a6881

A U.S. Navy PB-1 (Boeing Model 50) patrol plane, in 1925. The PB designation was first used for the Boeing model 50 flying boat which was built in 1925 for a nonstop flight to Hawaii. The US Navy had designated the aircraft PB-1 and given it serial A6881. The designation PB was the used again for the US Navy version of the B-17 Flying Fortress. On 31 July 1945 the US Navy ordered a single B-17F from the USAAF production line with the designation PB-1 and the BuNo 34106. Former B-17Gs were converted for the US Coast Guard as PB-1Gs and for the USN as PB-1Ws

See description for

Boeing Experimental Patrol Type 1 www.wikidata.org/wiki/Q890190

This was an experimental aircraft for the US Navy which "..was intended to use it to lead a pair of Naval Aircraft Factory PN-9s in an attempt to fly to Hawaii on 31 August 1925, but engine trouble led to its participation in the flight being cancelled." The negative has the date August 11, 1925 in the top right corner. I was unable to find this picture, but other similar photos of this aircraft were run. "Navy's giant planes make ready for Hawaiian Hop" San Antonio light. [volume] (San Antonio, Tex.), 09 Aug. 1925. Chronicling America: Historic American Newspapers. Lib. of Congress. (chroniclingamerica.loc.gov/lccn/sn85060004/1925-08-09/ed-...) "Midshipmen of the Naval Academy, Annapolis, being given their first instruction in flying" Evening star. [volume] (Washington, D.C.), 16 Aug. 1925. Chronicling America: Historic American Newspapers. Lib. of Congress. (chroniclingamerica.loc.gov/lccn/sn83045462/1925-08-16/ed-...)

The Boeing XPB-1 (BuNo A-6881) See: en.wikipedia.org/wiki/Boeing_XPB