Originally Posted by
Goldenrivett
Hi yanrair,
You need to include TAS effect with altitude.
In Pineteam's example of climbing away at 250 kts, climb thrust and 10 degrees of pitch works simply perfectly well. If you try to rely on Ground Speed and ignore wind component (when <50 kts) and TAS - then you will be in error by an additional 40 kts by 10,000 feet on the climb. (Your IAS must be in the range 160-260 kts - which is probably not safe).
KISS is the better solution.
Hi Pineteam
It is simple at all altitudes - KISS I agree with.
The correlation between IAS and TAS/GS looks like this – 50 kts per 10,000 feet.
IAS G/S
Sea Level 260
260 /0
FL 100 260
310 /+50
FL 200 260
360 /+100
FL 300 260
410 /+150
Cruise Alt (350 ish) 260
460 /+200
How to use this? You only need to memorise the approximate G/S/ TAS for four flight levels and you have a guide which would have saved Air France. If they had only stayed at the current conditions of about 2 degrees of pitch,
80% N1 (or whatever cruise power was at the time) IVSI ZERO (works off IRS as well as pressure changes) AND….
Kept the ground speed at 460 kts ( or whatever it was just after the failure) they would have had no difficulty in staying in full control. But they did not know this correlation.Or any correlation for that matter.
Here is a graph used in training in one airline...........
