A small what-if: Ju 52 with two engines and a retractable U/C instead of the 3-engined layout?

[nuuumannn]

But taking a Ju 52 and putting larger engines on the wings, smoothing up the nose and having the landing gear retract wasn't really going to do it either. It will help but as has been point out by others it may not be worth the expense and extra maintenance.

Agree. The Ju 52/3m was quite a rugged aeroplane and although not fast had very good short take-off characteristics. It could also handle quite a lot of punishment; it was very robust airframe, far more so than those Italian plywood and fabric machines.

The Germans should have thrown the Ju-52 to the dump and build the Italian Savoia-Marchetti S.M. 82 as a twin engined transport, powered by Gnome-Rhone 14N radials of 1,140 HP each or the BMW-Bramo 323 engine of 1,000 hp. The vertical stabilizer and rudder would have had to be enlarged to address engine out maneuvering capability. The resultant airplane could have carried 15,000 lbs of weight for at least 1,500 miles at 186 mph. For comparison, the C-47, with 2 R-1930s of 1,200 hp each, could carry about 10,000 lbs at least 1500 miles at 185 mph. The Ju-52 with its antiquated (even for the time) structure could not have made any better no matter what.

Um, the Ju 52/3m first flew in 1932, seven years before the SM.82. It was of all-metal construction when virtually everyone else was building wood and fabric aircraft or at least metal endoskeleton covered in fabric aircraft. Not only that, but structurally, the Italian aircraft was not as robust; it was welded steel tube with fabric and wood covering, with metal coverings forward. It's also quite big. And what would the Luftwaffe be sacrificing in doing this? The Junkers could take-off and land from shorter, less prepared strips compared to the bigger Italian aircraft. It was very reliable and easy to maintain. That goes out the window as soon as you add wooden structures to the mix in the conditions that the Junkers operated in places like the Eastern Front, for example.

It's size can be gauged here by using that universal yardstick unit of measurement, the P-51

SM.82

The only real drawback to the Ju 52/3m was its stately performance. The thing is very slow, but that enabled it to operate out of small spaces with ease; it's virtually unstallable with its massive wing area and dangly flaps and ailerons. it could take-off and land from almost anywhere. I've watched one do circuits and it has a terrifically slow approach speed and sort of plonks onto the ground and comes to a stop in a remarkably small distance.

This is what Eric Brown had to say about the Tante Ju:

"Slow and noisy though the Junkers undoubtedly was, it was also supremely reliable, a quality which, coupled with rugged construction, simplicity of operation and ease of maintenance in the field, made up the magic recipe that resulted in the fantastic longevity of the Ju 52/3m."

On the subject of no centre engine, Brown stated that with the middle engine out, the Ju 52/3m's overall speed dropped by only 12 mph. A different story if it were one of its outer engines, which reduced its speed by 19 mph.

 

[Thumpalumpacus]

On the subject of no centre engine, Brown stated that with the middle engine out, the Ju 52/3m's overall speed dropped by only 12 mph. A different story if it were one of its outer engines, which reduced its speed by 19 mph.

That puts a different perspective on what I wrote upthread about the cost-benefit-analysis of deleting the nose engine versus the weight and complexity of retractable gear. It might be worth it.

 

[nuuumannn]

That puts a different perspective on what I wrote upthread about the cost-benefit-analysis of deleting the nose engine versus the weight and complexity of retractable gear. It might be worth it.

You could be right, but is retractable gear necessary? You really aren't going to get a whole lot more performance out of it, for the cost of complexity, extra weight and increased sized nacelles, not to mention beefing up the hydraulic system to actuate the gear, or worse a manual system that takes a week to retract the gear. Having more powerful engines wouldn't go amiss, I'm sure. Drag-wise though, the thing is a flying shed with built-in headwinds, not exactly the purest in aerodynamic refinement!

 

[Thumpalumpacus]

You could be right, but is retractable gear necessary? You really aren't going to get a whole lot more performance out of it, for the cost of complexity, extra weight and increased sized nacelles, not to mention beefing up the hydraulic system to actuate the gear, or worse a manual system that takes a week to retract the gear. Having more powerful engines wouldn't go amiss, I'm sure. Drag-wise though, the thing is a flying shed with built-in headwinds, not exactly the purest in aerodynamic refinement!

That's pretty much my point so far as I have one, that the tradeoffs seem like a wash to me.

 

[Shortround6]

Considering the German proclivity to destroy 100s of Ju-52s in one day (Norway, Holland, Crete) the sooner they can shift to a 2 engine transport the better.

 

[GTX]

On a tangent, I've often wondered what might have been the result of the Focke-Wulf Fw 206 entering production/service:

 

[SaparotRob]

Every time someone tried to improve on the DC-3 they just came up with a DC-3.

 

[Denniss]

They should have gone the japanese and soviet way by license-producing the DC-3.

 

[nuuumannn]

Considering the German proclivity to destroy 100s of Ju-52s in one day (Norway, Holland, Crete) the sooner they can shift to a 2 engine transport the better.

I honestly don't think deleting an engine or building another type would prevent something like the losses at Crete and Norway from happening. We're talking transports after all.

 

[Shortround6]

I honestly don't think deleting an engine or building another type would prevent something like the losses at Crete and Norway from happening. We're talking transports after all.

It wouldn't have changed the battles themselves, it might have made rebuilding the transport squadrons a bit cheaper and easier.

 

[tomo pauk]

I honestly don't think deleting an engine or building another type would prevent something like the losses at Crete and Norway from happening. We're talking transports after all.

I'm sure that anyone would've say 'yes' to have a few thousand of engines free back then, less need for maintenance, as well as some fuel saved.
Or, not needing to make 2500-3000 BMW 132s so BMW can make extra 1500+- BMW 801s instead.

Not bad for a small what-if.

 

[nuuumannn]

it might have made rebuilding the transport squadrons a bit cheaper and easier.

I sincerely doubt that given the high utility, ease of maintenance and repair of the Ju 52/3m, not to mention its rugged reliability and ability to land just about anywhere. If anything, the Germans needed more transports, not necessarily different ones and changing from the Ju 52/3m in the middle of the war would have left the Germans desperately short.

 

[Shortround6]

I sincerely doubt that given the high utility, ease of maintenance and repair of the Ju 52/3m, not to mention its rugged reliability and ability to land just about anywhere. If anything, the Germans needed more transports, not necessarily different ones and changing from the Ju 52/3m in the middle of the war would have left the Germans desperately short.

I am advocating something like the Bristol Bombay or HP Harrow, and do it before the shooting starts.

One website for the Bombay says " It had a landing distance of only 260 yards (238 metres) and it could clear a 50 foot (15.2 metres) obstacle after a takeoff run of only 470 yards (430 metres). Those are still-air figures," but that is not official or even semi official. Also no weight is given. But if it could could do that it is not that far off what the Ju 52 could do.

Of course you can't take panels off a Quonset hut to repair battle damage anymore

 

[nuuumannn]

Or, not needing to make 2500-3000 BMW 132s so BMW can make extra 1500+- BMW 801s instead.

With a MASSIVE amount of hindsight. Especially since the Ju 52/3m first flew in 1932!

 

[nuuumannn]

I'm certainly not saying it couldn't be done, but should it? What is gained and what is lost by doing so? Does it even need to be done? I've never read about any dissatisfaction the Luftwaffe had with the Ju 52/3m, apart from the fact the Luftwaffe didn't have enough transports. Sure, it wasn't fast, but it's a transport and even applying the hindsight that the type got shot down in large numbers in almost every theatre it was used in, the addition of drag reduction measures to eke out better performance doesn't guarantee it won't be suffering the same fate.

 

[Shortround6]

Sure, it wasn't fast, but it's a transport and even applying the hindsight that the type got shot down in large numbers in almost every theatre it was used in, the addition of drag reduction measures to eke out better performance doesn't guarantee it won't be suffering the same fate.

IN large part the massive losses, at least the 1 day massacres,were due to using them as assault transports.
Landing in the middle of fire fights to put down the troops in the heart of the action and getting shot up by ground guns or despite the short field performance hitting something on landing that disabled the plane.

Plenty of pictures of Ju 52s wrecked near or on roads.
The type of plane would make no difference to those losses. Using a twin engine plane might make replacing losses easier.
Speed of a transport makes little difference to survival in the air. But a faster transport might make more trips in one day or week.
A Plane that can fly at 160mph for the same power as a plane flying at 120mph uses less fuel to fly the same distance.

Germans spent a lot of time and effort trying to improve/replace the Ju 52 a few years too late and trying to be too complicated.
A simpler solution, adopted earlier, might have paid for itself, not that it would actually change the war.

 

[tomo pauk]

I'm certainly not saying it couldn't be done, but should it? What is gained and what is lost by doing so? Does it even need to be done?

It should've been done. Gained - already covered in the thread. Lost - next to nothing. It needs to be done.

I've never read about any dissatisfaction the Luftwaffe had with the Ju 52/3m, apart from the fact the Luftwaffe didn't have enough transports.

Part of the reason why the LW didn't have enough of transports is that they could not produce enough of aircraft for their needs and the needs of their allies. Going for something like Ar 232, that uses 33% more engines than the Ju 52/3m increases the lift capability by 80-100%. A few thousands of engines will be needed in order to make many hundreds of them, though...
LW tried to patch the lack in the lift capability by employing Italian transports, by comandeered Ju 90s etc, while trying with several transports' designs (Ju 252, 352, Go 244, Ar 232, even the Gigant) once the shooting started. All of that signals that the transport aircraft they made in thousands was insufficient, and that replacements were too late.

 

[nuuumannn]

It should've been done.

Arguable. See below. The LW certainly never expressed any desire to do it, so according to whom exactly?

Gained - already covered in the thread. Lost - next to nothing.

Not correct, change in production introduces delays, which engine type would it use, the exsiting engines were not powerful enough so then what? Escalating another engine type? Impracticable when the LW has not expressed any desire to warrant such a change.

It needs to be done.

No, it didn't. There was no imperative from the LW that this was a necessity and there is no evidence at all of this. The LW needed more Ju 52/3ms. I'm sure the job could have done with another more powerful transport, but not at the cost of less existing types and a slower rate of production and delivery than what traditionally existed.

 

[Shortround6]

Not correct, change in production introduces delays, which engine type would it use, the exsiting engines were not powerful enough so then what? Escalating another engine type? Impracticable when the LW has not expressed any desire to warrant such a change.

This is arguable. The Ju-52 used an old version of the BMW 132 engine (used carbs for one thing?) and an older form of cylinder fins?
The newer version/s of the BMW 132 used fuel injection and came with a choice of 3 different supercharger gear ratios. If you were not interested in high altitude (10,000ft) you could get into the over 900hp range.
The difference in effort to manufacture should be small, depending on the fuel injection.

The Bramo 323 might be able to use similar machinery although castings/forgings would need to be changed over. That can get you to 1000hp per engine.

Swapping a pair of 960-1000hp 9 cylinder radials for a trio of 725hp 9 cylinder radials might be doable.

 

[tomo pauk]

Arguable. See below. The LW certainly never expressed any desire to do it, so according to whom exactly?

According to a simple math.
Ju 52/3m needed three engines with total power of 2000-2200 HP to carry 17 people (+crew) while other people's aircraft carried either more on same power, or same on less power. See the totally un-sexy Bristol Bombay - 24 people (+ crew) on two engines ( = 2020 HP). Or the derivatives of the DC-3 like the L2D, that carrier 4500 kg on 2000 HP, vs. 2000-2200 kg for the Ju 52.
The SM.72 carried 50% more on basically same power as what wartime Ju 52/3ms had.

Germany was not so rich to throw out the resources around.

Not correct, change in production introduces delays, which engine type would it use, the exsiting engines were not powerful enough so then what? Escalating another engine type? Impracticable when the LW has not expressed any desire to warrant such a change.

Engine types are specified in the 1st post. Production time will go down with 2 engines vs. three, both for the engine maker and airframe maker.
LW (not) specifying something was not always a good idea.

No, it didn't. There was no imperative from the LW that this was a necessity and there is no evidence at all of this. The LW needed more Ju 52/3ms. I'm sure the job could have done with another more powerful transport, but not at the cost of less existing types and a slower rate of production and delivery than what traditionally existed.

LW happily jumped on any Italian transport they were able to lay their hands, since the Ju 52 was mass-limited and size limited. They tried with two types of powered gliders, Ju 252 and 352, converted Ju 90, the Ar 232. Imperative was there.
Making more Ju 52s as-is was waste of resources. A 2-engined Ju 52 lowers the cost of the manufacturing of existing aircraft and leaves Germany with a big surplus of engines.