Raptor Composite Aircraft

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Dexacare, Mar 28, 2016.

Help Support HomeBuiltAirplanes Forum by donating:

  1. May 18, 2019 #581

    Mike Stewart

    Mike Stewart

    Mike Stewart

    Member

    Joined:
    Oct 11, 2010
    Messages:
    18
    Likes Received:
    5
    Location:
    San Diego, CA
    I think I know that Berkut. If it was the one owned by Ryan at KSDM at one time, it was the loudest airplane I've ever heard in flight, including Reno.
     
  2. May 19, 2019 #582

    flyboy2160

    flyboy2160

    flyboy2160

    Well-Known Member

    Joined:
    May 25, 2014
    Messages:
    314
    Likes Received:
    155
    Location:
    california, USA
    Is that somebody who can judge if this is suitable for a DARwin award? Or do we have to wait for the smoking hole in the ground?
     
    pictsidhe likes this.
  3. May 19, 2019 #583

    rv6ejguy

    rv6ejguy

    rv6ejguy

    Well-Known Member

    Joined:
    Jun 26, 2012
    Messages:
    3,749
    Likes Received:
    2,786
    Location:
    Calgary, Alberta, Canada
    It looks like DARs come in many different flavors and I doubt if many have any experience inspecting a turbocharged, pressurized, diesel, retractable pusher because there aren't any. This is an extremely complex Experimental. We know it won't perform as originally advertised, let's just hope it flies ok without stability, control, flutter or powerplant issues.
     
  4. May 20, 2019 #584

    Andy_RR

    Andy_RR

    Andy_RR

    Well-Known Member

    Joined:
    Sep 29, 2009
    Messages:
    175
    Likes Received:
    96
    Location:
    Melbourne, Australia
    WTAF are those wing fences about...? o_O
     
  5. May 20, 2019 #585

    rv6ejguy

    rv6ejguy

    rv6ejguy

    Well-Known Member

    Joined:
    Jun 26, 2012
    Messages:
    3,749
    Likes Received:
    2,786
    Location:
    Calgary, Alberta, Canada
    I believe those were intended to stop some Dutch Rolling tendency shown on the model at low speeds.
     
  6. May 20, 2019 #586

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    9,499
    Likes Received:
    6,255
    Location:
    97FL, Florida, USA
    How does the LE sweep angle of the Raptor compare to other canard aircraft? (It has a huge mass aft of the firewall.)


    BJC
     
  7. May 20, 2019 #587

    rv6ejguy

    rv6ejguy

    rv6ejguy

    Well-Known Member

    Joined:
    Jun 26, 2012
    Messages:
    3,749
    Likes Received:
    2,786
    Location:
    Calgary, Alberta, Canada
    I've wondered about the C of G myself with that 800+ pounds aft of the firewall. Given the fact that the aircraft weighs at least 1100 pounds more than first predicted (using Wayback Machine), it's clear Peter doesn't have a good handle on weight management and that likely extends to weight distribution as well. Could need a lump of lead in the nose to correct which is the last thing this design needs.

    It's unclear how much input Mark Bettosini, (an experienced designer) has had on the design but if non-designers like us here could see the bloated weight figures coming (though maybe not to this degree), wouldn't others close to the project be talking in Peter's ear about adding all these weighty systems? Then again, as before, Peter may not act on good advice from the experienced people he's consulting with.

    I saw a comment on the latest vid asking Peter if he still thought the prototype would meet the published performance predictions. I had to laugh. Peter didn't answer that one but it should be clear to ANY pilot that it won't, given the 900-1100lbs. the design is overweight. I can only assume that many posters on YT are not pilots or very ignorant ones.
     
    Last edited: May 20, 2019
  8. May 20, 2019 #588

    Marc Zeitlin

    Marc Zeitlin

    Marc Zeitlin

    Well-Known Member

    Joined:
    Dec 11, 2015
    Messages:
    467
    Likes Received:
    646
    Location:
    Tehachapi, CA
    On this airplane, given the designer, they could be anything whatsoever, including a poor attempt at a coffee maker. But let's assume not...

    If you take a look at Long-EZ's, COZY's, and Velocities (which this thing most closely resembles), you'll see that on MOST of them (and the ones built to plans, except for some Velocities) there's a lower winglet below the upper winglet (google pics of LE's or COZY's to see this). The reason the lower winglet is there is to help in restricting span-wise flow near the tip. Nat Puffer determined that on COZY MKIV's, removing the lower winglets decreased the deep stall resistant rear CG limit by about 0.5" - on the COZY MKIV, the lower winglets are mandatory (as much as anything is mandatory on EAB aircraft). So with them, the rear limit is 102" - without them, it would be 101.5".

    Now, I've assisted a few folks (one on an E-Racer and one on a stretched COZY MKIV) in designing/installing blended winglets, as the Raptor has (the E-Racer was the first canard to have them, back in 2007, IIRC). A few other folks have installed blended winglets on their canard aircraft in the interim as well. I made it clear to the owners of these planes that their CG range would shift forward because they didn't have lower winglets anymore. Some folks build standard, non-blended winglets, but leave off the lower winglet for aesthetic reasons, and as mentioned, some of the Velocity models didn't have lower winglets either (as well as winglets that were in-line with the leading edge of the wing, rather than shifted aft, but that's another topic).

    I'm going to GUESS that the idea behind these <horrible looking flat-plate> lower wing fences is to mimic the effect of the lower winglets on other canard aircraft and that they're put at the start of the wing blend to put them as far outboard as possible. This type of fence was something I had suggested to the other blended winglet folks, but they didn't try it (and obviously, it would have to be tested for deep stall resistance in both modes to determine if it was effective in reducing span-wise flow).

    With respect to BJC's question regarding wing sweep, the top view of the Raptor as seen here:


    if up-to-date, shows a sweep angle that looks essentially equivalent to the Long-EZ, COZY and Velocity (the Varieze had a higher sweep angle).

    And with respect to Ross's comments, paying any attention to the comments on YT is useless - none of those folks are engineers nor have any semblance of understanding of what's going on with this aircraft. Cheerleaders, at best.

    What's the current over/under on Empty Weight of the plane? Think it's gone over 3000 lb yet, with all the additional stuff that's been thrown at it?
     
    rv6ejguy and BJC like this.
  9. May 20, 2019 #589

    BoKu

    BoKu

    BoKu

    Well-Known Member HBA Supporter

    Joined:
    Aug 16, 2013
    Messages:
    2,275
    Likes Received:
    2,837
    Location:
    Western US
    Not to rathole this thread, but:

    "Blended Winglet" is an Aviation Partners, Inc. trademark that they use to describe their patented technology for developing smooth lofts for the transition between the wing and one or more winglet blades. They have in the past been aggressive at protecting both their patents and trademarks from other manufacturers. I don't think that they'd bother with us little folk, but I wouldn't put it past them to find it expedient to do so at some time in the future.

    When Brad Hill and I were working out the very smooth winglet transition for our sailplane, we were pretty careful to do so in a way that steers clear of AP's intellectual territories.

    --Bob K.
     
  10. May 21, 2019 #590

    Marc Zeitlin

    Marc Zeitlin

    Marc Zeitlin

    Well-Known Member

    Joined:
    Dec 11, 2015
    Messages:
    467
    Likes Received:
    646
    Location:
    Tehachapi, CA
    Oh, what the hell. Let's go for it.

    So a search of the patent/trademark listings indicates that API got their patent for "blended winglets" in 1994 and it has since expired (in 2013, according to the USPTO web site), meaning that anyone can sell "blended winglets". As far as trademarks go, there are only two live trademarks with the word "winglet" in them, neither of which belong to API (nor have anything to do with airplanes) and the 9 dead ones didn't belong to API either.

    So bring it on - they've got no IP to protect when I use the words "BLENDED WINGLET". HAH - I'll do it again "BLENDED WINGLET" :). And I don't even sell them - I just say the words every once in a while...
     
    bmcj and BoKu like this.
  11. May 21, 2019 #591

    mcrae0104

    mcrae0104

    mcrae0104

    Armchair Mafia Conspirator HBA Supporter

    Joined:
    Oct 27, 2009
    Messages:
    2,961
    Likes Received:
    1,955
    Location:
    BDU, BJC
    [​IMG]
     
    Andy_RR, wsimpso1 and BoKu like this.
  12. May 21, 2019 #592

    TMann

    TMann

    TMann

    Well-Known Member

    Joined:
    Aug 16, 2011
    Messages:
    148
    Likes Received:
    81
    Location:
    Omaha, NE
    o_O You'll poke your eye out!
     
    Andy_RR and BoKu like this.
  13. May 22, 2019 #593

    rv6ejguy

    rv6ejguy

    rv6ejguy

    Well-Known Member

    Joined:
    Jun 26, 2012
    Messages:
    3,749
    Likes Received:
    2,786
    Location:
    Calgary, Alberta, Canada
    Latest vid shows another failure on the main gear door actuation design so he's leaving the door off for now.

    Also showed the rad/ intercooler guide vane array in place but it's not sealed to the HXs at all so most of the air will just flow around these. Peter still doesn't understand the importance of delta P across HXs for most efficient cooling. The scoop inlet is huge, even in the closed position. I see lots of drag here. There are hundreds of hours into this variable geometry scoop now...

    Jeff and Devon are getting the last of the wing sanding close. Kudos there.
     
  14. May 22, 2019 #594

    canardlover

    canardlover

    canardlover

    Active Member

    Joined:
    May 3, 2012
    Messages:
    36
    Likes Received:
    37
    Location:
    Canton, Ga USA
    I preached weight consciousness and voiced concern for well ove

    I preached the importance of weight consciousness and adamantly voiced concern over all the unnecessary garbage being thrown into the airplane , not to mention one unnecessary oversized extremely heavy passenger side door amongst many other things. Mark did as well. We were both ignored and scoffed at by someone always thinking he knew better . Early on we threw our hands in the air and left it up to the Master Designer and project manager. We sincerely tried to keep it sane to no avail. Our recommendations were always second guessed. You have no idea the second guessing I went through during my efforts in correcting the aero problems discovered with the model. The models creation was a direct result of my apprehension upon seeing the original design and incidence/decalage settings that made no sense. At this point I respond just as Schultz did in the old Hogans Heroes TV show, " I know nothing" when asked why this or why that. New Motto comes from a little cartoon penguin , "Smile and wave boys,smile and wave".Nuff said.
     
    Topaz, anvegger, BoKu and 1 other person like this.
  15. May 22, 2019 #595

    mcrae0104

    mcrae0104

    mcrae0104

    Armchair Mafia Conspirator HBA Supporter

    Joined:
    Oct 27, 2009
    Messages:
    2,961
    Likes Received:
    1,955
    Location:
    BDU, BJC
  16. May 22, 2019 #596

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    9,499
    Likes Received:
    6,255
    Location:
    97FL, Florida, USA
    What is the current empty weight, and how much could it be reduced if redesigned?


    BJC
     
  17. May 22, 2019 #597

    rv6ejguy

    rv6ejguy

    rv6ejguy

    Well-Known Member

    Joined:
    Jun 26, 2012
    Messages:
    3,749
    Likes Received:
    2,786
    Location:
    Calgary, Alberta, Canada
    Ugh. I feel your pain here again Jeff, and Mark's too. Thanks for posting on this, you are doing fine work on the composite side. Stay in the shade while you are finishing that sanding outside.
     
    Topaz, Turbine Aeronautics and BoKu like this.
  18. May 23, 2019 #598

    Mark Z

    Mark Z

    Mark Z

    Well-Known Member

    Joined:
    Aug 29, 2012
    Messages:
    536
    Likes Received:
    251
    Location:
    Granbury, Texas USA 0TX0
    I’ve enjoyed watching you guys work. I know it’s hard when your heart isn’t in it.
     
  19. May 23, 2019 #599

    canardlover

    canardlover

    canardlover

    Active Member

    Joined:
    May 3, 2012
    Messages:
    36
    Likes Received:
    37
    Location:
    Canton, Ga USA
    Correct, it exhibited horrendous spiral instability. Wings level to 50+ degree bank angle in three rapid cycles. This occurred when arresting descent and beginning "flare " to establish normal canard approach deck angle before touchdown. First occurrence was quite a surprise.
     
    rv6ejguy likes this.
  20. May 23, 2019 #600

    canardlover

    canardlover

    canardlover

    Active Member

    Joined:
    May 3, 2012
    Messages:
    36
    Likes Received:
    37
    Location:
    Canton, Ga USA
    73"]flow[/QUOTE[/QUOTE]
     
    Markproa likes this.

Share This Page

arrow_white