I photographed these Waco Taperwing examples at the Waco Museum in Troy, Mich., and the WAAAM in Hood River, Ore., and the Rowland Freedom Center in Vacaville, Calif.
The “T” as the second letter designator indicates the Taperwing (as opposed to “S” for straightwing variants like ASO). The complex WACO naming structure can be found at this link. The first letter designates which engine was used.
1929 Waco ATO #A-118
Waco Museum 2018
1928 Waco ATO #A-20
WAAAM, Hood River 2021
WAAAM, Hood River 2023
1929 Waco CTO #AT-3005
WAAAM, Hood River 2021
Waco CTO
Based on information attached to the NC949H registration, this was originally a 1929 Waco 10 ASO #A-134 (Straightwing)