12. This airline offered the only nonstop flights between Houston and Cincinnati

Hard to believe if I hadn't seen it with my own eyes - and the airline is:

Piedmont, which served the route with two 737-200 "Pacemaker" nonstops per day.

13. These two airlines provided the only nonstop flights between Milwaukee and Kansas City (as of 10/15/1981)

And those two airlines would be United and Texas International

Being as the October 15th, 1981 edition of the OAG has been such a treasure trove of questions for schedule and route buffs, here are fifteen more questions from that terrific tome:

1. This airline operated the only nonstop flights between Orlando and Indianapolis with a single nonstop per day. No other airline offered any more than connecting service on this route. ANSWERED

2. The Chicago to Orlando route enjoyed considerably more competition with three airlines offering nonstop flights. One of those airlines offered a single daily nonstop operated with an all economy class configured jet. Name the airline and the aircraft type operated.

3. After a nice weekend in Cleveland, Ohio, you've been informed that you need to be in Rochester, New York on Monday morning. You could just hop on I-80/90 and drive there in about 4.5 hours but this airline offers a single early morning nonstop operated with a Convair 580. Never one to pass up a flight aboard an Allison 501 powered aircraft , you book yourself a seat on that morning flight, returning on the CVR flight later that evening. Which airline operates the Convair 580 in this market? ANSWERED

4. Three airlines offer a single nonstop flight each between Jacksonville, Florida and Washington DC's National Airport. Each of the airlines providing nonstop service on this route operates a jet built by a different manufacturer. Name the airlines and the equipment utilized.

5. This airline offers the only service of any type between Birmingham, Alabama and Houston, Texas with a single daily nonstop flight. Which airline is this?

6. This airline operated the only nonstop flights between Los Angeles and Baltimore. Both were operated with the same aircraft type but interestingly, one flight was operated in an all-coach configuration while the other offered both First Class and Coach. Name the airline and the equipment used.

7. This airline operated four nonstop Convair 580s a day between Columbus and Cleveland. And the airline is…?

8. Between New York and Puerto Plata in the Dominican Republic, two airlines offered nonstop service. One of them, the Dominican national airline, served the route with a twice weekly 727 flight. The other airline was a U.S. carrier that served the route with a twice weekly flight operated in an all economy configuration. Name thius U.S. airline and the equipment used on this route.

9. Which U.S. airline operated the only nonstop flights between Grand Turk, BWI and Puerto Plata in the Dominican Republic?

10. Name the only U.S. airline offering nonstop service between Los Angeles and Puerto Vallarta, Mexico

11. This airline offered a single daily nonstop flight between White Plains, New York and Bermuda. Name the airline and the aircraft it operated on this route.

12. This U.S. airline offered a single daily nonstop flight between El Paso Texas and Mazatlan, Mexico. The same airline also served Mazatlan thrice weekly from Albuquerque.

13. Which airline operated its jets along this route: PDX-RNO-SNA-LAS?

14. The complete routing for this airline’s Flight #009 was SLC-BOI-SEA. The flight was operated with a 737-200. What airline was this? ANSWERED

15. This foreign carrier enjoyed fifth freedom rights between Philadelphia and Toronto, operating a single nonstop that included dinner in both First Class and Coach. Which airline was this? ANSWERED