Sign in to follow this  
dmwalker

Question regarding the Wind Direction/Speed indication on th

Recommended Posts

What is the logic for when the wind direction/speed values are shown on the B777 ND?

In my case, they are not displayed at take-off until about 4400ft altitude. In some videos, they are shown just after V1. In the case of the PMDG Tutorial video, they were not shown at all.

Videos of real life take-offs don't usually focus on the ND but the few that I could see showed the values displaying at around V1 or VR.

There are similar differences during descent and landing, including real life videos.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

13 minutes ago, dmwalker said:

What is the logic for when the wind direction/speed values are shown on the B777 ND?

When there is wind - display it.

Most likely, the issue is that the wind is calm, so there's nothing to display.

The tutorial has you fly in clear weather, so this makes sense.

Share this post


Link to post
Share on other sites

The ND wind vector is shown when winds are above 5 kts I believe.  Should not have anything to do with phase of flight, I've seen it come alive during takeoff rolls.

Share this post


Link to post
Share on other sites

Like Dan says wind has to be above 5 knots.  Additionally the true airspeed has to be above 100 knots.

Share this post


Link to post
Share on other sites

I was going to ask about the airspeed. 100 knots makes sense as it seemed to be between 80 knots and V1.

Thank you.

Share this post


Link to post
Share on other sites
7 hours ago, dmwalker said:

I was going to ask about the airspeed. 100 knots makes sense as it seemed to be between 80 knots and V1.

Thank you.

Think about it... there is no direct wind sensor.  The wind speed and direction is calculated by the system based on IRS/GPS/DME sensors.  It cannot be calculated with any accuracy until the airframe is in motion and the value you see while on the ground is, ... well, I wouldn't put much confidence in the direction.

Share this post


Link to post
Share on other sites
8 hours ago, dmwalker said:

I was going to ask about the airspeed. 100 knots makes sense as it seemed to be between 80 knots and V1.

Thank you.

For the last 50 plus years all I have ever cared about is KIAS.  The aircraft tells me the rest. 🙂

Grace and Peace, 

Edited by Bluestar

Share this post


Link to post
Share on other sites
52 minutes ago, downscc said:

Think about it...

That's the hard part for me - the thinking - but now I understand. Thank you.

 

31 minutes ago, Bluestar said:

For the last 50 plus years all I have ever cared about is KIAS.  The aircraft tells me the rest.

"Words of wisdom from one who knows whereof he speaks."

Edited by dmwalker

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