Hello all!

 

So I'll often hear "don't over take the traffic" for aircrafton parallel landings. Particularily prominent at SFO. Anyways, Im wondering what are the details of this instruction. Is it usually a larger aircraft that is not allowed to pass a smaller, or the reverse? Perhaps to avoid a larger aircraft's wake turbulence? Also, two times in a row (while listening to LiveATC) I've heard "you may over take the traffic" why would the instruction change? In one these instances the aircraft asked why the other guy was allowed to pass to which the controllwer said because he is a 757. Any insight would be appreciated.

Hello Mitch,

 

I would guess that the smaller aircraft would generally be asked to stay in front of the larger aircraft, mainly for wake separation. I would hazard a guess that, because the 757 has such a low Vapp when lightly loaded, they would be coming in much slower than say, a trans-con 737-800. The 737 would either have to hold to avoid the 757 or be cleared to pass the 757... Just my $0.02.

 

http://www.pprune.org/archive/index.php/t-302132.html

http://www.flyertalk.com/forum/united-mileage-plus-pre-merger/98068-weird-happening-parallel-approach-sfo-paging-mark-rogers.html

 

Regards,

 

Frank

Hello Mitch,

 

I would guess that the smaller aircraft would generally be asked to stay in front of the larger aircraft, mainly for wake separation. I would hazard a guess that, because the 757 has such a low Vapp when lightly loaded, they would be coming in much slower than say, a trans-con 737-800. The 737 would either have to hold to avoid the 757 or be cleared to pass the 757... Just my $0.02.

 

http://www.pprune.or...p/t-302132.html

http://www.flyertalk...ark-rogers.html

 

Regards,

 

Frank

 

Thats what I was thinking but then I don't know why she told the 757 to pass another airplane. That would seem to contradict the purpose of dont overtake

Yes, because the runways are so close to each other at SFO, having a 747 or similar overtake a medium aircraft would cause problems as wake turbulence moves down and outwards if the winds are calm, or downward and across if there's a crosswind. I heard a BAW 747 pilot getting upset with an SFO approach controller when the controller failed to separate the 747 guys from medium jets 3 times causing the BAW crew having to go around 3 times because the 747 was faster and sequenced too close on the parallel approach to other planes.

As far as I know the 757 produces the worst wake torbulence conpared to any other airliner.

As far as I know the 757 produces the worst wake torbulence conpared to any other airliner.

 

For it's size yes, but not the worst by any means.

I've listened to the recording many times of the BA flight doing multiple Go Arounds at KSFO. They had to divert to KOAK and it was not a happy sounding crew. It's on liveatc.net and worth having a listen.

 

Chris K.

As far as I know the 757 produces the worst wake torbulence conpared to any other airliner.

 

which is why i don't understand why she would permit the 757 to pass a 737

 

I've listened to the recording many times of the BA flight doing multiple Go Arounds at KSFO. They had to divert to KOAK and it was not a happy sounding crew. It's on liveatc.net and worth having a listen.

 

Chris K.

 

whats the BA recording called? I'm trying to find it on liveatc

I'd love to hear it too!

whats the BA recording called? I'm trying to find it on liveatc

 

I can't find anything on Flightaware, BA's 2 daily 747s from LHR (BAW285/BAW287) all arrived at SFO without incident for the past week.

I can't find anything on Flightaware, BA's 2 daily 747s from LHR (BAW285/BAW287) all arrived at SFO without incident for the past week.

 

i found one on live atc of a BA 747 at KSFO having to divert after 2 failed landing attempts. But from the recordings, it was because of wind and miniumum fuel not because of other traffic.

I'll have to do some digging around but it's been awhile since I've heard it. I'm pretty sure the final go around was due to aircraft spacing (could be wrong), and they hit their minimums and had to divert to KOAK. This happened several years ago; not this week.

 

I'll see if I can dig around and find it.

 

Chris K.

It's been awhile since I listened and thought there were 3 go arounds; only 2. It's a fun listen. If you listen to the second part they were overtaking traffic and had to go around.

 

http://www.liveatc.n...or-the-evening/