1. Builder of first modern transport aircraft by general account?

2. Month and year of entry of service?

3. Builder's aircraft nomenclature?

4. Passenger full count?

5.What military aircraft was this quiz aircraft based upon?

This aircraft has a link to ye olde quizmaster, to be revealed when the quiz winner is announced.

1. Boeing

2.1933-02-08

3. Model 247, low wing, all metal, twin engine, retractable landing gear, 2 P&W R-1340-AN-1 Wasp engines

4. 10 Passengers, 400 lbs of mail

5. C-73 Transports

Good enough, Canonman, *****

My info source only differs in that the commercial aircraft was based on the Boeing B-9 bomber of 1931. Are they basically one and the same/similar?

Yes, the entry date of service was in February 1933, incidentally the month and year of my entry/birth. 2/4/1933