FAT which was founded in 1957 is the largest domestic airlines in Taiwan. It is operating 9 MD-82 and 7 Boeing-757 aircraft for over 100 flights per day. For their fleet they are in the need to overhaul a total of 24 sets of Pratt & Whitney JT8D and 20 sets of PW2000 engines. It was decided to peen all the blades in-house. That required a glass bead-peening machine for the blade section and steel shot machine for the root of the blade.

The Swiss manufacturer Baiker AG, a specialist for peening and blasting applications, was contracted by FAT to deliver the two machines. 
It was required to provide a turnkey solution including fixture and process development. Furthermore it was important for FAT to have machines, which could also handle other parts than blades such as hubs or disks. This in order to be prepared for possible future requirements.

Concept for the 2 Machines

Since the budget was limited, all features used for the machines were carefully evaluated to justify its cost. The design of glass bead and steel shot machine turned out to be almost identical with the exception of a larger filter and certain differences in the media recovery system for the glass bead process. Besides that both machines are equipped with a X/Y axis, PLC controlled oscillator, 4 nozzles, a turntable, pneumatic lifting door and Sweco sieve. A remote control simplifies the programming of the Mitsubishi PLC, which can store a number of different programs.
The equipment was build to fullfil Pratt & Whitney's specification SPOP 500 for glass beads and SPOP 501 for steel shot.

Internal Peening

One independently controlled "Plug & Play" rotation head for internal peening is available for both machines. The rotation head including its control box can be moved from one to the other machine. With this very cost effective solution both machines are able to carry out rather demanding internal peening applications.

Tooling

In order to have the machine operational immediately after start up, FAT requested that the blade tooling as well as the PLC programming is provided for a defined number of parts. Part samples have been sent to the manufacturer ahead of delivery to prepare all accordingly. In order to protract the blades where no peening was required, polytheran masking solutions have been provided. Since peening is an abrasive process, they had to be easily replaceable.

Training

Since FAT is a newcomer in the field of peening, training was a big issue. Besides receiving a machine operation training, the operators have been sent to the annual MFN & EI Shot Peening Workshop in Singapore where they could obtain a general peening know-how.

For information:
BAIKER  AG
Alipenstr. 1, 8152 Glattbrugg, Switzerland
Tel:  +41.1.810 7377, Fax: 810 9340
e-mail: info@baiker.ch
Internet: www.baiker.ch