Is this from the original AP/Manual or some new CAA procedure.
Original AP & SP's (servicing procedures). On fitting, there are the airframe aspects where the unit interfaces with the control runs. Ergonomics weren't invented back when this unit was designed and it's a bitch to replace. Then there are the electrical aspects where the plugs have to be fitted, the functional check carried out, and any adjustments made on the "trim pots", then you have ( in this case), to call one bloke in off holiday to do the elctrical indys and one bloke from Cambridge (Marshall Aerospace) to do the Airframe indys.
The electrical indys take as long to do as the functional (pumping airspeed into both pitot systems to check the function). By the time that you have been over the whole speed range at least 5 times and the independents have also been done on the pitot static system (which you had to disturb to replace the Art Feel Unit) you are looking at close to 3 hours.
Oberon
(Back to being on holiday)