UH-1 Drag Brace

[onemorepilot]

Has anyone ever heard of main rotor drag brace jamb nuts backing off in flight? I'm sure I know the answer to this, but I need to cover my bases.

[wcobra]

Over 40 years in the industry with 18 in the field on the Bell mediums and NEVER experienced that.  Possibly not torqued from the start ...?

[DGP]

I also have never heard of this happening.There have been cases of the brace breaking.I would also agree it may not have been tightened properly.I found the main corner bolts for the trany only finger tight on a 205 one time and this ship had been flying for a month like that.It was NOT a machine from the company that I was working with.

[DGP]

Good part of a DI on the medium is to put hands on those nuts! I haven't worked on a huey for a long time but I seem to remember that one end is left hand thread.

[onemorepilot]

Thanks for the input everyone. DOM is insisting that it was tight and backed off in flight. That didn't make sense to me, but I wanted to throw it out here before I pushed the issue. This is just one example of recent problems. Don't want to get into too much detail here, but it's time for DOM to retire... Sad story really and I don't want to be the one to push things, but we gotta do what we gotta do right?

Thanks again.

[onemorepilot]

And also, point taken DGP. I'm fairly new to the UH-1 and I have a lot to learn about it. Thanks.

[GrayHorizons]

you have to put things into perspective, any properly torqued piece of hardware should never just back off.

There always has to be something that causes it.

most times its incorrect torque loading in the first place. 

When you get into flight controls, and other important connections, they add a secondary locking, such as lockwire, loctite or self locking nuts.

I haven't been up around a medium head in a long time, but i dont recall any secondary locking. Realistically if only one nuts loose, the brace still is not going anywhere, the other nut still firmly holds the rod from rotating. However if two loosen, then the rod has the opportunity to turn at some point. I would hope someone finds the issue long before that causes problems.

I agree with you that the answer from your DOM is a bit off, but i dont think it should be the only factor into forcing his retirement unless theres been other issues.

 

[212wrench]

They should also be witness marked.  Black sharpie line works good, lasts longtime.

[onemorepilot]

GreyHorizons,

Agreed on all counts. I actually never thought of it as an "oh sh#t" moment due to the other jamb nut being tight. Also, my gut feeling was that this is not an issue because there is no secondary safety.

Unfortunately, there have been other issues; mast nut safety not installed on a 206 is only one other example, but we'll leave it there. In my mind, the bigger problem is the refusal to accept and address the systemic problems in the shop that cause these things to keep happening.

Here's the bad part: We have been working together and butting heads occasionally for over 20 years. Until recently, his work has been impeccable and I had a great deal of respect for his knowledge and experience. I just hate to see a guy end a long and respectable career this way.

[Heliian]

We have pretty high standards here in Canada, I'm assuming since you fly a UH-1 that you are not working in Canada.  Your gripes would not go unnoticed here.  It would be rare for the drag brace to loosen, unless it wasn't tight or you had a blade strike.  Leaving the lock off a 206 mast nut is a slip, where did the lock and bolt end up?

It sounds like you're working for a budget operator,  if they had a clue, they would acknowledge your problems and try to come up with a happy solution.