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This is the oil cooler air intake cowl prior to bead blasting. The front of the cowl sits at the lower edge of this picture.Note the dents in the intake door which will need planishing out. Each of the Dzus fasteners needs replacing as well. (photo via Pioneer Aero Ltd.)

Oil Cooler Air Intake:

The oil cooler air intake cowling and its associated door form the bottom section of the accessory bay cowling assembly. The example which came with the project was in good overall condition but required repairs and a good cleanup before it could return to service.

Intake Door Repairs:

The door is based around a tubular structure with skins welded onto it. While the sheet metal was in good overall condition, with only minor dents to planish out, the bar to which the actuating cable attaches was a different story. It was both bent and cracked. Pioneer Aero's engineers had to cut out the damaged sections of tubing and weld in replacement material. (photo via Pioneer Aero Ltd.)

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This mixture of oil and dirt, perhaps dating from WWII, was flushed out from inside the oil cooler intake door. As already noted, the door comprises a tubular structure with skins welded onto it, which meant that the inner and outer door skins could not be separated without incurring major damage to the part. Consequently, the only way to remove this oily muck was to scrape and flushed out through a tiny 1" gap! (photo via Pioneer Aero Ltd.)

Moveable Flap Repairs:

As images above reveal, the oil cooler air intake door features an inner flap which helps direct and smooth out the air flow as it enters the ductwork. Due to years of use, the aft edge of this flap had worn away in places. Thankfully, rather than discarding the part and fabricating an entirely new replacement, Pioneer's magicians were able to execute repairs to save most of this original component.

The finished part:

After effecting repairs, Pioneer Aero applied a coat of primer paint to the oil cooler air intake cowling components. They temporarily assembled the parts for trial installation in the accessory bay cowling to ensure everything fitted correctly.

Trial Fitting:

After completing repairs to the oil cooler air intake cowl, Pioneer Aero's engineers were finally able to trial fit the entire accessory bay cowling assembly.

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The oil cooler air intake cowl section, its door open, is seen here nestled within the entire accessory bay cowling and diaphragm assembly on the old MGM wind machine. (photo via Pioneer Aero Ltd.)