H-Beam

Parks Industries H-Beam

Parks Industries created the H-beam to satisfy the FAA's requirements to put "new metal" in the center section. Ken Bowdish has been involved with the H-beam since the early days and provided these pictures and description of the H-beam installation process.

These photos are taken directly from a poster board presentation Ken prepared for the Tullahoma fly-in in 2008 so they may look familiar to you. By "directly" I mean a direct scan of the very poster board you saw at Tullahoma -- so the quality is not the greatest...but a lot better than nothing.

Got some pictures that show off something about the H-beam? Send them our way at webmaster@t-34.com and we will put them on the website.

Click on images for larger version of the same picture.

	-31 Channel Being Removed Aircraft on jacks with wings removed. Wing attach fittings removed from -31 channel. 18 holes in bottom of fuselage to remove rivets in bottom of -31 channel. .31 channel slides out as shown.
	-31 Channel is kept with attach fittings as removed. This assembly will be used later to locate holes in the new H-Beam.
	Attach fitting with H-Lock fasteners that will be used to attach this fitting to the new H-Beam.
	Airplanes are processed in groups. this is a group of seven -31 channels and attach fittings from seven different airplanes. Parks Industries can process up to 10 airplanes at a time. This is done to reduce the manufacturing and eddy current inspection costs before the H-Beam can be installed.
	New H-Beams made from an extrusion and then machined are made from 2024-T 351 aluminum which is much heavier than the original -31 channel which is made from 2024-T4 aluminum.
	This is the locating fixture for drilling holes in new H-Beams. The removed -31 channel is used as a master with the attach fittings in place. Then with the attach fittings locked into position the -31 channel is released and replace with the H-Beam which is locked into the fixture and the attach fittings are now the drill bushings for drilling the holes in the H-Beam.
	The -31 channel has been released and replaced with the H-Beam. Clamps on the top show how the H-Beam is secured into the fixture. The entire fixture is then turned on its side and the holes are drilled in the milling machine. The fixture is then turned on its opposite site and the remaining holds are drilled. This process insure that the holes in the H-Beam and the holes in the center section carry through structure all line up perfectly.
	H-Beam drilled, deburred, primed, and painted. Ready for assembly.
	H-Lock fasteners holding attach fitting and H-Beam into center section assembly.
	Patch rivited on bottom of fuselage to cover 18 holes that were needed to drill out the rivets holding the -31 channel in place.

Updated on October 3, 2009. Click here to send feedback.