1 in 60 rules and rate of descent, another technic? correct?
Hi I have a question regarding 060 Navigation module. I have used another technique than the prescribed 1 in 60 rule for this question, and I get a different result. I'd like to know if this technique
is at least correct.
Question: Given ILS glide path 3.5 degrees, GS = 150 kts. What is the ROD?
They use the 1 in 60 rule: (3.5x150x100)/ 60 = 875= approx 900 ft/min.
I did geometry: drawing a triangle of speeds, with :
So the ROD is 7,85kts, which is 7,85NM/h, which is 7.85x6080 ft = 47728 ft/h which is (divided by 60min ) 795,47 ft/min close to 800 ft/min (NOT 900ft/min!)