5 x 3 =15 but 15 x 3 = 45
Microburst
Ok, your mention of too high – is not really high in my book at 15 miles, its only 425 feet and at 15 miles 425 feet above profile does not seem all that much, or maybe I`m wrong. Having said that, 3xheight for range is good down to 10,000 say, and then you can back calc 3xrange for height
Your comments on Open descent are as you suggested most favourable, I am still happy with 33 miles at FL100 – notwithstanding alt constraint or spd constraint,
I would be looking for Green Dot or 210 at about 12 miles out or 8 miles if making an abeam approach, at 280 kts decelling to 250.
Eng Anti-Ice Off would give me some cool gates, thus:-
33 miles 10,000 280 max clean
20 miles 6000 250 clean
12…3800 210 or Green Dot Flap 1
8 ….2500 180 or S speed Flap 1
4.5...1500 160 or F speed Flap 2 or 3 plus Gear.
Times to reduce speed are 350-210 2 mins 10 secs Dist 10 NM
===================350-280 1 min 6 NM
===================280-210 1 min 10 secs 4 NM
Using speedbrakes to aid decell will reduce these times by approximately 40% deployed and retracted gently. ADDED LATER ON: also the slight pitch up tendency due to speedbrake may help to decell more effectively but brisk speedbrake retraction may cause a pitch down and potential altitude bust.
I also favour the constant power technique, but that is for another day.
Last edited by Natstrackalpha; 12th Jun 2012 at 14:03.