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Q-talk 146 - Elevator Pivot Mod

by Jay Scheevel
Jay Sheevel Mid Span Elevator Pivot

For a few years I have been refining a redesign of the mid-span elevator pivot/support for the Q200. I have finalized the design and built and installed it on the elevator. I put the final plans (version3) in the files section of the Q-list. My original design is there also for comparison. In addition I put photos of the pivot as installed on the elevator in the photos section of the Q-list.

Jay Sheevel Mid Span Elevator Pivot
Jay Sheevel Mid Span Elevator Pivot

The design is robust strong and functions as intended. The design goals were to provide a pivot that would not require me to cut a hole in the torque tube, that could be visually inspected prior to flight without removing the elevator and would allow for easy maintenance. My design is loosely modeled after the elevator toque-tube hinge supports on all models of Waco's. Please have a look and comment if you care to. The interior of the foam cutout shown in the photos will be closed out with glass and/or flox prior to installation.

Jay Sheevel Mid Span Elevator Pivot

Folks should not try this until I have put some time on it [See message from Sam Hoskins below]. I think part of the issue with the failure accident [See also, the Tri-Q accident report from Branson, MO below] was determined to be corrosion. Corrosion may have also contributed to the same type of failure that was reported by Jon Finley, where he noticed that the pin for the mid span elevator pivot had broken when he was doing an annual.

Cheers,
Jay Scheevel
Tri-Q, still building


Jay,
This is an innovative solution to the mid-span issue. I look forward seeing how it works for you.

I do not remember the details, but we did have an in-flight failure of the mid-span elevator a few years ago [See accident report below], with dire consequences. The NTSB determined that the builder had removed more of the torque tube than the plans called for and that tube had failed.

Other builders: This is a radical departure from the plans and while it may seem like a good idea, and maybe it is, it is UNPROVEN. So, IMHO this does not mean that you should install it yourself, but that you should see how it works out for Jay, wait for his feedback, then proceed cautiously from that point. (This sage advice from someone who tends to jump in blindly).

Please keep us informed.

Sam Hoskins


To learn more about the accident caused by the mid-span elevator pivot failure, please do a search for “Tom Curry” here on the website. This should return the following results:

http://www.quickheads.com/q-talk-124-post-accident-update.html
http://www.quickheads.com/q-talk-125-odds-and-ends.html

I linked to the accident reports (with pictures) from the bottom of each of those articles so that they are easier to locate. Those links also appear here for your convenience.

Tom_Curry--Branson_MO_factual_report.pdf

Tom_Curry--Branson_MO_materials_factual.pdf

Builders, it should also be noted that many builders have flown thousands of hours with the mid span elevator pivot built “per plans,” So again, please be seriously consider the consequences of any departure from the plans.

Be safe guys.

Dan Yager
QBA Editor
www.quickheads.com