What’s up with the jack stands? - Page 2

edasmus · #16 07-13-23, 04:27 PM

Just came from my shop as my plane is getting it's annual inspection. My plane is on jacks per the photo. Only the co-pilot side boom is supporting the tail. There is no jack on the other boom. This is my 20th annual inspection with this shop. I have never seen both booms supported. Just my experience but I do not know for certain what the accepted practice is.

FYI, 58 pumps to manually extend the gear.

CO_Skymaster · #17 07-13-23, 08:28 PM

Thanks for the picture. I know about the hard points on the wings, by the strut. How is that third jack attached to the boom? Is it tied down through the tie down bolt, or is it sitting on top? The third one doesn't look like the same type of jack stand. That third jack location and how it sits is what I'm wondering about.

Karl

Kim Geyer · #18 07-13-23, 09:33 PM

We had the Cessna pads on the wings and the stayed installed. We had 2 under hoist safety stands from harbor freight that the tail boom would just sit on. When they are on jacks there is only about 50 lbs of weight on the tail stands. There is a third jack point just behind the nose gear door and you really must put a short jack there or it’s very easy for the plane to nose over if you look at Ed Coffman’s post and zoom in you can see the tail stands and the nose jack

edasmus · #19 07-13-23, 09:49 PM

I also took this pic today. It's the best I can do as I have a feeling if I go visit the shop tomorrow, the plane will be back on it's own "feet" by then. Hope this helps.

MD83driver · #20 07-13-23, 10:47 PM

From what I have seen here, there appear to be two versions of jack adapter locations. One on the aft spar web and the other just after the spare cap about one rivet hole spacing back, as in the original photo that started this thread. I have a '78 H model and my jack point is just behind the front spar. There are words either in the POH or maintenance manual on what jack adapter to use on my plane. I memory serves me correctly, Cessna gives either a description of how to make the jack adapters. Should be 4"X4" pads with rubber/silicone type barrier between it and the wing, that will spread out the load properly. I have attached an image of mine. As one can see from the picture, my mount hole is just behind the double row of rivets on the lower spar cap, it came from Cessna that way.

Kim Geyer · #21 07-14-23, 12:08 PM

Cessna P/N 1400110-2 is what we had on our 6 Skymasters.

CO_Skymaster · #22 07-15-23, 12:00 AM

OK, I see how it is setup now. I did not see the smaller jack on the front of the aircraft. I plan to go down to the hanger tomorrow and I will check under the nose of the aircraft.

Thanks for the picture, they help.

Karl

wslade2 · #23 07-17-23, 01:38 AM

For tailboom I took a countour copier from hardware store and made replica of underside of boom at the support location. I then test fitted cardboard template from that. I used the cardboard to draw a cutout on multiple squares of plywood. Ended up with about a 3 inch thick “U” of plywood that I then throughbolted some 2x4 legs. I lined the “U” with some foam rubber doormat. I made the whole set up short enough that I could put a hydraulic jack underneath it. Made two of these, one for each boom. Jacked them up with the plane.there was some running around from jack to jack. Did have to put some blocks underneath due to not enough reach of the jacks, so be ready for that.

The plane will try to tilt backwards as you raise the underwing jacks. I use the bogert jack adapters on the spar jackpoint screw hole at the wing. And yes there is jack point ball on belly behind nosegear.