A problem with autothrottles?

[stretch1365 40]

Hi all,

 

Took the 737NGX for a spin the other day, and during approach I noticed the following happening.

 

As I followed the approach, this one being fully automated, as I wanted to watch what happened, but the same thing has happened before flying an ILS approach manually too, with speed controlled by the autothrottle system. I noticed that as I slowed down using the speed control on the MCP panel, the autothrottle would reduce the engine power as expected, I would watch the speed drop to the speed selected. Then as the selected speed was passed the throttles wouldn't increase to build the speed back up again!.....................This usually occured at somewhere about 1000-2000ft altitude on my approach not miles away from the runway, and at slow speeds and nearly full flap settings.

 

This seemed a bit strange, my joystick throttle would then not work until the stall protection cut in and suddenly went to full throttle and the aircraft climbed rapidly which made landing impossible.

 

I'm sure this didn't happen a while back but I can't think that I have changed anything recently to make this happen.

 

I had a look on here first to see if I could see any similar comments which might answer my query.......but didn't.

 

Hope someone here can spot if I'm doing something wrong or if it's a snag with my 737! Hopefully it's the pilot not the plane!

 

Regards.

[Fabo 213]

That indeed is strange. See if you can repeat it and watch for FMA modes shown...

[stretch1365 40]

Hi Peter,

 

Thanks for the reply, I'll try and look out next time I have time to fly the 737NGX.........Although the other day I flew the MD11 for about 3 hrs and the same thing happened on approach, Fortunately the MD11 is fitted with stall protection and that kicked in to protect the approach speed!

 

This made me wonder if it's something to do with my sim, or maybe just the fact that it happens when I haven't used a particular aircraft for quite a while....................A while back I had to do a complete re-install and the weather at altitude went all wild with huge variations but now after a few weeks it seems to have calmed down, almost like these problems sort themselves out given the chance!

 

I don't know really but I'll just have to go flying again this weekend and see what happens.

 

Thanks again.

 

David.