Plans for De Havilland Beaver, Nooduyn Norseman or similar

[Orange4sky]

There’s a Norseman at Yanks Air Museum, just outside of Chino, that is almost done being restored but was not covered when I saw it in 2020. Wings are not covered either, I think. It’s a beauty. Wings are there in the hangar but I don’t have any pics. They would probably let you take measurements and pics.

OT but awesomely 70’s stylized doc about bush flying in Northern Canada featuring a well worn Norseman: Bush Pilot: Reflections on a Canadian Myth

 

[cheeka]

Turbines are much easier to maintain and more reliable. The manufacturing is just more complex. More reliable in the money world means no one has to touch them for hundreds of hours. That means fewer mechanics. Hour per mechanic touching it is more efficient. Not many moving parts in a jet; they just move fast. They know how to make a radial work great. I think TBOs over the years have gone from 500 in the thirties to 4000+ now. You get 7000 for a jet. At least in big jets. A new issue is fuel, especially from your state. Gasoline outlawed, doesn’t matter how good an engine is.

I agree with all that you said but that's assuming high usage like commercial aviation. For someone who flies twice or even thrice a week for about 4 hours per flight session, it just doesn't make economic sense. For commercial aviation, cost of capital acquisition is very high, which demands high utilization rates and so turbines are the way to go.

 

[cheeka]

Radials are big and draggy. One has to watch for hydraulic lock before startup. Bottom plugs foul easily. TBOs weren't so good. What's to love besides the vintage sound and appearance?

While they are big and draggy, the effects are more pronounced the faster you fly which thankfully for a bush plane is less of an issue. All the issues that you mentioned are rectified easily with modern manufacturing techniques and processes.

 

[cheeka]

There’s a Norseman at Yanks Air Museum, just outside of Chino, that is almost done being restored but was not covered when I saw it in 2020. Wings are not covered either, I think. It’s a beauty. Wings are there in the hangar but I don’t have any pics. They would probably let you take measurements and pics.

OT but awesomely 70’s stylized doc about bush flying in Northern Canada featuring a well worn Norseman: Bush Pilot: Reflections on a Canadian Myth

Thanks for sharing this!

 

[Angusnofangus]

While they are big and draggy, the effects are more pronounced the faster you fly which thankfully for a bush plane is less of an issue. All the issues that you mentioned are rectified easily with modern manufacturing techniques and processes.

A Beaver with the proper R-985 will get off the water quicker than a Turbo Beaver, burn half the fuel, and cost about 1/3 of said TB. It cruises a little slower, but, hey, it's probably the best bush plane ever.

 

[Dan Thomas]

While they are big and draggy, the effects are more pronounced the faster you fly which thankfully for a bush plane is less of an issue. All the issues that you mentioned are rectified easily with modern manufacturing techniques and processes.

What modern manufacturing process would prevent oil dripping off the crank into the lower cylinders and seeping past the rings into the combustion chamber, where the piston will collide with it and break everything?

Any inverted cylinder has this problem. Inverted engines have always had cylinders that extend into the crankcase considerably to prevent oil draining into them from the case walls during operation and after shutdown. My Auster's Gispy did. See how far they extend into that case:



And it still used a lot of oil.

Same thing with a radial:



No new radial designs are being designed and built, so no "new processes" are being incorporated. The radial's days are gone.

 

[planebuilder150]

search ebay, beaver drawings are available on disc.

 

[cheeka]

What modern manufacturing process would prevent oil dripping off the crank into the lower cylinders and seeping past the rings into the combustion chamber, where the piston will collide with it and break everything?

Any inverted cylinder has this problem. Inverted engines have always had cylinders that extend into the crankcase considerably to prevent oil draining into them from the case walls during operation and after shutdown. My Auster's Gispy did. See how far they extend into that case:

View attachment 124366

And it still used a lot of oil.

Same thing with a radial:

View attachment 124367

No new radial designs are being designed and built, so no "new processes" are being incorporated. The radial's days are gone.

A manual compression release for the lower cylinders can be incorporated into the heads where the oil is evacuated from the combustion chamber and collects in the rocker cover. If the compression release and spark plug are oriented wisely within the compression chamber, all the oil would drain through the release before they have had a chance to pool around the plug and cause fouling. As for the new processes, Simulation and thermal modelling is a powerful tool that we have which didn't exist back in the day. Material science has also progressed significantly where we are able to predict material expansion rates and optimize them for a close piston bore seal with a minimum of friction.

No new radial engines are being developed and designed because the market is heavily cartellized with the existing big players. Developing and manufacturing engines is a highly capital intensive undertaking and is just too risky for new players to enter the market, especially when it comes to certified engines. The average GA aircraft isn't the size of a Beaver or Norseman that require big radial engines, everyone's happy with a 172. That's why new radial engines aren't being developed, no big profits to be realized from the miniscule demand.

 

[Dan Thomas]

A manual compression release for the lower cylinders can be incorporated into the heads where the oil is evacuated from the combustion chamber and collects in the rocker cover. If the compression release and spark plug are oriented wisely within the compression chamber, all the oil would drain through the release before they have had a chance to pool around the plug and cause fouling. As for the new processes, Simulation and thermal modelling is a powerful tool that we have which didn't exist back in the day. Material science has also progressed significantly where we are able to predict material expansion rates and optimize them for a close piston bore seal with a minimum of friction.

No new radial engines are being developed and designed because the market is heavily cartellized with the existing big players. Developing and manufacturing engines is a highly capital intensive undertaking and is just too risky for new players to enter the market, especially when it comes to certified engines. The average GA aircraft isn't the size of a Beaver or Norseman that require big radial engines, everyone's happy with a 172. That's why new radial engines aren't being developed, no big profits to be realized from the miniscule demand.

Material expansion rates haven't changed. Aluminum still expands at twice the rate of steel, and unless you make the piston and cylinder both steel, or both aluminum, you have to have large clearances in air cooled engines. Steel pistons are far too heavy, and aluminum cylinders have been proven disastrous in cars in the 1960s and '70s already. And they were liquid-cooled. Air-cooling means much higher operating temps, and aluminum really doesn't do so well there. So what new metals would we have that would change all that?

Decompression valves to drain the oil are just another band-aid to fix a problem we really don't need. More stuff to maintain and fail and add cost.

172s. They use opposed engines because opposed engines, developed first in the late 1930s, made far more sense. Right up until the Cessna 180 replaced the Cessna 190/195 in 1953, some light airplanes were still using radials. The opposed engine offered far less drag and burned a lot less oil. It was more easily muffled. And easier to see over. Radials had better power-to-weight ratios, and that was about the only advantage. A really short crankshaft will do that. That power made sense in fighters and bombers, not in light airplanes, which didn't have to win a war.

About 40 years ago a Canadian company developed a large V-8 aircraft engine called the Orenda. It was aimed at airplanes like the Beaver and Otter, as well as, believe it or not, the King Air. It didn't pan out, for several reasons but one company is still fooling with it, probably in cropsprayers. The Beaver/Otter benefited far more from the turboprop conversions.
Orenda OE600 - Wikipedia

There are big opposed engines. Continental has a 360-HP version of their TSIO-550. Lycoming has the 400-HP IO-720. Very expensive, just as a radial would be.

As you say, new engine development is prohibitively expensive, even without the significant threats of outlawing internal combustion engines or the elimination of fossil fuels. Nobody is about to put money on such stuff now.

 

[pylon500]

Back on track, you were interested in structural analysis of the Beaver wing?
Just done some searching, but failed to find what I was looking for but;
I spent many years working on Beavers and as such would come across interesting things now and then. One such item was a (non)crash report of a guy with a couple of passengers in a float beaver somewhere in Canada/Alaska(?) who got caught up in IMC and lost control. When he finally recovered, he had managed to seriously overstress the plane to the extent that one wing bent up about 20º at the strut attach point. The aircraft was still flying (badly), and he managed to land it on river somewhere with all surviving.
I read all this in a folder that was floating around the workshop, and it included a photograph of the bent wing, showing how many of the rivets on top of the wing had sheared allowing the upper spar cap to bend into a Z shape, the outed cap jamming against some internal structure for the strut attach thus preventing the wing bending any further.
It was an astounding photograph, but I have never been able to find it on the internet.
I've had a pretty good look through this site [CURRENT COVER PAGE], but no luck.
Maybe someone out there has a copy of it...?

 

[galapoola]

How about the Broussard? Same engine, similar size and mission.

 

[Riggerrob]

How about the Broussard? Same engine, similar size and mission.

One rumor has it that the French Army wanted to buy DHC-2 Beavers for their war in Algeria, but French politicians insisted on a French-built airplane, so Max Holste designed the Brossard for the same role and same engine. Structurally, the Brossard looks like a simplified, more modern version of Beaver with an all sheet aluminum forward fuselage and Wittman style, flat spring main landing gear.

In comparison, DHC-2 has a forward fuselage made of welded steel tubing with thin aerodynamic fairings made of sheet aluminum.

 

[BBerson]

Pilates Porter was simple structure and lighter, produced up to 2019. Original was piston power.

Pilatus PC-6 Porter - Wikipedia

en.wikipedia.org

 

[cheeka]

Material expansion rates haven't changed. Aluminum still expands at twice the rate of steel, and unless you make the piston and cylinder both steel, or both aluminum, you have to have large clearances in air cooled engines. Steel pistons are far too heavy, and aluminum cylinders have been proven disastrous in cars in the 1960s and '70s already. And they were liquid-cooled. Air-cooling means much higher operating temps, and aluminum really doesn't do so well there. So what new metals would we have that would change all that?

Decompression valves to drain the oil are just another band-aid to fix a problem we really don't need. More stuff to maintain and fail and add cost.

172s. They use opposed engines because opposed engines, developed first in the late 1930s, made far more sense. Right up until the Cessna 180 replaced the Cessna 190/195 in 1953, some light airplanes were still using radials. The opposed engine offered far less drag and burned a lot less oil. It was more easily muffled. And easier to see over. Radials had better power-to-weight ratios, and that was about the only advantage. A really short crankshaft will do that. That power made sense in fighters and bombers, not in light airplanes, which didn't have to win a war.

About 40 years ago a Canadian company developed a large V-8 aircraft engine called the Orenda. It was aimed at airplanes like the Beaver and Otter, as well as, believe it or not, the King Air. It didn't pan out, for several reasons but one company is still fooling with it, probably in cropsprayers. The Beaver/Otter benefited far more from the turboprop conversions.
Orenda OE600 - Wikipedia

There are big opposed engines. Continental has a 360-HP version of their TSIO-550. Lycoming has the 400-HP IO-720. Very expensive, just as a radial would be.

As you say, new engine development is prohibitively expensive, even without the significant threats of outlawing internal combustion engines or the elimination of fossil fuels. Nobody is about to put money on such stuff now.

You mean to tell me Aluminum expands at twice the rate of steel irrespective of what alloy or composition or silicon content there is? And as for the Orenda 600, I don't see how you can compare an automotive engine that was converted for aviation use vs a purpose designed aircraft piston engine. The duty cycles are entirely different and one can't possibly expect the converted engine to have the same "life" as an aircraft piston engine.

 

[cheeka]

Back on track, you were interested in structural analysis of the Beaver wing?
Just done some searching, but failed to find what I was looking for but;
I spent many years working on Beavers and as such would come across interesting things now and then. One such item was a (non)crash report of a guy with a couple of passengers in a float beaver somewhere in Canada/Alaska(?) who got caught up in IMC and lost control. When he finally recovered, he had managed to seriously overstress the plane to the extent that one wing bent up about 20º at the strut attach point. The aircraft was still flying (badly), and he managed to land it on river somewhere with all surviving.
I read all this in a folder that was floating around the workshop, and it included a photograph of the bent wing, showing how many of the rivets on top of the wing had sheared allowing the upper spar cap to bend into a Z shape, the outed cap jamming against some internal structure for the strut attach thus preventing the wing bending any further.
It was an astounding photograph, but I have never been able to find it on the internet.
I've had a pretty good look through this site [CURRENT COVER PAGE], but no luck.
Maybe someone out there has a copy of it...?

This is exactly the kind of info I'm looking for, thanks for sharing the link.

 

[pylon500]

I think one of the weight increase mods that was done to the Beaver is a big plate we used to call a 'kite' (although it was more of a cruciform shape) that was riveted to the top of the wing above the strut attach point, to add more 'beef' and stability to the top skins supporting the spar.
My earlier mentioned photo of the partially collapsed wing shows what this plate is intended to prevent, but I can't find any evidence of the picture or even photos of the doubler plates fitted.
I haven't worked on Beavers now for about 16 years, and didn't really photograph 'day to day' work.

 

[Angusnofangus]

I think one of the weight increase mods that was done to the Beaver is a big plate we used to call a 'kite' (although it was more of a cruciform shape) that was riveted to the top of the wing above the strut attach point, to add more 'beef' and stability to the top skins supporting the spar.

I have done that mod also, and IIRC there was also a beef-up of the spar. All part of an increased gross weight upgrade when converting to Turbo Beaver I believe. It's been quite a few years for me also, and my memory is a bit suspect.

 

[Riggerrob]

DHC-2 designer Dick Hiscocks published a textbook "Design of Light Aircraft" about how to design an airplane. Mr. Hiscocks had a hand in designing the DHC Beaver, single Otter, Cariboo, Buffalo, Twin Otter, Dash 7 and Dash 8 STOL transports. During his later years he was an adjunct professor at University of British Columbia and assisted Murphy in designing wings for their Super Rebel STOL kitplane.

Hiscocks, Richard "Design of Light Aircraft" January 1, 1995, ISBN 978-0969980902

 

[Riggerrob]

You might want to look up Sherpa Aircraft Manufacturing in Scapoose, Oregon. Their K500 and K600 series are stretched and enlarged (generic) Piper Super Cub clones that are big enough to hold 5 or 8 humans and can mount a wide variety of piston and turboprop engines for STOL performance.
Keep in mind that Sherpa is classic fabric over steel tube construction.

 

[Dan Thomas]

You might want to look up Sherpa Aircraft Manufacturing in Scapoose, Oregon. Their K500 and K600 series are stretched and enlarged (generic) Piper Super Cub clones that are big enough to hold 5 or 8 humans and can mount a wide variety of piston and turboprop engines for STOL performance.
Keep in mind that Sherpa is classic fabric over steel tube construction.

Awesome airplanes. I'd forgotten about those.



You wouldn't build that for $250K either.