At 13:30 20 August 2003, John wrote:
Can these minimums apply to a (15-year-old) glider
student whose 40+ hours are dual only in a powered
aircraft (logged in a Cessna 140)?

Yes, assuming the flight time was properly logged per
FAR 61.51(a)-(c). The larger issue is whether any applicant's
proficiency upon fulfillment of minimum experience
requirements is sufficient to warrant a CFI endorsement
to take the practical test. (Note also that there are
no miminum experience requirements in order to solo
a glider - again, it's a matter of proficiency.)

Also can a private pilot written test (powered) apply
to a glider check ride requirement?

Nope. Per FAR 61.63(b)(5), the aspiring private glider
rated pilot would have to hold a private rating in
airplanes, rotorcraft, powered lift or airships in
order to skip the glider written.

Judy