airmail flight cover: Boeing 307 Stratoliner, first pressure-cabin test

Date:06/20/1939
Medium:Paper, ink
Credit Line: Gift of the Pan Am Association
Accession Number:2000.058.1336
Dimensions:3 3/4 x 6 1/2 inches (9.5 x 16.5 cm)
Collection:Aviation Archive
Category:Philately
Subcategory:Airmail Flight Cover
aircraft: Boeing 307 Stratoliner
company: Boeing
Description

Airmail flight cover, first cabin-pressure test, Boeing 307 Stratoliner; certificate adhered to left side of envelope with text and Boeing logo, dated June 20, 1939 and signed by test pilot E. Allen; postmarked June 23, 1939 in Seattle; no backstamp.

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<div id="sfomuseum-image-1527820395" class="sfomuseum-image" style="max-width:640px; margin:auto 0;">	 
  <a href="https://collection.sfomuseum.org/objects/1511923811/"><img src="https://static.sfomuseum.org/media/152/782/039/5/1527820395_dG7i4uRt5sJqTxAdBrxPkAKJubjduYlr_z.jpg" alt="airmail flight cover: Boeing 307 Stratoliner, first pressure-cabin test" /></a>
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    <div><strong>Airmail flight cover: Boeing 307 Stratoliner, first pressure-cabin test</strong> 06/20/1939</div>
    <div>Gift of the Pan Am Association</div>
    <div>Collection of SFO Museum <a href="https://collection.sfomuseum.org/objects/1511923811/">2000.058.1336</a></div>
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