Originally Posted by
Phantom Flyer
The answer is 18. You start the decent 18 miles prior to the point you want to be at FL180. If you're flying a "three holer" (727 to you young guys), even 18 is a huge variable with an aircraft that will come down at 6,000 fpm.
I'll have another pint of Guinness please.
G'Day Mates
6000 fpm, surely you jest. Once clocked the descent at over 10k fpm. Somewhere around 380 indicated with the boards down, therefore capable of a lot more (410 was VMO, if I remember correctly). How did that go? '27 is a safe airplane, climbs like a safe, descends like a safe. Fun airplane. Miss it.
To beat a dead horse: 3:1 for normal descents most jets (280 IAS), 1 mi for each 10 kts HW/TW, and 1 mi for every 10 kts of speed you want to loose. Most airplanes cant quite make 2:1 at barber pole. Keep doing the math on the way down and you'll nail your crossing restriction. Still do it with VNAV to cross check fat fingers and wintertime winds aloft. For interview, just do 3:1.
Cheers