Hi Jerek Rob and everybody else.
The issue Jarek has been discussing has been on my mind, hence this comment. During a pre flight inspection some months ago, I noticed that if the tailplane was pushed laterally at the tips, there was some movement. And it did make a sort of “Klunking” sound like Jarek described. Well, after the panic attack wore off. I took the tailplane off and that is when I found the slightly loose front rod end (ie where it screws into the elevator). Looking at the new (gold plated) rod end, I recall setting it up where I made a brass spacer under the rod end and adjusted the thickness to get the correct tailplane position (no lock nut… sorry about that) once in position, and aligned, I should have used Loctite to ensure it stayed in position. But after 4 years or so it actually came loose. Because it is a rod end hence can rotate a bit,… but only to the limit of the ball displacement on the pin the effect was that there was unacceptable lateral elevator movement. Fixed of course by tightening and Loctite. The thing is that the little pin is just to ensure the elevator does not move forward. It is not “structural “ as such. If the elevator is properly in place there will be no movement at all … should be as solid as a rock. So as Rob said … check ALL the brackets for tightness and check the expensive rod end. When I was restoring our (Ex Thai) Dimona I set up the new front rod end and found the diameter of the pin was smaller than the rod end. Fortunatly I was able to get a new replacement from Diamond. However it did open up a significant issue which relates mainly to the ex Thai Dimonas. That is if a civilian aircraft becomes part of a military outfit, the original type certificate requirements tend to be ignored. So they can modify and change things as they please with no reference to the original certification. So when we get our hands on to these ex military machines they have to comply with the original type certificate. This is not easy as there is generally no coherent record of things being done. So a REAL thorough inspection is critical. Even then some things are missed. For example our H36 .. as well as having the front elevator mounting pin the wrong diameter, it was also not high tensile. Also the 4 U/C attach rod ends were also not high tensile. The H36 currently being restored had its U/C mounting rod ends replace while in Thailand. But rather than access them thru the cockpit floor they took the direct approach and from the outside. In doing so managed to chop through the lower structural roving longerons in 4 places, this reducing the structural integrity of the structure. To give Wilf Hoffman credit, this Dimona did survive 20 plus years of action in Australia in that state where all the U/C loads were taken thru the external skin …. Until “splat” day Actually this should have been picked up when the aircraft was inspected to be put on the Australian register … but not the kind of thing you would expect or what we are used to as we do maintain our aircraft according to set rules and procedures. I have rattled on a bit here, but I am sure you all will find this quite interesting. Overall, I reckon the H36 is a fantastic little machine. Considering its age. It is quite simple to maintain and the engine … while does need ongoing maintenance, is reliable and so old that any expensive AD’s have well passed Best regards Ian Williams From: dog@lists.riverland.net.au On Behalf Of Jarek Steliga Sent: Thursday, 10 June 2021 8:13 a.m. To: Laurie Hoffman via dog <dog@lists.riverland.net.au> Subject: Re: [DOG mailing list] Dimona H36 Horizontal Stabilizer Slack Hi Rob, Yes, I will, but it may take me a few days. Regards Jarek On Wed, 9 Jun 2021 at 12:19, Rob Thompson <amessageto...@gmail.com <mailto:amessageto...@gmail.com> > wrote: Hi Jerek, Can you send a photo of the underside of the tailplane where the front pin goes into? regards Rob Rob Thompson 0429 493 828 On Wed, Jun 9, 2021 at 6:16 AM Jarek Steliga <jarekstel...@gmail.com <mailto:jarekstel...@gmail.com> > wrote: Hello again, Would someone care to have a look at the attached photos? This is how things were in autumn 2020 (with ca 20 hours of flight between then and now). 1. Safety pin retracted 2. Around the pin there is something that looks like attempted repair, but possibly it was done by the manufacturer. 3. Safety pin in lock position. 4. While trying to slide the tail plane back and forth, there can be heard metallic noise which seems to originate from these two pins Are owners of H36 partaking in this forum positive that there is no play on their tail planes when force is applied backward by pressing a hand against the middle of the leading edge? Anyway I am going of course to perform an inspection as suggested in earlier posts in this thread. Regards Jarek On Tue, 8 Jun 2021 at 12:01, Rob Thompson <amessageto...@gmail.com <mailto:amessageto...@gmail.com> > wrote: The tail area of a Dimona with a rigid tailwheel with such a heavy loading does get a pounding. regards Rob Rob Thompson 0429 493 828 On Tue, Jun 8, 2021 at 7:12 PM Ian Williams <i...@agcon.co.nz <mailto:i...@agcon.co.nz> > wrote: Can’t see how Rick. Of interest the major surgery on ex VH-GNW should be complete in about 3 weeks. Still a heap of minor surgery to do though . Best regards Ian Williams Sent from my iPhone On 8/06/2021, at 5:10 PM, Mister Sutton <ricinthel...@outlook.com <mailto:ricinthel...@outlook.com> > wrote: hi all just as a point of interest, those that have had issues with loose tail planes i am wondering if there is a correlation with the rigid tail wheel or the unit with rubber blocks or both? cheers ric On 5/06/2021 10:23 pm, Jarek Steliga wrote: <Horizontal Stabilizer Slack.jpg> <https://drive.google.com/file/d/1CFNLpdRX6LjFZibzpyI0SvOMkW_ic2oE/view?usp=drive_web> Horizontal Stabilizer Slack vid 1.mp4 <https://drive.google.com/file/d/1cpyc_EnVllXmkqnHitOG5XarYsKhEq1c/view?usp=drive_web> Horizontal Stabilizer Slack vid.mp4 Hello, We noticed a slight slack as demonstrated in the attached videos. In the photo you can see pieces of tape attached across the gap which visibly wrinkles when the stabilizer is pushed back and forth. The estimated travel is ca 2 mm. Is this an immediate cause for concern? Best regards Jarek Steliga
