Altitude separation FAO - IanF

[scotta]

Whats the minimum height seperation needed between flights?

I was on a flight from LCY to EDI last night. Looking out the window another flight came from the east and passed directly overhead FAST! Flightradar shows less than 1000ft seperation. That normal?

[NotoriousREV]

Can’t see the numbers on the vid. What was the height difference?

[scotta]

Can’t see the numbers on the vid. What was the height difference?

975 feet

go right to the start of the video it shows the height then i click on the second plane and scroll to the height.

[mik]

Vid plays fuzzy at the start for me.

Supposed to be minimum 1000ft separation AFAIK. I use FlightRadar, but not sure how accurate it is.... would probably need proper ATC data to assess, but 975ft sounds about right.

[Simon]

I think 1000 feet is the minimum, but if one plane is above the 'standard' pressure switchover (sorry, I forget the name) and one below it then that could allow for a small discrepancy.

[NotoriousREV]

Can’t see the numbers on the vid. What was the height difference?

975 feet

go right to the start of the video it shows the height then i click on the second plane and scroll to the height.

I get what you’re doing but the numbers aren’t viewable on a mobile phone even full screen

[mik]

More importantly, did you get the pilot to do a 1000rpm to vMax in 3rd?

[scotta]

Can’t see the numbers on the vid. What was the height difference?

975 feet

go right to the start of the video it shows the height then i click on the second plane and scroll to the height.

I get what you’re doing but the numbers aren’t viewable on a mobile phone even full screen

Sent you a higher res one by special message!

[Matty]

More importantly, did you get the pilot to do a 1000rpm to vMax in 3rd?

Reminds me of a story on the SR-71
https://nationalinterest.org/blog/buzz/ ... heck-72136

[Beany]

If we get a reply, and then the news channels start reporting a plane crash, I blame you guys.

[mik]

Dont come on here with your bad altitude Beany.

[Beany]

Dont come on here with your bad altitude Beany.

Ah, stick it up yer flaps.

[scotta]

Dont come on here with your bad altitude Beany.

Ah, stick it up yer flaps.

As long as we dont see your black box...

[nuttinnew]

Maybe so close because a flight was delayed. Was your ride on time?

[tim]

I am not IanF nor do I play him on TV, but I do know that Reduced Vertical Separation Minima is 1000ft with suitably equipped aircraft.

[Orange Cola]

1000ft between commercial aircraft sounds... close to me.

[mik]

Would you propose a Cure?

[Orange Cola]

Certainly wouldn’t be the Clash.

[IanF]

Few things affecting the separation- firstly for a more comfortable ride, the aircraft have a soft hold of their altitude and so fly +/- 50ft from their assigned level. Secondly the three separate air data sources on those aircraft have an acceptable variation of +/- 200ft at high altitudes. (Typically the difference is around 20-30ft). The transponder relates to a particular source on the flight deck which is not necessarily the same one as the autopilot is receiving its altitude info from. Finally, an aircraft hasn’t deviated from it’s assigned level until they are over 200ft away.

The aircraft have a system call tcas that monitors closure rates and prevents them getting too close and ATC have a predictive tool that highlights issues to them aswell.

Tl;dr.- 975ft is fine

[scotta]

Few things affecting the separation- firstly for a more comfortable ride, the aircraft have a soft hold of their altitude and so fly +/- 50ft from their assigned level. Secondly the three separate air data sources on those aircraft have an acceptable variation of +/- 200ft at high altitudes. (Typically the difference is around 20-30ft). The transponder relates to a particular source on the flight deck which is not necessarily the same one as the autopilot is receiving its altitude info from. Finally, an aircraft hasn’t deviated from it’s assigned level until they are over 200ft away.

The aircraft have a system call tcas that monitors closure rates and prevents them getting too close and ATC have a predictive tool that highlights issues to them aswell.

Tl;dr.- 975ft is fine

[mention]IanF[/mention] Ta