Having problems with Auto Pilot

[brianparker]

Although it's nice to be called a Captain, I'm afraid it's going to be a while until I qualify for first officer. 8-)

I have been flying around in the lovely 737 classic almost as a VFR aircraft. It flys beautiful like that by the way. 

But that's not what it's supposed to do and I'm starting to go further with the auto pilot, without FMC at the moment. (I'm getting crashes but that is another issue to be dealt with separately).

I'm noticing that in good weather at, for example a stable FL 200 with airspeed of 200 in level flight if I change the airspeed to 220 I get a flashing 0 indicator next to the indicated speed and the airspeed seems limited to somewhat less than I require. If I take manual control I have quite a bit of power left and can build the speed, switch back to auto throttle and I get the same behaviour within a few minutes. I'm feel sure I'm missing something or other.

Thanks for any assistance and advice.

[mmerelles]

1 minute ago, brianparker said:

Although it's nice to be called a Captain, I'm afraid it's going to be a while until I qualify for first officer. 8-)

I have been flying around in the lovely 737 classic almost as a VFR aircraft. It flys beautiful like that by the way. 

But that's not what it's supposed to do and I'm starting to go further with the auto pilot, without FMC at the moment. (I'm getting crashes but that is another issue to be dealt with separately).

I'm noticing that in good weather at, for example a stable FL 200 with airspeed of 200 in level flight if I change the airspeed to 220 I get a flashing 0 indicator next to the indicated speed and the airspeed seems limited to somewhat less than I require. If I take manual control I have quite a bit of power left and can build the speed, switch back to auto throttle and I get the same behaviour within a few minutes. I'm feel sure I'm missing something or other.

Thanks for any assistance and advice.

is a 0 or a 8? it seems you missed to rise the flaps up completely and the aircraft is protecting itself not to ripe them

if you use an external hardware lever for flaps, that is a very bad idea, because xplane does not support nullzone for flaps / speed brakes axis yet, so they seem to be closed but they may be still 0.00001% open

[brianparker]

23 hours ago, mmerelles said:

is a 0 or a 8? it seems you missed to rise the flaps up completely and the aircraft is protecting itself not to ripe them

if you use an external hardware lever for flaps, that is a very bad idea, because xplane does not support nullzone for flaps / speed brakes axis yet, so they seem to be closed but they may be still 0.00001% open

 

23 hours ago, mmerelles said:

is a 0 or a 8? it seems you missed to rise the flaps up completely and the aircraft is protecting itself not to ripe them

if you use an external hardware lever for flaps, that is a very bad idea, because xplane does not support nullzone for flaps / speed brakes axis yet, so they seem to be closed but they may be still 0.00001% open

Yes! It's an 8 usually, I tend not to notice this since I'm an old mainframe computer bloke and zeros and 8's tend to look very similar. Although I'm usually scrupulous about flaps, for my current flight that's exactly what I was doing wrong and it cleared the warning. Other ones though it's definitely not the case and I'll look into it after your advice.

Thanks a lot for your help, much appreciated.

 

[Litjan]

Hi Brian,

thanks for the feedback - I also enjoy just flying it around VFR, got to do that much too little in my time of really flying the 737 .

The flashing 8 is a sign that the autothrust reversion mode has kicked in - trying to help you from breaking the airplane or it´s passengers - It will spring to life if you get too fast for your current configuration, or too slow.

To get out of it, simply increase the selected speed (it will automatically pop to a speed that is still "just" safe) by 15kts in the "right direction" - the flashing should stop, and then you can resume normal flight.

Cheers, Jan

 

[brianparker]

Thank you all for your helpful advice, especially Jan. It tickles me that a pro 737 pilot likes chucking it around the sky in VFR.

 I'm gradually understanding more about this fantastic aircraft. There's a lot of fun and study here.

Groetjes.