Fairchild Dornier SA-227DC Metro (9100506)

According to Joe Baugher's published information, this a/c was manufactured by Fairchild/Swearingen as a C-26B Metro III. MSN would be DC-806M and USAF s/n 91-0506 was assigned to this aircraft... :-)

http://www.joebaugher.com/usaf_serials/1991.html

One other photo of this Metro, USAF s/n 91-0506, showing on FA... :-)

https://flightaware.com/photos/view/1216641-37b7be0301b222fe5e276cde7f3731dd9e417493/aircraft/910506/sort/date/page/1

My understanding is that when taken up by the U S Army, the tail number has an extra zero added to reflect this. Aircraft has been upgraded to a n E-version.

zimbo1956- That is true... U.S. Army a/c are assigned a 5 digit serial number with the two digit fiscal year number prefixed... a "dash" for a separator, of course.

However, when this a/c was first accepted for service, an U.S.A.F. s/n was assigned.

From Joe Baugher's information, this production run, "91-0502/0514", shows the following serial numbers going to the U.S. Army and U.S. Navy...

"0502, 0505, 0507, 0509, 0511, 0513 to US Army; 0502, 0512, 0514 to US Navy as C-26D".

91-0506 isn't present in those numbers.

(91-0502 shows twice... but evidently did go to the U.S. Navy per Joe Baugher's further information.)

Obviously, the C-26 in your photo was eventually transferred to the U.S. Army and upgraded from a C-26B to a C-26E variant.