Terrestrial Magntism

Question 1

Deivation

Answer 1

Ferromagnetic behaviour can be subdivided into two categories:

~soft magnetism:soft materials temporary effect,distorts the existing field

~hard magnetism:cause by permanent magnetism

Question 2

Compass swing

Answer 2

Deviation can be minimised by a compass swing

Procedure is carries out on the ground and with engines running and all relevant electrical services switched

Question 3

Compass swing is needed

Answer 3

~change of location involving a large change in latitude(dip)
~major changes in a/c
~a/c hit by lightning
~a/c parked in smae direction for along period
~when a new compass is fitted
~any time when compass or recorded deviation is suspect
~when specified in the a/c maintenance schedule
~specific cargo with magnets
~heavy landing on a northerly heading
~personal equipment