DO investigation must be completed in order to do any in the air activity. You can complete all of the ground work including the survival stuff though.
The above gives some references to not being able to complete aviation training until the DO packet is completed, but it also provides for a waiver by the Director or other competent authority if the member has already completed all training. Not sure how you can get the training though if you can't get airborne without a completed investigation. To participate in aviation and get the qual you have to have a DO investigation completed according to the last ALAUX dealing with the PSI.
D8 doesn't allow you to go airborne without the DO completion... That's the rules...
Our flotilla is very air-heavy, and I had to deal with this as the FSO-MT. It's not taking as long as it once was though the for checks.
I have read that particular document, and tried to deduce an answer to the question. The last paragraph seemed slightly obtuse, as you pointed out:
i. Allowance for interim certifications remains in place. Specifically, Auxiliarists who have received a favorable OS PSI determination, have submitted the requisite DO PSI package, and have completed all training requirements for qualification in any of the aviation program competencies may be granted interim certification for such by the Director or appropriate qualifying authority pending receipt of a Favorable DO PSI determination.
When you say it's not taking as long, what kind of time frame do you mean?
Not sure about your District there in Idaho -- but in D8CR, the Director approves all applicants to the AUXAIR training program. Actually, the civilian employee in his office will not send up a PSI for DO status unless it is approved by the Director. Thus, you have to be approved to enter the Observer/Air Crew training program by DIRAUX before your PSI package is determined to have the need for the DO status...
A member simply can't request a DO designation instead of the OS designation -- in anticipation of some future need.