Me 262/Fi-103R Reichenberg Mistel ? SO Aircraft ??

[aerospace]

The complete discussion in this thread has the same text as three to four pages in an average book. That seems too much for some participants to read. Nevertheless there are some interesting contributions to the discussion I would like to comment:

1) a means of rescue device was always fitted
The Daimler-Benz-SO-jet-bomber for example was meant to destroy convoy-vessel in the mid-Atlantic. If the pilot could manage to bail out over an exploding tanker and could make it into the sea, he has only to swim 2000 km to the German coast to be save. Is that the kind of rescue you are talking of? Seen through your eyes, every Japanese Kamikaze had means of rescue - but what was the impact on the pilot’s mission?
In 2014 I could talk to one surviving SO-pilot, than 92 years old. He volunteered as most of his comrades from a glider-unit for the Reichenberg. With a short-span glider Stummelhabicht they trained to attack clouds in two ways. A near vertical dive as a direct attack on a target and a cut-under attack to simulate the torpedo-like warhead against ships. He never flew a Reichenberg before the unit was disbanded and he was transferred to a fighter squadron. They were treated like being "living deaths", best food, accommodation and entertainment and it was promised that the nation would take care for their families. The moral was very high. But it was said that if they refuse to fly an ordered mission they would have been shot. He told me, that was no problem to the volunteers, all had accepted death -"it was a very different time".

2) Why not just convert a manned Me 262?
That is a good idea! With the new Jumo 004 C a 262 must have been able to carry around 3 tons of bomb-load. This would have been sufficient for the SO-purpose. The issue must have been the time it takes to develop a sub-type of an existing aircraft. New load factors and changes to the airframe causes a lot of new computations and tests for loads, elastics and flutter-safety. So the quick solution is to take two completely designed and certified aircraft and combine them.

3) What was the gain in payload from adding the Reichenberg?
The duty was not to add some more payload to the 262-bomb, but to add a pilot that would guide the explosive 100 percent into the target.

4) There is not enough space within the fuselage of the ‘Reichenberg’ to install the instruments
If you would have ever looked into a Reichenberg cockpit you would have recognized that there is a lot of space for the two Jumo-controls needed. Please see Re_cockpit_01.jpg.

5) The fast disconnection system between both airplanes would have been very complex
Letting beside that there is no disconnection, it would have been not more complex than for other Mistel!

6) It does not make much sense to risk two highly valuable turbojets and a well trained Me 262 pilot in a suicide mission
If it does not make sense to you, please see point 12. It could make sense to other people in previous times and a different situation.

7) it would have been much more efficient to use another Me 262 as piloted airplane capable to return to base with the pilot alive?
Yes - now you got it! That are two different approaches. That is what we talked of when discussing the Me262/Me262-Mistel. When this 262/262 has been on the drawing-boards, what advantage could have a new designed Reichenberg/Me262-Mistel? Only that one flies with a returning pilot and the other in a SO-mission.

8) If this type of Mistel would try to fly with turbojets and pulsejets working SIMULTANEOUSLY, the vibration of the Argus would destroy the connecting struts.
I must mention that I am part of a small group restoring ww2 aircraft and missiles and so have worked for the Luftwaffe-museum at Berlin-Gatow to restore their V-1. Yes, the Schmidt-Argus is vibrating, but it is more the noise that causes problems. See picture Fi103_01.jpg and Fi103_02.jpg that show the pneumatic control system of this guided bomb that is very sensitive to vibration and has to be very accurate to bring the Fi 103 into the target area. It works directly under the running engine who's mount is depicted at right. And please compare the cockpit-picture of Alexander Kuncze's fine restored Reichenberg, where the brain of the pilot is even closer to the engine - destroyed by vibrations?
For more Fi 103 pictures please visit:
www.daedalus-berlin.de (sorry - text only in german).

9) the Argus had a useful life of just 20 minutes.
Yes, the Schmidt-Argus has a short life time. That is why I suppose that this engine is running on full power only at take-off and during the attack. For cruise it must be powered down. Otherwise the mistel would make no use of the Me 262's longer range.

10) It would also not have had much strategic sense trying to sink one of the 72 aircrafts carriers the Allies had at the beginning of 1945. This was a time to destroy bridges to stop the Red Army.
I have never been a commander of an army. But I would imagine that concentrating only on a single issue would mean to lose the battle. If the bombers continue to destroy factory after factory and city after city - there is nothing left to defend and you would have no weapons for your soldiers.

11) I'll try to explain, why it may not have been a "SO-Gerät"
Do not argue what it is not - bring arguments what it is. I am looking forward reading your analysis!

12) suitable as an area weapon
What could a young man 1944 motivate to fly a suicide-mission? Take only one small excerpt from the document of the Daimler-Benz-SO-jet-bomber: "… with one man as a Self-Sacrifyer and with a charge of 2.5 tons in the fuselage-nose …" "… operated for the combat against vessel-targets, especially for the destruction of tank-vessels . A single destroyed tanker of 15 000 tons causes the loss of fuel for 3 full size bomber attacks against Germany to the enemy." "The thought to sacrifice one single man and a single aircraft ... to prevent 3 of such full size bomber attacks is to my judgment a respectable one."
Everybody in Germany remembered the Hamburg-raid of 1943, where 3 bomber attacks killed around 35 000 civilians, wounded around 125 000 and destroyed one of the oldest towns in Germany within two days.
Does someone here has even the slightest doubt that in 1944 there had been enough men willing to exchange their life to save thousands or up to 35 000 civilians? Captured allied crews and documents clearly proofed that the only target of the "Operation Gomorrha" was to kill as many civilians as possible and to cause terror and fear. Captured crews later stated that it was the plan of the Allies to "Hamburgize" every major city in Germany. And Dresden was still to come.
"Area weapon" - what a nonsense! Thousands of such aircraft approaching London? What would motivate this pilots? To destroy the bathroom of the King at Buckingham Palace?

 

[steelpillow]

Thank you again U.W.Jack for a full and fascinating reply.

I'd just like to comment on the pulse jet. Noise and vibration are really the same thing here. The bigger difference is that a machine with an operational life of only a few minutes need not be as vibration-proof as a re-usable warplane such as the Me 328, nor do the ears of a pilot with only a few minutes to live need to avoid partial deafness. Even then, it took some effort to solve the vibration problems with the V1/Reichenberg, so it is possible that the Me262 Mistel combination might have needed some development to do the same. One problem the Me 328 found was that the pulse jets only worked well at low altitude. The idea of using it only for takeoff and the final dive makes a lot of sense.

 

[Jemiba]

First, thanks for your elaborate answer, second.

About 1) :
That during the last years of WW II SO units were established, that's
beyond doubt. That any means of precaution to save the pilot would have been more or
less for morale only, probably, too, although it may have allowed one pilot to fly
at least two missions. The example of the exploding tanker is somewhat meaningless,
I think, as attacks on the wide open sea would have been impossible with the available
SO weapons and secondly : How many tankers were crossing the Atlantic alone ? There
were a number of missions, where the soldiers rescue was seen in their capture.
But as mentioned before, that's not the main point of this discussion.

About 2) :
The Me 262 fighter had an empty weight of 3,800 kg. Removing weapons (334 kg), ammo
(150 kg), armour (196 kg) and maybe even the landing gear (estimated 300 kg) would
reduce this to 2,820 kg, that gives a difference of 3,580 kg to the stated MTOW of
6.800 kg. The normal fuel load of 1,500 l/ 1270 kg gave a range of about 1,000 km.
So, for the stated range of about 500 km not even the more powerful Jumo 004C would
have been needed. And removing the mentioned componenets certainly wouldn't be the
development of a new variant.

About 3) :
See 2), for a suicide mission, an "emptied" Me 262 would have been the quicker way, not
to mention, that this solution would have saved the full speed of the Me 262, whereas
the combination would have been slower without doubt.

About 4) :
You're right, there would have been sufficient space. The manned version of the
Fi 103 would have had sufficient space for the additional instrumentation. Only the
transmsission of the input via the control column was needed and this was done via
potentiometers, not very big devices, not even back then. And the device, that translated
those commands in the lower unit was integrated into the "Kurssteuerung" (command unit).

About 5) :
You're right, it wouldn't have been more complex, than in the other Mistel types. It was
tested and proven, maybe it would have had to be modified for higher attack velocities.

About 6) :
You're right, there were designs for Mistel combination using Ju 287 as lower components !
As mentioned, jet engines had a much shorter life span, but could be manufactured with much
less man hours.

About 7) :
Maybe because a Reichenberg was simpler, easier and would have freed Me 262 for other tasks ?

About 8)
Your article mentions, that the pulse jet of the Fi 103R would have been shut down for cruise
flight. If the Me 262 could have accomplished cruise flight alone, I can hardly see much reason
for the pulse jet at all ! For take-off rocket boosters could have been used and for the terminal
dive, any additional vibrations may have reduced accuracy. So, combining both, to my opinion only
makes sense for the use as a conventional Mistel.

About 9 ) :
The simple fact, that quite a lot of V1 reached a target at their maximum range of about 280 km,
proves the "20 minutes lifespan" to be wrong, as it certainly hadn't a V(max) of 840 km/h, had it ?
The As 014 certainly was a short-lived engine, AFAIK the main limitation came from the spring loaded
pistons. But that would have been a point ceratinly to be cured quite quickly with the use of higher
quality materials.

About 10 ) :
"... This was a time to destroy bridges to stop the Red Army." Exactly for such missions the "conventional"
Mistel had been designed, too, but proven too slow. And those Mistels were fitted with a shaped charged
warhead to achieve a better efficiency.

About 11) :
"Do not argue what it is not - bring arguments what it is. "
Just one simple question : Do you have a reliable source, stating that this combination was meant
as a suicide weapon ?
You mentioned a drawing showing it, is it somehow labelled as "SO-Flugzeug" ? I have the feeling, we
are discussing just drawn conclusions, not provable facts. Don't get me wrong, that's absolutely ok,
history is something, that has to be interpreted. But it an interpretation should be marked as such,
as well as main sources should be shown, or at least mentioned, because only then those interested can
conceive their own opinion. For example, the document about the load of explosives of the Me 262, to
my opinion has so many inconsistencies, that I would regard it as highly dubious. We both know about
susceptibility of that market !

About 12 ) :
The DB project is known, we have a thread here, mentioning it, I think. Those "manned missiles" should
be carried by a big carrier aircraft, AFAIK. But In 1945 the Me 262/Reichenberg Mistel hardly would have
had any chance to reach a tanker in the Atlantic!
Did you have a precise look at the drawing you posted ?
What you see in the nose with that sting-like fuse looks exactly like a shaped charge to me. And from
all technical-tactical thoughts, that would have been a wise decision, as even a very strong explosion
at the outside of the hull of a tanker may just have led to a deep dent or severe whole, but the effect
of the explosion may not have gone into deep. A shaped charge without doubt would !
Remember, a simple explosion brings not even 50 % of its effects to bear to the target.
But many thanks for that drawing, it gives an idea, why Me 262 as explosive carrier could remain externally
unaltered, besides the deletion of the cockpit.
"Area weapon" - what a nonsense! ". In the form, you've described the combination of the Me 262 and the
Fi 103R it would have been an "area weapon", similar to an aerial mine or a modern FAE (Fuel-Air-Explosive),
not meant to destroy point targets, but "soft" targets (houses, troops and so on) over a great area. But a high
accuarcy isn't needed for such missions. So, why sacrifice a pilot for it ? And no, I don't think, that destroying
"the bathroom of the King at Buckingham Palace" would have motivated any suicide pilot. Maybe the irony
about that point was lost in my post, sorry for that.
But a mission like that to my opinion would have been the only reasonable use for a suicide Mistel of that
configuration !

So, here are the arguments, what it to my opinion is: A proposal for a Mistel with a Fi 103R Reichenberg as
upper component, that was meant to bring home the pilot. A suicide weapon could have been realised much easier,
without the need for using up two aircraft, even offering higher speed and accuracy. If the layout with the lower
component just filled with explosives, as mentioned in that document, would have been used, that loss of speed
would not even have been compensated by a much higher explosive power !
Again, I wouldn't completely deny, that such a proposal was made. Other, even less practical weapon systems
were proposed and sometimes, if those ideas fell on fertile ground, even resources for development and testing
were allocated ! So, why not here, too ? But I really would like to hang on to the believe, that at least the
biggest part of the aviational branch of the German industry had kept some common sense ...

 

[hesham]

Hi,


I think it was a real design,here is from Krylya Rodine 7/2006,anther Me-262 used
as a Mistel aircraft.

 

[Jemiba]

I think it was a real design,....

Principally, there's not much doubt, that ther was a Mistel design using a Me 262 as lower component,
carrying explosives and a Fi 103R as upper component. U.W.Jack mentioned a manufacturers drawing
showing it and this claim and such a combination seems plausible to me. Even better, if we could see that
drawing ...
The unanswered question here just is, if it was a "SO Waffe" (self-sacrifice/suicde weapon), or not.

 

[steelpillow]

The unanswered question here just is, if it was a "SO Waffe" (self-sacrifice/suicde weapon), or not.

To me that question is solidly answered. Consider simply these points:

1. The various heavy nose modifications proposed for the Fi103, that would have moved the centre of gravity in flight and made it unflyable. These would not have been contemplated if the craft were to separate.

2. Insufficient range of the Fi103 to get back home, meaning an almost certain bail-out over potentially lethal waters or enemy-occupied land. Better to stay with the ship and pilot her in. Now I know some folks here think the pilots would have been chicken, but the history and established psychology of such suicide projects testifies otherwise.

3. Use of the Fi103 in other contemporary SO projects. It was the thinking of the moment.

I would suggest that the burden rests wholly on the "survivalists" to demonstrate a viable technical case. Vague "would they have thought/done that?" doubts are wholly inadequate to counter the above considerations. But if there is a viable technical case, I would genuinely like to see it.

 

[Jemiba]

About 1.:
We still don't know at all the modifications to the Fi 103R for the use as Mistel guiding aircraft,
or better we don't have reliable data about that Mistel at all. For example, a two seat training
version was fitted with a second cockpit much further forward (see U.W.Jackspost #30), so there
would be enough room for changes.

About 2.:
Replacing the warhead at least partly with fuel tanks. Still don't know, where the given range of
500 km comes from, but with correct distribution of the fuel load it could be possible, especially
if we remember, that the Fi 103R was fitted only with one instead of two pressure air tanks.

About 3.: Transfered to other types, an argument like "the Fi 103R was once considered as a SO aircraft,
so it was always and only considered as a SO aircraft" would mean, that no Ju 88, Do 215/217 would
have entered service as a night fighter, or the Fw 200 would have never been used as a maritime recce
aircraft, as principally it was a passenger aircraft, wasn't it ?
You're right, suicide attacks were planned in Germany, too, but again my question: Where's the benefit of
this combination compared to a modified Me 262 ? The slower airspeed, due to the higher drag/interference
of those two closely coupled aircraft ? The without doubt more difficult handling, that would have even needed
better trained pilots ? The higher cost of two aircraft against a single one, without the benefit of a much higher
weapons effect ?
I know, there were quite a lot of unrealistic German projects towards the end of the war, but this one as a suicide
weapon would even be unplausible, I think. But maybe the designer spent a lot of time not in the airraid shelter,
but in the wine cellar ?

 

[steelpillow]

About 1.:
We still don't know at all the modifications to the Fi 103R for the use as Mistel guiding aircraft,
or better we don't have reliable data about that Mistel at all. For example, a two seat training
version was fitted with a second cockpit much further forward (see U.W.Jackspost #30), so there
would be enough room for changes.

My point is about CG movement during separated flight. Too many such variants were proposed for them to be simply brushed aside by a single example which does not vary the CG.

About 2.:
Replacing the warhead at least partly with fuel tanks. Still don't know, where the given range of
500 km comes from, but with correct distribution of the fuel load it could be possible, especially
if we remember, that the Fi 103R was fitted only with one instead of two pressure air tanks.

It's not just about fuel tankage, these pulse jets had a very short operating life. The Fi103R had a range of 330 km (205 miles). U.W.Jack said that he estimated the total range as 500 km, and even that was based on the pulse jet shutting down during cruise. The proposition that such an inherently short-life powerplant would run for an extra 500 km on the way home, even if the fuselage could accept the tankage, is not consistent with the available technology.

About 3.: Transfered to other types, an argument like "the Fi 103R was once considered as a SO aircraft,
so it was always and only considered as a SO aircraft" would mean, that no Ju 88, Do 215/217 would
have entered service as a night fighter, or the Fw 200 would have never been used as a maritime recce
aircraft, as principally it was a passenger aircraft, wasn't it ?
You're right, suicide attacks were planned in Germany, too, but again my question: Where's the benefit of
this combination compared to a modified Me 262 ? The slower airspeed, due to the higher drag/interference
of those two closely coupled aircraft ? The without doubt more difficult handling, that would have even needed
better trained pilots ? The higher cost of two aircraft against a single one, without the benefit of a much higher
weapons effect ?

The point is that the manned Fi103 was never seriously considered for anything else. Your logic-chopping verges on the facetious.

The benefit of adding the Fi103 was surmised by U.W. Jack to be the time saved in using two certified production airframes rather than develop, productionise and certify a new and more powerful variant of the Me 262. I'll buy that, as all these high-speed jets took a long time to reach service (flutter investigations throughout the speed range were one big reason) and the SO 262 would have arrived too late. You don't have to buy it, of course.

 

[Jemiba]

The point is that the manned Fi103 was never seriously considered for anything else.

To me a typical argumentum e contrario, that's just reasoned by itself.

It's not just about fuel tankage, these pulse jets had a very short operating life. The Fi103R had a range of 330 km (205 miles). U.W.Jack said that he estimated the total range as 500 km, and even that was based on the pulse jet shutting down during cruise. The proposition that such an inherently short-life powerplant would run for an extra 500 km on the way home, even if the fuselage could accept the tankage, is not consistent with the available technology.

The Me 328, using the Argus As 014, too, is credited with a range of about 480 km, compared with its stated
speed needing an engine life of at least 30 minutes. Those pulse jets probably had no incorporated self-destrction !

 

[Jemiba]

I don't want to hold a monolog here, don’t know, if it is of much interest for many of you.
But that case to me is a good example, how false information are coming into being, although
here it’s more or less a minor case, as just the modus operandi of a given aircraft/Mistel
combination is given wrong, to my opinion. Annoying nevertheless, I think, as it’s stated in
a magazine, so it quite probably will be cited in the future and that error is here to stay.
And we know, how hard it is, to correct such things!
As I pointed out in my older posts, the Me 262/Fi 103R Reichenberg is said to have been shown
by a manufacturers drawing. The idea, that it was a “SO-Gerät” (suicide aircraft) was based on
the assumption, that the load of explosives of the Reichenberg was considered as too small for
being effective and that the Me 262 would have been used as an additional charge.
As prove, a document is stated, that mentions 3 variants of filling the Me 262 with solid and
liquid explosives. So I made a calculation to check it, please see the attached file.

For short, my conclusion is: That variant wouldn’t have been able to fly. So that document
not only is highly dubious because of its appearance , but its contents are implausible.
To my opinion it’s just a fake and worthless as an argument for that Me 262 Mistel simply
would have been filled with explosives.
But that was the mentioned raison d’être for adding the Reichenberg, or better, the other way
round, no matter of the really small gain of explosive power, compared to a Me 262 as an explosive
carrier on its own, as explained before. For a SO-Me 262 Mistel carrying a shaped charge , there
would have been no reason, either, as a single, manned Me 262 would have been faster and
more maneuverable, so more survivable and not the least cheaper.

But I'm open for discussion !

 

[athpilot]

Thank you Jemiba for your good summary of the case! I fully agree with you. Your calculations should have been done by the author himself before he stated to have found a sensation. As long as the document (and the mentioned original drawing) is not shown or at least the author tells in what archive he had found it (every aviationhistorian does it this way!) to me it´s a fake too.

 

[steelpillow]

We have put up some good cases to argue over the technicalities. I'd say there is enough doubt that only independent examination of the original sources can clarify what really is an issue and what is just a red herring. And I certainly agree that includes verifying whether the sources date from 1945 or 2014.

 

[hesham]

Hi,


here is the Mistel variants.


Flugzeug Classic 7-2015

 

[Jemiba]

Yes, that are Mistel variants, that are known and some of them actually were
flown, others were proposed and there are actually sources, proving that.
In the case, that led to this topic, the question was, if there really was a Mistel
with the mentioned components and if it actually was intended as a suicide
aircraft. For both points, we are still waiting for a credible confirmation.
I think, I'll move that topic to the theoretical/speculative section, if we'll don't
see hard evidence during the next time ... something I honestly cannot believe in ! :
But the author of that article still is here from time to time, so let's see.

 

[steelpillow]

Yes, I think speculative is a good place for this discussion. We have waited a good while for confirmation of the source and it has not been offered. If it does come through, the topic can always be moved back again.

 

[sgeorges4]

My two cent: just an idea that wasn't meaned to be produced or if it was mean to be produced then it wasn't too far in therm of devllopment (rough drawing,scheme or just an idea in the mind of semeone).