updated version) to use on flights from and to other airports. Everything worked fine apart from the autoland. Well, to be more precise: apart from turning on Cmd B in order to autoland. Even though I followed the tutorial (when to do what) as strictly as possible, I always got into trouble when the tutorial says to engage Cmd B. You should do that after pressing APP. But everytime I did that, pressing Cmd B resulted in Cmd A turning off... and vice versa. This usually led to some frantic buttonpressing until suddenly things seemed to stick... and the autoland (usually) went well, despite all. After some time I found out that you should wait with turning on Cmd B until you can enter Vref+5 in the speed window! So engage VOR/LOC, when LOC is intercepted engage APP but do NOT yet turn on Cmd B after that! Simply proceed as you should, lowering flaps at the right moment, lowering gear, etc. until you see you can actually enter Vref+5 in the Speed window on the MCP (which btw might only happen quite close to landing already, but that doesn't seem to matter)! As soon as you can do that, you can also engage Cmd B and both A and B will stay on at that moment and the autoland will be completed without any need for panic. This probably is old news for veteran pilots but 'discovering' this made my appraoches a lot more relaxed. ;) Obviously you have to adapt everything from the tutorial to your current flight: the order in which I have to lower flaps, engage VOR/LOC, etc. usually is a bit (or a lot) different from the tutorial flight (because for instance you often approach the airport at a different height, angle, speed, etc. etc.). It just never occured to me that enabling Cmd B for autoland isn't something that has to follow enabling APP directly! The tutorial led me to believe this was sort of 'one step', but it's not. So if you are also having problems with enabling Cmd B and Cmd A turning off, wait until you can enter Vref and all should be fine.

Interesting !.........................But !!!! If you can't press CMD B immediately after pressing APP then you are doing something wrong.Once in APP mode you can engage the second autopilot anytime (or immediately) before 800 ft.That goes for either fail operational or fail passive and with either MCP (Honeywell or Collins) Flaps and Vref speeds have nothing to do with being able to engage a second autopilot. I will presume you are using Hotfix 3 !!

Also if you are enabling Fail Operational mode,CMD will only come on and allow LAND 3 if you select the Flaps 35 VREF+5(not FLAPS 40) in the CDU and apply that speed to the MCP. Alex Chung

Whoa flaps 35? or flaps 30?

I noticed the same thing. Even after plane was tracking localizer I still could not engage two CMD at same time. At some point down the approach they both stayed on. I think it was below 1500 feet but not sure. You say it is when the ASI goes from blank to Vref+5 speed. Didn't pay attention to that although when it did engage I noticed that ASI was showing Vref+5. I will try again and pay close attention to what you discovered. Thank you for the info.

Also if you are enabling Fail Operational mode,CMD will only come on and allow LAND 3 if you select the Flaps 35 VREF+5(not FLAPS 40) in the CDU and apply that speed to the MCP. Alex Chung

According to the FCOM1 autoland can be with Flaps 30 OR FLAPS 40. FCOM1 L.10.6. I have no problem using Flaps 40 if necessary and still get full autoland and I am using Fail Operational Mode equipment.

Whoa flaps 35? or flaps 30?

30' NG doesn't have a 35 silly :(

Interesting !.........................But !!!! If you can't press CMD B immediately after pressing APP then you are doing something wrong.Once in APP mode you can engage the second autopilot anytime (and immediately) before 800 ft.That goes for either fail operational or fail passive and with either MCP (Honeywell or Collins)

Well, I certainly won't argue with a Retired 737NG Pilot! But I can't see what I am doing wrong... As I said I follow the tutorial to the letter, but whenever I enable APP I can not enable BOTH AP's: turning on one always turns of the other... until I am in a certain configuration (which is when you can enter Vref+5 on the MCP). Well, maybe this means I am flying in too fast during intercepting LOC and G/S, but I never have to use speedbrakes or anything like that and I always get great and smooth autolandings... I know my 'tip' isn't an explanation: it's just a 'trick' that helps me to perform good landings and I don't know why it works like it does (and apparently I am not the only one who has problems with this). Would be great of course to find out why it works like it does on ALL my flights!

Well, I certainly won't argue with a Retired 737NG Pilot! But I can't see what I am doing wrong... As I said I follow the tutorial to the letter, but whenever I enable APP I can not enable BOTH AP's: turning on one always turns of the other... until I am in a certain configuration (which is when you can enter Vref+5 on the MCP). Well, maybe this means I am flying in too fast during intercepting LOC and G/S, but I never have to use speedbrakes or anything like that and I always get great and smooth autolandings... I know my 'tip' isn't an explanation: it's just a 'trick' that helps me to perform good landings and I don't know why it works like it does (and apparently I am not the only one who has problems with this). Would be great of course to find out why it works like it does on ALL my flights!

A screenshot would be a big help !! Only use VOR/LOC if you are still to high for the glideslope ! Fred.

Whoa flaps 35? or flaps 30?

Sorry, Flaps 30 was what I meant Alex Chung

A screenshot would be a big help !! Only use VOR/LOC if you are still to high for the glideslope ! Fred.

Ok, so if you are low enough, you can skip VOR/LOC and enable APP right away? Anyway, during my next flight I will not wait for the Speed window to 'open' before enabling Cmd B but I'll do it right after turning on APP and make a screenshot if Cmd A is turned off automatically. I also think that will help a lot. BTW For me there is no problem at all because things do work fine (in the end) but if I am apparently doing something wrong, I really like to find out what it is!

Ok, so if you are low enough, you can skip VOR/LOC and enable APP right away? Anyway, during my next flight I will not wait for the Speed window to 'open' before enabling Cmd B but I'll do it right after turning on APP and make a screenshot if Cmd A is turned off automatically. I also think that will help a lot. BTW For me there is no problem at all because things do work fine (in the end) but if I am apparently doing something wrong, I really like to find out what it is!

That is correct ! A good rule of thumb is to be at 3000 ft (if possible) 10 miles out.That will facilitate localiser capture first and then glideslope.Use the runway dotted centre line on the ND to put yourself on a good Localizer intercept heading.30-45 degress is good in most cases.Press APP and that is all you should need for Localizer and glideslope capture. One reason that I can think of regarding your problem is that you might not be on a good intercept for the localizer when you pressed APP.Very important that you are not too high at this stage.

One reason that I can think of regarding your problem is that you might not be on a good intercept for the localizer when you pressed APP.Very important that you are not too high at this stage.

Well, I can say that isn't the reason (I think ) because (up to now) I always only press APP when LOC is already intercepted. Usually approaches are perfect thanks to the FMC calculations (and me carefuly picking a good transition that brings me on a good approach path to the runway).

That is correct ! A good rule of thumb is to be at 3000 ft (if possible) 10 miles out.That will facilitate localiser capture first and then glideslope.Use the runway dotted centre line on the ND to put yourself on a good Localizer intercept heading.30-45 degress is good in most cases.Press APP and that is all you should need for Localizer and glideslope capture. One reason that I can think of regarding your problem is that you might not be on a good intercept for the localizer when you pressed APP.Very important that you are not too high at this stage.

The way I usually do it is to use the V/S mode/LNAV to intercept the G/S dot from just above/below (at altitudes of up to 6000 ft AGL) then follow it with V/S until G/S capture. For final approaches where the loc course is less than 45 degrees from the intercept course, this is a very useful and highly interactive method. I recommend giving it a go.