Jump to content

Sign in to follow this  
LeifApex

737 descend before reaching T/D and mid-flight

Recommended Posts

"Real pilot would disco(nnect) the autopilot….."

Why should they disconnect the a/p?

If I was ordered to descent from FL390 to FL370 I would simply use V/S (vertical speed) mode by setting -1000 ft per minute descent rate (by keeping the A/P on)...why make things complicated when the solution is easier?

And if I think that I'll will have to mantain FL370 for a while I'll adjust the new "cruise level" into my CRUISE PAGE of my CDU and, of course reset also 37000 ft into my overhead pressurization cruise altitude window…

Best Regards

Andrea Buono

  • Upvote 1

Share this post


Link to post
Share on other sites

All you have to do is select the new altitude on the MCP Altitude Window and hit ALT INTV. The airplane will descend on VNAV PTH at a fixed rate of 1000fpm. If you plan to stay long enough at that new altitude, just set up a new CRZ ALT in the CRZ page and change the FLT ALT on the presurization panel. If that's not a new cruise level and you expect to continue descending, when they give you a new cleared level, just set it in the MCP, the airplane will catch the new VNAV PTH and fly it.
Sometimes the instruction is "descend now" and some other times it's "descent at discretion". In one case, you don't have to start your descent until you hit your TOD. In the other case, ATC expect you to descend with at least 500fpm.

  • Like 2
  • Upvote 1

Omar Josef
737/757/767

Share this post


Link to post
Share on other sites

 

On 12/25/2018 at 4:59 PM, vadriver said:

not the first choice near "coffin corner"... the OP's scenario.

Even at max altitude you have a fairly decent range of speed and maneuver margin. I've had to hand bomb it from cruise a few times due to failures causing us to be non-rvsm. 

 


 

Capt. Jason W. -  Airline Captain

Share this post


Link to post
Share on other sites
On 12/25/2018 at 4:59 PM, vadriver said:

not the first choice near "coffin corner"... the OP's scenario.

I think it was a joke. Hence the laugh emoji.


Matt Cee

Share this post


Link to post
Share on other sites
1 hour ago, Spin737 said:

I think it was a joke. Hence the laugh emoji.

Knowing his faible for the 707 and shooting the IGS13 into kai tak manually with raw data it definitely was one 😄 


,

Share this post


Link to post
Share on other sites

I'm not sure if it's the proper procedure, but what I do is dial in the new alt on the MCP, then change the cruise alt in the FMC.
Once in a while the airplane will not seem to respond. If/when that happens I'll just click the VNAV button on the MCP off then on again.
That seems to wake it up.

If ATC has instructed me to 'descend via the XXXXX approach' (STAR) I'll select one of the waypoints where the alt restriction is in the 4-7,000' range AGL (for example 6,000' on app to KLAX would be equivalent to 11,000' on app to KDEN). I'll set the MCP to that alt. I like to start my descent 10-15nm before I reach the calculated TOD in the FMC, especially if I have a healthy tailwind.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
  • Donation Goals

    AVSIM's 2020 Fundraising Goal

    Donate to our annual general fundraising goal. This donation keeps our doors open and providing you service 24 x 7 x 365. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. We reset this goal every new year for the following year's goal.


    42%
    $10,670.00 of $25,000.00 Donate Now
×
×
  • Create New...