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.
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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.