Boeing XP-8.
USAAC
between circa 1928 and circa 1929 <div style="display: none;">date QS:P,+1928-00-00T00:00:00Z/8,P1319,+1928-00-00T00:00:00Z/9,P1326,+1929-00-00T00:00:00Z/9,P1480,Q5727902</div>
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