High Altitude Wind Speed

[chrisnel]

Hi all, I'm new on here and not a flying professional - just an interested spectator - so treat me gentle!
Flew from Manchester to Southampton yesterday morning and we got there a lot quicker than normal. In fact we took off 45 mins late but arrived only 15 mins late!
In welcoming us to the flight the captain announced that we would catch up time as there was a strong tail wind. Am sure he said of 200mph - maybe I misheard. Could that have been correct? Perhaps he actually said 100mph - even so that seems quite a breeze! Is it normal to get much faster winds at higher levels than down on the ground. I said I was a novice at this!
Look forward to comments.
Chris

[BOAC]

Yes - I have seen well over 200 KNOTS (around 230mph) in my time.

[Cloud Bunny]

Yeah the winds down at ground level rarely reflect what is going on 'upstairs'. There has been a couple of jetstreams (high velocity winds) passing over/close to the UK over the last few days and they can get upto quite some speeds. 200mph sounds plausible. Had similar coming back from Southern Spain recently, only it was a headwind!

[eastern wiseguy]

http://www.wunderground.com/global/R...JetStream.html
Have a look here. The jetstream can be likened to a fast flowing "river" of air. You can see from the example that the speeds do increase quite significantly as altitude increases. This also explains why flights to Europe from the US are generally quicker than flights to the US from Europe.

[K.Whyjelly]

First off, apologies for the quality of the snap but it was a bit dark and a lot bumpy At the time of the morning I took this picture I was just wishing I was in a warm comfy bed not just starting my Atlantic crossing!!

Top left gives ground speed and TAS and just below is the W/V in this case 262 degrees and a velocity of 172kts (which is about 198mph I think).

The wind was due to a strong jet (see above notes) and was a result of Hurricane Noel(??)

Delving into the dim and distant past I seem to recall from ATPL Met that the strongest jet, the subtropical jet at about 30N runs out over China and Japan at up to 300kts

[arem]

<<at up to 300kts>>

cant say I've seen it that high but 250kts I have seen - ANC-NRT one day our gs was below 300kts for a short time - think I may have a picture somewhere - so that was 280kts+ hwc. Sapporro's weather took on some added significance that day!

[chrisnel]

Many thanks for the responses. KW, have "tweaked" your pic slightly so numbers are more readable. That's fascinating, thank you. Pardon my complete ignorance but am assuming TAS is true air speed?
It all makes sense now. So it seems feasible then that a 200mph tailwind helped to halve the journey time south to Southampton. And was probably also the reason why we took our time getting back north the same day.

[The Flying Pram]

There can be significant changes in wind speed/direction even at much lower levels. Many is the time I have taken off in a light (5-7kt) breeze, only to find at 1000ft it's 15-20kt. This could easily increase to 30kt or more at 2-3000ft, which makes a hell of a difference to me as my microlight only cruises at 45kt!! Near the East coast we often get an "Inversion" where a cold easterly wind suddenly gives way to a much warmer westerly flow, some times at as little as 600ft.

[AnthonyGA]

The question that I find myself asking is: How abrupt are the transitions between these wind speeds? A 200-knot wind at 30,000 feet should be harmless enough in itself (albeit frustrating if you're trying to fly against it), but an abrupt transition between a layer at 200 kts and one at 180 kts could be pretty scary. A change in direction would be equally unsettling.

So ... how abrupt are the transitions at high altitudes? Can you feel it (I've been a passenger in airliners and felt turbulence, but of course I had no way of knowing wind speeds at the time)? I seem to recall reading that the transitions were a significant source of CAT.

[AircraftOperations]

Going back to the original post:

"In fact we took off 45 mins late but arrived only 15 mins late!"

Don't forget that airlines build in a lot of time to their schedules to allow them to arrive "on time" or "early" as often as possible.

Between 15 and 25 minutes is regularly built in at Manchester for taxi times once the aircraft departs the gate. If you can get airborne quickly, you can be sometimes be 10-15 minutes ahead of schedule as you are taking off - even if you departed the gate at the time stated on your ticket.

[chiglet]

Don't forget thr 111 Sqn Hurricane which flew from Turnhouse to Northolt in less than an hour.....can't be bothered to Google it
watp,iktch

[perkin]

The first Fighter Command squadron to receive Hurricanes was No. 111, commanded by Sqdn. Ldr. John Gillan, based at Northolt before Christmas 1937; and it was the squadron's C.O. who flew one of the new fighters from Turnhouse, Edinburgh to Northolt, London at an average ground speed of 408.75 mph (659.27km/h) - a feat which earned the pilot the nickname "Downwind Gillan" for all time.

Source - http://www.chilbolton.com/chilbolton-at-war.htm

[Mungo Man]

Some of the fastest aircraft groundspeeds by aircraft type...

http://www.speedrecords.tk/

Like the one of a 744 with a 240 kt tailwind giving a GS of 736kts or 846mph!!

[cats_five]

Originally Posted by AnthonyGA

The question that I find myself asking is: How abrupt are the transitions between these wind speeds? A 200-knot wind at 30,000 feet should be harmless enough in itself (albeit frustrating if you're trying to fly against it), but an abrupt transition between a layer at 200 kts and one at 180 kts could be pretty scary. A change in direction would be equally unsettling.

So ... how abrupt are the transitions at high altitudes? Can you feel it (I've been a passenger in airliners and felt turbulence, but of course I had no way of knowing wind speeds at the time)? I seem to recall reading that the transitions were a significant source of CAT.

It varies. If you look in the Met Office site, they have an aviation briefing service available. It's free, you have to register but I've never had any spam from them. Form F214 gives wind strenght & direction details at a number of locations across the UK, along with temperature. Each box contains a altitude in thousands of feet AMSL followed wind direction, wind speed (knots) and temperature in degrees C for that altitude.

http://secure.metoffice.gov.uk/aviation/index.jsp

[Sven Sixtoo]

How abrupt is the wind change?

In late January I was bouncing round the Scottish mountains trying to find a missing person. On the surface it was 20-25 kts (about 30mph max). We were spat out of the mountains at 47 kts at 2000 ft. We gave up and went home downwind at 5500 ft, where the wind was 80 kts.

Sven

[Tmbstory]

Jet Stream winds

Chrisnel,

The Jet Stream winds in the Japan area are often at least 200 knots and are called the "Toyko Express", fast to the west coast of the USA and slow back to Toyko.

[SpringHeeledJack]

I had the luck to be on a DC-10 in the 90's that had a block time of 5 hrs 20 mins between Miami, FL and Paris, France. IIRC the 'normal' flight time was around 7.5 hrs and the advantage was won through an unusually fast jetstream. This was sometime in the month of March. I vaguely remember the figure of 'over 200km/h' being mentioned.

For once it worked to my advantage and i was able to take a previously unworkable connection and saved myself half a day of waiting around the terminals in a jet-lagged stupour

Regards


SHJ