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Peter Anson

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Posts posted by Peter Anson

  1. The demonstration of aluminium brazing in the video posted by JG3 is quite impressive so long as you remember that the samples of aluminium he is using are probably very low strength alloys.  A few people have mentioned the reduction in strength in the heat effected zone of the metal being welded.  It's worth remembering that the reduction could be even more pronounced in aluminium alloys than in steel.  From Matweb, here are a few values of the yield strength of a few common aircraft materials in both their high and low strength forms:

     

    6061-T0    49MPa     6061-T6    276MPa

     

    2024-T0   76 MPa     2024-T3    310MPa

     

    7075-T0   103MPa    7075-T6   462MPa

     

    Any of these materials initially in their high strength form, if heated above about 200°C will eventually turn into the low strength form, and the higher the temperature the faster it will happen.  I think that of these materials, only 6061 is suitable for welding, but you can see from the figures you could be reducing the strength of 6061 by 80%.  The brazing rods in the video melted at about 700°F, or 370°C, easily high enough to reduce the strength of the material being brazed.

     

     

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  2. Went pretty well didn't it? Direct is a bit more time than I like to spend flying alone. Good effort   How does she like the HOT take offs? Nev.

     

    Big engine, little plane, so hot take-offs are no problem.  I was a bit surprised on one take off to notice one CHT go to 150°C so just eased the climb rate.

     

    $144 to park the plane inside for a week! Nobody tells you about those charges when they extol the virtues of flying away in your own plane.

     

    Well, that was for 12 days and I did know in advance that I would be paying to park there.  I have parked in the open there a couple of times in the past for $5 per day but was happy to get the undercover parking.  If it comes to that, I effectively pay about $40 per week to hangar my aircraft all year round so $12 per day on a casual basis didn't seem too bad.  The other aspect of this is that when you are talking to people about hangar costs they are imagining a Cessna sized aircraft, not something with a 22ft wingspan.

     

     

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  3. Who needs the airlines when you own a Sonex?  Well, I have to admit I often do, but if I had flown Qantas or Virgin Blue I wouldn't have had this great photo opportunity.

     

     

    Except for the chance to take a photo of my Sonex with an aircraft that my father once flew, this was a pretty arduous trip, one during which I thought several times that I had made the wrong call. I have flown (and written about) doing the flight from Kyneton to Rockhampton a couple of times before, but doing a long flight is always a bit of an adventure and sometimes it can be a bit more adventurous than you wanted. Here's a link to my blog: http://www.ansoneng.com/sample-page/sonex-trips/who-needs-an-airline-when-you-have-a-sonex/

     

    Peter

     

     

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  4. I use a Wombot (Australian assembled from the usual Chinese parts) printer for making parts such as this NACA duct. Starting 3D printing even with a fully assembled printer has a steep learning curve. To successfully print ABS you need a fully enclosed printer.

     

     

    These ducts are printed in carbon fibre reinforced PLA but are not necessarily any stronger than ordinary PLA because in one direction the strength of the part still depends on the bond strength between layers.  Some models of Markforged printers can insert a continuous strand of glass or carbon fibre into the print so they are structural in two dimensions but still just rely on bond strength in the third dimension but they do at least have the potential to make structural parts.  Printers with that capability are very expensive, I think around $20K.  I have made (sort of) structural parts like impellers for water pumps but the only really structural things I have made are nylon blades for a brush cutter.

     

    Peter

     

     

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  5. Yep, sounds like us. We were using distance-to-go off the ipad to locate each other. The headwind on Monday was the strongest I have experienced. Great for bragging rights if you were going the other way though. I remember doing a trip home from Narromine a couple of years ago when I had 160 knots on my GPS for part of the trip. Reckon I could have beaten that easily.

     

     

  6. Your comment about not making a good WW2 pilot by not seeing an aircraft would not wash with those who were there. An account from one of the "few" Tom Neil in his 70th anniversary speech noted that for the most part he flew and saw nothing. He survived but lost 5 aircraft.

    I must have read 5 or 6 accounts by WW2 fighter pilots about being in a furious dog fight among dozens of aircraft and suddenly finding themselves alone without another aircraft in sight. I have enormous difficulty spotting other aircraft near me. In the blog I mentioned passing underneath one of the Bristells, but I didn't see him until I was within a couple of hundred metres. Good thing he wasn't coming the other way. It reinforces the need to fly at the correct cruise height, but even that becomes problematic when you are flying north or south.

     

     

  7. For a good looking curvy WW2 fighter you can't go past an F4U Corsair.

    At the Antique Aircraft fly-in at Echuca a couple of years ago I saw a P51 and a Corsair flying in formation. They both looked great but surprisingly the Corsair looked quite portly compared with the Mustang.  For a really purposeful looking aircraft I don't think you can go past the FW190.  Kurt Tank was behind several very good aircraft designs and we were probably a bit lucky that more of them didn't make it into mass production.

     

    The TBM Avenger takes the prize for Fugly in my books

    If you think that's ugly have a look at a Grumman Duck!

    Hmmm.  I think a biplane trainer made a forced landing on top of a speedboat and the designers at Grumman thought "Hey, that could work".

     

     

  8. All of these famous aircraft had their faults, as do many modern aircraft, but they were the best that the various combatants could produce at the time.  Compare them with some  of the aircraft that were obsolete within a few years of their design;  the Bolton Paul Defiant, Brewster Buffalo, nearly all of the early British bombers or the ME110 as a day fighter.  It took actual combat to show up those faults and the theory of air combat was changing rapidly.  In this the Axis forces started with the advantage of more recent combat experience.

     

    Producing combat aircraft in large numbers was such a massive undertaking that  even in the heat of war it sometimes took years to turn things around.  The allies accepted staggering heavy bomber losses when they had DeHavilland Mosquitoes that could carry substantial bomb loads and had far fewer losses.  Germany continued to produce vast numbers of ME109s right to the end of the war even though the FW190s were superior.

     

    Probably all of the combatants mythologized their own aircraft to some extent.  For the British, it's the Spitfire, for the Americans it's the Mustang, and for a time when things were going well for the Germans, it was the Stuka, which I guess shows that an aircraft doesn't even have to be pretty to be mythologized.

     

     

  9. I tried two things.  My ipad has a folding lid cover which incorporates a couple of magnets in the lid.  In the right position it can really muck up a compass readings (180 degrees error) so I also tried it without the cover attached. The ipad itself parked about 100mm from the compass will deflect the needle by 10 degrees - obviously enough to get you lost.  Have to admit that I rarely use my compass, only as a check and backup to the GPS bearing shown on my phone.

     

    Another Peter

     

     

  10. Interesting! I like the Sonex. Being financially crippled, I am an ultralight enthusiast, but the Sonex seems a strong great flying little plane. They get some less than favorable reviews at a couple blogs here. "Under powered, Sonex guys never fly their planes anywhere," bla bla bla. Not the case! I attend a fly in at Recklaw Texas, and there is a group of 6 Sonex flyers that come here from all over the USA. Even the couple guys flying Monet's aerovee conversion have no complaints about power. As far as structural durability, I am no engineer, and would stay within Monet's guidelines for a power plant. One day I hope to own a Sonex. Possibly with Jabiru's flat 6.

    Hi Charlie, I'd agree with everything you say and have done many trips in my Sonex. See http://www.ansoneng.com/sample-page/sonex-trips/ for reports on some of them. When I started building my Sonex, I too was a little financially crippled because I already had an aircraft and couldn't afford two of them so I built mine from scratch. You can still do that with the Sonex (as well as some Zenith models I think). It took me longer than I had hoped, 6 years, but that just meant the expense was also spread over 6 years. The dribble of money on the Sonex was small enough that it had little effect on the family finances and at the end I had a fantastic little aeroplane. My Sonex has withstood loads in Thermals that would have ripped the wings off my previous aircraft. On the other hand my previous aircraft would have been 50 knots slower when it hit the thermal so maybe it wouldn't have been a problem.

     

    I am not familiar with the Sonex but I am guessing thatthe designer overbuilt to a degree the most critical areas subject to stress and fatigue so that fatigue should never be aworry in any flyers/owners lifetime..

    You are correct, and I think the Sonex designers certainly aimed for this, but my point was that the consequence of adding weight to the build could be that fatigue life does become a worry. John Monnett is obviously not happy about people changing the MAUW of his design, but this isn't just a Sonex thing. It applies to all metal aircraft.
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