Mental Calculations for CPL/IR

[ATIS31]

Hi All
Im trying to get up to speed with doing Mental Maths :ugh:(its been a while) I am considering going on and doing my CPL/IR and was wondering what all Mental Calculations I would have to do in mid flight when doing CPL Nav and for IR. Can anyone give me some pointers ?

Thanks ATIS

[RTN11]

3 x table is good, 3 x height to lose (ft) = distance required (nm)

6 x table for any time related calcs (.1 of an hour = 6 mins, so 1/10 of ground speed is a 6 min chunk)

[Da-20 monkey]

100 knots would be 1,7 nmiles per minute, ect.

To go from degrees to gradient, times 2 minus 1.

wind correction thumb rules are also helpful.

[mustang.spitfire]

I don't know if I can help you, but I can speak about the ATPL cd series from Oxford !

I have some of them and I can suggest to you !

They're really well done !

cheers !

[bravobravo74]

As a rule try to do things simply and use rules of thumb wherever possible.

It's best to know the max. drift that corresponds to various wind speeds for the type of aircraft that you're flying off by heart.

Get proficient in the use of the clock code for calculating headings and groundspeeds. Similarly, get used to thinking about how long you have before reaching a certain point based on, obviously, speed and distance.

Master a method of dead reckoning heading correction - there are several but you only need to be able to do two at the most.

Know the elevation of the terrain around you so that you can convert an altitude reading to a height AGL. This isn't nav-related but it's useful for PFLs.

Be able to calculate a headwind or tailwind component based on wind velocity and heading. This is especially important for the outbound leg of the hold.

Be able to multiply a groundspeed by five in order to find the required rate of descent for an instrument approach. A table is often on the approach plate but you don't want to have to look at this unnecessarily.