Unusual Airplanes: Ju-52-3m

As a very special novelty, Hannes Heppe showcased his not-quite-finished Ju-52-3m at the air show. “3m” does not refer to a particularly exclusive special edition. The designation simply stands for three engines. After all, Junkers initially built the single-engine version, the Ju-52-1m, which, however, disappeared from the scene fairly quickly. After the air show, the author of this article had the opportunity to conduct an exclusive interview with the builder and owner of this fantastic aircraft.

Hermann: The Ju-52 is particularly popular in Switzerland. JU-Air operates three aircraft in Dübendorf. They are used to conduct regular sightseeing flights and city tours. Even after nearly thirty years of service, these flights are still regularly booked to capacity. Hannes, what made you decide to build a replica of this extraordinary aircraft?

Hannes: Even the sound of a single Moki engine really thrilled me. At our regular get-together, my aviation friends and I suddenly started raving about it. We wondered what a model with three Mokis would sound like. I couldn’t get that thought out of my head, and I was suddenly fascinated by the challenge of whether such a project would even be feasible. The 1:4.8 scale resulted from the given engine size, and—having just retired—I simply wanted to do something crazy for a change.

Hermann: What was the biggest challenge in building this Ju-52?

Hannes: In model building, I’ve always been interested in models that don’t just come from a kit. The most exciting part is thinking through problems for which there’s apparently

There’s no solution at first. That was also a big part of the appeal of the Ju.

Hermann: Your Ju looks very impressive even as a model. What are its technical specifications?

Hannes: Wingspan 6.09 m, length 4.07 m, weight 98 kg. Powerplant: 3 Moki radial engines, each with 5 cylinders, a displacement of 215 cm³, and 13 PS of power. The engines feature electronic ignition and drive 3-blade propellers. The propellers currently installed aren’t quite true to the original yet and will soon be replaced with a version that’s even more true to the prototype. Incidentally, the Lufthansa Ju always had 3-blade propellers—unlike the Ju aircraft in Switzerland.

Hermann: The Ju-52-3m isn’t very well known here. Is there even a single airworthy example left?

Hannes: Of course, but the Lufthansa Ju probably won’t be seen in Switzerland anytime soon. The original aircraft has a long and troubled history. Originally built for Lufthansa in 1936, it was briefly used by the Luftwaffe at one point, then returned to service with Lufthansa until 1945. After experiencing technical problems in Norway, a new aircraft was built using parts from another Ju-52 manufactured in 1943. It flew for various airlines in Scandinavia, was sold to Ecuador in 1957, and remained in service there for another five years. It was then retired and later sold to the U.S., where the now-restored Ju flew for several years as “Iron Annie” under—

gone. In 1984, it was purchased by Lufthansa and transferred to Hamburg, where it underwent extensive restoration and was recertified as a commercial aircraft of the “highest class.” Since then, the Ju-52 has been operating regular sightseeing flights from Hamburg and three other locations in northern Germany. It carries about 10,000 passengers annually and is just as often fully booked there as its counterparts in Dübendorf.

Hermann: How long did it take you to build this model?

Hannes: About 3,000 hours so far, over the course of 2½ years. It was completed in May 2010. The maiden flight and acceptance flight took place on May 19, 2010, before the corrugated sheet metal was installed. The aircraft was built and flown using the classic Styrofoam/wood construction method. The corrugated sheet metal skinning was added in a subsequent step during the winter of 2010–2011.

Hermann: So how did the Ju end up with its corrugated sheet metal skin?

Hannes: You couldn’t just buy the right sheet metal at the nearest store. That’s why

We had to make the corrugated sheet metal from litho sheet ourselves. This required three pairs of rollers for each, since the Ju 3 has three different corrugation widths. This made it possible to create a faithfully reproduced skin.

Hermann: Is the build now complete?

Hannes: In addition to the propeller replacement I already mentioned, I plan to continue working on the aircraft’s interior. It’s likely that two pilots will soon take their seats in the cockpit. I’m also currently designing and building a hydraulic brake for the model to help control its tendency to swerve during takeoff and landing, even in light crosswinds.

Hermann: Will your JU also participate in the 30th anniversary of JU-AIR next fall on September 15, 2012?

Hannes: I’d certainly be interested. But I don’t want to make any promises just yet, since participation also depends on the event organizer.

Hermann: Thank you very much—also on behalf of the many enthusiastic spectators—for the presentation of this extraordinary aircraft.

By the way: Even the “real Tante Ju” from Dübendorf couldn’t miss the chance to see her counterpart on Saturday and flew in especially for a short sightseeing flight over the Hausen airfield.

Hermann Mettler