Under what circumstances does a flying club need to do 100-hour inspections? I am part of a not-for-profit 501(c)7 flying club that owns a handful of airplanes. These airplanes may be used only by the club members. Members pay monthly membership dues; and pay for Tach time to use the airplanes.

Are our aircraft subject to the requirement of 100-hour inspections?

Possible contributing factors:


Some members are flight instructors, who offer flight instruction in these airplanes.
The students (Receiving dual instruction) may or may not be members themeselves.
A club rule says that only approved club flight instructors may offer instruction in club aircraft.


Does one of these bullet points trigger a requirement for 100-hour inspections?

The relevant FAR is 91.409, which says in part "no person may give flight instruction for hire in an aircraft which that person provides, unless within the preceding 100 hours of time in service the aircraft has received an annual or 100-hour inspection".

If we required student pilots to become members of the club prior to receiving any instruction, would we no longer be subject to requiring 100-hour inspections?
AOPA addresses this very matter in their question of the month found here


  A flying club aircraft normally would not need to receive 100-hour
  inspections.  FAR 91.409b requires a 100-hour inspection when a person
  receives instruction from a flight instructor who also provides the
  aircraft.  The FAA guidance further clarifies that the 100-hour is
  required when a person is providing flight instruction for hire in the
  instructor’s personal aircraft.


Your issues arise with these two points 


  
  The students (Receiving dual instruction) may or may not be members themeselves.
  A club rule says that only approved club flight instructors may offer instruction in club aircraft.
  


As the answer goes on to state 


  Some clubs require a flight instructor to be a member prior to giving
  instruction in club aircraft.  In this case, the FAA doesn’t view this
  as an issue as long as three conditions are met:  
  
  
  There must be no contractual relationship between the member-instructor and the flying club for the provision of flight
  instruction.
  The member-instructor is not recommended or given preference by the flying club. 
  The club members are free to choose instructors who are not club members. 
  
  
  If any one of these conditions is not met, then a 100-hour inspection
  would be required for the club aircraft.