Jim Sower

I've been seriously toying with the idea of mounting the canard AND hte wings BOTH with ONE degree POSITIVE incidence. That would result in the fuselage pointing 1 deg lower in all flight conditions and would increase (most noticably on final approach) forward visibility a good bit. Try flying 5-10 kts faster on final and notice what that does to foreard visibility. I might have to adjust the engine mounts to change the thrust line a bit, and perhaps slope the top nose down a little more than I slope the bottom up, but that might look kind of snarky anyway. Just a theory .... Jim S.

Two props for O-235 Long-EZ (or Vari-EZ?). One is a G-A 62x64 with a largish dink that has been refurbished by Clark Lydick at Performance (who approves it as a good long-term spare). The other is a Performance 62x62 also refurbished by Lydick. 6" extension and [vanilla] spinner. Props and extension are SAE-1 (4-3/8"). Main Prop $400, spare $250, extension $200. Catskill, NY

Dale, <... two independant tanks with a mechanical valve. KISS seems to be screaming at me ...Return feeds ... have a mechanical valve...> What screams at me is SIX fuel lines INSIDE the passenger compartment John, The feed-from/return-to-right configuration and the dedicated-strake-to-strake routing is, IMO, toss-up by any standard. I don't mind a sump, but I sort of distrust remote valves. You don't like the sump and distrust my single route to the pumps. It's a judgement call, and I guess it's all been said. Pre positioning blank outlets top and bottom of fuselage structure into strakes is still a champion idea. Gives you all manner of flexibility, maintainability and growth/evolution potential at virtually no cost. How big a footprint will your duplex pump/filter plumbing occupy on the firewall? will they be on the "hot" side or in the hell hole under the gear bow (my choice if there's room). How about isolated, independently fused, dedicated circuits to the pumps/return valve? Photocell low-level detectors in the lines/blisters to warn of an empty tank just before the motor stops? Best, Jim S.

John, You've got me pretty well convinced about the "Single Failure Point" or SFP of my idea. So as long as we're on that subject: 1. What drives your fuel pump? Hellacious switch or relay (SFP)? 2. What drives your return selector - switch or relay (SFP)? 3. I presume that the return selector is a screw driven valve controlled by a DPDT switch and will fail in the position it's in when the lights go out. True? I further presume that the motor/screw turns itself off when it arrives at the selected position (FP?). True? Have any of those "scrwe operated electric valves" ever been known to fail midway? 4. The Cozy design selector, your duplex pump/return system and my draw-from-right system involve roughly equal pilot workload for fuel management, so that issue is sort of a wash. 5. I VERY much like your idea of installing a "blank" 1/4 NPT Al plate at the top and bottom of each tank (along with an 1/8" NPT for the vent:o) as the simplest way to mix and match various design ideas and allow things to evolve with minimal effort. 6. However, EVERY joint and fitting is a FP, even if not a glaring one. 7. I feel that the sump-in-hell-hole gets some unwarranted knee-jerk negative reaction. Would a 3-5 gal sump in the hell hole, perhaps under the gear bow, pose any more danger to anyone than the couple of feet of ribs, floxed blindly to the strake between the cockpit/cabin and the fuel tank that you've ALREADY got? A sump tank in the hell hole (not to be confused with the cabin) should not constitute any more of a danger, IMO, than all the plumbing the design system puts in the cabin area proper. 'Nuff for now .... Jim S.

John, I still think your earlier idea of: "Always draw from tank 'A' and use a Facet pump to even things out" and returning excess fuel from rail to sump is still the best idea. Pros: Simple, inexpensive, minimal plumbing Allows for simple, accurate fuel flow NO plumbing in cabin - and only minimal plumbing in hell hole NO selector valve - remote or otherwise Simple, easy fuel management Best way NOT to avoid running out of fuel in short final Cons: Sump If you are drawing from the Right (easiest to check as Nat suggested)strake into a sump, and from the sump into your fuel pump/filter/etc. system and back to the sump from the rail, you have traded having a sump for three fuel lines in the cabin ~ about even I'd say. Now, "T" in a line from the Left strake to the Right strake line near the tank and put your Facet pump in that line. Then, install your fuel flow transducer between that "T" and the sump. You -could- put in all manner of trick stuff to warn you when the Supply (Right) strake was too high or low, but you'd need that just as badly with the good old "Left-Right-Off" system. But let's just pretend, for the sake of argument, that you are capable of monitoring your fuel, at least in the supply tank, without AI, just like a real grown-up. As a flight progresses, you'll ALWAYS end up transferring ALL of the fuel out of the Left strake into the Right one. Unlike the design "Left-Right-Off" system, which requires you to run one tank "Pump Empty" as the ONLY way to avoid the possibility of running out of fuel with 3-5 gal in the "unselected" tank. This scavenging procedure is dicey on a good day, and absolutely HARROWING in a situation when you really think you'll actually need that last few gallons. I know. I've been there. I don't ever want to be there again. In my view, the compelling reasons for this configuration are that it has the simplest fuel management system, the best way to get accurate fuel flow, and the safest in that it gives you the MOST assurances that late in the flight you'll have ALL the fuel on board in the "selected" tank Just a theory .... Jim S.

I agree that baffling is always required. I further agree that most cooling problems can be traced to poor baffling. I am a case in point. I bought both my airplanes. My EZ had cooling problems caused by baffling that had gaps in it you could throw a cat through. It took me a LONG time to fix that (no plans, just trying to figure out how to fix the design and fabrication problems I found). I did all the sheet metal and silicone over and added glass-RTV head/barrel wraps. When it was all done, I had much better cooling, but still hated the design. Like sealing off the exhaust. Damned if you do (the exhaust now pre- heats the cooling air) and damned if you don't (the cooling air all squirts out around the exhaust pipes). Also, baffling the starter and alternator, and that HUGE area below the cylinders (and putting an oil cooler in the bulkhead formed) all adds up to rendering updraft cooling a lot more trouble than it's worth. Downdraft OTOH starts with the short "fences" around the top of the engine on three sides (that you had on your downdraft system) and add another short fence to the aft face (#1,3 cylinders). You're done. All the lower baffling (most difficult to fabricate, maintain and most apt to leak)is eliminated. Lay up a glass plenum that screws to the "fences". The fences are easier to make since they don't include any silicone seals. Access to everything in the engine compartment is VASTLY improved. Since we're not pre-heating the cooling air going to the cylinders, we need less air ~ smaller inlets ~ lower cooling drag. Downdraft minimizes plenum size, air volume needs, silicone sealing and the structure (weight and complexity) on the engine associated with baffling. It maximizes cooling efficiency, simplicity and ease of construction and maintenance. Looks to me like all plus's and no minus's. The only downside I can see is that downdraft, not having been widely done, requires you to do some development yourself. Even that is minimal since that part of the process has been done enough times to minimize what you have to actually DESIGN yourself. Just a theory .... Jim S.

I am really REALLY interested in downdraft cooling. I have a Long-EZ that is laid up with airframe damage that, when fixed, will be given an O-320 engine that I hope to downdraft. Some of the fast-fliers have done this, and I will generally follow their "proven" methods. My immediate problem is a (flying) Velocity that doesn't cool worth a flip. It has these pisant armpit scoops and updraft cooling. I have sent for the Velocity downdraft templates (which should work just fine on a Cozy). I feel that one LAAAARRGE advantage of downdraft cooling is the reduction in baffling to practically nothing. You build a little fence around the top of the engine and that's it. You make a fiberglass plenum that screws onto the top of the "fence" and connects to the inlet ducting. It seems MUCH simpler to make and offers way better access to the engine than conventional baffling. I'm looking for ideas on the details. It seems that retrofit is a bit tougher than putting it in original, but not much. Jim Sower

<... peddle goes to the floor (have you tried pumping it? which would indicated air in the system, or is the brakes just fading you (due to heating up) when you land....> Both actually. The pedal starts out OK, but as I slow down, it gets lower and fades. Doesn't seem to go all the way to the floor, but close. If it's true that air in caliper will expand when hot and the increased volume will allow more pedal, then that's what's happening. however, that diesn't make much sense, because the air in the caliper is trapped, and to increase volume, it must also *vastly* increase pressure, which would have the *opposite* effect. Just compressing the air in the caliper back to its original volume would require a great deal of pressure. The hotter the air, the more pressure would be required to keep it at it's original volume. But my brake pedal gradually drops toward the floor during rollout. I'm shotgunning it now. I have inverted the calipers and rebuilt the master cylinders so far. I am going to bleed some more and see what happens. If I can find an appropriate fitting, I will stop up the cylinder and see if it holds hard pressure in the master cylinder without leaking. Get's confusing .... Jim S.

<... make sure they're ... right type... K or J... That's what I was wondering. I thought there were more than one type, but I didn't know how many. I guess I'll have to look up the mfgr and find out what type I have. Might as well buy from mfgr if I've done that research with him. Thanks for the heads up ... Jim S.

Hey all, I am suspecting my CHTs are too optimistic since I am using bayonet probes on the lower regions of an updraft engine. Are there off-the-shelf (generic) plug gasket probes that I can replace my bayonet probes with? Or do I have to go to manufacturer? Just wonderin' where to turn .... Jim S.

Hey all, I'm trying to troubleshoot my brakes on my Velocity FG (Clevelands driven by Nissan clutch master cylinders). When I start out, they are pretty good. Not crisp and stiff like I'd prefer, but they stop and steer acceptably. On landing, particularly when I brake hard to make the midfield turnoff, they fade and go almost to the floor. I have pretty marginal steering back to the hangar, but they're back OK the next day (or after a couple of hours rest on turnaround. There's no fluid loss. Just very bad brakes after a hard use that come back to not good, but just as adequate as they ever are. The bleeding nipple is on the top of the caliper so they have to be bled down from the master cylinder, and I know that's bad and I'm going to change it so I can backflush the system and move the bubbles out in the direction they want to go anyway instead of oscillating them up and down in the strut. Anyway, I had a failure last night. After fading on rollout, they steered back on the taxiway but the right side failed utterly in front of the fueling station. I had to shut down to stop at all. It did NOT come back at all after fueling. What I can't figure out is where and how the failure could be happening if there is no loss of fluid. I'm leaning toward the master cylinder since that's the only place I can imagine at all that could switch back and forth between adequate and bad with no fluid loss. Everything together seems to contradict Mr Newton. Why does this crap always happen to me?? Jim S.