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Fellow Coupers, I just removed the spring steel landing gear legs from my Alon in order to clean and inspect them. I thought I would pass along what I learned about the bolts that attach the gear leg to the center section main spar carry-through assembly. This info applies primarily to the Alons with the spring steel gear legs, although the vendor info may be of some use for owners of other models as well. There are three 3/8ths inch bolts that attach the top of each gear leg to the center section main spar carry-through assembly. These bolts are special Internal Wrenching (Allen Head) bolts. The bolts that I removed had some minor staining from rust on them, and a couple of them showed some wear on the smooth part of the shank. Because of the way they looked, and the fact that a friend of mine found one of these bolts broken in half in his gear leg, I decided to replace the bolts with new ones. The Alon parts manual (Fig 32, Index 1) shows these bolts to be NAS146-35 bolts. However, the Alon Parts Manual also only shows the original type landing gear leg, not the spring steel gear leg. According to the Skybolt Catalog, an NAS146-35 bolt has a length of 2 - 3/16ths inches ( or 35/16ths). The bolts that I removed from my spring steel gear were only 2 - 1/16th inches long. This length translates into a NAS146-32. So the bolts that were originally installed in my spring steel gear legs were not the ones shown in the parts manual for the original style gear leg. After making several phone calls, I learned the following information: 1. The NAS144 through NAS158 series of bolts has been superseded by the MS20004 through MS20024 series of bolts. The NAS series was "inactivated" as of October 1, 1986 according to the National Aerospace Standards Committee specification for the NAS144 thru 158 bolt. This specification has a note on it reading "Inactive for new design after October 1, 1986. Use MS20004 through MS20024." The NAS series of bolts may be available somewhere as old stock, but nobody that I talked with knew where to start looking for them. 2. The NAS146-32 bolt that was installed by the factory in my plane has been superseded by an MS20006-22 bolt. The MS20006-22 has a length of 2.062 inches and grip length of 1.375 inches, which matches exactly the dimensions of the bolts removed from my plane. 3. I only found one supplier for these MS20006-22 bolts. The supplier is H C Pacific in California. Phone 909-598-0509. Cost was $12.50 each. The sales rep that I talked with was Mike Orsendy (sp?). They had these bolts in stock. Hope this info is of some use. As always, all of this is just my opinion, is subject to being wrong, and should be verified with your licensed mechanic before you use any of it!! Good Flying, Wayne DelRossi Alon N5618F ==^================================================================ This email was sent to: [EMAIL PROTECTED] EASY UNSUBSCRIBE click here: http://topica.com/u/?aVxiLm.aVzvvT Or send an email to: [EMAIL PROTECTED] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
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