rule of five

[jetinder0810]

india dgca atpl jan 2013 question on rule of five. given FL, Temp, IAS, dist to dest, time late at dest. Calculate inc in speed to make good ATa at dest. sol- use rule of five. could someone shed some light on this rule. thanks

[N5748E]

Basically in almost any Gen. Nav. question, when they give you "FL, Temp, IAS" it's to immediately be converted into TAS, and if you have a wind component it helps to convert to GS. This is done on the whizz wheel or CRP.

so e.g you are going to be 5 min late flying at TAS 100kt, with dist to dest being 100NM, to reach there without being 5 min late, you have to fly faster, so at TAS 100kt and dist 100 Nm means I'll reach in an hour, if I'll be 5 min late means I actually want to reach in 55min, I should be flying at about 109KT, so my increase in speed should be 9kt.

Bristol question bank was worth every penny.