Sunday, July 6, 2008

Cessna 195s in Bad Dürkheim

About a month ago I went to a small airshow at the Bad Dürkheim aerodrome (EDRF), in the Palatinate (Pfalz) region of Germany. The airshow was a celebration of the 40th birthday of the aerodrome, and featured open-air concerts, in-flight and static demonstrations, and even a religious service on Sunday morning. Unfortunately I could only spend an hour or so there on Sunday afternoon, but this was definitely worth it.

The most beautiful aircraft on display was certainly the Cessna 195. There were two of them actually: N3446V, a Cessna 195A and N3081B, a Cessna 195B. Both were manufactured right at the beginning of the 50s.

Actually, this airshow was more of a fly-in than an airshow: only pilots and their guests could approach the planes, the rest of us had to stay behind the fence. This wasn't too bad since on our side of the fence was the mobile beer machine, with good local German beer on the tap.

Contrary to later models such as the 172 which uses bracing struts for transferring some of the wing load effort from the wing to the fuselage, the 195 uses a cantilever wing and therefore can do without the bracing struts. This of course makes the plane look a lot more elegant, and surely provides for better in-flight pictures. It's hard to find a photo taken from inside the cockpit of a 172 that does not have a bracing strut somewhere.

The engine is a Jacobs 7-cylinder radial engine, which immediately gives the airplane this "classic" look. The paint job on N3446V above very nicely highlights the 14 "bumps" around the engine. I suspect these bumps house the cams and cam springs for the valves on either side of the cylinder head, hence 14 such bumps for 7 cylinders. But that's only my educated guess based on this vintage advertisement for a Jacobs radial engine.

The model A had a Jacobs R755-9, 245 hp engine, while the model B got upgraded to a R755-B2 engine with 275 hp. According to, the engines were relatively cheap to buy after the war due to the large amount of military surplus, and some engines can still today be found in their original crate!

The website of the International Cessna 195 Club has a very nice recording of the sound of a radial engine starting up. Their website is actually a mine for information, including a report on a test flight of the 195 published in the October 47 issue of Flying. The editor commented on the lack of visibility due to the big radial engine in front and on the price tag of $13,750, which put it outside of the reach of most private plane owners at the time.

On the positive side, the editor remarked that "maneuverability in the air is excellent,and the controls are light and easy to operate, even for a woman". I wonder what kind of reaction the last four words of that sentence would attract if they appeared in Flying today. More than one aviatrix would certainly be offended, but then again, judging a past era according to today's standards is a major sin in historical research, so I won't go there.

Writing this blog entry I realised I didn't know much about radial engines. After a bit of research I realised they are really just like "regular" in-line piston engines, except that the pistons are arranged in a circle on a single plane. The video below sums it all.

The advantages of using radial engines for airplanes are multiple. They can be very efficiently air-cooled because they all move in the same plane, which happens to be orthogonal to the incoming airflow. They deliver power at lower rpms, which means no gearbox needed between the engine and the propeller. And near the middle of the twentieth century, their power on weight ratio was much better than for other types of engines, which obviously helped with aircraft performance.

The 195 is now firmly on my list of airplanes I want to fly some day, or at least sit in as a passenger. But flying would be so much better. According to the VH-Register, there are only 4 Cessna 195 in Australia: VH-KES, VH-ONF, VH-AVZ and VH-BVD. The last one is even registered to an owner near the Redcliffe aerodrome, but I haven't seen it there yet. Its latest red and white livery is absolutely gorgeous with the Southern Cross painted on the tail.

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