BOC: Me 262, Prince of turbojets

[John A. Swartz]

O.K., I've shown my ignorance in wondering about when people were
considering breaking the sound barrier - I thought Yeager's famous
flight was in the 50s, and not in 1947, 2 years after the ME-262 "may"
have broken the barrier.

First off, I should point out, for those who don't know, the most
excellent website www.stormbirds.com, which is not only dedicated to the
ME-262, but also discusses a current project to rebuild working ME-262's
- yes, you could own one of your own!

Anyway, on this site, there is an account of Hans Guido, although it
does not discuss breaking the sound barrier - but, at the bottom of his
account is a link to the following site which does discuss this:

http://www.unsere-luftwaffe.de/mach1/index.htm

>From that site:

"Who was Really the First?


When Chuck Yeager made his "memorable" flight with the Bell X-1 on 14
October 1947 it was certainly not the first time that anyone had
exceeded Mach 1.

Doubtless a small group of engineers at Messerschmitt had already been
researching into supersonic flight in 1944/45 and the Me262 was perhaps
already a first step in this direction, although it was still a subsonic
aircraft. Shortly before the end of the war Messerschmitt attempted to
improve on the performance of the Me262 with the development of the Me
1101 and two other variants which he already had on the drawing board.
At the end of the war the first Me 1101, although far from being ready
for a first flight, was in an advanced stage of construction at
Oberammergau where it was inspected by a development team from the
American company Bell and then taken to the USA. Bell was almost
certainly already working on the development of the X-1 at this time as
a supersonic aircraft. Admittedly the X-1 was a rocket powered aircraft
whereas the Me262 was a jet powered aircraft.

It is amazing to consider the performance that was achieved by the
Me262, despite the fact that it was still not fully developed and the
poor quality of wartime construction in 1944/45 which was due to the
aircraft being hastily built in large numbers in different factories,
partly by foreign workers and often with defective materials. The
aircraft was designed for a maximum speed of 1000 km/ h but at that time
none of us operational pilots were aware of the existence of the, "sound
barrier" - this expression was only later invented by Prof Ackeret from
Zurich. G.Mutke spoke on several occasions to Prof. Ackeret in Zürich in
the summer of 1945 although they did not discuss this subject.

The pilots were under strict instructions not to exceed 950 km/h,
although there was no mention in these instructions of altitude. In fact
Me262s had occasionally crashed without the pilots being able to make
any report. We can surmise today that these crashes were caused by
pilots approaching the sound barrier and entering the area of buffeting
or even crossing into the transonic area or perhaps even breaking
through the sound barrier. The aircraft were then not able to withstand
the resulting stresses and shock waves and finally broke up. lt would be
natural for pilots to push their aircraft to the limits and some would
therefore almost certainly have attempted to fly in excess of 1000 km/h
although at this time the variation in the speed of sound with altitude
was unknown. lt is not surprising that these pilots did not report their
attempts since they were threatened with severe disciplinary action if
they flew the aircraft at more than 950 km/h or did anything which
caused damage to these very valuable aircraft. Apart from the existence
of these unexplained crashes we have no direct evidence to support the
theory that they were caused by pilots approaching the sound barrier.

On a flight with a Me262, flown by G.Mutke, on 9 April 1945 over
Innsbruck he entered a 40°~50° dive under full power from about 36.000
ft and broke through the sound barrier as a result of a combination
offactors which on this occasion combined together in a positive manner.
His claim is supported by the fact that the controls of the aircraft
became totally ineffective shortly before reaching the sound barrier and
then full control was regained a few moments later. At the same time
both engines flamed-out and the aircraft suffered severe damage. lt is
as a result of a pure coincidence that he came to realise that he must
have exceeded Mach 1 on this flight on 9 April 1945 with the Me262
"Weisse 9" from III EJG-2. This occurred during a discussion with a
group of test pilots during the international meeting "50 Years of Jet
Powered Flight" held in Munich in 1989..

In a discussion with Wolfgang Späte, a well known test pilot and colonel
in the German Luftwaffe, who became involved in the Me163 programme as
early as 1942 and then later, after the war, carried out supersonic
flights in France, we established that the sound barrier must have been
broken on G.Mutke's flight in the Me262. This is based on the fact that
the aircraft became uncontrollable during a strong and short buffeting
phase and then control was regained, while the airspeed indicator
remained on the stop at 1100 km/h, and both engines suffered a
flame-out. This was published in the report of the meeting.

One of the main points often repeated during later discussions was that
the Me 262 was a subsonic aircraft and that neither the wing-sweep nor
the wing thickness were suitable for supersonic flight. The wing-sweep
was always considered to be a critical factor but this was later proved
incorrect as the Bell X-1 and the F 104 were supersonic aircraft and had
straight wings ,i.e. zero wing-sweep. The maximum thickness ot the
aerofoil (about 11% for the Me 262) also plays an important role and is
one of the reasons that when an aircraft will result. This was the case
with Mutke's flight on 9 April 1945 when the Me 262 Weisse 9 was so
badly damaged that it was no longer repairable.

Today of course we know a lot more about the so-called "sound barrier",
even though some factors are still not quite clear, and we can clearly
differentiate between the configurations required for subsonic and
supersonic aircraft. However at that time many pilots world-wide,
especially in America and England, lost their lives due to ignorance of
this critical area of flight. In G.Mutke's opinion, and with hindsight,
the decisive factor was often that the pilots approached the sound
barrier very cautiously, tentatively and slowly thereby exposing the
aircraft to the heavy loads, shocks and vibrations of the buffeting area
for too long so that the aircraft finally suffered material failure and broke-up.

In the quest to exceed Mach 1 we must differentiate between the pilot's
performance and that of the aircraft (the skills of the design
engineers). The pilot's contribution is relatively minor since if the
aircraft is capable of exceeding Mach 1 then it will do so without
requiring any special skills from the pilot. This is certainly G.Mutke's experience."


The page has more information, including some discussion about Chalmers
H. (Slick) Goodlin having flown supersonic 6 months earlier than Yeager.
 Interesting stuff.


Of most interest to BOC fans might be that this ME-262 "supersonic"
flight took place on 9 April 1945 over Innsbruck (Austria) - not "over
Westphalia", BUT "in April of '45"!  :-)

John