CWS pitch and level off

[Jack C 8]

If yo are climbing out on AP and lets say you have 15000 set on the mcp. Lets say at 10000 you override the pitch mode by force the control column forward. The AP will got into CWS P and keep its lateral mode in tact. Now approaching 14000, IF I remember correctly the AP SHOULD reengage the pitch control and level off at 14000. I just flew the NGX and didn't do this. It continued the climb right through 15000 and the pitch bars didn't even reengage. Its been a while since I've been on the NG but can someone on the team verify this is what the NG is supposed to do. 

Jack Colwill

[Spin737 102]

Not on the team, but: If you are in CWS-P from 10,000, the plane should go in to ALT ACQ and ALT HOLD at 15,000.

 

It could be a fiddly thing with your A/P engagement settings. You'd have to ask a sim expert on that.

[Jack C 8]

Yeah that's what I thought Matt. I'll check my controller and see if it's not conflicting.

Jack Colwill

[downscc 1,327]

Check the FMA too, I'd expect a white pitch mode status until ALT ACQ.  I've never tried it so it could be a feature missing and if so it's be great to have a trouble ticket submitted with a reference to documentation that supports this feature.  From the trouble ticket it becomes an item in the bug tracking system, otherwise it stands a good chance of being lost.

[Spin737 102]

 

 

Check the FMA too, I'd expect a white pitch mode status until ALT ACQ.

 

IIRC it won't have a mode and the pitch bar will bias out. CWS-P should be in yellow on the PFD. Once you're in ALT ACQ, you'll get the FMA and the pitch bar back.

[downscc 1,327]

IIRC it won't have a mode and the pitch bar will bias out. CWS-P should be in yellow on the PFD. Once you're in ALT ACQ, you'll get the FMA and the pitch bar back.

That makes more sense. Thanks Matt.

[Guest]

Probably something for the next update and I don't know if this is a change to all Boeing aircraft or just our 737's but since about a year ago you can no longer engage A/P CWS by overriding the control column, it will disconnect the A/P whilst maintain any active flight director pitch and roll modes.

 

You can only engage CWS by pushing a CWS switch, engaging an A/P without a pitch and/or roll mode or deselecting a pitch/roll mode with the A/P engaged or a route discontinuity (CRS R).

Once CWS is engaged you can then use the control wheel to climb and descend and as Matt said, when approaching your cleared MCP altitude CWS P will chance to ALT ACQ then ALT HOLD.

With CWS engaged you are basically flying the aircraft through the A/P, I've never used it intentionally.
 

[Stearmandriver 2,270]

Only times I've tried it out was by deselecting VNAV when climbing on autopilot, so I could smooth out the pitch changes in turbulence. This works well because if you do it this way, you're still in CMD - which means that you have altitude protection because the autopilot will capture the set altitude for you.

[ALF1 15]

When you do that, what happens with the pitch mode annunciation. You are climbing at N1 climb power in the A/T right ?, how do you get airspeed protection ?

[Spin737 102]

When you do that, what happens with the pitch mode annunciation. You are climbing at N1 climb power in the A/T right ?, how do you get airspeed protection ?

I don't think that'll have a reversion mode, so it's up to you!

 

If you keep an eye on the pitch during normal flight, you can set an approximate pitch. Say 9 deg to start and go from there as you climb.

[ALF1 15]

Thanks Matt, no pitch bar you say on the FD.

 

What happens if you are using the single cue V command bars type FD ?

[Stearmandriver 2,270]

Correct, no FD pitch bar. Pitch mode annunciation is the small CWS. No airspeed protection; you're controlling the pitch and therefore the climb speed. It's just like flying raw data, but for pitch only. I think it's important to distinguish entering CWS this way vs pushing the CWS button though; because I think if you push the CWS button you don't get any altitude protection and therefore can't do this in RVSM airspace. If you start in CMD and then deselect the pitch mode, the autopilot will still intervene and capture the set altitude.

 

No idea what happens with V bars. Worth a try in the NGX!

[ALF1 15]

Got it ! thanks to the pros. This has been a learning experience. I will try it in the NGX because I fly with the single cue V

[Spin737 102]

 

 

What happens if you are using the single cue V command bars type FD ?

 

I have wanted to know that for a long time, myself!

 

I started airline flying on a single-cue and I miss it quite a bit.

 

 

 

the plane should go in to ALT ACQ and ALT HOLD

 

I did a level off from CWS-P and it did NOT go in to ALT ACQ, it went directly to ALT HOLD.