View Full Version : 757 threshold speeds
Quietplease
13th Aug 2009, 09:37
Can anyone tell me what is a typical threshold speed for a 757?
Is 115kts in a steeply banked orbit at 3 miles finals a safe speed?
Have a look at Gatwick Webtrak for 17th July between 0410 and 0415 and see if it looks like an acceptable approach.
At 0412.29 the speed is 134kts and 11seconds later it is 115kts.
Would this have triggered a stick shake and account for the large handful of thrust which was applied and woke me from my well earned retirees slumber?
dwshimoda
13th Aug 2009, 09:54
Depends on the weight. I've had Vref's of 109kts at weights of about 66 tonnes, so Vapp of 114kts with the right wind conditions.
You can't tell the angle of bank from the track.
Sorry it woke you up, but I love the smell of RB-211's in the morning...
Edited to add: as Adverse Bump points out - you are looking at ground speed, not airspeed - there can be a big difference.
...and just before you get savaged again by the wannabee mods, QP (or, of course, moved by the real ones:)), have you thought it might be flying an IAS of (134-115)/2 kts ie 125 ish with a 10 kt wind?
BillS
13th Aug 2009, 12:41
Metar Egkk 170320z Vrb02kt 7000 Few006 Bkn009 15/14 Q1004
Not forgetting that well-known Welshman, Dai Urnal, of course:)
The wind may be variable on the ground at EGKK but may be quite different sliding down the CDA at different altitudes.
Basil
13th Aug 2009, 13:29
Just looked at the WebTrak thingy - whatever will they think of next?
I'd guess roughly rate 1 turn using 25deg bank or less.
Perhaps one noticed decreasing IAS and gave it a little handful.
Pilots do this all the time and it's quite normal :rolleyes:
Rainboe
13th Aug 2009, 19:42
Autothrottle has it anyway!
Quietplease
14th Aug 2009, 21:39
Has anyone else looked at the Webtrack? It is all rather odd. 2300ft at about 4 miles and a mile south of the centre line. Whatever happened to a standard go around from there. When did a 360 orbit become a substitute. The print out of the Webtrack shows a turn rate of 90 degrees in 24 seconds,rather more than rate 1, for part of the orbit.
I can tell the difference between a normal small power adjustment and something sounding like climb thrust - I thought it was a departing aircraft deviating for weather until Gatwick noise sent the print out.