Discussion
Yep. Guidance calls for 3 minute/7NM gap between an A380 and 737/A320 size aircraft.
A business jet was written off after flying through an A380 wake en-route.
https://www.flightsafetyaustralia.com/2018/01/down...
A business jet was written off after flying through an A380 wake en-route.
https://www.flightsafetyaustralia.com/2018/01/down...
In still/certain light wind conditions, wake can linger for a long time, and can easily cause even a large jet to be thrown around.
There’s a required separation of 4-8 miles between jets on approach, depending on their heft. This has the added disadvantage of a headwind slowing down the aircraft arrival rate - as aircraft take longer to cover said 4-8 miles.
Wake turbulence is potentially nasty business - but because wake dissipates faster when there’s wind, Heathrow devised a time-based separation procedure which is now spreading to other large airports which operate close to max capacity.
This allows aircraft to be closer-spaced on approach, while maintaining the ‘wake safety’ of the previous distance-based separation. In turn, this maintains the aircraft arrival rate.
There’s a required separation of 4-8 miles between jets on approach, depending on their heft. This has the added disadvantage of a headwind slowing down the aircraft arrival rate - as aircraft take longer to cover said 4-8 miles.
Wake turbulence is potentially nasty business - but because wake dissipates faster when there’s wind, Heathrow devised a time-based separation procedure which is now spreading to other large airports which operate close to max capacity.
This allows aircraft to be closer-spaced on approach, while maintaining the ‘wake safety’ of the previous distance-based separation. In turn, this maintains the aircraft arrival rate.
As a fairly frequent flier on smaller planes out of LHR, I always groan when I see an A380 in the queue in front of our plane.
Have witnessed wake turbulence once, fortunately almost at cruising altitude. Sudden and absolutely like nothing else. I can understand why it would be avoided at all costs near the ground.
Have witnessed wake turbulence once, fortunately almost at cruising altitude. Sudden and absolutely like nothing else. I can understand why it would be avoided at all costs near the ground.
mcdjl said:
If you stand in the right place at Donington Park you can hear the wake whistle through the catch fencing a good few seconds after a plane has landed at East Mids airport next door.
Easy to experience at Heathrow as well, and the whistle made by the A380 is very noticably louder and of longer duration than any other aircraft.This is a nice little video I watched a while ago that explains things: https://youtu.be/XBZULOoe94U
Found it quite interesting.
Found it quite interesting.
If anyone remembers that horrific New York crash where the tail fin snapped off an Airbus, that was, I believe, in part because it flew through the wake of a large aircraft from the aircraft in front.
https://en.wikipedia.org/wiki/American_Airlines_Fl...
https://en.wikipedia.org/wiki/American_Airlines_Fl...
b
hstewie said:
hstewie said: If anyone remembers that horrific New York crash where the tail fin snapped off an Airbus, that was, I believe, in part because it flew through the wake of a large aircraft from the aircraft in front.
https://en.wikipedia.org/wiki/American_Airlines_Fl...
That wasn't the cause of the accident. NTSB found that the crash resulted from the separation of the vertical stabiliser, caused by the pilot's unnecessary / excessive inputs to the rudder pedals. https://en.wikipedia.org/wiki/American_Airlines_Fl...
Puggit said:
As a fairly frequent flier on smaller planes out of LHR, I always groan when I see an A380 in the queue in front of our plane.
Have witnessed wake turbulence once, fortunately almost at cruising altitude. Sudden and absolutely like nothing else. I can understand why it would be avoided at all costs near the ground.
Highly unlikely to have been wake turbulence at altitude, sounds more like CAT (Clear Air Turbulence).Have witnessed wake turbulence once, fortunately almost at cruising altitude. Sudden and absolutely like nothing else. I can understand why it would be avoided at all costs near the ground.
48k said:
Highly unlikely to have been wake turbulence at altitude, sounds more like CAT (Clear Air Turbulence).
I’ve hit wake turbulence many times at altitude. Definitely not as prevalent but in the right conditions (routinely over the still-air polar routes, same direction aircraft 1000 above) you may well get a gutful of it. My company send us off as a flock to Europe in a minimally-spaced conga line, same routing (for the first 9 hours), same jet, same weights and therefore same altitudes. Consequently I seem to spend half my life offset a mile or two upwind of the airway centreline.
DanL said:
This is a nice little video I watched a while ago that explains things: https://youtu.be/XBZULOoe94U
Found it quite interesting.
I might have to add him. As an enthusiastic newbie to the aviation industry I've learned a lot from Wendover and others.Found it quite interesting.
48k said:
Highly unlikely to have been wake turbulence at altitude, sounds more like CAT (Clear Air Turbulence).
I’ve lost count of the number of reports I’ve had to file as an Air Traffic Controller regarding wake turbulence encounters at altitude. As Testaburger says in the age of extremely accurate navigation it’s common for aircraft to fly in a very neat line and consequently occasionally encounter the wake of aircraft in front. Not limited to the A380 either although it is the worst offender for obvious reasons48k said:
Interesting cheers chaps, I sit corrected. I'd always associated wake turbulance with being low and slow.
That’s generally the case - aerodynamically the wing configured for takeoff produces a bigger wake. Also, the wind is generally far greater up there, which dissipates the wake more quickly.
Even with required separation you can get caught up in it for a while. As I mentioned, I’m usually in a conga line of identical departing aircraft flying the same departure track. It’s very common to be flying in their wake from takeoff up to altitude - so we’ll either dial the speed back to increase the climb gradient or perhaps decline a corner-cutting shortcut that the preceding jet got, so we escape their path. The navigational accuracy of these things is deeply impressive now!
Just some pointless info for you
louiebaby said:
DanL said:
This is a nice little video I watched a while ago that explains things: https://youtu.be/XBZULOoe94U
Found it quite interesting.
I might have to add him. As an enthusiastic newbie to the aviation industry I've learned a lot from Wendover and others.Found it quite interesting.
Gassing Station | Boats, Planes & Trains | Top of Page | What's New | My Stuff