I have a, friend who is, aeronautical engineer but he is not a CASA part 21 engineer but works through an insured engineer.
Re accepting NZ they should but for example JS1 got full certification in NZ but in AU is, still experimental. CASA did accept the NZCAA wing tip tanks in PA25 so who knows! Lockie is in France now but owns a DG400 glider and knows every rule in the CASA book. Ian McPhee 0428847642 On Sun, 18 Jun. 2023, 8:33 am Rob Thompson, <amessageto...@gmail.com> wrote: > Good work you are doing in response to this problem! > > The Airmaster/Sensnich prop option sounds like a winner. Certainly in > Australia a STC can be a trial to achieve but once you get there you own it > and you should be able to recoup your time and costs by charging a fair fee > for other owners. I think a NZ STC is automatically accepted in Australia. > > Are your blades T or BT? > > It is concerning that the cracks can't be seen without removing the > counterweights. Sounds like a strong case for removing them at every annual > inspection and penetrant die check the ferrules. Reinstalling them can be a > little time consuming. I have found the BT prop takes a bit of fiddling to > get the counterweight angle just right between being too hard to change > pitch and having it too easy and unexpectedly jumping into coarse.... > usually on take off. > > Is it time to notify the gliding authorities so that they can get an AD > out to owners? > > Attached is the HO-V62R manual for anyone who may not have it. > > regards > Rob > > Rob Thompson > 0429 493 828 > > > > On Sat, Jun 17, 2023 at 8:11 PM Ian WIlliams <i...@agcon.co.nz> wrote: > >> Hi All, >> >> >> >> I guess this is a rather tricky subject so I will be as circumspect as >> possible. >> >> >> >> Our H36 has been out of the air now for 6 mths because of a serious and >> potentially dangerous propellor problem (along with 2 other HO-V62 props.) >> >> >> >> The issue relates to cracking of the ferrells (those bands of metal at >> the base of each blade which the counter weights are clamped on to). >> >> We have had 2 types of cracking … one which was a hairline crack >> extending horizontally around the Ferrell (quite difficult to see) and the >> other which was very obvious from the top to bottom of the Ferrell. Both >> not visible with the counterweights fitted. >> >> >> >> Of the 3 cracked prop ferrells, (2 * Grob 109’s and our H36) all aircraft >> have been hangered >> >> >> >> Obviously I am far from happy. The support from Hoffmann has not been >> anywhere as one would expect. The impression I have is that they seem to >> be not willing to support these small props into the future. An example is >> their unwillingness to provide the only Australian (and New Zealand) >> service company (For the HO-V62 prop) with any approved Technical data >> despite the fact that they sent one of their engineers to Germany for a >> technical training course. This really is a very bad state of affairs. >> >> >> >> There could be a few reasons why the ferrells are cracking Possible a >> manufacturing problem relating to the Ferrell material (aluminium .. what >> composition etc) or insufficient epoxy infusion of the wood material at the >> root end making it more susceptible to humidity and hence expansion Or >> faulty maintenance. >> >> >> >> So right now I am in the process of attempting to get some sort of >> approval to install a 2 blade electric controlled Airmaster prop (which >> uses Sensnich composite blades) A real plus is they are constant speed so >> would really enhance the Dimona’s total operation … nice because of >> thinner, more efficient blade design and adjustable preset prop positions >> including feather. Their operation is the same as a standard CSU >> operation except there are 3 preset RPM setpoints as well as totally >> adjustable like a normal oil pressure type CSU. And quite simple to >> install. >> >> >> >> In New Zealand, maintenance of gliders and repairs are carried out by NZG >> approved engineers but anything outside of that follows the standard GA >> rules. >> >> >> >> Currently I have >> >> - Ordered a set of blades (Ordered by Airmaster to Sensnich) right >> hand rotation 62 inch total prop diameter 2 blades. >> - Discussed the idea with Diamond Canada who have suggested to >> seriously look at an NZ STC to do this. I am OK to carry out the >> engineering work / documentation and if approved could be available for >> other H36 owners >> - Discussed with Nigel Baker (Limbach Australia) who also has had >> similar issues with the Hoffmann HO-V62 props and was supportive of the >> idea >> >> >> >> There is a lot of info on youtube about the technical aspects of the >> airmaster props. Being a NZ company of course has its advantage for us. >> MT also produce a prop (TSO’d) the problem is both the cost, delivery >> delay and down here in NZ, freight costs are a real killer. >> >> >> >> So that’s where I am at. I would like to hear opinions from other H36 >> owners if possible. >> >> >> >> Best regards >> >> >> >> Ian Williams >> >> Drury >> >> New Zealand >> >> >> >> Engineer for .. >> >> ZK-GCB >> >> ZK-GPH >> >> ZK-GNW >> >> ZK-GOC >> >> >> >> >> > > --------------------------------------------------------------------- > You are subscribed to the Dimona Owners Group mailing list. > This list is archived in public. http://waikeriegliding.com/dog/ > To unsubscribe, send email to: dog-unsubscr...@lists.riverland.net.au
