Determine if the sentence is true based on the text below:
Phoebe Omlie had a valid pilots license in 1973.

Phoebe Jane Fairgrave Omlie (November 21, 1902 July 17, 1975) was an American aviation pioneer, particularly noted for her accomplishments as an early female aviator. Omlie was the first woman to receive an airplane mechanic's license, the first licensed female transport pilot, and the first woman to be appointed to a federal position in the aviation field.
It's impossible to say