Is Flight Instruction in your own Aircraft Legal?

[tmpffisch]

I can't find any references at the moment, but the aircraft would have to be reclassified into airwork to begin with.

That is listed in the very first part of the CAR, Part 1, 2. Interpretation

For the purposes of these regulations:
(a) an aircraft that is flying or operating for a commercial purpose referred to in paragraph 206 (1) (a) shall be taken to be employed in aerial work operations;
(b) an aircraft that is flying or operating for a commercial purpose referred to in paragraph 206 (1) (b) shall be taken to be employed in charter operations;
(c) an aircraft that is flying or operating for the commercial purpose referred to in paragraph 206 (1) (c) shall be taken to be employed in regular public transport operations; and
(d) an aircraft that is flying or operating for the purpose of, or in the course of:
(i) the personal transportation of the owner of the aircraft;
(ii) aerial spotting where no remuneration is received by the pilot or the owner of the aircraft or by any person or organisation on whose behalf the spotting is conducted;
(iii) agricultural operations on land owned and occupied by the owner of the aircraft;
(iv) aerial photography where no remuneration is received by the pilot or the owner of the aircraft or by any person or organisation on whose behalf the photography is conducted;
(v) the carriage of persons or the carriage of goods without a charge for the carriage being made other than the carriage, for the purposes of trade, of goods being the property of the pilot, the owner or the hirer of the aircraft;
(va) the carriage of persons in accordance with subregulation (7A);
(vi) the carriage of goods otherwise than for the purposes of trade;
(vii) conversion training for the purpose of endorsement of an additional type or category of aircraft in a pilot licence; or
(viii) any other activity of a kind substantially similar to any of those specified in subparagraphs (i) to (vi) (inclusive);
shall be taken to be employed in private operations.

(Paragraph 206 lists flight training as a commercial operation incidentally.)

I have read/heard about schools letting this happen, depends whether it is allowable by their insurance etc, but it is definatly possible.