Or end up in jail when the investigation pins it on you for not following the procedures......ie Helios
He follows the (at this time unclear) procedure.
The final report says at page 116:
Originally Posted by AIRCRAFT ACCIDENT REPORT
...
Finally, the Board considered it important to determine whether the AMM Task, “Cabin Pressure Leak Test”, called for the pressurization mode selector to be returned to the AUTO position following such a test. AMM Task 05-51-91-702-001 was examined. Its last action item stated “F. Put the Airplane Back to its Initial Condition” and specifically contained 3 actions sub-items as follows:
(1) checking the pitot static system, if necessary,
(2) opening the equipment cooling flow control valve, and
(3) returning the equipment cooling fan switches to NORMAL if previously
selected to ALTERNATE.
The Board was of the opinion that the AMM instructions were vague in making such a broad reference to an aircraft’s “initial condition” and that the three actions items listed did not include returning the pressurization mode selector to the AUTO position, although the AMM Task explicitly required setting that selector to the MAN (manual) position for the Test. In this respect, the Board concluded that if the Ground Engineer number one had not returned the mode selector to the AUTO position, this could not be considered an omission as there was no specific requirement to do so.
(highlighted by me)