So interesting Nigel and Konrad. It is a worry. Personally I would never use a cabin heat in a motorglider and is one of the first things I block off but I guess you guys in SA may need cabin heat on some occasions!!!! (I did my diamond Height guess 30 years ago to 28000ft in Aust and I survived without a heater in PIK20E!!)
When I flew XOO h36 locally 5 months ago when in RH side I felt warm feet only to find the the cable was not shutting off -- ease to fix. 25 years ago the LAME would ALWAYS make me remove the jacket around the muffler for cabin heat looking for cracks covered up by the cover. Also reminds me of warm feet in RH side of old falke 10 years ago and all it had was a layer of SS only. I immediately added 5 layers of foil tape to the firewall in the area of exhaust pipe and stopped the inbuilt foot heater!!!! I add metal shields to engine pipes to stop heat radiating eg Generator in falke (falke generator is on front RH side of engine) My aircraft welder hates it but I get engine piped coated with ceramic coating and only costs $40 a pipe I seem to remember. It does really stop radiated heat. We must never let our guard down re heat/fire/cracks etc around motorgliders. Ian M On 18 May 2015 at 01:30, Konrad Maierhofer <[email protected]> wrote: > Hi Nige, > > the firewall on my repair looks much better. The airframe has 5000+ hrs > and had the 914 turbo charged engine installed. It turned brown but I > wouldn't be worried. The other two rectangular brown spots are the ground > cooper straps. > > Konrad Maierhofer > > PO Box 1027, Nuriootpa SA 5355 > Mobile: +61 4 5760 1974 > > email: [email protected] > > ------------------------------ > *Von:* [email protected] [mailto:[email protected]] *Im > Auftrag von *Nigel Baker > *Gesendet:* Sonntag, 17. Mai 2015 16:43 > *An:* DOGS > *Betreff:* [DOG mailing list] HK36 Heads up > > > > Hi All. > This is a heads up for the HK36, It does not apply to the H36 as it uses a > different system. > I have started on my HK36 Project. More on that later. > I removed the Stainless Steel barrier from the firewall and then removed > the firewall completely. This was because the damage was so extensive to > the glass that it is easier to make it again and secondly as I am changing > engines it is better to start with a clean slate. > When I removed the S.S. barrier I discovered severe heat damage to the > glass of the firewall immediately behind the cabin heat valve. > This would only ever be detected as far as I can see in the event someone > does what I have done and would basically be when extensive accident damage > had occurred as in this case and repairs were undertaken. Image 1 shows the > damage from the front of the firewall with the S.S barrier removed. > Image 2 is of the firewall after removal. The shot is taken looking up at > the bottom edge of the firewall. Forward is to the right in the image. The > heat damaged area is the glass box that is fixed to the rear of the > firewall. The heated air is passed through this box in 2 directions. Up the > vertical channel to deliver it to the top of the instrument panel for the > canopy demisting. The other direction is via 2 holes about 40mm diameter in > either side of the centre console sides and provides heated air to the > rudder pedal area to keep your tootsies warm. I don’t think there is a > structural problem with the damage due to the location being a good > distance from the engine mounting points and the damage is localised. > However the resin has turned a bit brittle and I really wonder how much > more heat would be needed for combustion especially as it is behind the S.S > barrier. Food for thought. So the heads up is for owners of the HK36 > version of the Dimona to have a look. I have found this is easily checked > once you are aware of the problem. With modern technology there are cheap > inspection tools giving visual inspection in small tight places. With > little effort a Snake Cam or similar can be passed through one of the foot > warming vent holes and pointed forward. The brown colour of the damaged > glass is clearly visible from the rear. > It will be interesting to see if this is a one off or if other aircraft > have suffered the same issue. > Let me know if you find anything. > Cheers. > Nige. > > > > --------------------------------------------------------------------- > You are subscribed to the Dimona Owners Group mailing list. > To unsubscribe, send email to: [email protected] >
