Monday, June 14, 2010

DC-7 tanker: aircraft jacks (1 of 3)

Last December, I wrote a series of articles up close and personal with a DC-7 air tanker, thanks to the help of the pilot of T-62, Larry Kraus. A couple of months ago, Larry Kraus sent me a couple of pictures of (Butler's) T-66 as it was sitting on a ramp outside of Butler's maintenance hanger in Redmond with it's retardant tanks removed. According to Larry, the retardant tank was on a dolly in the maintenance hanger getting some repair work. These two photos are shown above. I looked at these photos and asked Larry what was hanging from T-66's tail.

This is Larry's reply:
It's a home made combination tail stand and nosewheel jack adapter.Sometimes when it snows heavily around here,enough weight in wet snow will accumulate on the horizontal stabilizers and elevators to cause the tail to squat down enough under the weight to lift the nosewheel off the ground. This is undesirable, especially if the wind is blowing.

So, with the tailstand in place, the tail can't settle enough (before the tailstand touches the ground) to lift the nosewheel clear.If you look closely at the pictures,you'll see holes in the vertical shaft of the tailstand and a metal pin inserted near the top.The shaft is actually two concentric shafts (a smaller diameter one inside the outer shaft) that can be adjusted to lengthen the shaft and the pinned to the new length by aligning the holes in the shafts.

Larry goes on to explain how this device is attached to the DC-7:
The "Y" shaped fixture that connects the tailstand to the hole in the tailskid (with another pin) is removable. The actual top of the shaft is concave to mate with a jacking adapter that's permanetly mounted on the airplane just aft of (behind) the nosewheel well on the belly of the airplane. 

In the photo below, Larry has put in a blue arrow showing the location of the nosewheel jackpad underneath the boarding ladder in the picture.

And Larry sent me a photo of T-66 as showing the repaired retardant tank just before it was put back in T-66. The retardant tank is below T-66 on the dolly.

Next up: more jacks used on the DC-7 tankers, changing tires, and self sufficiency

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