ORA.GEN210 (c)
The organisation shall have sufficient qualified personnel for the planned tasks and activities to be performed in accordance with the applicable requirements.
If the part-time instructor is there when training is planned to take place, you comply.
ORA.ATO.110 (b)
The HT's responsibilities shall include:
- ensuring that the training provided is in compliance with Part-FCL and, in the case of flight test training, that the relevant requirements of Part-21and the training program has been established.
- ensuring the satisfactory integration of flight training in an aircraft or a flight simulation training device (FSTD) and theoretical knowledge instruction; and
- supervising the progress of individual students.
None of that requires the HT's attendance 24/7. provided you can show that you are achieving the above while overseas, you comply