Good News for JU-AIR Ju-52's

[JohnTerrell]

Following the crash of HB-HOT last year, and the grounding of the remaining JU-AIR Ju-52's, there is finally some goods, reported by JU-AIR last week: https://www.ju-air.ch/de/medieninformat ... Q5Ks2hCl6g

Having begun already, they will be overhauling and rebuilding their three Ju-52's, and in doing so will effectively be zero-timing the airframes. In addition, they will be converting them to R-1340 engines. The first receiving this work is HB-HOS, and it is expected to be completed and flying again as early as the spring of 2021.

Dübendorf, June 5, 2019. JU-AIR has begun to overhaul its three JU-52's from scratch. The work will be carried out by certified specialist companies and will take about two years. For the resumption of flight operations in spring 2021, the maintenance of the aircraft will be reorganized.

After several months of planning, the overhaul of the historic JU-52's has begun. First, the aircraft and their parts are being digitally measured to produce three-dimensional, computerized blueprints. The major project is being carried out by JUNKERS Flugzeugwerke, which has committed numerous specialist companies from Germany and abroad. All stages of work are being overseen by the Federal Office of Civil Aviation before, during and after implementation. At the end of the extensive work, the three aircraft will be practically new.

All safety-relevant, load-bearing parts of the wing construction will be preventively replaced due to their age. As new parts for the eighty-year old aircraft are no longer available, hundreds of individual parts must be re-manufactured by authorized partners. First, the original parts are measured digitally. Afterwards, components such as wings, stabilizers and controls are modeled in the computer. With this data, the individual parts are then reconstructed. Around 90 percent of the wing parts are replaced in this way.

The overhaul of the wings will take place in Malters (LU). Hull, tail, suspension, control system, as well as all other systems are meanwhile overhauled in Dübendorf. Again, the work is carried out by professionals by certified specialist companies.

The project is closely followed by the Federal Office of Civil Aviation. The individual work steps are described in detail in advance and checked by the Federal Office. After approval, they will be executed and can be checked again by the Federal Office.

Farewell to the BMW engines...

The engines of the three aircraft are being replaced. For the BMW radial engines of the type "132" used so far, spare parts are no longer available as BMW discontinued the construction of this type of engine in 1944. The cost of a long-term continued operation of these aircraft engines would increase year by year.

JU-AIR has therefore decided to replace them with Pratt & Whitney's R-1340 "Wasp" radial engines. The "Wasp" radial engines are no longer being rebuilt, but they were produced in such large numbers that they are still very widespread worldwide. Rebuilt engines and replacement parts are well available. Pratt & Whitney engines were regularly seen on the JU-52; The aircraft were partly delivered with the radial engines of the American manufacturer.

Ju-52 HB-HOS is the first of the three to be refurbished. It was delivered in late summer of 1939 brand new to the Swiss Air Force and remained until 1981 in the service of the army. In 1983 it was taken over by JU-AIR and has since been part of its active fleet continuously. The overhaul of the other two JU-52's will begin later. The exact schedule also depends on how work on the first aircraft progresses.

It is planned that HB-HOS will return to flight operations in the spring of 2021. With regard to the resumption of flight operations, the maintenance of aircraft and engines will be reorganized. The clarifications are in progress. JU-AIR is also supported by external experts and monitored by the Federal Office for Civil Aviation.

JU-AIR will keep you informed about the progress of work on its website and on Facebook. In addition, the revision of the fuselage in the Dübendorf aviation museum can be visited on special tours. Details will be communicated in a timely manner.

[OD/NG]

Fantastic news! With the grounding of the JU-AIR fleet along with D-AQUI no longer giving passenger rides, I don't believe there is anywhere in the world to get a ride in a Ju-52.

I was beginning to think that this was the end of the time for most Ju-52's, but I'm happy they have a solution. Those restorations/IRAN's on the remaining fleet sound super expensive. I'm wondering how they are funding that? Is all that expertise doing the work for JU-Air for free or do they have a financial benefactor? Anybody know?

[JohnB]

P&W to the rescue...again!

[Chris Brame]

Wonder if any other Ju-52 owners would be able to buy into this operation to get a few more examples into the air? Volume discount!

[DB2]

That's good news but why the 1340? I realize some Ju-52s were originally powered with 1340s, but that is 20% (?) drop in HP vs the BMW 132. From what I've read, the recent crash was caused by a stall/spin at high altitude, so I don't understand why they would go with a smaller engine given high altitude summer flights are typical for them.

It would seem like an 1820 would be a much more suitable (and more powerful) replacement for the BMW 132, even if it was slightly derated. According to Wikipedia, the weights and dimensions between those two engines are essentially identical.

[JohnTerrell]

The engines will be the geared-type R-1340's, spinning three-blade props, just like those that have already been installed/in-use on the MAM/Yagen Ju-52 and the Lufthansa Ju-52. There have been a few restored T-6's with that engine fitted as well, and with it they're called a "Super Six" for the gain in performance. I believe the maximum output is around 800hp.

[DB2]

JT - I'm continually in awe of your knowledge of vintage aircraft, but I'm personally not aware of any 1340s that can put out 800 hp - AFAIK they top out at 600 hp with the -S1H1G, which is geared and found (with a 3-blade prop) on DHC Otters and radial-engined AT-501s ag aircraft (and retrofitted to some T-6s). No doubt, that combo offers increased thrust over a stock T-6 pairing of 1340 and a 2-blade prop, but I would still expect a potential performance degradation on the Ju-52, vs the BMW 132s, unless the 1340 blower is able to maintain MP better at higher altitudes. A few of the "Super T-6s" I'm aware of do have 1820s.

[Matt Gunsch]

The geared 1340s are 600hp, same as the direct drive, but they can turn a larger prop at a slower speed, which is more efficient. One of the 6s I used to fly with had the geared engine and he could walk away from a stock 6 and in formation was great when he was on outside turns since he had more use of the power from the engine, that said, 3 blade props on a Ju-52 just don't look right.....

[JohnTerrell]

Thank you fellas for the clarification on the hp output!

The Military Aviation Museum/Jerry Yagen Ju-52 and the Lufthansa Ju-52 are both powered by geared R-1340's, while the South African Ju-52 ZS-AFA is powered by R-1820's (with T-6 style cowlings). Both HB-HOY in Switzerland and F-AZJU in France, however, remain powered by BMW engines.

[Noha307]

The major project is being carried out by JUNKERS Flugzeugwerke, which has committed numerous specialist companies from Germany and abroad.

W̶h̶a̶t̶ ̶i̶s̶ ̶J̶u̶n̶k̶e̶r̶s̶ ̶F̶l̶u̶g̶z̶e̶u̶g̶w̶e̶r̶k̶e̶?̶ ̶O̶b̶v̶i̶o̶u̶s̶l̶y̶ ̶t̶h̶e̶ ̶o̶r̶i̶g̶i̶n̶a̶l̶ ̶c̶o̶m̶p̶a̶n̶y̶ ̶d̶o̶e̶s̶n̶'̶t̶ ̶e̶x̶i̶s̶t̶ ̶a̶n̶y̶m̶o̶r̶e̶ ̶-̶ ̶h̶a̶v̶i̶n̶g̶ ̶b̶e̶e̶n̶ ̶i̶n̶c̶o̶r̶p̶o̶r̶a̶t̶e̶d̶ ̶i̶n̶t̶o̶ ̶M̶B̶B̶ ̶i̶n̶ ̶t̶h̶e̶ ̶1̶9̶6̶0̶s̶.̶ ̶T̶h̶e̶r̶e̶ ̶i̶s̶ ̶a̶ ̶H̶u̶g̶o̶ ̶J̶u̶n̶k̶e̶r̶s̶ ̶W̶e̶r̶k̶e̶ ̶G̶m̶b̶H̶ ̶t̶h̶a̶t̶ ̶r̶u̶n̶s̶ ̶J̶u̶n̶k̶e̶r̶s̶.̶d̶e̶,̶ ̶b̶u̶t̶ ̶t̶h̶e̶y̶ ̶a̶r̶e̶ ̶h̶a̶r̶d̶l̶y̶ ̶a̶n̶ ̶a̶i̶r̶c̶r̶a̶f̶t̶ ̶m̶a̶n̶u̶f̶a̶c̶t̶u̶r̶e̶r̶.̶ ̶(̶T̶h̶e̶y̶ ̶d̶o̶ ̶h̶a̶v̶e̶ ̶a̶ ̶s̶h̶o̶p̶ ̶t̶h̶a̶t̶ ̶s̶e̶l̶l̶s̶ ̶w̶a̶t̶c̶h̶e̶s̶,̶ ̶t̶h̶o̶u̶g̶h̶.̶)̶ ̶C̶l̶i̶c̶k̶i̶n̶g̶ ̶t̶h̶e̶ ̶J̶u̶n̶k̶e̶r̶s̶ ̶n̶a̶m̶e̶ ̶i̶n̶ ̶t̶h̶e̶ ̶u̶p̶p̶e̶r̶ ̶r̶i̶g̶h̶t̶ ̶o̶f̶ ̶t̶h̶e̶ ̶w̶e̶b̶s̶i̶t̶e̶ ̶t̶a̶k̶e̶s̶ ̶y̶o̶u̶ ̶t̶o̶ ̶t̶h̶e̶ ̶B̶o̶s̶c̶h̶ ̶T̶h̶e̶r̶m̶o̶t̶e̶c̶h̶n̶o̶l̶o̶g̶y̶ ̶w̶e̶b̶s̶i̶t̶e̶.̶ ̶T̶h̶e̶r̶e̶ ̶i̶s̶ ̶a̶l̶s̶o̶ ̶a̶ ̶T̶e̶c̶h̶n̶i̶k̶m̶u̶s̶e̶u̶m̶ ̶"̶H̶u̶g̶o̶ ̶J̶u̶n̶k̶e̶r̶s̶"̶ ̶D̶e̶s̶s̶a̶u̶,̶ ̶b̶u̶t̶ ̶t̶h̶e̶y̶ ̶a̶r̶e̶ ̶j̶u̶s̶t̶ ̶a̶n̶ ̶a̶s̶s̶o̶c̶i̶a̶t̶i̶o̶n̶ ̶t̶h̶a̶t̶ ̶r̶u̶n̶s̶ ̶a̶ ̶m̶u̶s̶e̶u̶m̶.̶

S̶o̶ ̶w̶h̶o̶ ̶i̶s̶ ̶t̶h̶i̶s̶ ̶c̶o̶m̶p̶a̶n̶y̶ ̶d̶o̶i̶n̶g̶ ̶t̶h̶e̶ ̶r̶e̶m̶a̶n̶u̶f̶a̶c̶t̶u̶r̶i̶n̶g̶?̶

I assume that this is the same company that built the flyable Junkers F13 replica.

[Invader26]

The Wirraway is fitted with the geared R-1340 - 600hp.

Power to the Swiss for taking up this challenge. I can't wait to see them back in the air. Maybe Julie Andrews could come out of retirement and sing "The Hills Are Alive with the Sound of Music!" - the PW orchestra playing.