Full FAA Chronology at this link.
19300215: The Aeronautics Branch announced that it had issued the first rating under the Airport Rating Regulations to the municipal airport at Pontiac, Mich. The airport received the highest possible rating, A-1-A. The designation system enabled pilots to know at a glance what facilities to expect at any of the rated airports, which the Branch inspected in response to voluntary applications by airport operators. The program was part of the Aeronautics Branch’s efforts to encourage airport development through promotional activites, disseminating technical and statistical information, and giving expert advice to municipalities.
19460215: The Lockheed L-049 Constellation went into U.S. domestic passenger service. Designed for a three-man crew, the Constellation had a separate panel and side-facing seat for a flight engineer.