Measures for Progress: A History of the National Bureau of Standards

AUTOMOBILES AND AIRCRAFT 285
Testing a duralumin girder from. the wreckage of the Shenandoah in 1925. The girder
is shown ready for combined column and transverse tests in the 2,300,000-pound
capacity Emery testing machine at the Bureau. The verdict was "embrittlement by
corrosion."
ing a protective coating of aluminum, but the last two U.S. dirigibles were
not to survive long enough to prove the coating. Although the German-built
Los Angeles flew for 9 years before it was decommissioned in 1932, neither
the Navy's 785-foot Akron (ZR—4), completed in 1931, nor her sister ship
the Macon (ZR—5), ready in 1933, lasted 2 years beyond their maiden
flights.189
Reacting as much to the Shenandoah disaster as to the unpopular
(i)urt.martiahng of air-power enthusiast Brig. Gen. William Mitchell, who
believed in planes, not dirigibles, Congress in 1927 raised the Army Air
Service to corps level and authorized assistant secretaries for aeronautics
in the War, Navy, and Commerce Departments. Design was standardized
to enable industry to build up a reserve of war planes. And in support of
civil aviation, the National Bureau of Standards, designated the research
agency of Commerce's new Aeronautical Division, was directed to accelerate
189 See John Toland, Ships in the Sky (New York: Holt, 1957), passim. Germany's
Graf Zeppelin lasted almost 10 years before it was decommissioned in 1938, but the
explosion of the Hindenburg while landing at Lakehurst that same year put an end to
further investment in sky queens.