Not your everyday landing partner!
 

Hi fellas

Went up for a spin in a Tecnam Sierra from Boeing Field just south of Seattle this afternoon. On the way back on long finals we were told that "you've got a heavy cargo aircraft, one of those big scary green ones coming up behind you and will be passing you on short finals landing on 13R" we were heading for 13L so my friend elected to do 3 orbits and wait for the Boeing 747LCF (large cargo freighter) and its big wake pass us by.

Just 4 weeks ago this same cargo aircraft landed on 13R as a 172 was on short finals on 13L and the wake carried across the field causing the Cessna to almost crash, it recovered at 200ft thankfully.

Anyway, it was an awesome sight to see that new cargo aircarft come out of the low cloud above us and pass us by, still in the same green primer scheme. Its call sign was '747 experimental', a british accent on its radion too. As far as I know its just finishing its certification and who knows could have arrived at Boeing field for the paint shop.

Just thought I'd share this.

By the way the LCF is as ugly as it is in the photos:p

Did you get any photos???

On a more serious note, though, does anyone happen to know the wake vortex separation requirements for parallel runways off the top of their head? If not, I'll have a go at looking them up.

FFF
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If the runways are more than a required distance apart (laterally) they have no vortex separation requirements between the two runways. If they are not that required distance apart they are treated the same as a single runway for vortex separation.

IIRC it is something like 1300m lateral sep to allow "independent" operation.

My one and only encounter with wake turbulence scared the crap out of me. It was an Airbus 320 and it was so strong, even with full aeileron and bootfulls of rudder we were still rolling the wrong way. I thought we we're going to go all the way over (at 1500'). Full power and a yank it up got us above it saved the day.....nasty......

I've experienced it once. Into Leeds/Bradford behind a 737 if my memory serves me well. Absolutely frightening. Fortuately the instructor reacted very quickly. We were high and behind and had followed all the ATC delays with orbits and long downwind, it still caught us out though.

Looking back, was an excellent training exercise to increase my awareness more than any book reading could ever do :ok:

Regarding when wake turb seperation comes into play.

Norwegian RFL-1 (our MATS pt.1)

Chapter 5, section 8.3.1, subsection b, part IV

"paralell runways, when the distance between the runway centerlines are less then 760 meter".

It does not come into force with VFR arrivals, it's "caution wake turbulence" only. Only IFR arrivals, and all departures are seperated wake wise.

It's not marked as deviating from ICAO standards.

It still sounds scary to routinely allow light AC traffic to a paralell so close operationg heavy traffic.
It does not really matter that much that the THR is so offset on RWY31.
Looks like it's max 250 meters between the 2 rwys on google maps.

The one and only time I experienced wake turbulence was about 28 years ago at Castle Donnington Airport as it was known in those days when landing in a PA28 after a heavy had just departed.

Despite holding at the eastern cooling towers and draging out the base and finals for what I thought was long enough for the turbulence to have disappated, the turbulence still remaining, had the aircraft yawing across the runway's width during the flare which although not an insurmountable problem to deal with, was still a bit unnerving for a relatively low time pilot, as I was at the time.

As one had to pay the landing fees in the tower in those days, I took the opportunity to discuss the probability of the turbulence still being present some 4 to 5 mnutes following the departure of the heavy.

The conjecture we reached following these discussions and based on the observations of the controllers of previous similar occurences, was that with the wind being light and variable at the time of my landing, there was every possiblity that the wake turbulence from the departing heavy could be drifting around for a few minutes.

We did discuss the possibilities of a developing thermal causing the drift but this idea was thrown out, as on thermally days, the controllers would often see dust devils being kicked up on the airfield and they had observed none at all on this particular day, despite the fact that the ground was very dry and the surface hot.

Anyone had any similar experiences on days when the wind was light and variable?

Video!
 

I've just tried out this Youtube thing so you can see my video there - its poxy quality from my mobile but you can make out clearly the (wet) runways which are real close and the LCF taxiing back after his landing some 5-6 minutes earlier.

Enjoy!:8

http://www.youtube.com/watch?v=z_Nm9jqJBjA

That is a REALLY ugly aircraft - and the standard 747 is (at least to me) a real good looker.

Very reminiscent of the Beluga, only larger!
http://i11.photobucket.com/albums/a1...cal/beluga.jpg

Not had the experience but especially on light wind days the vortex can stay around longer and drift over the runway rather than dissipate.

More ugly than the Beluga, Guppy and a Daewoo Nexia combined!

Flyin'Dutch'


Saw this on another PPRuNe thread



http://s45.photobucket.com/albums/f8...r/th_HEAVY.jpg

Regards
Barshifter

I enjoyed the video...

There are some pics of a similar a/c here: http://www.airliners.net/discussions....main/2942140/

See also http://www.flightglobal.com/Articles...ng+out+in.html which says: Andy :ok:

Boeing Field
 

Gosh, it has been a while since I saw Boeing Field from that viewpoint. Wonderful flying thereabouts, Irishwingz. Have you flown into Vashon yet? Talk about short!