Conversation so far:
How did Arnold Palmer become a pilot?
Arnold Palmer's early fear of flying was what led him to pursue his pilot certificate.
Did Arnold Palmer get over his fear of flying?
What year did Arnold Palmer get his pilot's license?
Did Arnold Palmer get any recognition for his work flying?
On Arnold Palmer's 70th birthday in 1999, Westmoreland County Airport in Latrobe was renamed Arnold Palmer Regional Airport in his honor.
Did Arnold Palmer fly commercial or military flights?

Question: For how long did arnold palmer have his pilot's license?
Self-contained rewrite: How long did Arnold Palmer have his pilot's license?