Under EASA, such operations can only be conducted on a 'Permit to Fly' basis (issued from Cologne). Logical really as any operation that takes the helicopter below its certification basis (or outside the MEL/MMEL) has associated - and somewhat unknown - risks.
Only the takeoff as far as TDP, or it's military equivalent, is unknown.
In the RAF, the limited power takeoff technique was routinely practiced, for this very eventuality.