Jump to content

Marc Zeitlin

Verified Members
  • Content Count

  • Joined

  • Last visited

  • Days Won


Everything posted by Marc Zeitlin

  1. Marc Zeitlin

    Sales I've seen

    There are only two reasons that anyone lists aircraft that are worth $35K - $50K for $75K or $117K. And those are that they're hallucinating, or that they've told their spouse that they're going to sell the plane but don't really want to. Because there is zero chance that either one of those planes (or a few of the COZY's that are for sale) will sell for anywhere near their asking price. This MIGHT be a $45K plane, but I'd have to see it to know.
  2. Marc Zeitlin

    hangar electricity and other rants

    I'm not a lawyer, nor do I play one on TV, but the policy you point to above specifically say, in Section II(d): "While sponsors may adopt more restrictive rules for use of hangars, the FAA will generally not consider items to interfere with the aeronautical use of the hangar unless the items:" blah, blah, blah. So the FAA allows sponsors to be MORE restrictive, as long as you're not interfering with aeronautical use, with 5 "unless the items" definitions of interfering, none of which mention maintenance. I'm not arguing that they're not being assholes by prohibiting maintenance - I certainly believe they are - but it's not a slam dunk that you'd win any argument in court, given the statement that the sponsor can adopt MORE restrictive rules. I think an argument can be made that you're interfering with aeronautical use by prohibiting maintenance, but I also believe that an argument can be made that you're allowed to prohibit it. Don't know who wins that argument. Now, section 22 of the sponsor assurances document is stronger - paragraph (f) says: "It will not exercise or grant any right or privilege which operates to prevent any person, firm, or corporation operating aircraft on the airport from performing any services on its own aircraft with its own employees [including, but not limited to maintenance, repair, and fueling] that it may choose to perform." Which seems pretty clear, BUT, paragraph (i) gives them an out, by saying: "The sponsor may prohibit or limit any given type, kind or class of aeronautical use of the airport if such action is necessary for the safe operation of the airport or necessary to serve the civil aviation needs of the public." So all the sponsor has to do is claim (wrongfully, but they can claim it) that the activity will prevent the airport from being safe. Uggghhh.
  3. Marc Zeitlin

    Kent's Long-EZ project

    A few references: https://www.aopa.org/news-and-media/all-news/2011/may/19/impossible-turn-practice-makes-possible indicates (without any supporting evidence) BG speed and a 45 degree bank. They don't say whether that's BG in a turn or S&L, but since 1G BG is all anyone ever reports, that's what I'll assume they mean. In my plane at the GW's I was at, BG is somewhere in the 80 - 85 KIAS region. This: http://pilatusowners.org/wp-content/uploads/2014/01/US-Navy-turnback-study-1982.pdf is an empirical study that tested success with your parameters - just above stall speed, with different bank angles - 30 degrees and 45 degrees seemed to work the best in these test cases. This: http://peter-ftp.co.uk/aviation/misc-euroga/2013-turnback.pdf is a theoretical analysis, but is backed up with empirical results from testing, and recommends a speed of 5% above the stall speed IN THE TURN. So we may be saying similar things here, due to the differences between stall speeds in the 45 degree bank turns and at 1G (a factor of about 1.2). My airplane stalls, in the configurations I was testing, at about 62 KIAS. So with a 45 degree bank, the stall speed would be 74.5 KIAS. Now add on the 5% margin recommended in the last reference, and we're at 78 KIAS - almost exactly the 80 KIAS I noted was the best case for us. There's no way MY plane could do a 65 KIAS indicated turn at 45 degrees of bank - I'd be below my indicated stall speed and there's obviously be no margin on top of the stall speed. If we assume that (as is always the case) between min sink speed and stall, the descent rate increases, then it's better to be somewhat above stall, which the 80 KIAS gives me, per the last reference's recommendations. I think that the canard capability to get right up to stall speed makes this maneuver a lot safer than in a conventional plane, where a 45 degree bank at 5% over stall speed is pretty much begging for a stall/spin accident.
  4. Marc Zeitlin

    Kent's Long-EZ project

    I've practiced this in my plane as well. We did a Vx climbout until at 100 ft., then Vy climbout. At 400 ft. AGL, we chopped the throttle, and then waited 4 seconds (to simulate the "WTF JUST HAPPENED" reaction time of the average human being before the training kicks in). At that point, I started a turnback, set the airspeed to BEST GLIDE (NOT just above stall - BG is about 80 KIAS, with a 62 KIAS stall speed), and as Kent says, about a 45 degree bank (which IS optimal). It's certainly exciting - making 45 degree turns when 200 ft. AGL and offset a few hundred feet from the runway is not usual, to say the least. But in a COZY MKIV, it works. I think Kent could do it at 300 ft AGL because he didn't wait 4 seconds - if you do wait, I don't think you're making it back. I would tend to agree that 500 ft. AGL might be the lowest I'd try it in a real surprise situation, but it would also depend on what's around, CG, GW, etc. I was very surprised, the first time I tried this, at how close to not making it we weren't - it really wasn't a squeaker - we probably touched down a few hundred ft. from the threshold. We tried a few different bank angles and a few different speeds. The best performance was always at best glide (L/D) speed, and with about a 45 degree bank.
  5. Marc Zeitlin

    Sales I've seen

    OT here, but why do you think that installing HC pistons is a major change? I wouldn't consider them that, as an A&P. Per 21.93, the only part of the definition that this MIGHT apply to is the "operational characteristics", but I'd argue that "OC's" mean the operating envelope of the aircraft, and installing HC pistons does not change the stall speed or Vne, or the max. G load, or..... and so wouldn't be a major change. Now, it might be a good idea to get new OL's, just so that major changes can be made (many VE's have OL's that prohibit major changes without a new AC, so eventually, you might have to do this), but I wouldn't argue that more HP from the same engine is a major change. Obviously, YMMV.
  6. You have apparently cornered the world market on Speed Canards - you must love the strange beasts ­čśÇ. I assume the question of "why are there none flying" is in regard to the SQ2K. There are one or two flying in the US, but a substantial number of the ones that ever flew have crashed, at least two of them fatally. The rest have been deregistered. Most of the few that were started were never finished. There's one at Chino that may fly soon, but it has many issues that need to be addressed first due to, well, let's just say builder deviations in structure. The main problem with the SQ2K is that it's a lousy excuse for an aircraft, IMO. Between the Lancair IV-P and the SQ2K, I have to say that you've chosen a couple of planes with fatal accident records that are far worse than the EAB population as a whole, and even further worse than the GA population as a whole. At least the IV-P gives you something in return for the risk you take... I'm not sure what your definition of a "normal" aircraft is, but while Velocity seems to have achieved adequate cooling with downdraft systems on their aircraft, most LE's, VE's, COZY's, etc. use updraft cooling, as getting sufficient air to enter the engine compartment from on top of the strakes takes a fair bit of engineering, testing and tweaking. Depending upon who you copy, you may get a successful downdraft system, but updraft is far easier to get to be successful. My $0.02.
  7. Marc Zeitlin

    Nose tire

    Nose Tire: Nose Tube:
  8. Marc Zeitlin

    Re-do... part 2

    That's not a vortilon, it's a drooped leading edge. It was an early standard modification to the plane to help with the aerodynamics that was later replaced by the standard three vortilons on each wing that you see on the LE of most VE's and Long-EZ's. It worked, but the vortilons were a lot easier to fabricate and install. I'd suggest reading the plans completely and then reading through all the CP's completely at least three times, then reading all the CSA newsletters, too. That' way, you'll know what you're looking at...
  9. Marc Zeitlin

    Re-do... part 2

    I disagree. It looks to me as though there are multiple spots on the left gear leg that are crushed, down near the axle and up about 2/3 way. Hard to tell from a pic, at least with regard to the top (without closeups), but the bottom - that looks like substantial damage. Also, it looks like something is going on on the bottom of the strut near the TE, but from this pic, it's impossible to tell what. And if the gear leg is damaged from a hard landing, the chances are good that the fuselage attach points are also compromised - you'll need to jack the plane up and push/pull fore/aft on the wheels to check for relative motion at the attach points. Any motion more than 1/16" - 1/8" fore/aft at the axle means some damage at the attach points. Anything more than 1/8" and I begin to recommend repairs.
  10. Marc Zeitlin

    Sales I've seen

    With any pusher aircraft that has a CAP (Complete Aircraft Parachute), that concern exists. But many pushers (particularly light aircraft) have CAP's, and have been tested. BRS designs their lanyards to be able to withstand getting caught in the prop, but the recommendation is to shut off the engine prior to pulling the chute. What would actually happen in any particular incident? No one has a clue. This customer (and the Berkut customer for whom I also worked with FFC to install a BRS) did a lot of night flight over rough terrain, as well as IFR and night IFR over rough terrain. They felt that in those cases, coming straight down slowly would be safer than any type of flight into terrain, even if the plane was completely under control.
  11. Marc Zeitlin

    Sales I've seen

    The top of the turtleback was thinned so that the rocket could blast a hole - BRS gives recommendations for what it can get through. The red tube is the attach point for the forward lanyards, and the rear lanyards attach to the top interior engine mounts. Let's hope we never have to find out if it would work, because we obviously never tested it. There was substantial modification to the fuselage sides to take the deceleration loads, which BRS states can get to 9G's.
  12. Marc Zeitlin

    Sales I've seen

    I did the engineering for that chute install, and Burrall did the install. Interesting that it's for sale just a few years later.
  13. Marc Zeitlin

    Open-Ez wing spar-cap thickness (thicker than a Long?)

    Your point 1) above is exactly incorrect. It's MOST important to cut the cap troughs to the right dimensions and then fill them to the top with fiberglass, however many plies it takes. Since the tape thickness has varied substantially over the years, the overall thickness of the cap is what matters, not how many plies one put down to get there. The ONLY thing that matters is correct trough depth. Point 2) is correct, but apparently Cameron believes that they are not identical. I don't have either OE or LE "M" drawings/templates, so I can't settle this debate.
  14. Marc Zeitlin

    Engine out landings

    So I generally chop the power about midfield downwind, so all of my landings are "engine out", with idle thrust only. About 90% of the time I don't have to add power. My MO is to always be high and have a lot of excess energy - it's easy to get rid of with LB, rudders and slips. The accident you reference was a COZY MKIV (N795DB), not a Velocity, and the judgement errors there were many. Poor fuel management, WAY too wide on downwind, and trying to stretch the glide when a perfectly good field was right there - I think that it was way more than "possibly". Along with engineless landings, folks need to practice engine loss on takeoff - that's an eye opener, as was discussed on the mailing list 8 - 9 months ago.
  15. Marc Zeitlin

    Kent's Long-EZ project

    And I clearly understood it as such :-). While I'm happy to get a "happy customer report", it wasn't necessary to defend me. I particularly liked the paraffin soaked wick - reminded me of the old Lucas electrical system in English sports cars - an elaborate system of tallow candles, was how they were described.
  16. Marc Zeitlin

    Kent's Long-EZ project

    I'm sorry - what? I missed that - too busy here eating caviar and grapes that the servants have peeled for me. We roast the servants after they've outlived their usefulness using benjamins as the fuel for the BBQ fire. The riches I've obtained from this business fund all the Boeing Business Jets that Burnside Aerospace leases. Back to playing in my pile of jewels...
  17. Marc Zeitlin

    Kent's Long-EZ project

    With fuel injection and balanced EGT's, the CHT stay relatively even at a much wider range of power settings.
  18. Marc Zeitlin

    Kent's Long-EZ project

    The dams are per COZY MKIV plans.
  19. Marc Zeitlin

    Cutting 7075-T6 Aluminum

    Try a tighter radius. You're bending it at a radius of 3 - 5 times the thickness - go to 1 - 2 t and it'll start to crack.
  20. Marc Zeitlin

    Sales I've seen

    You had a good Pre-Buy examination from a canard knowledgeable expert, of course, yes? And read up on all the wing attach fitting corrosion issues associated with multiple Varieze aircraft, and the implications thereof? And understand that VE's are (per RAF) limited to 2.5G positive and 1.5G negative loading? And have sat in and flown VE's to make sure that you fit and like them?
  21. Marc Zeitlin

    New Winglets and Rudders

    OK, so new the forum software doesn't easily allow for reasonable in-line reply formatting. Or if it does, it's not clear how to do it. Great. Onward. First, why do you think you have to build a whole new winglet? From the single pic from a weird angle that you posted, it looks like the damage is concentrated only at the tip. If this is correct, then this is a few hours of non-structural repair work, and some cosmetics. Second, my cousin's step-sister told me something once, but I didn't believe it. What makes someone think that the winglets are causing "too much" drag, and what does someone think would be better, and what would the ramifications of any proposed change be? Aerodynamically, and structurally? If you're not a structural or aerodynamic engineer, it's probably a bad idea to be changing aerodynamics or structures. There are many drag reduction modifications for VE's, LE's, COZY's and the like, and none of them involve changing the winglets. Blending, maybe. But not changing... Third, what makes you think that the winglet needs to be stiffer? What problem are you trying to solve? What failures have occurred due to lack of stiffness?
  22. Marc Zeitlin

    Kent's Long-EZ project

    quarts per hour? In which case you're WAY over the Lycoming specification of 2 quarts/hour that no one in their right mind would fly with if their engine was using that much oil, or hours per quart, in which case you're certainly on the high side of usage but not crazy high. Units matter... With an Ellison, you will be lucky if you can get all four cylinders to lean out the same amount before the engine gets rough - I never could, with mine, no matter what I tried. Hence the move to FI, and now all four cylinders lean very nicely - always white inside all four pipes, and I can get from 2750 RPM to 2400 RPM at altitude merely by pulling back the mixture. Anything in between is doable, and anything less than about 2650 RPM is LOP.
  23. Marc Zeitlin

    New Facebook Group for Cozy Mk IV Pilots & Builders

    Because two mailing lists, two web fora, and multiple generic facebook pages (which are horrible places to attempt to actually collect information) aren't enough?
  24. Marc Zeitlin

    Kent's Long-EZ project

    First, I am always impressed by Kent's willingness and ability to make stuff that most folks just purchase. Second, you might think that a CHT probe should last forever, but I've had two or three die on my over the course of 15 years. I have (for the past 10 years, anyway) used Dynon probes with my Dynon EMS. So for CHT probes, I HIGHLY recommend using bayonet mount probes (which the $38 Dynon probes are), since you can install and remove them with a quarter turn, and it's easy to adjust the compression of the spring to achieve good contact. Having worked on many engines that have the probes screwed into the head, it's a total PITA to install/remove them, whereas installing the bayonet mounts themselves only requires a long, large slotted screwdriver - the probes themselves install with fingers into the adapters. My $0.02.