News Letter 1941 Jul-Dec - Air Force Historical Studies Office

..
An Equipment
Review
GERMAN AIRCRAFT AND ENGINES ANALYZED
THE
ME - 110 FIGHTER
THE DB-601A ENGINE
A thoroughgoing, detailed analysis of a captured
Messerschmitt ME-IIO pursuit plane, one of the
mainstays of the fighter arm of the Luftwaffe, has
just been completed by the Vul tee Aircraft Companv.
This airplane, shot down over England late in 1940,
reached the United States last April. Despite a
crash landing, it suffered comparatively little
damage. R.W. Palmer, vice president of Vultee,
prepared the following report on the ship.
The ME-110 is a twin-engined, low-wing all-metal
three place land monoplane primarily designed as a
fast multi-place fighter but readily adapted to
light bombing and attack missions. The crew consists
of a pilot, a radio operator-navigator and a
rear gunner. The airplane weighs approximately
15,300 pounds fully loaded, has a wing span of 53
feet 4 inches, a length of 40 feet 6 inches and a
wing area of 414 square feet. The high speed of
the airplane is reported at 365 miles per hour,
while the cruising range is 565 miles at 301 miles
per hour. Power is supplied by two Daimler-Benz
engines developing 1,050 horsepower each.
It was not surprising to find that German ingenuity
had developed a design admirably suited to
mass production and manufactured with excellent
workmanship, although reports of shoddy construction
were fairly prevalent. This has been done at
little sacrifice of weight or aerodynamic efficiency.
Sub-Assembly Time Reduced
The air methods give an interesting comparison
with our current practice in two particular respects.
Larger, simpler on" ..piece component parts
are used, reducing the numbe r of man hours for subassembly
work. As manufacturers in this country
are getting larger quanti ty orders and consequently
can spend more money on tooling and equipment this
trend is increasing here.
Even more striking are the differences between
their methods of assembling major components and
ours. The junction points of the ME-110 have the
connecting fittings reduced to a minimum and each
fitting has considerable freedom of adjustment so
that a fairly large discrepancy in accuracy of
dimensions is easily taken care of. This contrasts
with our method of a large number of attachment
fittings unadjustable and requiring very accurate
jigging.
The advantage, particularly when 5ub-assemblies
(Next page, Col. 2)
OCTOBER /941 15
Sometime ago the Wright Aeronautical Corporation
had the opportunity of studying a Mercedes-Benz
DB-601A aircraft engine, which had powered atienerschmitt
fighter. The power plant was torn down,
bit by bit, with every part being subjected to a
detailed analysis. Raymond W. Young, of the corporation,
reports that a comparison between the major
parts of typical high production German and American
aircraft engines emphasizes that:
1.The materials used in the DB-601A are quite
on a par with those used for similar purposes in
the Wright Cyclone and other Adlerican engines.
2.There isno apparent sacrifice in the quality
of material used in German engines up to the time,
at least, when this particular one was produced,
which is believed to be late in 1939.
While the engine first presented a somewhat discouraging
appearance upon being unpacked, with its
dull black finish and a dangling mass of wires,
controls, fuel, oil and coolant lines, etc., it
soon became apparent that good design, high quali ty
and excellent workmanship lay behind its somewhat
homely exterior, Mr. Young says. The general workmanship
indicates the application of suitable
machine tools, skilled operators and efficient
personnel. Handiwork in polishing highly stressed
parts is of the highest order, but no useless effort
has been expended where there is not a direct
return in increased reliability or performance.
Its general design reflects a ruggedness and reliability
which has always characterized Mercedes-
Benz products, while the relatively low rating indicates
conservatism in output for the sa~e of
improved reliability and increased service life.
Attention To Details
Careful attention has been paid, according to Mr.
Young, to seemingly unimportant details which may
mean the difference between success and failure in
a given design. Specific reference in this connection
is made to the doweling and serrating of
joints to eliminate chafing and ultimate trouble;
also to the shot hardening of stressed steel surfaces
in intimate contact to reduce fretting and
fatigue
failures.
With possibly several minor exceptions, the design
represents good mass production practice for
the use of special purpose machine tools. While
the grinding of gears is on a par with American
(Next page, Col. 1.)