 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| HomeDiscussion Groups General AviationLearningIFRHomebuiltSoaringUltralightRotary-wingCountry Specific Australian GroupUK GroupRelated Topics BoatsCarsMotorcyclesMore Topics ... |
Aviation Forum / General / Homebuilt / September 2008Avia Economia, Part 3
You Motorheads will like this Part :-) Primary Gliders are designed to be dismantled. The fuselage breaks down into two pieces. The horizontal stabilizer un-pins, as does the rudder. Control cables are fitted with turn-buckles at key points, allowing the cables to be divided, their free ends coiled and stored in suitably marked bags, along with a dash of rat poison. The wings of course, are designed to come off, the control cables are coiled & bagged as mentioned above. The break-down of a Primary Glider is mostly common sense but it also reflects the components that make up its structure, and in doing so defines the logical sequence of the manufacture of those components, such as the rudder, stabilizer, aft fuselage and so on. This is worth mentioning here because a Primary Glider is not a project with a definable end. As soon as the first one is finished you will find there is enough interest to begin collecting materials for another -- and enough people to keep it flying. But this post is about what to do with your Primary when it's NOT flying. You store it in its trailer. In its dismantled state a Primary Glider occupies a space about 16 feet in length, 5 feet in height and four feet in width. Add an extra foot to those dimensions for 'working room' and you have the approximate dimensions of the glider's required storage space. Your task is to turn those dimensions into a trailer. Weight of the glider is not a factor here. At an absolute maximum a Primary Glider will weigh no more than 180 pounds, assuming it is built with ballast weights and a heavy skid. A more realistic figure would be about 130 pounds. The weight you need to worry about is that of the trailer's chassis & body. Here again, the weight is not very much but its CG must be taken into account. As a rule, start with the largest wheels you can find, with 15" or 16" rims being preferred. Do a rough estimate of the trailer's weight and locate the axle accordingly. When under-weigh a glider trailer can be an awkward tow. It may be necessary to re-locate the axle or even to add a ballasting mass. Be sure to take the required tongue-length into account and provide the trailer with a steerable third-wheel and jack-stands or stabilizers to keep the trailer firmly in place when loading and unloading the glider. The fun part of this assignment has to do with what you decide to build the trailer from. Aluminum monocoque construction should be high on your list since it provides an opportunity to introduce Chapter members to riveting and the forming of aluminum parts. If you live in a country where birch plywood is inexpensive, it will probably prove more practical than aluminum. Fabric(!) over a wooden frame is a valid method, assuming the trailer can be stored in a secure area. Finally, if your funds are limited you may have to consider a steel frame welded from conduit and covered with corrugated roofing panels. I will include a couple of drawings of a typical glider trailer but a big part of this project is to encourage input at the local level. We can also expect to have the real glider folks point us toward some photos of the real thing. -R.S.Hoover > You Motorheads will like this Part :-) > > I will include a couple of drawings of a typical glider trailer but a > big part of this project is to encourage input at the local level. We > can also expect to have the real glider folks point us toward some > photos of the real thing. Ok, I don't qualify as a "real glider folk" - but I will do some pointing anyhow: http://www.soaridaho.com/Schreder/Construction/Trailer_Design_1/Trailer.html  SignatureGeoff The Sea Hawk at Wow Way d0t Com remove spaces and make the obvious substitutions to reply by mail When immigration is outlawed, only outlaws will immigrate. > You Motorheads will like this Part :-) > > I will include a couple of drawings of a typical glider trailer but a > big part of this project is to encourage input at the local level. We > can also expect to have the real glider folks point us toward some > photos of the real thing. Ok, I don't qualify as a "real glider folk" - but I will do some pointing anyhow: http://www.soaridaho.com/Schreder/Construction/Trailer_Design_1/Trailer.html SignatureGeoff The Sea Hawk at Wow Way d0t Com remove spaces and make the obvious substitutions to reply by mail When immigration is outlawed, only outlaws will immigrate. On Sep 19, 1:59 pm, "Capt. Geoffrey Thorpe" <The Sea Hawk @See My Sig.com> wrote: > Ok, I don't qualify as a "real glider folk" - but I will do some pointing > anyhow: ------------------------------------------------------------------------- Dear Captain, Thank you for a very good first effort. Some of the details we should expect from the Motorheads will be the Tongue Height and Tongue Load, which will tell us which vehicles can safely handle the load. In that regard, we are most interested in the ability of the prime-mover to BRAKE the load rather than get it underway. We also need to put extra emphasis on the vehicle code for the State in which the trailer is registered. Some rather silly rules are often applied to trailers -Bob >We can also expect to have the real glider folks point us toward some >photos of the real thing. For better or worse, primarys are no longer a part of the "real" glider scene, except in the occasional flight demo or as a museum exhibit. However, the very first red-blooded USA-made Schweizer glider was a primary, the SGP 1-1. You can see one here along with its original designers : http://www.sacusa.com/corporate/history.asp . In looking for this gem, I found it interesting that when one Goggles "primary glider" the thing that floats nearly to the top is an old blog page from one RS Hoover. Even though I am a glider CFI, I have never had a chance to actually fly a primary. In fact, the only guy I know who ever has flown one is dead. However, this is the Internet, so lack of experience need not imply lack of opinion. ;-) So here goes: For several reasons, I don't think primary gliders should have any role in initial flight training (a good subject for another thread) but I do think that building a primary might be a worthy project for an EAA chapter. As Bob has said, a building a primary could be a great and affordable learning experience. Once built, it could be kept up in the hanger rafters to be taken down to be flown by all at the annual chapter picnic. When the members are done flying the thing and its time to break out the beer and hotdogs, mount it on a little GC stand, point it into the wind, and let the kids "fly" it to their heart's content. Any wind over 8-10 mph will likely be enough to make the controls effective. With it fastened to terra-firma, the kids won't be able to hurt it and it certainly won't hurt them. If it ever happens, I would sure like to be there, and would hope to be allowed to add a few seconds of PIC time to my logbook. SignatureVaughn ........................................................ Nothing personal, but if you are posting through Google Groups I may not receive your message. Google refuses to control the flood of spam messages originating in their system, so on any given day I may or may not have Google blocked. Try a real NNTP server & news reader program and you will never go back. All you need is access to an NNTP server (AKA "news server") and a news reader program. You probably already have a news reader program in your computer (Hint: Outlook Express). Assuming that your Usenet needs are modest, use http://news.aioe.org/ for free and/or http://www.teranews.com/ for a one-time $3.95 setup fee. ......................................................... Will poofread for food. > For several reasons, I don't think primary gliders should have any role in > initial flight training (a good subject for another thread) --------------------------------------------------------------------------------------- Dear Vaughn, Thank you for posting the URL of the strut-braced primary glider. This is nearly an exact copy of the primary whose drawings I will post... as soon as I find them :-) But my view of who should be flying the thing is diametrically opposed to yours. I want to get youngsters into the air as early -- and as often -- as possible. By using ballast weights we should be able to launch everyone, right down to nine year olds. With foot restraints, shoulder harness and a hard-hat, there's virtually no combination of attitude & altitude that could result in injury to the pilot. Indeed, I would like to see a 'work-up' system, where the builders earn 'Flying Points' by working on the construction of the glider. In the same way, once it its built, the 'Bungee Crew' earns 'Flying Points' by stretching-out the bungees. Points may also be earned by returning the glider to the launch point and doing maintenance. (I was allowed to wash & wax wings. Didja know Primary Gliders have HUGE wings? :-) Give a kid a task, you'd be surprised how well they do WITHOUT any intervention from us know-it-all adults. -R.S. Hoover >> For several reasons, I don't think primary gliders should have any role in >> initial flight training (a good subject for another thread) [quoted text clipped - 23 lines] > >-R.S. Hoover opinion without direct experience thankfully. my read of primary gliders years ago was that they fell out of favour because of spinal injuries on hard landings. now these days we have polystyrene in blocks which is one of the most useful el cheapo spinal protection systems on the planet. you simply make the seat out of a big block of the stuff and hotwire the seat profile to something comfortable. you could hotwire each kid his/her own seat base and velcro it in place. if the ballast to make each pilot weight constant was incorporated at the very base of this block it would make a pretty good spinal protection system. these days as well we should be able to find an aerofoil with decent characteristics and a docile stall break. I'm not averse to Bob's line of thinking here. My original exposure to the Primary Glider design was in an old book "The Model Aircraft Book" by F.J.Camm the editor of 'Practical mechanics' this details a number of designs from around 1935 and ends with a full writeup and construction plans of a Zoegling type primary glider by "E.W.T" btw Bob I went out to the workshop and had a look for the book in the middle of typing this. it sits here beside me. if you want I can scan the 28 pages of the complete building article and email them over to you. btw the most perfect glider approach and landing I've ever watched was completed by a little redheaded 17 year old girl in an air cadets camp. she was flying the club puchatec solo, bought it in absolutely wings level, rumbled the wheel on and came to a stop still wings level then just slowly sat a wingtip down. when she hopped out and rose to her full height she was only 4'8". what a little dynamo. there is plenty of evidence that these ideas can work. those air cadet camps used to solo between 10 and 30 kids every season. Stealth Pilot > my read of primary gliders years ago was that they fell out of favour > because of spinal injuries on hard landings. > Stealth Pilot ------------------------------------------------------------------------------------- That should probably read 'head & spine.' In the late 1930's they introduced an 'improved' primary having a strut from the nose of the skid to the forward end of the 'towel-bar' wing support. With only a SEAT BELT, these gliders soon became known by an assortment of colorful -- but true names: Head Splitter, Face Smasher, Jaw Breaker, etc. Since the program had grown into a bureaucracy it was impossible to immediately scrap the new, improved design and go back to the old version. Any of the 44xx series has a very good stall profile, especially if you fatten the thing up: 4415 or even 4418. With a wing that fat the stall is a sort of bobble rather than the nose-dives typical with the sharp-nosed Gottengein series. Indeed, the thing's glide ratio is no more than 8:1 if that. The use of a WHEEL instead of a skid alone goes a long way toward preventing nose-overs. Ideally, the novices are launched so their landing will be into an area of tall grass, which acts as a brake. As they become more skilled you can move to mown fields or even sand. The need for a shoulder harness connected far enough aft so as to prevent compression of the spine should be understood from the outset, along with the need for foot/shoe restraints. Ditto for a crash-hat. But I think the best 'instructor' is the kids themselves, watching -- and critiquing -- every flight. ------------------------------------------------------------------------------------- One of the best training devices is referred to as 'The Object' in a derisive manner. It consists of the SCHEMATIC of a glider mounted on a pivot. An engine fitted with a propeller blows on the thing and the student is required to keep it balanced. It sounds easy, especially if you're a pilot. Take it from me, it is damned difficult. But most youngsters master it in only two or three sessions -- often faster than an experienced pilot. Nowadays, I wonder if we could afford the gasoline. ------------------------------------------------------------------------------------------------- Whatever its short-comings, I contend that the primary glider is worthy of consideration for the simple reason that we have run out of other options. I see people giving themselves a pat on the back for turning out one or two pilots at a cost that would beggar the AVERAGE American, when what we need are literally THOUSANDS of new airmen. It's ironic that, given how much airmen have given to our nation -- from crop dusting to fighting fires and a thousand chores in between -- history will show that the one group we've failed to help is ourselves. -R.S.Hoover >Any of the 44xx series has a very good stall profile, especially if >you fatten the thing up: 4415 or even 4418. give me another name for the NACA 4418 :-) ...well 4417 if you want to pick nits :-) :-) >One of the best training devices is referred to as 'The Object' in a >derisive manner. It consists of the SCHEMATIC of a glider mounted on [quoted text clipped - 6 lines] > >Nowadays, I wonder if we could afford the gasoline. sounds awfully like fun doesnt it. the gyrocopters had something similar that just needed a stiff breeze and you could lift against a tether to a nearby post. I never proceeded on to fly a benson but that tethered machine was a lot of fun. >------------------------------------------------------------------------------------------------- > [quoted text clipped - 12 lines] > >-R.S.Hoover in australia we are 1 in 738 of the population. we get no end of nonsense heaped on us as a legacy of the poorly understood aviation safety culture, where a bolt missing is seen as a heinous crime needing extensive hand wringing and meaningless investigations. all coming from people who quite happily speed past each other separated by a 4 inch wide paint line thinking nothing of the risk. personally though I would plug for a slightly better glider. the indonesian airforce used a small number of winch launched schweitzer 2-32 gliders that made an incredible number of launces each flying day. we looked on with some envy at the use they made of those cute little yellow gliders towed up off Medan airport in the early 70's. I've never seen a published design for them though. if you have a look on www.fsglider.de there are a number of really cute gliders. (it is a flight simmers page) the DFS Habicht 6m looks a really cute design. with some modern building techniques I cant see any of these being beyond some supported and motivated kids. --- history will show that we allowed a group of government paid non flying stooges the world over to hold us to ransom to their 1930's certification system and allowed them to continually beat us into non existence. what a stupid lot we are to let it get to this. we need to phase out government paid aviation safety employees. Stealth Pilot (who ignores these non pilots and goes flying) > opinion without direct experience thankfully. Who said that? I am a CFIG who has instructed many kids in gliders. I imagine that some of them are in the front offices of Boeings and Airbuses by now. Before I took my first glider lesson I learned about kids and gliders by watching a master teach my own daughter. I watched her solo at the minimum age, safe within the bones of a Schweizer 2-33. You? Vaughn >> opinion without direct experience thankfully. > [quoted text clipped - 7 lines] > >Vaughn Bwahahahahahahahhh I reckon that I could tweak your levers and turn you into as much of a kookie boy as maxie. I'm almost starting to see Bertie's reasoning. for heavens sake the comment was prefacing my own paragraph. since you need it in braille I'll rephrase. I havent pranged a primary glider so my following comments are based on reading of other peoples experiences... and so forth as before. oh, and I was thankfull that I hadnt had the experience personally. CFIG ...baloney. You'd make more of an impression admitting that you were a FIG-JAM. Moi? I fly a Tailwind when I can get it all flying in formation together. My son flies gliders. My son in law is a flying instructor. my two year old grandson can sit in an aircraft and rattle off the prestart checklist. My daughter was laid flat on her back with grass allergies the entire time of the gliding school and never solo'd. The son in law intends to redress that when he gets the chance. and ...and ...and we do it all upside down!!! Stealth pilot from the land downunder. > Moi? > I fly a Tailwind when I can get it all flying in formation together. [quoted text clipped - 5 lines] > time of the gliding school and never solo'd. The son in law intends to > redress that when he gets the chance. So we have determined that you have no direct experience instructing in gliders. Thanks Vaughn >> Moi? >> I fly a Tailwind when I can get it all flying in formation together. [quoted text clipped - 11 lines] >Thanks >Vaughn were we supposed to? how many hours do you have instructing in primary gliders? veedubber was discussing ways to reinvigorate grass roots aviation cheaply and without the clamp of officialdom. now com'on you dont even know what FIG-JAM means do you? :-) Stealth Pilot veeduber@isp.com schreef: > Primary Gliders are designed to be dismantled. > (...) Could someone kindly elighten me as to the definition (more or less) of a PRIMARY glider? Does it mean one's FIRST glider? Or a glider for primary flight training? TIA? > veeduber@isp.com schreef: > [quoted text clipped - 3 lines] > Could someone kindly elighten me as to the definition > (more or less) of a PRIMARY glider? Try here: http://en.wikipedia.org/wiki/Primary_glider > Does it mean one's FIRST glider? No > Or a glider for primary flight training? The name probably came from its use in training. My one (departed) friend who had time in a primary did so as a member of the MIT gliding club in the 1940's. They would tow the glider with an old truck. The student was (naturally) in the glider, while the instructor sat in the back of the truck and yelled helpful hints through a megaphone. He never mentioned bungee launching, but for more advanced flights they converted the same truck to a winch by jacking up one rear wheel and attaching an empty wheel that served as a pulley. Vaughn > TIA? |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2009 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.