Date: Tue, 03 Dec 1996 22:43:49 -0500 From: Jim Hocut Subject: Re: COZY: electric landing brake > >i am preparing to glass the exterior fuselage bottom and >am wondering if there are any extra plies or hardpoints >i should install in anticipation of wayne lanza's set-up? Just looked thru some old notes, I talked to Wayne about this when I placed a verbal order WAY BACK IN AUGUST (Wayne ?). The only changes Wayne recommended to me were to 1) Make the plywood insert in the landing brake 1" wider than stock, leaving the edge of it that's closest to the centerline in the stock position. 2) Mark the bottom surface of your map pocket on the outside of the seat back brace, then draw a 2nd line 1/2" below that, before you install the brace, to aid in locating the actuator before you. 3) The cutout in the floor will be wider than stock, but you can wait to cut that out 'till you have the actuator in hand. Hope this helps. Jim Hocut jhocut@mindspring.com by SERV04.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01ICLS8USNVM0001WX@SERV04.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Wed, 4 Dec 1996 07:55:40 PST Date: Wed, 04 Dec 1996 07:57:19 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: electric landing brake >> >>i am preparing to glass the exterior fuselage bottom and >>am wondering if there are any extra plies or hardpoints >>i should install in anticipation of wayne lanza's set-up? > > >Just looked thru some old notes, I talked to Wayne about this when >I placed a verbal order WAY BACK IN AUGUST (Wayne ?). > >The only changes Wayne recommended to me were to >1) Make the plywood insert in the landing brake 1" wider than > stock, leaving the edge of it that's closest to the centerline in > the stock position. > >2) Mark the bottom surface of your map pocket on the outside of >the seat back brace, then draw a 2nd line 1/2" below that, before >you install the brace, to aid in locating the actuator before you. > >3) The cutout in the floor will be wider than stock, but you can >wait to cut that out 'till you have the actuator in hand. > >Hope this helps. > >Jim Hocut >jhocut@mindspring.com I don't know how the Cozy differs from my Long EZ, in the case of the manually actuated landing brake, but I guess I just have to ask: why the electric conversion? What could be lighter and simpler than the manual setup? I don't see how the electric actuator could provide for overspeed protection, in the event the pilot forgets to retract it, sometime (a certainty, sooner or later), unless there is some type of slip clutch arrangement. I have already heard of one failure in the open position that created a great deal of difficulty in climbing and cooling. The only advantage I can see is that you get to flip a switch instead of pull a lever. Am I missing something? --Howard Rogers, 415-926-4052 hrogers@slac.stanford.edu Date: Wed, 04 Dec 1996 11:31:12 -0500 From: william l kleb Organization: NASA Langley Research Center Subject: Re: COZY: electric landing brake Howard Rogers wrote: > > why the electric conversion? cost is comparable to the brock parts, i don't have a naca scoop (so failure in the down position is not a cooling factor), and i would like all the space i can get in the front (side-by-side) seating in the iv. seems like the "overspeed" issue is the same for either setup. > advantage I can see is that you get to flip a switch instead of pull a > lever. > that and more room is just about it---at least from my perspective. --- bil kleb (w.l.kleb@larc.nasa.gov) 72 bellanca 7gcbc 9? cz4 -> aerocanar by SERV04.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01ICN70HZWEK0003DI@SERV04.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Thu, 5 Dec 1996 08:09:37 PST Date: Thu, 05 Dec 1996 08:11:17 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: electric landing brake >Hi Howard, > I'm not responding to your questions just to defend my >speed brake kit, but would like to cover the issues briefly. > > Your concerns regarding complications arrising from the >brake left open are certainly valid. My recommendations >to builders is to add a microswitch to sense that the >brake is closed. If it's not & the throttle is advanced, >then set it up to squawk! > Over speed can be another issue. One of my (personal) >dislikes about the "johnson bar" is the thought of it >slamming down near my fingers especially if my hand is >close to the quadrant. Yeah, I know, I'm a chicken! >I feel that's something we need to be aware of, just >like overspeeding the flaps in a Cessna. Wayne, This is certainly a valid point. I haven't flown my EZ yet, but I have thought about this also. I had considered adding a small "dashpot" to dampen the closing motion, but of course that's more weight. > > As far as simplicity and weight goes... The real appeal >of the electric system is that it IS simpler than the >cables & pulleys & springs in the manual system. It also >DOES weigh less, typical installation is about 2 pounds. >As far as flipping a switch vs the lever, well... Yes, I believe I'm familiar with this type of actuator, and It is quite reliable and simple. I also have electric flaps in my Grumman that have been trouble-free for the seven years I have been flying it. However, I would still prefer the old Johnson bar flaps I had in my Cherokee, because I know that, some day, my flap motor will fail, and probably ruin a trip, unless it happens on my home field (not Murphy likely). Hence my affinity for a manual system. > > My only concern would be in the loss of electrical power. >In that case the brake would be the last of my worries. This one I must disagree with. If you lost your ability to extend the brake, it would be a non-event. Just a flatter approach. If you lost your ability to retract it, it could cause a lot of problems that definitely fit into the "first prority: fly the airplane" category. An example that comes to mind would be a go-around situation, such as all the airplanes in the que just behind the guy just behind me were forced to do about a month and a half ago at Palo Alto Airport. The guy who landed right after me folded a nose gear on his Bonanza right after touchdown, and the runway was closed for over an hour. Everyone else did a go-around and went away somewhere else. Or how about an attempted Instrument Approach with a missed procedure that requires a robust climb? With all that extra drag and lousy cooling, you *COULD* be in more than a little trouble. I know that these things aren't likely, in the grand statistical scheme of things, but I also know that I have experienced one electrical failure in my 1500 hours of flying, and I would be surprised if it were the last. >There are two of the same type of actuator in all of the >Velocity's, one for the brake & one for pitch trim. The >dependability of the electrics is really good. You are correct. I guess another intangible is that I like the "feel" through the controls of the airloads involved. I also hate overly boosted "no-feel" power brakes on a car. Just a personal quirk. > >Take Care & Safe Flying, Wayne Lanza You, too. --Howard Rogers, 415-926-4052 hrogers@slac.stanford.edu Date: Thu, 05 Dec 1996 15:39:36 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: electric landing brake I have now taken off twice with the speed brake out and can still climb at 1500 ft per min. No overheating to the engine because of armpit cooling instead of the belly NACA inlet. I also have left it out to see what full power and speed would do. 160 Knots was top speed and a slight shake in the airframe that was felt on the rudder pedals. In a go- around with the speed flap out it is a non problem with the airpits scoops. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com NEW homepage address: http://www.binary.net/aerocad Date: Thu, 05 Dec 1996 11:17:00 -0500 From: william l kleb Organization: NASA Langley Research Center Subject: Re: COZY: electric landing brake wayne responded personally for fear of "vendor use of the list", but this doesn't appear to fit that category and should benefit others. (he gave permission to post.) Wayne Lanza wrote: > > You won't need to do any special lay-ups on the outside of > the fuselage. The only thing that really changes (on the > outside) is the size & shape of the slot in the floor. What > I recommend to builders, is to leave the foam in the brake > recess area raw until the slot is cut & fitted. The only > special 'glass work is on the triangular seat-back braces, > where the mounting bolts are located. The mounts require > you to build up solid glass in the braces the same way > that the foam is filled in solid for the nose gear attach > points. > If you are going to order a speed brake kit, e-mail me > when you are about ready to order. Lead times on the > actuators can be 6 weeks, if I'm out of stock. I try to > keep stock on hand, but the actuators a really getting > expensive & sitting on alot of inventory is prohibitive. > and for ready-reference: Wayne Lanza 9425 Honeysuckle Drive Sebastian, Fl 32976 (561) 664-8953 voice/fax --- bil kleb (w.l.kleb@larc.nasa.gov) 72 bellanca 7gcbc 9? cz4 -> aerocanard Date: 05 Dec 96 14:33:01 EST From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Belly Board / Landing Brake Hi to All, >Wayne Lanza wrote to Howard Johnson: > Over speed can be another issue. One of my (personal) dislikes about the "johnson bar" is the thought of it slamming down near my fingers especially if my hand is close to the quadrant. Yeah, I know, I'm a chicken! I feel that's something we need to be aware of, just like overspeeding the flaps in a Cessna.< I would just like to pass along that it does hurt VERY badly when that belly board / landing brake closes on your hand ! I was test flying a Long-EZ and was in the pattern. I put the belly board out and a few seconds latter, the handle closed on my hand while I had a hold of the throttle handle. I thought for many minutes / hours that 2 or 3 of the bones in my hand were broken. Fortunately not (I think), just very badly bruised. The rigging for the belly board was out of adjustment the owner said, so closed at lower speeds than designed. Needless to say, I was always nervous in subsequent flights of having that handle smash my hand again. Worries of an actuator failure or electrical failure on a go-around or touch-and-go leaving the belly board out and the runway clobbered behind you is one argument for the engine intake scoops to be under the strakes, but I still like the cleaner NACA scoop. Besides, I can more easily close off the NACA scoop like a cowl flap (right Cliff). Is anyone working on / figured out a mechanical retract to override the electric actuator to retract the belly board in the event of an actuator failure or electrical failure that doesn't weigh a ton (I know, more complex)? Or, we can just look at the statistics, play the odds and decide how close a friend Murphy is (I know, more personal choices). HTH. Infinity's Forever, JD Date: Thu, 5 Dec 1996 14:51:31 -0500 From: Phillip.Johnson@kan.lmcda.lmco.com (phillip johnson) Subject: COZY: Belly Board / Landing Brake Food for thought. Everyone seems very concerned about the reliability of the electric speed brake mechanism. Has any one actually looked carefully at the handraulic system and determined that it is more reliable. The fewer moving parts of the electric system may actually be more reliable. Phillip Johnson From: Lee Devlin Subject: Re: COZY: Belly Board / Landing Brake Date: Thu, 05 Dec 1996 14:55:23 MST > > Food for thought. > > Everyone seems very concerned about the reliability of the electric > speed brake mechanism. Has any one actually looked carefully at the > handraulic system and determined that it is more reliable. The fewer > moving parts of the electric system may actually be more reliable. I don't think the issue is as much the reliability of the control mechanism as it is the failure mode. If the motor fails or experiences an open circuit when the speed brake is deployed it will stay deployed and cut off air to the NACA scoop for the engine. There has only been one reported case where this has been a problem and that was when a pilot had used the speed brake to lose altitude in a hurry and when he attempted to retract it the circuit opened. Then he had to fly for another 15 minutes to reach an airport and that was enough to completely cook his engine. I generally don't use the speed brake until I'm on final approach and depending on my glide, I may not deploy it until just before touch down. I do it primarily to help prevent rocks thrown by the front tire from hitting the prop. I can keep my hand out of its path when it's deployed since at this stage the throttle, mixture, and carb heat don't need to be fiddled with. The manual speed brake is virtually impossible to take off with while deployed since I always keep my hand on the throttle during takeoff and the brake handle sticks up when deployed and doesn't allow me to do this comfortably. I like the simpler approach whenever possible and so I'm pretty sure I'll be using a manual system in my Cozy. The mechanical system has only a mechanical likage to fail which many times gives ample warning via a sense of feel. In the case of a motorized speed brake, you have a simpler mechanical linkage but in addition you have components like the alternator, voltage regulator, battery, wiring, switches, fusing element, motor bearings, motor windings, winding thermal protection, brushes, and electrical connections, all of which are subject to failure eventually. Lee Devlin | HP Greeley Division | Long EZ N36MX Piper Colt N4986Z | 700 71st Ave. | Cozy MK IV under const. 'Spirit of rec.aviation'| Greeley, CO 80634 | (Chapter 10) Date: Thu, 5 Dec 1996 17:57:42 -0500 From: CCady@aol.com Subject: Re: COZY: Belly Board / Landing Brake In a message dated 96-12-05 14:53:31 EST, you write: << Food for thought. Everyone seems very concerned about the reliability of the electric speed brake mechanism. Has any one actually looked carefully at the handraulic system and determined that it is more reliable. The fewer moving parts of the electric system may actually be more reliable. Phillip Johnson >> Funny you should mention this. On my old Long-Ez I had the speed brake want to close on me also. Then on one flight the cable jumped off the pully and the speed brake would not retract. Luckily I was on the ground when I found that I could not retract it. I installed a small aluminum turnbuckle in one cable so I could adjust it and make it tight. I have a electric actuator speed brake now and I think it's pretty reliable. I might suggest that you only hit the switch for the speed brake on final and pretty sure that you aren't going to have to go around. If you have a NACA cooling scoop on the belly and the speed brake is stuck down your cooling is shot. I can lower my nose gear with a wider door on it and see the cylinder head temps start to climb! I think the side scoops might be better after all. Cliff Posted-Date: Thu, 5 Dec 1996 17:03:31 -0600 (CST) Date: Thu, 05 Dec 1996 17:04:32 -0600 From: Darren DeLoach Subject: Re: COZY: electric landing brake >I know >that these things aren't likely, in the grand statistical scheme of things, >but I also know that I have experienced one electrical failure in my 1500 >hours of flying, and I would be surprised if it were the last. > I've personally had two electrical failures in the past three years, both on coast-to-coast cross-country trips, one in a Cherokee 6 and one in a C182RG. The first one was my fault (never forget the human element!), the second one a combination of an A&P using the wrong alternator belt and a bit of simultaneous bad luck. Bottom line is the same, though: they can and do happen, sometimes at truly bad moments ... (plus I've always liked Piper Johnson bar flap levers more than Cessna flap toggles,levers). -- Darren DeLoach Sales & Software http://www.deloach.com Date: Fri, 06 Dec 1996 02:12:29 -0500 From: Jim Hocut Subject: Re: COZY: electric landing brake There have been many good points made about reliability and the problems encountered if for some reason the speed brake stays deployed and you need to do a go-around etc. I don't have an actuator in hand yet, but when I have all the hardware laying on my workbench I intend to see if I can't come up with a simple/safe method of yanking a locking pin so that the brake will retract. Don't know if this is doable or not, but seems that it's worth looking at. Jim Hocut jhocut@mindspring.com Date: Fri, 6 Dec 1996 06:32:29 -0500 From: SMilesCozy@aol.com Subject: Re: COZY: Belly Board / Landing Brake In a message dated 96-12-05 19:20:25 EST, you write: >Wayne Lanza wrote to Howard Johnson: > Over speed can be another issue. One of my (personal) dislikes about > the "johnson bar" is the thought of it >slamming down near my fingers especially if my hand is close to the quadrant. > Yeah, I know, I'm a chicken! I feel that's something we need to be aware of, > just like overspeeding the flaps in a Cessna.< >> This may be a stupid question but here it goes, isn't the landing brake on the MkIV an over center arrangment, and if so how would it close by itself? Steve Miles Cozy MkIV 272 >> From: Marc J. Zeitlin Subject: Re: COZY: Belly Board / Landing Brake (fwd) Date: Fri, 6 Dec 96 9:29:09 EST Steve Miles wrote; > This may be a stupid question but here it goes, isn't the landing brake on >the MkIV an over center arrangment, and if so how would it close by itself? Yes, but not much. There's some tweaking and adjusting that must be done to get it to stay open up to the right speed. Pushing on it hard enough will get it to pop through (pretty explosively, apparently, at least from what I've heard, and Jim Newman has experienced ;-) ). And there are no stupid questions - just stupid answers. -- Marc J. Zeitlin Email: marcz@an.hp.com by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01ICOLO6JP0K00002I@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Fri, 6 Dec 1996 08:20:28 PST Date: Fri, 06 Dec 1996 08:22:12 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Belly Board / Landing Brake >In a message dated 96-12-05 19:20:25 EST, you write: > > >Wayne Lanza wrote to Howard Johnson: *********Who is Howard JOHNSON?************ > > Over speed can be another issue. One of my (personal) dislikes about > > the "johnson bar" is the thought of it > >slamming down near my fingers especially if my hand is close to the >quadrant. > > Yeah, I know, I'm a chicken! I feel that's something we need to be aware >of, > > just like overspeeding the flaps in a Cessna.< >> > > This may be a stupid question but here it goes, isn't the landing brake on >the MkIV an over center arrangment, and if so how would it close by itself? > > Steve Miles > Cozy MkIV 272 >> Steve, Not a stupid question, at all. The answer is: yes, it does go over center, but with a spring. When the air load is sufficiently strong, the belly brake deflects (against the spring-pressure) to bring it BACK over center, which results in the unpleasant rapid closing that has been referred to here. Since belly brake work is among the last few tasks I have to complete on the airframe, I am really appreciative of this recent discussion on the subject. Perhaps I had minimized the importance of an inadvertant and unexpected closing, with the resulting broken-hand syndrome. This leads me to consider the possibilities of installing a "dashpot" or small hydraulic shock-absorber of some sort to the system. I will go back to the drawings and see if I can find a convenient place to attatch one to the mechanism. If I can't find one that meets my specs, I might have to make one. Howard Rogers, A&P 2005148 --Howard Rogers, 415-926-4052 hrogers@slac.stanford.edu by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01ICOLO6JP0K00002I@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Fri, 6 Dec 1996 08:20:25 PST Date: Fri, 06 Dec 1996 08:22:09 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Belly Board / Landing Brake >In a message dated 96-12-05 14:53:31 EST, you write: > ><< Food for thought. > > Everyone seems very concerned about the reliability of the electric > speed brake mechanism. Has any one actually looked carefully at the > handraulic system and determined that it is more reliable. The fewer > moving parts of the electric system may actually be more reliable. > > Phillip Johnson >> > >Funny you should mention this. On my old Long-Ez I had the speed brake want >to close on me also. Then on one flight the cable jumped off the pully and >the speed brake would not retract. Luckily I was on the ground when I found >that I could not retract it. I installed a small aluminum turnbuckle in one >cable so I could adjust it and make it tight. > >I have a electric actuator speed brake now and I think it's pretty reliable. > I might suggest that you only hit the switch for the speed brake on final >and pretty sure that you aren't going to have to go around. If you have a >NACA cooling scoop on the belly and the speed brake is stuck down your >cooling is shot. I can lower my nose gear with a wider door on it and see >the cylinder head temps start to climb! I think the side scoops might be >better after all. > >Cliff Cliff, Thanks for the failure mode warning re: the mechancial landing brake system. I will just add another warning to the pile. If you installed an aluminum turnbuckle, my guess is that it is a hardware store item, as I am not aware of an aircraft quality aluminum turnbuckles. The hardware store variety is usually made from an aluminum extrusion that is cut off, and the cross sectional piece makes up the body of the turnbuckle. The pull-out strength, in tension, of these turnbuckles is dismal, at best. I can say this, from experience. As a youth, I unwisely chose a pair of these to cinch down my motorcycle on a trailer, and one of them pulled completely out, dropping the bike and doing considerable damage. I never liked the non-tensioned feature of the original plans, and was planning to use a turnbuckle, myself. A huge variety, in almost any size required, is usually available at your friendly local aircraft junkyard (excuse me, "recycler"). I'd hate to see a second failure, due to the correction of your first one. Howard Rogers A&P 2005148 Date: Fri, 6 Dec 1996 22:39:18 -0500 From: AllegroAvi@aol.com Subject: COZY: PRO Elect. Landing brake. In light of all the talk about landing brakes... I recently installed one, as well as electric pitch trim. In three hundred hours of flying my Cozy I never knew what a pain in the rear that awful manual brake was, and the electric pitch improved the plane an equal or greater amount. The discussion has not been whether or not the elect. brake works I realize, but for what it's worth, yes, there are risks to failure of the system and I've thought about them more since reading all this, but the benifits are in my opinion very definitely there. It has made my airplane a lot more of a precision tool, I have ready control over engine cooling on descent, I can modulate the brake on final to get a sort of fingertip control of my glide path I've never had.... Well obviously I'm sold! Stop Me! Robin du Bois Date: Sat, 07 Dec 1996 00:05:32 -0500 From: Mahan Subject: Re: COZY: Belly Board / Landing Brake Howard Rogers wrote: > inadvertant and unexpected closing, with the resulting broken-hand > syndrome. Howard, I think the worry about a damaged hand is overblown. I've been whacked by the landing brake handle on my long-EZ numerous times. Yes, it hurts. I usually slow down to about 5 kn under its 95 kn retraction speed, then pop it out. It only karate-chops me if my approach gets screwed up for some reason, say, a dive to one side to miss a bird. In nine years of flying I've been hit by it maybe three or four times. I use it for every landing because if you lose your engine on approach and are used to "setting up" your approach with it, retracting it allows you to "stretch" your glide. It makes about 200 fpm difference in glide at 80 kn. Fred in Florida Date: Fri, 13 Dec 1996 12:45:44 -0500 From: SMilesCozy@aol.com Subject: COZY: Re: Cozy Landing Brake Dear Group, Not to sound stupid or revisit a dead issue again, but concerning the over-center arangement of the landing brake. If my understanding is correct, once over-center, the more pressure applied should just force the mechanism harder against it's stops, correct? Then it should require a reduction in force to bring it over-center again to begin the retract phase. The only way I see that it could slam shut, if installed properly, would be to shear off the stops. Kind of like chinese finger cuffs. Please clariffy if I misunderstand the workings of the over-center locking device. Sincerely, Steve Miles Cozy MkIV 272 by SERV05.SLAC.STANFORD.EDU (PMDF V5.1-4 #16063) with SMTP id <01ICYN8ORU0Q00040Q@SERV05.SLAC.STANFORD.EDU> for cozy_builders@hpwarhw.an.hp.com; Fri, 13 Dec 1996 12:53:03 PST Date: Fri, 13 Dec 1996 12:55:06 -0700 From: hrogers@SLAC.Stanford.EDU (Howard Rogers) Subject: Re: COZY: Re: Cozy Landing Brake >Dear Group, >Not to sound stupid or revisit a dead issue again, but concerning the >over-center arangement of the landing brake. If my understanding is correct, >once over-center, the more pressure applied should just force the mechanism >harder against it's stops, correct? Then it should require a reduction in >force to bring it over-center again to begin the retract phase. The only way >I see that it could slam shut, if installed properly, would be to shear off >the stops. Kind of like chinese finger cuffs. Please clariffy if I >misunderstand the workings of the over-center locking device. > >Sincerely, >Steve Miles >Cozy MkIV 272 Steve, You would be absolutely correct in your analysis of the behavior of an "over-center" mechanism, but this one is slightly different. It has a spring, not a solid link, that exerts force on the linkage, once over-center. As air-loads build up with increasing airspeed, the landing brake gradually deflects (against the spring pressure), until the mechanism goes back over-center again, to the "retract" side. Hence, the wrist-thwacking. Study the drawing carefully, and it will become clear. Howard Rogers, A&P 2005148 --Howard Rogers, 415-926-4052 hrogers@slac.stanford.edu Date: Fri, 13 Dec 1996 15:27:46 -0500 From: SMilesCozy@aol.com Subject: Re: COZY: Re: Cozy Landing Brake In a message dated 96-12-13 13:21:05 EST, you write: << It's not quite overcenter, it's just VERY close to it, with springs holding the system there. Go fast enough and it will slam closed. Richard Riley>> I'm still confused...nothing new there... ;^), I'm looking at drawing M-28 of the MkIV plans, the detail of the landing brake shows it "over center", with the spring applying pressure to keep it over-center. Drawing a straight line from the AN525-10R10 pivot at the LB 18, through the CZLB 21 arm, to the AN525-10R10 pivot of CZLB21, with the CZLB15 and CZLB21 pivot at the stop. The pivot of the LB 18 appears to be, linearly, (sp.) "over-center" of the CZLB 15 pivot point. Which would cause any additional pressure to try force it through the stop. (...whew...) Am I missing something, or can slight variations in dimensions, ie. moving LB 18 less than 3.9" from hinge line, cause the system not to go over-center. It would appear that the limiting factor in this arrangement would be the muscle to deploy the brake at speed, Thanks in advance for helping me understand this. Sincerely, Steve Miles Cozy MkIV 272 Date: Fri, 13 Dec 1996 17:42:00 -0500 From: SMilesCozy@aol.com Subject: Re: COZY: Re: Cozy Landing Brake In a message dated 96-12-13 15:58:15 EST, you write: << It has a spring, not a solid link, that exerts force on the linkage, once over-center. As air-loads build up with increasing airspeed, the landing brake gradually deflects (against the spring pressure), until the mechanism goes back over-center again, to the "retract" side. Hence, the wrist-thwacking. Study the drawing carefully, and it will become clear. Howard Rogers, A&P 2005148 --Howard Rogers, 415-926-4052 >> As I look at drawing M 28 of the MkIV plans, it appears that spring LB 12 connected to CZLB 10 actually holds the brake over center. Perhaps to prevent gusts or turbulence from releasing pressure and allowing unit to slam closed. Other than that spring, it appears to be a solid mechanical link to the over center mechanism. Could this be a change from the Vari, Long, or III. Sincerely, Steve Miles Cozy MkIV 272