3 types of error:
Earth Rate = 15 x sin lat (this is a rate of error)
Therefore:
Amount of Earth Rate Error = 15 sin lat x Flight time
Latitude Nut = 15 x sin lat (this is a rate of error)
Therefore:
Amount of Lat Nut error = 15 sin lat x Flight time
A correctly set latitude nut corrects for earth rate (look at the +/- table on page 9.3)
Transport wander = Degrees of longitude travelled x sin lat
For this question....no hourly correction has been set....ie no latitude nut correction....so we need to calculate Earth Rate and Transport Wander.
Earth Rate = 15 x sin 61 x 1.5 = 20
Transport wander = 20 x sin 61 = 17
Looking at the +/- table, both these errors are minus errors, so total error is -37.
We start with 090T, 000Gyro
We finish with 095T, so with no error we would expect 005Gyro
However, we have -37 of error, (005 - 37) = 328.