Flight Crews: The preceding comments were made by engineers
thinking primarily of the commercial possibilities of the diesel.
Following are comments by flight crewmembers about the operating
characteristics of the Packard diesel. The former were largely
optimistic. Most of them were only familiar with the aeronautical diesel
as a design project and therefore did not have the practical experience
necessary to understand all of its limitations. The latter were
pessimistic, as they knew firsthand various shortcomings of the engine
which only became apparent when it was operated.

Clarence D. Chamberlin, pioneer pilot:

My only experience with the Packard diesel was in a Lockheed "Vega"
which I owned back about 1932. The Wright J-5 had been replaced
with the 225 hp Packard Diesel. My main complaint was the excessive
fumes. When I would come home at night my wife would greet me with,
"You have been flying that oil burner again." It was so bad that
passengers' clothing would smell like a smoky oil stove for hours
after a flight.

Looking backward, it is my guess that the Diesel would have had
only a limited period of acceptance even if all mistakes had been
avoided. It is easier and cheaper to get performance with lighter
and more powerful engines and longer runways than by refining the
airplane. Fuel economy of an engine has ceased to be the deciding
factor. Higher utilization of a high speed Jet at least in part
offsets the inefficient use of fuel. The only time the Diesel had a
chance was from the middle 20's perhaps on thru WW-2 for certain
things due to gasoline shortage. To sum it up, the thing that
licked them worst was the use of a single valve for inlet and
exhaust making it impossible to collect and keep the fumes out of
the fuselage.[24]

Ruth Nichols, prominent aviatrix:

I was flying Chamberlin's diesel-powered Lockheed, in which a month
before I had made an official altitude record for both men and
women in aircraft powered by an engine of that type. The record, I
believe, still holds. It was a rugged, dependable plane whose
experimental oil-burning engine nevertheless had a number of bugs.
For one thing, it was constantly blowing out glow-plugs used for
warming the fuel mixture, and when that happened long white plumes
of smoke would stream out, giving spectators the impre