Jump to content

David Staten

  • Content Count

  • Joined

  • Last visited

Community Reputation

10 Good

About David Staten

  • Rank

Personal Information

  • Location (Public)
    Houston, TX

Project/Build Information

  • Plane
    Velocity (173/SE/XL/SUV/Twin)
  • Plane (Other/Details)
    Velocity SUV Mazda 13B Rotary
  1. Use a magnetic coupling. Magnet is outside the fluid path and is motor driven. Pump impeller is ferrous core, and is inside the fluid path and not directly mechanically linked to the pump drive/magnet.
  2. I would use the manufacturer's recommendation and install it inside the cabin. In a crash, planes tumble.. cartwheel... bulkheads crack. Wings shear, floors buckle. I would rather not add having to worry if the copper tape antenna survived on whatever surface it was bonded to. If you had to roll your own, I'd make a metal whip, 1/2 wave or full wave... Something that doesn't require a ground plane, and have the whip inside the cabin somewhere.. behind the seats.. something.
  3. Everyone has an opinion on this matter.. and mine is.. that in over 50 hours of flying Grumman Tigers and Cheetahs, after my initial checkout I didn't loose any takeoff performance for this reason (differential braking for steering). I lined up facing a few degrees right of center.. and the initial left turning tendency would center the plane up (on initial acceleration right) about the time the rudder became effective from the slipstream. And with the exception of an RV type, I have to admit that the Grumman also had great short field takeoff performance.. part flaps and climb out right at VX (stall horn blares, but the plane levitates....) Nosewheel steering is a nonissue, when proper training and experience is provided. Its cheaper, less complex, and permits more nimble movement on the ramp. We now return you to your normally scheduled canard issues
  4. Not a dumb question at all.. we've got the glide slope antennae on the floor of the velocity.. one nav antenna in the wing.. the other on the back of the floor of the fuse... all foil. no diplexer needed. no splitting of signal and signal loss.. Just foil.. glass, toroids, coax and tape. And this is on a dual ILS setup (and marker beacon antenna on the keel too, just for grins)
  5. I guess if you REALLY know what you REALLY want, I'm sure there's a way to do this. BUT.. you can turn MUCH tighter with a pivoting nosewheel as opposed to a steerable kind. This comes in handy in a crowded group hangar or crowded ramp. Differential braking is the way to go. You dont have to ride the brakes.. Quick jabs to start and stop turns work just fine. Landing with the nose gear up is not a life altering experience. A little fiberglass work and you are back in business, and if you have a TRUE emergency where you need to stop on the ground QUICK, sucking up the nose gear is one way to do it. What bothers you the most? A retracting nose gear or a pivoting nosewheel? Do you feel its unsafe? or you have no experience with this arrangement? Go fly a grumman cheetah or tiger if one is nearby you. Same arrangement (pivoting nosegear) but on fixed gear.
  6. reposted hot off the presses from the Canard Aviator's yahoo group.. from Mr Strong himself..
  7. Excellent choice... Sorry I am late replying to this thread As someone else mentioned, even though this engine makes only 135 hp (on the dynomometer, I presume), you need to understand that this powerplant is being used to replace gasoline powerplants that make over 200 hp. The key is Torque from the Diesels being able to generate equivalent THRUST despite lower HP. What this means: One engine should suffice. Diesel reliability being what it is.. should provide adequate reliability. As others have said, Velocity is a kit-built plane. In short, NO. The factory manufactures certain parts - fuselage shell, spar's, strakes, doors. If cost is such an overwhelming factor that you cannot afford to buy the kit, then how do you propose to buy ONE Aero-Diesel engine, let alone two? Have you actually checked the prices on them? If you must have a plans built, then I would say go with a Cozy, and if you must, scale it up a few points. The Velocity XL was made to handle the larger engines that people wanted to keep putting on the Standard versions.. its not all that much bigger.. and all that extra HP does is burn more fuel. If you dont want to spend 10 years on it, then don't deviate from plans doing all sorts of fancy customization ESPECIALLY without a solid background in aircraft design/engineering. I'm not saying DONT do it.. but if you do, prepare to be challenged, and prepare to fix ONE problem and have two or three others pop up as a result of that fix. Deviations from other peoples proven design add time and problems. Flying multi-engine aircraft adds a level of complexity above that of single engine aircraft, ESPECIALLY in emergency procedures (such as one engine out). This complexity demands proficiency, or it will come back to bite you in the worst way. Twin engine aircraft have greater fuel costs and maintenance costs as compared to single engine aircraft. Some people have characterized the cost as THREE times the cost of a single engine aircraft with equivalent seats, due to maintenance and systems complexity. That may not translate as well to homebuilts, but its a good data point to consider. If you have a reliable enough powerplant, what is it about your mission that dictates the need for a twin engine aircraft?
  8. You can do transatlantic flight with the longest overwater leg only being 4-500 miles max. I cant for the life of me envision wanting to be in a small plane cockpit for 12-15 hours... but what you describe is do-able. Talk to your doctor about DVT prophylaxis before taking any super long trips like that. Dave
  9. Im all for informed discussion and informed decisionmaking, and while I've come across some very informative persons with regards to the rotary, I also seen more than a few who seize on the notion that 3 moving parts AUTOMATICALLY confers improved reliability and efficiency. I'm not accusing you of this directly, and I'm in no position to seek an apology from anyone. This is more of an open issue. Right now, the jury is out on the reliability aspect, and much of that is the result of the peripherals added, not the core engine itself, but an engine failure and power loss leading to an off field landing or WORSE is a bad event, regardless of wether the core engine or an accessory was at fault. I am speculating that Chris and I will have our rotary fired up and ready for taxi testing within the next 60 days. We are doing a few unique things, on a block that we rebuilt and modified ourselves. I will not kid you that money was a BIG motivator on our powerplant choice and we did our homework. I have read every scrap I can about the rotary, others installs, others experiences good AND bad, and about auto conversions in general. In this vein, I consider myself an advocate for rotary power, but I am cautiously optimistic about how well it will work. I called BS on the notion that a torque wrench and a $15 set of sockets is all you needed for a rebuild. Thats not semantics. Thats potentially misleading. My OPINION is simply that while advocating in favor of the rotary, you were a little enthusiastic and stretched it a bit. I don't think you intended to lie or intentionally mislead anyone. The same sort of embellishment is happening with fuel burns, power generated, installed weight and so forth in other settings. There's really not that much DATA out there in an aviation setting, so what little bits we have are precious. If someone who doesn't KNOW any better starts basing decisions on little embellished snippets such as these and doesn't get the straight scoop, they are going to feel lied to regarding the rotary... hardly something that will increase our ranks. Its about knowing the risks and weak points and working with them, not putting your head in the sand. Mark isn't a rotary basher either. He's simply a cautious engineering type. I dont always agree with him, and some folks have trouble with the way he says things, but I must admit I find his postings to be rational, accurate when dealing with facts, and defensible when dealing with opinions. I apologize if this has turned into something personal.. that was not my intent. My intent was to set the record straight, firmly, regarding what I felt was misleading information. Dave
  10. I'm sorry... I like the rotary.. I rebuilt one, have a second one for a spare, and have torn a total of 4 apart, and I can assure you the above statement is pure BS. The big 2 1/4 inch nut on the back ALONE requires 300 foot pounds of torque. The wrench that can do that is a THOUSAND dollars unless you can borrow one as I did. The NUT requires a socket that cost me $50 bucks new and wasnt available for much cheaper used. Torque multipliers that allow ordinary torque wrenches to reach that torque range rarely sell for under $100 on ebay and cost many times that value new. I needed a heavy duty impact wrench to get that big nut off in the first place, not my ordinary cheap harbor frieght one. That big wrench cost nearly $70 at a pawn shop. I tried a big LONG cheater pipe.. all I did was move the engine around.. the bolt held. I have a full set of metric impact sockets. I have a set of micrometers for measuring wear. I have gap gauges, thread gauges, feelers, a dial indicator.. and I had NONE of this when I started this project. I can assure you it costs a HELL of a lot more than a cheap $15 metric socket set from harbor freight if you want to do the job right and without breaking tools or yourself. I'm very pro-rotary. Im installing one. But I am just as annoyed as Mark when folks "wave their hands and proclaim to the masses 'three moving parts'" That is a gross oversimplification and naive. It does the rotary community a disservice when that gets emphasized above all else. Dave
  11. Value is in the eyes of the beholder. Nat is right.. and wrong too. Resale value is practically meaningless if you never plan to sell the plane. The word on the street is that auto-conversions of any flavor tend to have less resale value than certified engines because of the "unknown" factor. This "unknown" factor is a bigger player in true custom engine installs (such as the rotary, since there are few firewall forward options out there, if any, anymore) as compared to packaged auto conversions. To me, if it works as it should, the rotary will perform just as well or BETTER than the certified engine it replaces, for much less initial and continuing maintenance cost. Considering a new engine IO-360 with composite adjustable prop would run over $30,000 new, and I am able to get same if not better performance with less than $7,000 outlay, I wouldnt be offended if the resale value was $15-20,000 less than someone who had an identical plane with a certified package. Im sure if someone had a factory Mistral package installed at its $30,000 outlay it would likely keep its value in a resale scenario. But.. again..those of us building our own dont plan on parting with it anytime soon, and those who have, I have noticed, sometimes offer the airframe for sale separate from the rotary engine, selling the airframe to whomever wants it, and the rotary to others in the rotary community. Best of both worlds. Dave
  12. You need to make an effort to get to the Mid-Winter Rotary fest being hosted by Bill Eslick in GRANBURY TEXAS, right down the road from you. Feb 10-12. http://www.weslick.com/rotorfest.htm You will get to see many many rotaries in person, up close, and talk with the builders. Dave Houston
  13. Just how high are you wanting to take your unpressurized, piston powered aircraft? You can wear a mask with high concentration oxygen "comfortably" into the lower flight levels and be able to breathe normally. If you are observant you can even get an MBU regulator, mask and blinker off ebay or from a surplus store. Dave
  14. Since you guys have addressed the physics and pathophysiology of this pretty well, I am not going to waste bandwidth restating what has been explained at least twice. My contribution will be to clarify the magnitudes (or lack of) involved in the lungs when they breath. Sea Level atmospheric pressure is 14.7 PSI/760 torrs/29.92 inches of mercury. If you were to take a glass column of mercury and hold it such that an open end of the column were in a bowl of mercury, and the sealed end was at the vertical end, the atmospheric pressure would push the mercury in the column to a height of nearly 30 inches. Now.. Imagine we are using water.. the column of water would be 33.9 FEET of water.. 14.7 psi of sea level standard day air pressure would be THAT tall... even at say.. 10,000 feet, where you have 1/3'rd less atmospheric pressure, that column of water is 22 feet. Now.. translate this to the ventilator patients I deal with on a daily basis in the intensive care unit. We measure airway pressures in CENTIMETERS of water. The "otherwise healthy" average patient's inhalation pressure and exhalation pressure, UNASSISTED (there are vent modes that do this) are on the order of 20-30 CENTIMETERS of water.. When they have severe disease, it may take pressures of 60 or more CENTIMETERS of water to force air in... when they cough it may reach 100 CENTIMETERS of water pressure. This translates to less than 3.5 feet on a water manometer in a worst case scenario and is less than 1 foot in normal breathing. This translates to 0.44 psi at sea level. The body deals poorly with large differentials in actual pressure. More than about 1 psi and you cant hold your breath against the air trying to leave your body. To address the original poster, you cant simply pressurize the mask to successfully breathe AIR at high altitudes.. and in the case of VERY high altitudes, you cant use pure ox in a pressurized mask. You have to pressurize the entire pilot - either a suit.. or a cabin. As Marc and Waiter have already addressed, its all about the pressure imposed by the oxygen content in the inspired air. Dave
  15. You can, but from what I've been told it wont work as well. What you are describing is having the rads in series. You will get less heat out of the system (from what I have had described to me) doing this, as compared to having both in parralel with each other, both ducted to have airflow going over them. You can put the fan somewhere ELSE with a very weak spring and hinge on a large flapper. Turn the fan on when on the ground or at low forward speed, and if the ram air isnt strong enough to blow the flapper down, the fan will force air over the rads. I am using two Goldwing M/C rads. Each was designed for a 1100 cc M/C engine. Each comes with a 12v fan, and I will likely find a way to use them. I plan to mount them in parralel. This splits the water flow between the two rads, slowing it down, allowing it more time to transfer heat to the air. Each rad will also have the hottest possible water going into it, so that you can therefore transfer the greatest amount of heat. I hope you meant that every PSI INCREASES the BP of water by 10 degrees. Sounds nifty but keep in mind that Rotaries dont tolerate overheating well, and lose power/compression when this occurs. Granted, more cooling occurs through the OIL (up to 30% of it) as compared to water, but making the cooling system capable of handling more heat in this manner may backfire. Maybe it will work for you. Again, there are ways to mount rads in the airflow without putting the fan in the way, yet still being able to use the fan. The big scoop on the bottom of the LEZ lends itself to having a large enough area for this. The LEZ's with the top cowl mounted scoops may be even better for this, as you can put EACH in the airflow. If you are building from new, you may even put an oil cooler in the nose, velocity style, to permit cabin heat from waste heat from the oil. You have lots of options at your disposal. Truth is, you will have to find what works best for you, and like some of the military folks around here can vouch for, no plan survives first contact with the "enemy". Recommended TBO hasnt been established, per se. Highest time that I am aware of is about 1400 hours, and that is Tracy Crook's. He is flying a Renesis now, so the old engine was REPLACED but not because it NEEDED to be. I did some math a ways back, and 2000 hrs engine time would have been 110,000 miles at highway speeds in a car (but not at the same RPMS, etc). I can appreciate the hesitation regarding your own overhaul, and if you choose to let Bruce do it, thats fine. He will do it RIGHT. A local "expert" may not, as John Slade can attest to (he frequents elsewhere, but his website is www.canardaviation.com). But, if you arent going to port the engine, know how to follow instructions to the T, and how to read a micrometer, and how to use simple tools, you should be able to do a rotary overhaul yourself. It will be a big confidence booster and also will validate the skills to do your own repairs in the future if needed. Nothing like knowing it was done right cause you did it yourself. Bruce sells a tape that breaks it down. The main "aviaton mod" doesnt involve overhaul, and involves replacing a thermal pellet valve in the hollow e-shaft with a slug. Good luck, Dave
  • Create New...

Important Information