White bug on speed tape during approach - clarification re: use ?

[WilloW_737 5]

Greetings

 

Concerning the white-coloured bug located on the speed tape,  that is displayed when you select VREF in the CDU.  The bug reads VREF + 20.

 

I have been told that this bug is used as reference for two things - 1:  as a speed marker for one engine only during TOGA; and 2: as a bug to set the MCP speed to when making your initial descent after the Initial Approach FIX (IAF).

 

Can someone clarify its this please ??

 

Thank You,    WilloW

[WilloW_737 5]

Hi

 

92 views and no one knows the answer....   Surely there are a few real B737 pilots or a PMDG developer that can provide clarification on the use of the white bug.

 

Thanks,    WilloW

[scandinavian13 5,192]

 

 

92 views and no one knows the answer....   Surely there are a few real B737 pilots or a PMDG developer that can provide clarification on the use of the white bug.

 

Not sure what you need clarification on since it seems you've answered the question for yourself with this:

 

 

 

I have been told that this bug is used as reference for two things - 1:  as a speed marker for one engine only during TOGA; and 2: as a bug to set the MCP speed to when making your initial descent after the Initial Approach FIX (IAF).

 

1 is pretty self-explanatory. It's a single engine speed for climb during TOGA. It's similar to the concepts of Vx or Vy (in this case, either Vxse or Vyse with the 'se' for single engine, and my bet would be that it's Vyse).

2 is also pretty self-explanatory. It's a bug to set your speed to when making an initial descent after the IAF of the approach. You don't want to fly your approach at 240, or 220. The bug is simply a guide to get you closer to Vref prior to getting fully configured and settled on Vref + 5.

 

I guess the better question here would be what are you not understanding with these two concepts that requires clarification? That's probably why you're seeing that the topic has views without responses.

 

Also, real names here, please:

http://forum.avsim.net/topic/245586-you-must-sign-your-full-real-name-to-posts-to-use-this-forum-posts-without-names-will-be-deleted/

[Spin737 102]

On departure, don't bank more than 15 degrees and don't start flap retraction until you're above the bug.

 

On approach, hmm. Single engine failure target speed for a failure on final.

 

It's funny. There really isn't much in the books. I think it might be vestigial from the -100 and -200.

[WilloW_737 5]

Hi Kyle and Matt

 

Many thanks for your explanation.  I understand the concepts Kyle, but did not understand the purpose of the white bug because as Matt stated, I could not find much information concerning this in any literature.  I probably should have worded my question differently.  I just found it odd that the bug was there yet nothing had been really documented concerning its use.

 

Thank you again.   Best,   Iain (aka WilloW)

[scandinavian13 5,192]

 

 

Many thanks for your explanation.  I understand the concepts Kyle, but did not understand the purpose of the white bug because as Matt stated, I could not find much information concerning this in any literature.  I probably should have worded my question differently.  I just found it odd that the bug was there yet nothing had been really documented concerning its use.

 

Valid question. I was just a little confused as to what more you wanted out of it. I honestly hadn't paid much attention to it, so I'm glad you asked despite the confusion.