Flaws in 737 and FMC

[Mike Maxham]

Hello, I’m Mike. Ima real life 737 3/4/800 Cpt. I had bought the 737 to use because I’m off for my health reasons. I noticed a few flaws in the programming with the Aircraft and FMC.             
#1. as you are on take off roll at 80 kts, the dual que command bars do not come up. The the command switch on, on the MCP panel, must be on. They come on to insure 2nd climb segment and pitch 15* in case of an engine failure. As long as you have your heading bug on the runway of use, you will get guidance. At 400 AGL, is when you either select Lnav or heading select on the MCP for course guidance. At 1000’ AGL is you power call out. Either Vnav on the MCP or climb thrust, speed 210,220, 230 and selecting N1 on the MCP and when you have cleaned up “ flaps up” you select Vnav. Then once you have these selected, your command bars will now have a pitch and roll mode.

#2  The FMC. 
there are a few good flaws that differ from the real aircraft. Let’s say you would like to descend and cross a fix, let’s say 20 miles from the fix at a certain altitude. You would put the fix in the scratch pad. Ie.  IWA/-20 and select it on the fix with the left buttons it will come up. And then on the right side buttons you would speed and altitude ie. 240/10000 and select EXC. then go to your descent page, on that page, you will see the fix and V/S ie.1800 fpm. A top of descent ie. 30 miles where you can use the Vnav option and select Descent now “ that option does no exist on your FMC” wait till get to TOD on its own “ which I don’t like. It puts the aircraft at a 3000’ FPM descent. Or, you can use you V/S mode “ Vertical Speed. “ I use this mode quite a bit when I am flying into and airport with a STAR and I can control the V/S ie. Let say your descent page says 1700 fpm, I would select 1800 fpm for nice comfortable ride”   This option on your FMC does not exist  :(  

Please fell free to contact me

thank you and have a good one 

Mike Maxham

B737 Captain 

 

 

 

[Litjan]

Hi Mike,

About your observations - first, those are very welcome. I have flown the 737 for 10 years, but only the "Classic" variants. I stopped in 2012 (after being CPT for 4 years on it), and we modeled our aircraft after the variants I flew back then - so they aren´t incorporating any newer enhancements, updates to the FMC version or other airline options.

The horizontal flight-director bar was modeled after videos I took of ours during the takeoff run. It stays on the bottom of the EADI until about 80kts or so - then move up swiftly to 15 degrees - you are obviously not supposed to follow them at this time, only after liftoff will they give valid guidance to stay at V2+15 (adjusted for any subsequent speed changes within a certain range).

The VNAV options for descent are not fleshed out yet - we are still working on it. What kind of "works" is an unencumbered descent with no horizontal restrictions, anything else will likely not work and I encourage to use more basic modes along with "old fashioned descent planning" to manage your descents.

Here are some links to what to expect from version 1.33:

https://forums.x-pilot.com/forums/topic/8526-things-that-are-not-going-to-be-in-v133/

https://forums.x-pilot.com/forums/topic/17981-version-133-known-bugs-and-workarounds/

Cheers, Jan

 

[Mike Maxham]

Hi Jan, 

 Thank you so much for getting back with me with the issues. I can completely understand that all the bugs are not worked out yet and there is hope. It is a great program to fly and so far the most realistic. Cameron has been very patient with me and guiding me with the correct answers.

 I too mostly fly the classic. 4 years in aircraft and 2 as a Cpt. I love it so much. I do fly the 800 as well, but there are round dials in the screens. Sense we have 3 different types of 737, they all must have round gauges just like Southwest did.

 

[Litjan]

14 minutes ago, Mike Maxham said:

I love it so much.

Hi Mike,

we do share that feeling! The years on the 737 were the best in my airline career, flying the 747-400 was nice...but you rarely ever flew it. Maybe from OM to touchdown .

They sent me on to the A320 in 2012 and I still miss my 737 every time I fly with a FAC or SEC...

Please keep the feedback coming, we are currently in the big "VNAV rewrite" - it is a complex beast and the initial attempt (as you found out), fell short of the target. Our last big push fixed a lot of problems with the lateral procedures, especially with entering and amending them...and we feel we have reached a fairly stable state with those. To get there with VNAV is our declared goal.

Cheers, Jan