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    Engine failure turn back.

    I don't think enough is made of the unusual and potentially startling severity of the maneuvers required to make a turn back successful below the absolute minimum plus about 30%. The descriptors of "windshield full of dirt and no horizon" are very real, as is "controls to the stops" to execute...
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    Engine failure turn back.

    A lightly loaded 172 needs 400' to get the job done most of the time. A fully loaded 182 can barely get the job done at 600 feet from Vx, and that's while executing eye-popping maneuvers that most pilots have never even attempted on purpose. Total failure on departure at Vx requires going to...
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    Prop shaft

    Seems reasonable. It's a large problem.
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    Announcing SoFIS - An Open Source EFIS

    The heli is partially a consumer tech demonstration project. The mission needs for the electronics are low compared to the data bottleneck. The heli is partially a consumer tech demo project common in some areas of aerospace in recent decades. I'm not an expert in the Ingenuity. I happen to...
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    Prop shaft

    An important and common means of reducing resonance gain and increasing resonance frequencies is to employ a redrive to match inertia. This will be a problem for the application here but it's an important concept to know about. I've used the concept quite a bit to kill large moving load...
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    Prop shaft

    The patents and literature specifically cite resonance damping. I don't know how they dissipate the heat. But the poiseuille shearing would have a similar response to drop the low pass crossover frequency as a spring or torsional modulus change.
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    Prop shaft

    https://www.vibratechtvd.com/torsional-dampers
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    Announcing SoFIS - An Open Source EFIS

    Funny you should mention this. The Mars rover Perseverance uses a PowerPC 750, a single core platform that has been around since 1998 or so. It runs at 233 MHz. The Snapdragon 801 processor in my current cell phone is the same chip being used in the Mars helicopter Ingenuity about to be taken...
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    Announcing SoFIS - An Open Source EFIS

    This is a crucial distinction. But throwing money at the problem doesn't solve anything. Sound execution and components does. The environment in a small GA airplane is similar to a '57 Chevy, albeit with a few strong rf emitters present. Things are noisy, and I'm all to familiar with that...
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    Announcing SoFIS - An Open Source EFIS

    It's good to see another effort out there. It's repetitive to see criticism that shrieks to say this is an application too demanding for inexpensive hardware or middle of the road programming skills. That's pure projection of fundamental misunderstandings of the requirements of the problems and...
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    Mountain plane

    Hang gliders are far, far easier and safer to operate in unstable airflows than paragliders. That doesn't make hang gliders appropriate, just safer than paragliders. Ive flown HG's for 35 years, and PG's for 25 years (including in the Andes). Neither would be practical on a regular basis, but a...
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    pics from failed Autofight PSRU

    Billski's observations are correct. It's a fool's errand to use these. The gear surfaces exhibit significant work hardening and spallation, not just the obvious incipient surface failure shown in one view. If you were to do a hardness test in different areas of the face, you would likely see...
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    Wanted machinist

    I'd like their info.
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    Wanted machinist

    The costs and availability of machine shops in the US have transitioned from difficult to unobtanium in a decade. I'd recommend mfg.com to get one offs back in your hands from overseas at far lower cost, and possibly faster than you'll even get a call back from an American shop. I have a...
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    Looking for split bearings similar to MS-27646-42 aka B542DD - main stick roll axis bearings.

    Split rollers of any variety really only begin being available off the shelf at somewhere around 2" id in my experience. If you were simply told it was desirable, I would encourage skepticism. Plain bearings can exhibit very good performance when sized properly, and split bearings in this...
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