
Underwood
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Skyranger
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UK
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Underwood's Achievements

Well-known member (3/3)
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Underwood started following Popham 2025 , The Cavorite X7 eVTOL flies , Voltage Regulator Failed and 6 others
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Small ducted fans are very inefficient and though only used for a small portion of the flight the aircraft has to carry the weight of them all the time even when they dont provide any lift or thrust, add to that the compromised wing structure that will incur a further weight penalty and the mechanism to retract and extend the wing section and its just more snake oil.
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Voltage Regulator Failed
Underwood replied to skippydiesel's topic in Instruments, Radios and Electronics
Well it has an alternator as standard (produces AC), but if you mean a car type alternator with a built in reg/rec then yes you can fit one. -
How long is the Warranty?
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Rotax 912 with Ducati Regulator/rectifier....normaly fitted with a light that comes on when the master switch is engaged and remains on till the engine's generator is producing sufficient voltage then goes off. on shutdown of the engine the ligght will come back on untill the master is turned off. A quick question to those who have the above with a capacitor across the regulators output, when you switch the master off, does the charge indicator light go off immediately or does it slowly fade out taking a second or 2?
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High-wing RV-15: progress report from Van's
Underwood replied to Garfly's topic in AUS/NZ General Discussion
This has been in prototype for quite some time now which could be a good thing. It looks the business and a modern all metal light Bush capable Taildragger is very much needed imo. If I could afford one It would be right at the top of my list. -
That regulator seems like a waste of money to me. Firstly the claim to provide Anti Lock simply by placing a pressure limit is Bogus, It can only work for one specific combination of ground friction, tyre pressure and weight on wheel, anything outside of that one set of parameters and you are either going to lock the brake or not be able to exert maximum braking force. True anti lock that works in all situations needs a wheel speed sensor. Secondly the other feature of balancing both brake's pressure is a negative one if you want to lock one side to turn sharp. An odd contraption P.S. your symptoms could be the result of leaking internal piston seals, unusual for both to fail the same though unless the wrong brake fluid was used which can wreck some seals
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https://www.ebay.co.uk/itm/387325211088?_skw=100psi+10bar++Stainless+Pressure+Transducer+Sensor+Oil+Fuel+5v&var=654583436388&itmmeta=01JTXK10RAC4KBZ4XXCH3HSA0J&hash=item5a2e61b1d0:g:jRUAAOSwLy9iC3sT&itmprp=enc%3AAQAKAAABIFkggFvd1GGDu0w3yXCmi1faiUPSueSOxbzWx0BagonCFC4mNVy8GwHwiPfwv7ku%2FFh%2FYNlWYeIvZf00lLcYfUtx8IlH%2FLkwkI1k43SlgX1ee5GGHcK5oOqqDJufyV0qIEl4kyuegvTh9OKhCtU5ZWuEQK%2FWKajxeTX%2FUsFBoQW1wtCBD8LEWfvM7FfYtD2p7xMS0LW1sjUTjAStTCKQ9j9IGQNrwJTnLDQYJhfhqgAhQzllKlm1l6AaqqQltIflrcbpNIdXms4ZmkgnYjOSog7RajI7h6z%2FZSEGUOIliyrm8IQuzjsW7YKJe7mDY0u3HL4zHtpKvYlcKDxF3W3jz7EduUFUbmLpQEwdvv1utWyr%2BxaCqLpBIFlaa8qpKlpCQA%3D%3D|tkp%3ABFBM3o2Es9dl
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Type "oil pressure sender in to Ebay (probably amazon also) and you'll find many oil pressure senders both VDO type and the solid state types equivalent to Honeywell. I bought one of the cheapo Solid state senders to link to an MGL EMS and it worked fine. Have to ensure you get the correct thread (or fit an adaptor) and pressure range.
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Hirth made some decent 2 strokes in the 50-70hp range (still do), but they never got enough sales to challenge Rotax in that area. Perhaps now rotax has left that market they may get more of a look in. Seems their is still some interest in the 50-70hp range with SSDR types becoming available to buy like the Merlin https://en.wikipedia.org/wiki/TechProAviation_Merlin_100 and a couple of open structure types that I forget their names right now
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Aircraft down Lanyon Dve near Tharwa ACT
Underwood replied to Methusala's topic in Aircraft Incidents and Accidents
EFATO?, looks like the prop was stopped when it hit. What a shame they are lovely aeroplanes, if a little underpowered -
Unfortunately they stop making them a long time ago and 503s, even 582s are getting rare to find new stock. Second hand is always an option but I doubt there are many 447s left with much life left in their cranks
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UK SSDR spec is 35 knots/ 40mph or under stall The guy at the show with the Ultracruiser was stating 25mph, must be a substantial increase in wing area from the hummelbird to get such a difference in stall speed. perhaps there are also weight savings in the ultracruiser build.
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The SSDR class here in the UK allows the choice of engine entirely up to the builder. Someone actually got the smaller winged Hummelbird like yours I believe into the SSDR class, but I don't know how he managed to get the stall speed low enough. perhaps Vortex generators would get it down sufficiently?
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Decided to fly in on the Friday Evening so as to avoid the Chaos of Saturday. Been in many times before and it gets a bit daft on Saturday when there are often up to 10 aircraft in the circuit and overhead with at least 3 often more on final at any one time. As it turned out quite a few had the same Idea and it was already busy friday evening. Met some friends and went down the Pub for some food and drinks so a nice evening. Weather was good which is fairly unusual for the Show its often horrible. Trade presence wasnt huge it hasnt been in recent years, mostly new very expensive 600kg imported stuff that to my mind doesnt really fit in the Microlight Ethos. On a more realistic side I did see someone has started selling the Hummel Ultracruiser as it now fits in the SSDR class over here, kit or full builds available, only the engine choice isnt great either a 1/2 VW which are rubbish from what I've seen of one fitted to a bloke I know's Hummelbird or an unspecified V Twin (probably a B&S derivative) Didnt get inspired to take many pics, but here's my Nynja and the Ultracruiser...
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Emergency landing at golf course, Los Angeles
Underwood replied to danny_galaga's topic in Aircraft Incidents and Accidents
Some might say a couple of points should be deducted for not taking out a few golfers but all in all a Great Job saving that one.👍