Junkers Ju 52/3m engine mounting angle

[GrahamB]

Thanks Ed.

While you may be right in stating the design purpose of the outward cant, I think that the photographic evidence of BMW-powered Ju 52 aircraft was that this was eliminated. There is another excellent print in Classic's 'Transporter Vol 2, page 134. Again, the photographer was more or less in perfect alignment with the starboard engine nacelle, with the cowling fixed at a highly asymmetrical position and clearly angled inwards (relative to the wing leading edge). Other standard views from positions ahead of the wings do not show the outward cant that would be exagerrated if the observer was in front of the outer engines. Using the angle of the undercarriage (wheels) will show that the cowling front is parallel to them - it usually seen with an orientation between that of the wheels and the central cowling - which is what one would expect. Some photographs that imply that the observer was directly perpendicular to the front of the central cowling are the best - the outer cowling front is just visible, mirroring the slight apparent dispacement of the wheels, and certainly not showing the amount expected of the 5-6 degrees of backsweep of the wing leading edge.

Best wishes

Graham

[ArtieBob]

IMHO, after trying to make drawings from aircraft photos, it is very difficult to determine either linear or angular dimensions accurately. In the case of most WWII LW types the manuals are available, which should answer most questions similar to this one. I only have at hand the Kennblatt Ju 52/3m (see) g4e BIS g8e, g10e, g14e dated 27.4.1944. It seems pretty clear from the 3 view drawing that the propellor arc is parallel to the aft swept leading edge of the wing and is not perpandicular to the fore and aft centerline of the fuselage.

Best regards,

Artie Bob

[George Hopp]

Here is how Junkers saw this aircraft. From Teil 0 of the manual on the Ju 52/3m g5e.

[GrahamB]

Hi George,

many thanks for this - it looks as if I am on a hiding to nothing with this one, although I remain unconvinced but happy to retire hurt in the face of what seems overwhelming 'official' evidence and previous literature. If Junkers is calling the figure a 'g5e' then there is something wrong with previous accounts. According to Manfred Griehl in the Flugzeug Profile 24 (= english translation version Schiffer Profile14) the g5e was introduced in 1941, a transport version well after the time when Aunti Ju was a bomber with a ventral dustbin turret. Stapfer, Mau and Punka in the Squadron/Signal 'In action no 186) say 1939 was the year of production for this variant - again after the bomber role had been changed to transport. All a bit confusing. I suspect that the manual's drawing is only basic and generic.

Why I am tearing my hair out over this is a mystery!

Kia ora

Graham

[George Hopp]

I have noticed this with other a/c manuals. Once they draw up an a/c; unless it really changes, they just keep using the same drawing.

[pstrany]

Okay, the examples I will cite are from a Spanish version of the Ju 52, but I think they can safely be applied to most German-built aircraft as well.
Picture #1 will show that the nacelle and cowling ar indeed an odd (and misleading) shape. The nacelle is almost perpendicular to the line of flight, but the cowling does angle outward. The mating of the two is very strange, I had to stare at it a while to get it.
Picture #2 will show that while the center engine is perpendicular to the line of flight, the left engine does cant outward. This was shot from a distance with a zoom, which helps to eliminate the distortion found in close-up shots.
These pictures were taken of the Spanish-built Ju 52 at the US Air Force Museum in Dayton, Ohio.

Paul

[GrahamB]

Hi Paul,

thanks for the two photos! I can't say that they really help - the one from the rear of the nacelle could be interpreted the other way: the corrugations are parallel to the line of flight (fact) while the nacelle is slightly canted outwards (fact), probably at the 6 degrees to make the front end parallel to the wing leading edge (6 degrees backsweep) - the cowling is similar but not identical to the German BMW versions and to my currently biased mind appears aligned in with the line of flight. Perhaps its asymmetry leads to the misperception and is what got me interested in this aspect anyway.

The second photo merely shows what would be expected if photo is taken ahead of the outer cowling - note apparent angle of the undercarriage. Maybe the slight angle involved (6 degrees) is just not resolvable with this photographic material. I wish I could transport myself to an authentic Ju 52, with original engine mounting - perhaps it was capable of being adjusted according to trim requirements of the individual aircraft?

There are many more issues to do with the Ju 52's morphology (engine intakes/exhausts/de-icing systems particularly - many variations and combinations) that have been poorly dealt with in the literature, although the beautiful illustrations in Classic's Transporter volumes are almost (not quite) spot on.

Cheers

Graham