How a Boeing jet engine inlet was rescued to become a seat in a home office.
by John Wood
My daughter Diana and I picked out a Boeing 707 engine inlet at the aircraft boneyard in Tucson and had it shipped back to our home in Massachusetts. We were unable to identify the tail number of the aircraft but believe it was delivered to Qantas Airways in Australia in 1965. It ended its days with Tampa Cargo flying fresh flowers from Columbia to Florida, before being seized for cocaine smuggling:
We left unneeded parts behind in Arizona but it still weighed 365 pounds on the pallet when it arrived at home. I located a scrapped Pratt & Whitney JT3D guide vane disk in Connecticut. It came from MIT's version of the 707 based at Hanscom Field. The disk is a welded titanium structure and weighs 96 pounds. I strapped this to the roof of our SUV and received some interesting looks on the highway driving home:
We had to cut the inlet down to 28 inches fore-to-aft so it will fit through a household door. Diana assisted in drilling out rivets:
This early fanjet engine did not receive sufficient ram air at low speed, so eight spring-loaded cast aluminum doors were installed around the cowling. A great deal of internal structure of the inlet had to be cut away so the guide vane disk would fit inside. It was originally a foot or two aft, at the very front of the engine. With so many compound curves, the carpenter's rule of 'measure twice and cut once' was key. Jigs and fixtures were an important part of the project:
I discovered the miracle of the plasma cutter and don't see how I lived so long without one. It permitted precision metal cutting in tight quarters, without damage to nearby structure - not easy with other tools:
These engines did not produce enough bleed air to pressurize the 707 cabin so turbo-compressors were mounted in 'snouts' on top of three of the four engines. These fairings had to be cut down to proper length and doublers added to beef up the cut edge:
Doublers were cut from the excess material and added to the delicate cut aft edge of the cowling.
After weeks of work the inlet was brought up from the 'face down' position. Paint had been roughly stripped. When finished, the cowling would hang off the wall as if a jet had just flown into the room. The guide m< disk would sit in back with a simulated fan disk behind that, indirect LED strip lighting would provide a light. A conformal memory foam cushion would be on the bottom of the inlet as well as in the position of the bullet spinner in the center back. A weight reduction program was undertaken to bring the assembly down to 265 pounds empty, with the plan to hang it on the wall using three studs and cleat hangers.
An empty third-car garage served a workshop for this good-sized project:
The next step was producing a simulated first-stage fan including mid-span shroud on fan blades and twist in each blade. This rear view shows a highly modified 18-inch cake pan as fan hub with plasma-cut slots.
The tedious process of cutting, assembling and hand-fitting the fan blades was completed. Now the inlet was flipped over, completely stripped and partly disassembled in preparation for polishing the aluminum. The cast aluminum doors were removed, wet sanded and polished.
Located inside the inlet hub was be the 'brain' of the project - three power supplies to control a blower, vibrator motors and LED lighting. Three radio-controlled lamp dimmers control these.
After months of cutting, disassembly, cleaning and polishing, the pieces were put back together. The blow-in doors with new silicone foam rubber seals were installed with new stainless steel fasteners. Original left and right Pratt and Whitney decals were found on eBay and applied. Sheet metal joints were masked with tape and re-sealed with black silicone caulk.
The next step involved completing 36 first-stage fan blades that included LED lighting strips hidden behind the leading edge of each. Grandson Padraig Nugent conducted a quality inspection:
The engine inlet was assembled, turned upright and placed in the cradle build for moving. A talented electronics designer built a circuit board to sequence the LED strips to create the illusion of fan rotation. Shown here with LED lighting, bare boards for upholstery foam in back, and an old airline seat in the bottom:
Aircraft plywood was steamed, and laminated to make the seat bottom. It formed a compound curve, like a section of an hourglass. Various grades of conformal foam were used to make three cushions. Ergonomic seat design was employed including comfortable seat angles, lumbar support and armrests. A custom hotrod shop covered the foam with upholstery... a skill not possessed by the author.
Perhaps the most realistic part of the project was the installation of an industrial-strength vacuum cleaner blower in the 'snout' on top. When an 'Engine Start' button is pushed, this blower ramps up over 30 seconds, sounding just like a real jet engine starting. It is quite an experience for someone seated in the 'chair.'
The military continues to operate versions of the Boeing 707 with updated and far more efficient engines. Some of the old JT3D engines have been converted to natural gas pipeline compressors after they have lived their useful life on aircraft.