A few more Documented Facts, Features and Answers to a few Common Questions concerning our Oleo Strut Main Retracts for Canards in random order (see other tabs for further details) :
1) DEMONSTRATED 12+% ( 19 to 23+ MPH for a stock Long-EZ (LE) with a 118 HP 0-235 Lycoming /// 25+ MPH for LE/Cozy III with a 160 HP 0-320 Lycoming ) faster cruise TAS speed. Even Burt Rutan guesstimated a LE would cruise 12 to 14 knots / 13.8 to 16.1 mph faster with the main gear retracted. Therefore, better economy / MPG — Saving you MONEY $$$ — adding our Main Retracts pays for itself in a short time ! A Long-EZ, or any other 2, 3 or 4 place Long-EZ derivative Canard aircraft, with a 200 HP engine should cruise 220+ MPH, depending on how well you did building your scratch built Sport Aircraft, and the prop used ;
2) If you don’t think retracting the main gear gains any, or very little, speed, watch this short video on Fluid Dynamics of Drag ;
3) Yes, the main retracts can operate off FAA Approved grass and non-paved runways ;
4) The Half Fork is designed for the the 5.00 x 5 Matco wheels, brakes, & axles . Other wheels & axles are ~1.25+” wider than Matcos, therefore the tire center-line is not down the center-line of the strut; and, other brakes do not have enough Brake Kinetic Energy Requirements per FAR Part 23.735 ( i.e. — NOT enough Stopping Force / Ability for any high performance, complex canard aircraft ) ;
5) Faster take-off acceleration, therefore shorter take-off distance, and rotates sooner. Aircraft climb and roll rate increased, too ;
6) No more down pitching moment from the fixed main gear ( and drag ) during cruise requiring nose UP trim to compensate ( which is more drag ) ;
7) Drop Tested per FAR’s for a 2200 lb. gross aircraft on 2 different aircraft with the owners help on their own planes ( 1 aircraft was even tested with the tanks full of water, which is 36 lbs. more weight in the fuel tanks than before! ), and Taxi and Flight tested per FAA by the owners in their own planes ( see DVD ). Approved by US, Canadian, French and Brazilian FAA’s ;
8) Strakes asymmetrically load tested to a sustained 6 g’s for over 10+ minutes with the tanks full of water ( see DVD ) ;
9) Demonstrated — strakes and center section spar are stronger. SAFER ( see info pack ) ;
10) With Infinity 1 Main Retracts on your LE Pride and Joy, your Turn-Over Angle (TOA) is 48.4º, which is less than the 50º TOA ( or less ) rough terrain recommendation. Therefore, ground handling is greatly improved, better braking and no more brake problems. Also, a much wider track ( 9.1+ ft. for the Long-EZ & Cosy // 11.1+ ft. for the Cozy MK-IV & AeroCanard ) means no more Foreign Object Damage ( FOD ) thrown from the main gear tires into the prop. Look at General Aviation ( GA ) aircraft which typically have a TOA of 55º, or less. This is considered to be Maximum Safe. ” NOTE ( from any landing gear design books ): Under no circumstance should TOA ever exceed 60º ” ! Fixed gear tandem canard aircraft TOA is 64.2º !! Retract attempts on other tandem canard aircraft main mount axle points are 4″ narrower per side and 4.5″+ aft of the standard fixed gear axle FS location, meaning a longer take-off roll, lower / very low crosswind capabilities and poor aerodynamic braking capabilities on landing, among other limitations. Their TOA is 67 to 70+º, too !!! ( see info pack & DVD ) ;
11) The main retract gear is triple redundant in extension — it is virtually impossible not to get the gear Down. The side brace is mechanically locked down by an internally mechanically locking actuator. Once the gear is locked Down, it cannot come UP, or ever fold, without first applying hydraulic pressure to unlock the internal actuator mechanical Down lock — another Safety Feature ;
12) Totally flush strake bottom and top — no unsightly gear door bumps or blisters. Also, unlike other attempts at Main Gear Retracts for canards, our Main Gear Doors totally covers the wheel wells ( see DVD ) ;
13) Yes, the aircraft still sits level like with the fixed main gear, so take-off rotation is not affected. Total Main Retract Strut stroke is about 7.0″ with Weight-Off-Wheels. Nominally, 4.2″ of the oleo strut remains visible with Weight-On-Wheels at GW ;
14) If you could bottom out the strut ( which is only 4.2″ nominal height at GW, and ~7″ stroke W-of-W ) — we couldn’t do it in a per FAR 2200 lb. worst case, 16+ units high angle-of-attack ( which tests forward motion simultaneously ) Drop Test scenario, you will not/cannot hit the prop. If you drop it in that hard with either a fiberglass fixed or retract main gear, you WILL hit the prop ;
15) Both retraction and extension time takes approximately 12 seconds ;
16) Each complete Retractable Oleo Strut Main Gear Assembly weighs only 32 lbs., and comes ready to install. Long-EZ’s and Cozy III’s add ~17 lbs. of ballast in the nose, Cozy MK-IV’s and AeroCanard’s add 30 to 60 lbs. in the nose. The pump only weighs 10 lbs., replacing most/much of the dead weight ballast needed in the nose. Retrofits to a flying stock Long-EZ or Cosy III only adds about 40 lbs., but you gain 875 lbs. of main landing gear carrying capability, from 1325 lbs. to 2200 lbs., by changing to the Infinity 1 Main Retract System — a really nice trade. Cozy MK-IV’s and AeroCanard’s add no weight ;
17) Total fuel loss is only about 8+ gallons for retrofits to stock Long-EZ’s and Cozy III’s with already completed strakes — none for original construction ( see info pack ) ;
18) Lost 8 lbs. of flying weight on a stock flying Long-EZ, compared to his LE fixed fiberglass main gear, by installing the I-1 Main Gear Oleo Strut Retract System — range remained the same, MPG increased, and he gets there faster ( see info pack ) ;
19) The axle Fuselage Station (FS) is at the SAME FS as the fixed main gear. Therefore, take-off rotation is NOT affected. Aircraft now easily rolls at idle power, too, and “turns on a dime” — all other canards can NOT do this. No more tire toe-in or cant ( tilt ) — tires face straight ahead. So, tires and brakes last much longer, saving you $$$’s ( see DVD ) ;
20) Empty weight CG moved forward 0.68″ for a Long-EZ 🙂 . All canard empty weight CG’s would move forward about the same — this main retract installation does not move the empty weight CG aft ( which wouldn’t hurt anything if it actually did ), which has a tolerance of +/- 2″ ;
21) No need to lift the wing up so the main gear will spring back so it doesn’t take-a-set from sitting in the sun every time you move &/or fly your aircraft with either fiberglass fixed or fiberglass retract main gear ;
22) Professionally designed, engineered, and drawn in Solid Works. All the main gear parts are CNC machined. MIL SPEC ‘O-rings’ and fasteners used throughout ;
23) The wings have been load tested to 50.03% more torque on the center section spar than our Retractable Oleo Main Landing Gear would ever impose — meaning a 149.97% Safety Margin. And oh, this is all done at 2200 lbs. with fuel tanks full of water ! The LE fixed main gear and nose strut is only designed for a landing GW of 1325 lbs. ( see info pack for torque analysis and DVD for Drop Test results ) ;
24) If you land short of the runway and tear out our mains ( which is repairable ), they do not tear out the fuel tanks, which can happen with production aircraft, or with other Sport Aircraft with fixed or retract main gear, since the fuel is forward and inboard of our main gear mounting points. If you tear out either of the fiberglass fixed or fiberglass retract main gear protruding out of the fuselage bottom under the passengers back, your passenger(s) will come out of the bottom of the aircraft ( which has happened ! ) ;
25) The installation time is no longer nor harder to do than installing the plans fixed fiberglass main gear — most say easier. In fact, one builder did it in 3 days! ;
26) Also, even MORE GOOD NEWS! Now you can have a normal diameter sized prop for the HP of your engine. Ya see, you must allow for a larger Safety Factor for both fixed or retract fiberglass main gear because they both will bow outboard extra far from a hard landing ( ours will NOT do this! ). Therefore, you are stuck with a small diameter, not near as efficient as you could have, prop. In fact, with our main retracts, you could have a prop as large as 72″ in diameter ~10.85″ aft of the plans location for the small wood prop ( a little larger in diameter if you are forward of 10.85″ aft ), equating to higher prop efficiency with a larger prop and the prop is in much cleaner air, which means better overall aircraft performance, and a faster cruise. Plot it out for yourself. And, a 3 blade prop is best ( yes, I know they cost more, but they’re sure worth it! ) ;
27) 89 sets have already been shipped and are being installed — 15 have already flown from around the world ; 10 more sets are ready for delivery ; Hundreds more are forthcoming.
Additional Answers to Questions Specific to the Cozy MK-IV and the AeroCanard ( and to the above ) in random order :
28) It has been assumed by many that there is very little drag from the fiberglass fixed main gear because the fiberglass fixed main gear strut is tear-drop shaped with wheel pants. Yes, there is obviously less drag with an airfoil shaped strut and using wheel pants, but obviously not near as much as retracting the mains. ALL our customers have reported demonstrated 19 to 25+ mph INCREASE in cruise speed ( depending on engine HP, prop used, aircraft weight and quality of overall aircraft workmanship/finish ) because their main gear is now retracted. Unless the nay-sayers are willing to say ALL these people are flat out liars, one cannot deny the multiple documented facts ( see above and info pack ) ;
29) It has been illogically stated that “a retractable main gear could not possibly be as strong or as light as the fixed ( main ) gear” — LOL, this statement really cracks me up. This is simply not true if referring to our oleo strut main retracts — everyone knows this ( just look at them ) ! If this statement were true, why do so many aircraft designs have oleo strut retractable landing gear?!? But, this statement may be true for other attempts at fiberglass main retracts for canards — I don’t know. You’ll have to determine this for yourself. See our info pack and DVD for the facts about our main retracts ;
30) It has been erroneously stated that “retracting the main gear into the strake would sacrifice fuel capacity”. In fact, there is NO fuel loss for the Cozy MK-IV or AeroCanard with the fuel sump under the rear seat, like most are doing now. In fact, you will probably GAIN 1 to 3 gallons. Therefore, the range is increased, NOT decreased. You are faster and have the same, or more, gas on board, with better MPG, which saves you $MONEY$, meaning our main retracts pay for themselves in a short time ( see info pack ) ;
31) It has been misleadingly stated that you will “only travel 5 or 10 knots faster, have to land more often from fuel ( letting down from 10,000 ft, spending 1/2 hour on the ground, and climbing back to 10,000 ft. ), therefore would not be cost effective”. You can figure this one out all by yourself from the facts above ( obviously this statement is not true ). Again, even Burt Rutan guesstimated a LE would cruise 12 to 14 knots / 13.8 to 16.1 mph faster with the main gear UP ;
32) The uninformed want you to think “insurance costs would increase” just because the mains retract — not true! Our Long-EZ, Cosy, and canard customers insurance have NOT gone up! And lets get something else straight, these aircraft are already complex, high-performance aircraft because of the retractable nose strut, Belly Board and higher speeds — AND, your plane is Experimental to boot. If anything, insurance would go down since it is SAFER to have all 3 gear UP in an off-field landing; and, in fact, may go down for many other reasons. Also, insurance companies ALREADY consider your aircraft as *WITH* Retractable Landing Gear ( AND as a complex, high-performance aircraft ), whether the Main Gear retracts or not, and you pay accordingly ;
33) Some have deceivingly said that our gear is not insurable — not true! In fact, the insurance companies are very impressed with our gear, stating how ‘substantial’ they are, and that our main retracts “are much better than other landing gear they have ever seen on other Sport Aircraft” ( document letter from insurance carrier in hand if you want to read it ). If your insurance goes up, or you can’t get insurance, it’s because of the Safety Record and/or experience of **YOU** and the kind of people flying that type of aircraft, and/or the safety record of that aircraft as a whole, NOT just because you added retractable main gear — that’s silly to think this. Remember, your plane is ALREADY a complex, high-performance, retract aircraft BEFORE you add our main retracts! NOTE — most builders do not insure for Hull ( invest that money for a rainy day ), they just have Liability ( which is cheap ) — even the “designer(s)” did this. After all, if you ding your toy, you will be the one fixing it ;
34) Once our main retracts are installed, they are virtually maintenance free. Therefore, there’s no increase in maintenance costs ;
35) It has been falsely stated that installing our main retracts would “increase building time” — not so! In fact, customers are demonstrating every installation that there is less build time compared to installing the fixed main gear — AND, more fun, educational and rewarding to do ;
36) Some will try to convince you, “that retractable main gear are subject to failure ( to go DN )”. Maybe for others, but this is not true of our gear. It is impossible not to get our main gear down and locked easily every time under any situation. The gear is held up hydraulically (9g capable ) — no mechanical UP-locks to get out of adjustment keeping the mains from coming DN. Our main retracts are double redundant DN, just like production aircraft are ;
37) A naive person has stated, “Located outboard on the spar, when the gear goes DN and one leg stay’s up, you got a problem with yaw that you don’t want at slow flight”. This is impossible for the UP and DN hydraulic lines are ‘T’ed together — the gear ALWAYS go UP and DN together ;
38) This same person also stated, “your always landing on your box spar putting load’s on it that it was not meant to have.” As I’ve said earlier, the wing imposes substantially more bending and torque loads on the center section spar than our Main Retracts ever could. Also, most all landing gear ( retracts or fixed ), including the Beech Starship, mounts the gear on the center section spar ;
39) Another truly intelligent person has stated, “Thanks for pointing out the sadly obvious ( this is to the Mr. Naive ). Those gear at the end of the spar always scared the bejesus out of me. It looks like it was engineered by someone eyeballing an EZ from ten yards, over the top of his thumb, and saying, ‘Hmmm… right about there looks good…” Well shut my mouth — yep, that’s how we did it! ;
40) Another fellow has wisely speculated, “I understand that the gear has to compress ( get shorter ) to fit in the wheel well by putting pressure on the other side of the strut. If this fails I bet anything the gear won’t come down!” ( I’ll bet he does well at Las Vegas, too. ) Not true! You only need to compress the oleos prior to retraction on Long-EZ and Cosy III aircraft because their strakes are a little short with the gear UP and Weight-Off-Wheels ( the tire bumps into the fuselage ). The Cozy MK-IV, AeroCanard, or other 4 seat canard aircraft do not need to compress the oleos prior to retraction, but they lose about 2 gallons of the gas they gain above the fixed gear fuel capacity. Also, we HAVE failed the oleo strut compression ( which could only occur with either a pump or motor failure AND a bad leak of ONLY the compression line — again, BOTH must occur, which is statistically virtually a zero % possibility ) into the wheel well, and by pulling with just 2 fingers simulating a little ‘g’, the gear came right out of the wheel well when the gear switch was put DN, and that’s with the wheel well walls made near vertical. If the wheel well walls closest to the fuselage are made with a slight draft angle, a little ‘g’ would not be needed ;
41) A poor pilot will try to tell you, “you may forget to lower the gear” as a “reason” not to install main retracts ( they are just admitting their own limitations and problems, not yours, and should have their nose gear fixed down permanently also, if they are that worried ). Lets get something else straight ( again ) — these canard aircraft are ALREADY a retractable gear aircraft because of the retractable NOSE gear — if you are “forgetful”, you will forget the nose as well. But you will have horns and lights going off if you ever “forget” to put the nose gear down. This kind of forgetfulness, “Forgetfulness, ( forgetting to lower ) the gear”, is like forgetting to put your pants on, or to remove nose ballast when flying with a heavy front seat passenger. If a pilot justifies to you why not to put in retractable main gear because s/he may forget, they are ignoring checklists, horns, lights, training and procedures. There is a much bigger underlying problem here — one must wonder why these individuals are even driving a car, let alone still flying ( and/or have an ulterior motive, so consider carefully the source of these rare, bizarre statements ). Fortunately, by having the mains retracted, too, the plane will be soooo sleek, the pilot will not be able to slow down normally to land once he begins his descent from the perch ( abeam the numbers ) in the pattern to land, and THIS will flag in his/her mind big time that the gear ( all 3 ) are not down if s/he has “forgot”. So having all 3 retracted, compared to just the nose strut, would be safer, for you couldn’t forget them — you’d be too fast to land normally. Also, you could easily install the same feature that Piper has in some of their aircraft, that when the throttle is reduced/power is back and airspeed drops below 100 MPH IAS, the landing gear AUTOMATICALLY extends — their insurance is cheaper, too, because of this feature ;
42) Nay-sayers ignorantly want you to believe that in the event of an off-field landing, our retractable main gear attached to the center section main spar ( just like most all other production aircraft in the world including the prototype Beech Starship) “would probably cause more structural damage, including rupturing of the fuel tanks and increased likelihood of fire”. This is absolutely absurd! These few people obviously have no concept or proper training of operating **any** complex retractable gear small aircraft!! If you have an off-field landing with **any** small aircraft with retractable gear, all 3 gear would be UP — no damage to the spar or fuel tanks would occur from our main retracts, and minor damage to the overall aircraft. Fact is, with the mains fixed down, the fixed main gear will probably flip the plane over in an off-field landing possibly killing you and/or your passenger(s) ( already happened! ); or, they will catch those power lines ( already happened! ) where our main retracts won’t; or, the fixed main gear will tear out and the rear seat passenger(s) could be hanging out the bottom of the plane ( already happened! ) dragging along the pavement when the gear rips out the bottom of the fuselage — Again NOTE: all of these events have already occurred way too many times. In fact, inadvertent off-field landings is one of the main reasons many of our customers have decided to put in our main retracts — SAFER ;
43) A few think that installing main retracts would “increase building cost at least $4000” — that’s not exactly true. Our main retract kit is only $5995. Subtract out the fixed main gear, labor, and hardware, the building cost increase would be much less than the return on your investment. So, a $4000 increase in the overall production of your dream machine — 5% to 8% of the overall plane costs — is a small drop in the bucket when you consider all the benefits our main retracts gain you. The increase in speed alone pays for the main retracts in economy ( better MPG ) in a very short time, and there’s less wear and tear on the brakes, and the increased speed may get you around, or ahead of, a weather front ( what’s that worth to you just once? — ask your spouse ) ;
44) As I said earlier, there should be no weight gain, but a few have reported somehow adding 1 to 7 lbs. to the empty weight. Still a pretty good trade for all that you get, don’t you think! ;
45) As stated earlier, our retractable oleo strut main gear have been drop tested at 2200 lbs. per FAR ( with the fuel tanks full of water ), which is 150 lbs. more than the published GW of the Cozy MK-IV and AeroCanard ;
46) You do not need to compress the oleo struts prior to retraction if you don’t want to for the Cozy MK-IV, AeroCanard, or any other 4 seat canard ( except SQ-2000 ). Just for the Long-EZ and Cosy/Cozy III/Cozy Classic ;
47) Someone ( we’ll call “A” ) relayed a friend’s personal belief ( we’ll call “B” ) ‘that during take off, if the main wing begins to fly before the canard and unloads the main gear, the oleo struts begin to extend, raising the aircraft’s aft section and effectively decreasing AOA’. ANSWER: NO! — if so, someone better warn Beechcraft, AV Tec 400, Jet Cruiser, etc. In reality ( “A” figured ), ‘the nose lifts off before the main wing begins to fly ( carrying load off the main gear )’. ANSWER: YES!! — the canard begins to fly first and the plane rotates. If the wing begins to fly before the canard, then the canard is stalled — a plane that really does this has some serious canard problems whether the mains are our main retract oleos, fixed main gear oleos, fixed fiberglass hoop main gear, retract fiberglass main gear, or retract fiberglass hoop main gear. “A” reasoned, “I hadn’t thought about this before and now wonder if the main wing does start lifting at this time, wouldn’t the hoop style fixed gear also stand up creating a negative AOA too?” ANSWER: CORRECT!!! — logic prevails when one thinks this through 🙂 . UPDATE: we have since found out that the canard slot of the aircraft referenced above was irregularly shaped, wavy, and very rough. The leading edge of the canard and strake had 6″ of packing tape on it to try and protect the leading edges from people leaning on the plane when they looked in the cockpit. The right half of the canard had a bad twist forward in it. The canard was erroneously shortened 12″ instead of 6″ per plans change ( I wouldn’t shorten it at all ). And the worst thing, the engine was mounted horizontally, not canted upward per the plans. From all these build errors, no wonder the plane would not rotate properly! ;
48) Logic and common sense dictates that ANY aircraft that cruises 150+ MPH should have all 3 gear retracted [ and a constant speed prop 🙂 ]. In other words, put your money into a larger engine, turbo charge it, hang a 3 blade constant speed prop ( take-off distant would be cut 40+% ), and, of course, retract the mains, so that you can go faster and get out ahead of and/or around and/or over that weather front quicker. Then, you won’t need to buy ( at least in the beginning of your project ) — and rely on — that full IFR panel, and that $8,000 to $20,000+ EFIS, that you might use once in a blue moon ( AND, you might be rusty ) — put your money into the plane in the beginning, not the panel, particularly if money is tight ( yeesss, having a full IFR panel eventually is a REALLY nice thing to have, but you can always easily add to the panel over time ) ;
49) So bottom line — don’t listen to the handful of jealous poltroon nay-sayers out there who don’t know what they are talking about, for obviously they have never read this Retractable Main Landing Gear page on our web site, and/or read our info pack, and/or seen our DVD, and/or even seen our main retract gear, and/or installed our main gear, and/or talked to our customers, and/or have even talked to us. Ask them why they are saying what they do, and to state their facts. You’ll find NONE have a valid argument, let alone any facts. Again, they’ve never contacted us to get all the facts, let alone ever own or have ever installed a set of our main retracts — just simply call us and find out the facts for yourself!!! And ALWAYS remember, these few who slander and liable us have ulterior motives for what they are trying to convince you of, sad to say. How pathetic 🙁 !!!!!