When are you legally obligated to file IFR flight plan

[shurshot17]

For ground school, i was told to find the answer, when to do you HAVE to file IFR. Obviously the smart answer is always. However, my understanding is, if you are departing from an uncontrolled airport, and flying in uncontrolled airspace, you only need a flight itinerary.

Any one confirm or correct me?

Thanks!

[Ahmaxpower]

From the AIM

RAC 3.6.1
No PIC shall operate an aircraft in IFR flight unless an IFR flight plan has been filed. A PIC may file an IFR flight itinerary instead of an IFR plan where:
(a) the flight is conducted in part or in whole, outside controlled airspace; or
(b) facilities are inadequate to permit the communication of flight plan information to an ATC unit, an FSS or a CARS.
Notwithstanding any of the requirements mentioned above, pilots are required to file a flight plan when operating between Canada and a foreign state.

[photofly]

See specifically CAR 602.73.

[ScudRunner]

Keep your transponder off and you will fine.

[Panama Jack]

You should feel fortunate that your Instructor and school ask you to research this. It is an area of weakness identified on page 52 of the 2010 Human Resource Study of the Commercial Pilot in Canada:

Another concern identified by some operators in interviews and focus groups was that
training programs seem to be built on the assumption that fixed-wing pilots will always
be flying by IFR in controlled airspace. One operator stated that he sees a real lack of
“understanding of the air space. It seems that the whole IFR system training is done in
the context of controlled air space.”

This issue was particularly salient to Northern operators. Some Northern operators have
older aircraft that may not be equipped to fly IFR, and/or their operations require that
the pilot have an understanding of the rules for flying in uncontrolled airspace.
According to one Northern operator, “…pilots coming into this environment don’t seem
to understand when they need a clearance and when they do not.” Another focus group
participant said, in relation to technical skills deficiencies, that, “People who come out of
training, they are being trained on instruments, but they need to get their head out of
the cockpit and look out the window… We’re still 80% VFR (Visual Flight Rules).”