Ducted fan aircraft

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by jthunt, Mar 17, 2012.

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  1. Oct 10, 2018 #1281

    blane.c

    blane.c

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  2. Oct 11, 2018 #1282

    Malish

    Malish

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    Just started installation of retractable landing gear on aircraft. Nose gear are installed and also hydraulic power unit.
    All controls of landing gear hydraulic system will be installed in the nose cone, for easy excess and close location to pilot cabin.
    Main L\G will be powered from there too.

    PA111719 (Large).jpg PA111720 (Large).jpg PA111723 (Large).jpg PA111725.jpg
     
  3. Oct 12, 2018 #1283

    Malish

    Malish

    Malish

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    Today we're installed "emergency gear down" hand pump

    PA121732 (Large).jpg PA121734 (Large).jpg PA121735 (Large).jpg
     
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  4. Oct 12, 2018 #1284

    henryk

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    =very clever thing!
     
  5. Oct 12, 2018 #1285

    Vigilant1

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    Looks good. If the hydraulic system isn't intact (e.g. blown seal somewhere, etc), is there a way to unlock the mains and shake them down, or a wire to pull them overcenter and into the downlock, etc?
     
  6. Oct 12, 2018 #1286

    Malish

    Malish

    Malish

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    No way for main gears, they will not lock, same way it's will be on Cessna's or Lancair IV aircraft. This is problem with main landing gear go into back of fuselage and they will not go to overcenter against airflow, if no hydraulic fluid left for "hand pump".
     
  7. Oct 12, 2018 #1287

    Doggzilla

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    Since its a ducted fan and doesnt have a prop to strike against the ground, he could technically just get away with some skid pads.

    Some aluminum "knee pads" right where the aircraft makes contact with the ground when its gear up. Just riveted or epoxied on.

    This way the fuselage wouldn't be making direct contact and the pads would take the scraping instead of the expensive composite fuselage.
     
  8. Oct 12, 2018 #1288

    henryk

    henryk

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    =big problem with dust in air inlets...

    =NO upper inlets!

    http://www.reaa.ru/yabbfiles/Attachments/130KM3YG5P-46460__Large_.JPG
     
  9. Oct 12, 2018 #1289

    rv6ejguy

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    Some aircraft used a compressed gas cylinder teed into the hydraulic line with a valve. You could remote mount the bottle, freeing up some space near your feet and it works even if there is no fluid left. Maybe something to consider for production models.
     
  10. Oct 12, 2018 #1290

    Doggzilla

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  11. Oct 13, 2018 #1291

    Vigilant1

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    The T-37 had a setup like that, something like 3000 psi in a small "blowdown bottle." One shot.
     
  12. Oct 13, 2018 #1292

    henryk

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  13. Oct 13, 2018 #1293

    Vigilant1

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    Seems like a good weight for this. I would think 1.1 liters at 4500 psi should be enough, unless there's a massive leak. I suppose a check valve would be needed to assure the air goes only to the gear cylinders, not to the hydraulic pump. This approach might be lighter and more likely to work than the hand pump if the fluid leaks out, but would require more work and possible damaged parts to test it. High adventure!
     
  14. Oct 13, 2018 #1294

    henryk

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  15. Oct 18, 2018 #1295

    Malish

    Malish

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    Main landing gear on this aircraft, still be somewhat intruded in air stream, we didn't want to cut main structure of airframe. To do this, we did restrict travel of landing gear legs in retracted position, by installation of extra support(it's can be seen on photo). This is only for prototype aircraft, next aircraft mains will be fully enclosed.
    Front gear is fully retractable into nose cone and have wheel well doors.
    We're know, that this prototype aircraft will lose some performance in cruise speeds, but doing this, we will save time and money to certify this aircraft with new landing gear.

    PA121737 (Large).jpg PA121738 (Large).jpg P7270177 (Large) (Large).jpg P7270214 (Large) (Large).jpg
     
  16. Oct 18, 2018 #1296

    Vigilant1

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    Very nice. Unrelated: I've always appreciated aircraft designed to minimize damage in the event of a gear-up landing. The A-10 and some other airplanes leave the retracted wheels down a little below the main airframe, covered by gear doors with a small blister. In the event of a gear-up landing, with a little luck the gear doors scrub through and the tire touches the ground before anything else and begins rolling, and the only significant damage is to the gear doors (and the pilot's pride--and insurance rates). "Those who have and those who will . . ."
     
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  17. Oct 18, 2018 #1297

    Doggzilla

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    Yes, its extremely important to protect the fuselage from belly landings, even if its just some aluminum skid plates glued to the most vulnerable part of the belly.

    A few pounds of sacrificial aluminum or steel could save a lot of expensive work if there is ever a belly landing.
     
  18. Nov 1, 2018 #1298

    Malish

    Malish

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    Installation of retracts almost done.

    PA311750 (Large).jpg PA311751 (Large).jpg PA311752 (Large).jpg
     
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  19. Nov 1, 2018 #1299

    henryk

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  20. Nov 1, 2018 #1300

    Malish

    Malish

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    No problem with that, "large engine(LS6)" - a lat of heat! Cabin heater working wonderful - in the winter we can fly in T - shorts!
     
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