What counts as reummeration
If money changes hands for the purpose of the flight (other than cost sharing with the pilot) then its not a Private Flight.
If a pilot receives payment or benefits in kind it is a form of remuneration.
The simple check is: If the flight doesn't go, will any payment or benefit still be made. If the answer is No then it is clearly for the purpose of the flight!
There are two separate issues: payment for a flight which can be public transport or aerial work both of which require a suitably qualified pilot and probably an Air Operators Certificate; and payment of the pilot which can only be made to a Commercial pilot except where there are exemptions e.g. some Flying Instructors. Parachute dropping is aerial work, as is Glider Tugging.
An interesting point in the UK ANO Schedule 8 is that a UK PPL holder may conduct Parachute dropping and glider tugging but the privileges is not included in a UK JAA PPL
UK PPL
(ii) he may fly such an aeroplane for the purpose of aerial work which consists
of:
(aa) towing a glider in flight; or
(bb) a flight for the purpose of dropping of persons by parachute;
in either case in an aeroplane owned, or operated under arrangements
entered into, by a flying club of which the holder of the licence and any
person carried in the aircraft or in any glider towed by the aircraft are
members;
JAA PPL
Privileges and conditions:
(1) Subject to paragraph (4) and to any conditions specified in respect of the licence, the privileges of the holder of a Private Pilot Licence (Aeroplane) are to act, but not for remuneration, as pilot in command or co-pilot of any aeroplane specified in a class or type rating included in Part XII of the licence engaged in non-revenue flights.
The only aerial work exemption on A JAA licence is for Flight Instruction. To drop parachutists or tug gliders there is the issue of paying for a drop or tug, both of which constitute revenue flights. Unless there is an exemption somewhere!