duration excitement, and with the
apparent decision to allow that record to stand permanently at its
present level, trials for straight time in the air without
replenishment of supplies begin to regain a proper degree of
appreciation. No other record, unless it be some of those for speed
with substantial dead loads, is of such importance as the non-stop
distance and duration marks. No other has such bearing upon
precisely those qualities of aerodynamic efficiency, fuel economy,
and reliability of airplane and powerplant that most affect
commercial usefulness. It is more than three years since the
duration record left American shores, and it has been more than
doubled in that time. Its return is very welcome.

It is doubly welcome for being made with a fundamentally new type
of engine. The diesel principle is not a commercial monopoly. It is
open to anyone. Already two different designs in America, and one
or two in Europe, have been in the air. For certain purposes, at
least, it seems reasonable to expect that its special advantages
will bring it into widespread use. Every practical demonstration of
the progress of the diesel toward realizing its theoretical
possibilities in the air as it has realized them on the land and at
sea is a bit of progress toward better and more economical
commercial flying, and so benefits the whole industry. The fourth,
and next, main element in the demonstration will be provided when
diesels go into regular service on some well-known transport line
as standard equipment, and the accumulation of data on performance
under normal service conditions begins. We believe that that will
happen before the end of 1932.

Many men, from Dr. Rudolf Diesel to Walter Lees and Frederic
Brossy, have had direct or indirect hands in the making of this
record. The greatest of all contributions was that of Lionel M.
Woolson, who created the engine and flew with it in every test and
brought it through its early troubles to the point of readiness for
the commercial market. The flight that lasted four days and three
nights is his memorial, quite as much as is the bronze plaque
unveiled last April in the Detroit show hangar.

[Illustration: Figure 6.--Stinson SM-1DX "Detroiter." This airplane,
powered with original Packard DR-980 diesel engine,