Bob Moore wrote in
46.128:

Guillermo wrote
There are many unclear parts in the FAR where there are different
interpretations among pilots. However, I would say that 99% of the
pilots would agree with the interpretation that anyone who is not a
required crewmember in an airplane is considered a passenger.

I must be the 1% that knows better.

First, posters in this thread are not distinguishing between the
definitions in Part 1 for "crewmember" and "flight crewmember".
There are several categories of individuals aboard aircraft that do
not posess airman certificates and yet are designated as "crewmember".

FAR Part 1
Crewmember means a person assigned to perform duty in an aircraft
during flight time.

Some of these are obvious....Flight Attendants, Medical Attendants,
Flight Test Engineers, Loadmasters and even "Grooms" accompanying a
load of racehorses are listed on the manifest as "crewmembers". It is
common for airlines to staff a flight with more than the FAA required
minimum number of Flight Attendants. Are they listed on the passenger
manifest? Of course not, they, although not "required crewmembers" are
none-the-less, crewmembers.

"(2) For the purpose of meeting the requirements of paragraph (a)(1) of
this section, a person may act as a pilot in command of an aircraft under
day VFR or day IFR, **** provided no persons or property are carried on
board the aircraft, other than those necessary for the conduct of the
flight. **** "

It doesn't matter what you call the guy in the right seat. For the purpose
of meeting 61.57, the person in the right seat is not necessary for the
conduct of the flight, and therefore doesn't belong there.

The implication being that perhaps if you DON'T log the landings you make
for the purpose of currency, you could assign the other pilot a task, call
him a crewmember, and still fly somewhere. But you cannot carry persons or
property that are not necessary for the conduct of the flight in a 61.57
currency flight.