PPL can only sign the MR for that flight. CPL signature is valid all day
I digress
:
SPL signature is valid for one hour and ATPL signature is valid all week.
Now if it's for NVFR then the DI is valid for 2 hours for a NVFR pilot but if a MECIR pilot signs the MR it is valid all night (and until first light despite the fact that its a new day). However if said MECIR pilot is not current but holds a NVFR then it's only valid for 2 hours unless co-signed by a LAME with at least a PPL.
Let us not forget that CAO 88.1.0 Para 78.6(r) (limited distribution) specifies that:
"If said aircraft has tailwheel undercarriage then [all the above] applies with the additional condition that it be well understood that any self-respecting CPL/ATPL who actually re-signs after a perfectly entitled and licenced PPL:
a) march directly across the road (without looking either way before crossing) and
b) find the nearest Pilot Licence holder (not being the holder of a Student Pilot Licence) and
C) declare himself/herself a total uu@nker and
D) pull down his/her dacks and prepare for the cane.
A word of warning, from my reading of the CARs an Offence against CAO 88.1.0 Para 78.6(r) substitutes a breach of Strict Liability (refer to the Criminal Code).
Hey, don't blame me
I don't write the rules, I just make them up as I go to suit myself.