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Marc Zeitlin

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Marc Zeitlin last won the day on November 26

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About Marc Zeitlin

  • Rank
    Flying Cozy MKIV N83MZ
  • Birthday 08/06/1957

Flying Information

  • Flying Status
    Flying - 1600 hrs.
  • Registration Number
    N83MZ
  • Airport Base
    KTSP

Personal Information

  • Real Name (Public)
    Marc J. Zeitlin
  • Location (Public)
    Tehachapi, CA 93561
  • Occupation
    Principal - Burnside Aerospace
  • Bio
    www.mdzeitlin.com/Marc/bio.html

Project/Build Information

  • Plane
    Cozy Mark IV
  • Plane (Other/Details)
    COZY MKIV
  • Plans Number
    386

Contact Methods

  • City
    Tehachapi
  • State/Province
    CA
  • Country
    United States
  • Email (Visible)
    marc_zeitlin@alum.mit.edu
  • Phone Number
    978-502-5251
  • Website URL
    http://www.cozybuilders.org/

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  1. This is certainly one place where air might exit (that I forgot to mention), but in my case, I have covers over the main spar openings aft of the seats in the cabin, with only very small openings around some wiring, so while this might be part of where the air is going, it's hard for me to believe that all the air coming in through my vents is going out through a couple of 1/4" annuli around some wiring bundles. If you don't have a cover over the spar, then yes - this could be a major source of exit air.
  2. Nick Ugolini is the only person that claims to have sealed their cabin up so tight that they actually need to provide a dedicated air outlet. Given the leakiness of most of these planes, it's rare that a dedicated outlet would be required. I can tell you that on my plane, I've spend a lot of time sealing my nose gear area, canard perimeter, elevator offsets through the fuselage sides, fuselage top perimeter, and canopy seal. It's pretty tight, with no noticeable air leaks in any of those places. My engine muff heater will keep my feet warm and the cabin at 30F - 40F above ambient. My two large diameter air vents: https://www.aircraftspruce.com/catalog/appages/largealumavblack.php will just about blow me into the back seat when fully open, taking in air from the NACAs on the fuselage sides. But I have no dedicated outlet(s), and I can safely say that I have NFC how the air gets out, but it obviously does. Maybe through the two holes in the top of the landing gear bulkhead area, even though they have loosely fitted covers? Maybe through the electrical conduit channels into the lower cowl? Maybe through the rear curvature of the canopy, above and behind my head, so I wouldn't know if air was flowing in that area? No idea. Almost none of the planes I work on have dedicated outlets, and no-one complains that they can't get air to flow in through their cooling vent. Now, that doesn't mean that you shouldn't install a dedicated vent, and I've seen a few in the turtleback, next to or aft of the passenger's head area. If you have one and don't need it, it doesn't hurt, but if you don't have one and need it (unlikely, but possible) you'll want one. My $0.02.
  3. If you even get that. John McAvoy, after a 3 year retrofit on his Long-EZ, noted that at some altitudes he was getting exactly zip for a speed increase, and at best a 2- 3 kt. increase (IIRC) and still had the loss of fuel capacity. I'm 100% with Kent here - completely against retractable mains on a standard Long-EZ or COZY that cruises in the 160 - 180 KTAS range. Do a good job on your wheel pants, gear leg fairings and intersection fairings and you'll be in about the same place with far less maintenance and cost.
  4. I have a Defiant POH PDF. Email me.
  5. Depends on the type of plane. As Kent indicated, in COZY's and LE's, they generally go on the firewall above the spar. On VE's, that's not available, so they tend to go in the hellhole (which is a nightmare, unless you've got a hellhole access cover underneath the landing gear, and even then... Some VE's have an enlarged hellhole access hole in the rear seat seatback, and mount the box on the back of a cover for the hole, with service loops for the wiring.
  6. So the manual says that if you have ESP turned on, ESP takes effect when the plane is 500 ft. AGL and the A/P is NOT engaged. I don't see anything about being able to disengage it with the CWS or A/P "off" button, since it's on even when the A/P is off. Now, I don't know if you've got a G3X or a G5 - with the G5, low airspeed protection is not available, but with the G3X, it is. While discussing random stuff yesterday with an Air Force F-16/F-35 test pilot friend with whom I work on various projects and also whose COZY MKIV aircraft with a full G3X/GNS750 panel I maintain, he mentioned that he doesn't like the ESP functionality, because it will sometimes do unexpected things. A similar one of which, described below, has happened to him: Imagine that for some reason, your IAS isn't working correctly - blockage in the pitot tube, bugs in the pitot tube, leak in the pitot tube - whatever. It's early in your test flight period, and you don't know the plane well yet. And you've told the system that the minimum airspeed you want to maintain is 75 KIAS. So you take off, but your IAS stays at 43 KIAS, for some reason. You've had enough instruction in a COZY MKIV to realize that you wouldn't be in the air if that's true, and that judging by the attitude of the airplane, you're probably at 80 - 90 KIAS. You get to 500 ft. AGL, the ESP freaks out and bunts the plane over to try to maintain 75 KIAS, but keeps pushing harder because all it sees is 43 KIAS. You're now impersonating Popeye, wrestling with a new plane early in the Phase I period that's trying to dive into the ground, while trying to figure out WTF is going on, and trying to figure out how to get into the correct menu to turn the F-ing ESP system off, if you even figure out that THAT's the problem within the next minute or so. No thanks. No A/P, no retracting landing gear, no ESP, no automation (except data collection), until you've determined manually that the aircraft is working correctly per the plans and POH, and using electronic assistants, as much as I am an advocate for them in a PROVEN aircraft with KNOWN characteristics, is not what I'd recommend.
  7. Phase I activities are done regularly out of KMER - that's where the Valkyrie tests are ongoing (another project with which I had a small bit of review work). No problem testing there, and yes - with the huge runway and flat ground around, it's a good place for testing. Hmmm. Not sure how I feel about that - I'd probably refrain from turning the A/P on until I knew how the plane flew... Given the similarity in wing/canard positioning and fuselage size to the COZY MKIV, I'd normalize the COZY FS's to the SQ's, and use the COZY first flight box as my starting point, near the front. Not the front of the whole envelope. Aileron fences work well on the highly swept VE wings. On Long-EZ / COZY wings (same as SQ) the reports are unclear - some folks say they made a difference in low speed handling - others say there was no difference. I have no data on this one way or the other - I haven't tested them on my plane (probably should, someday - its on the list). Be happy to come up for a visit. Once or twice a year we fly into Gnoss to go sailing with a Long-EZ friend out of Sausalito, where he is a member of a sailing club. My wife loves Sausalito.
  8. To the extent that one can tell from digital pics, Joel's work certainly looks top-notch. Obviously a good thing. I would suggest that you read the accident reports here: http://cozybuilders.org/N2992_Accident_Eval/index.html and here: http://www.kathrynsreport.com/2012/08/1-dead-in-crash-of-single-engine-plane.html and make whatever changes to the aircraft's doors and seats are necessary to increase the safety of the plane. Given it's E-Racer heritage, I'd also recommend (not that I don't recommend this for ALL E-AB aircraft, but especially for kit aircraft that were never fully tested by the MFG's) that you perform an intensely complete exploration of the performance envelope during the Phase I period, both structurally and aerodynamically. When I examined the SQ2K that's for sale in San Diego (and I strongly recommend that no one ever purchase that plane with the intent of flying it, as it should never leave the ground again) I saw many design and fabrication issues that I thought were marginal. I do not know enough about what the kit is or the plans say to determine whether those marginalities were part of the design, in which case modifications may have to be made (rudder pedal attachment to achieve necessary stiffness, Master Cylinder mounting, fuel vents inside the cabin, etc.) or whether they were builder mods, in which case you won't have to deal with those stupidities. I'm also not at all a fan of the glassed in nature of the canard - I think that's a maintenance nightmare in the case of needing to modify or repair anything. But it does look like you got the best of the breed in Joel's project, and I hope that you can get it flying safely and with the testing necessary to prove that it is so.
  9. (1) and (2), yes. Since the longeron incidence angle will be about 1.5 - 2.5 degrees (nose up) in cruise, that puts the thrust line just about level in cruise. (3) is approximately correct, but will depend on what engine you're using and who you bought your engine mount from (or how you fabricated it).
  10. Ummm, I'm pretty sure you were informed that the engine needs a rebuild - that there's substantial corrosion inside, right? There's no way you should fly that engine in it's current condition. And that corrosion was diagnosed a couple of years ago, so it can only have gotten worse (corrosion never fixes itself...).
  11. I went to the Aircraft Spruce website and searched for "flox". This was the first link: https://www.aircraftspruce.com/catalog/cmpages/flockedcotton.php
  12. Joe D. gave you some useful reference points. I'd point you to pages 52 through 61 of the POH, which shows performance for an O-235 LE. That's at an MGW of 1000 - 1400 lb, so at 1500 lb., figure a bit worse than the 1400 lb. curves. CG actually has at least as large an effect on top speed as MGW, so flying at the rearmost CG position (103") will get you the best performance.
  13. The short answer to the title of this thread is "kind of" - a 970 lb. LE with an O-235 that you expect to fly regularly is on the heavy side. The performance will still be better than a C-172, but a plane 50 - 100 lb. lighter would be better. At 970 lb., the implication is that if you ever upgraded to an O-320, you'd be well over 1000 lb. - that's a heavy Long-EZ, even if one sets one's MGW to 1500 - 1680 lb. Competent? Flyable? Safe? Sure. There are many LE's in this weight range. Now, it may not be easy to find a lighter LE - most are a lot heavier than they should have been. And given the relative performance of this plane against spam-cans, it'll still be better (probably substantially so). So I'm not saying don't get it - just make sure you know what you're getting, and for Cthulhu's sake, get a Pre-Buy examination from someone like me or FreeFlight Composites who knows what they're looking at and can advise you clearly of what you're getting into.
  14. I recommended to Izzy that Evan take a look at Tom's plane (N40TD). It is NOT flyable and it needs an engine rebuild (and it wouldn't hurt it to rip out the panel and electrical system), but it looked like a structurally sound plane that could be turned into a nice plane with some elbow grease and TLC.

The Canard Zone

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