Volume 8 No 3 Jun 1957.pdf - Lakes Gliding Club

Glider Maintenanceby R. C. Stafford-AlienThis article is the first chapter ofa "Maintenance Handbook" which will be published by theBritish Gliding Association. The aUlhor, who look a leading part in reviving the Oxford GlidingClub after the war, is now Manager ofthe London Gliding Club. The purpose ofthe beok is 10help privale owners, and people operaling gliding clubs in OUJ-of-1h£-way places, to keep thei,.machines in a good Slale ofairworthiness; and it should also be useful to the man who hopes10 get B.G.A. approval for his work.E may define Maintenance as work sort of toffee-apple of dust, sand and mudW carru;d out on a glider to prevent forming around the hinge. To strip everydeterioration, or to delay its effects, while hinge is a long job. Now, heavy oil doesrepairs may be defined as operations to creep into the bearing surfaces, and it doesrectify damage. These two definitions are not take long to go round a. glider and put aclearly not perfect since they do, in a sense, drop on each hinge.overlap. However, they are good enough The points which do require regularfor our purposes.attention are as follows:-Let us deal with Maintenance first. How- 1. The release hooks.ever much money we layout on the pur- 2. All control surface hinges.chase of a brand new "Super-Heaven" sail- 3. All pulley bearings (bearings onlyplaner it will, from the moment we take please).delivery, begin to deteriorate. But, by 4. Stick bearings and torque tubetaking a little thought, and putting in some bearings.work on it, we can keep that sailplane in 5. All control lever bearings and the pinsvirtually brand new condition. The first which connect the levers to the rods orthing we must deal with is:-Lubricationcables.6. Landing wheels unless of the sealedball-bearing type.It is more or less axiomatic that, wheremetal rubs on metal, some lubricant should You cannot do any hann by overbeused to reduce friction and pre1tent wear. lubricating provided (and this is important)In the general structure and control system the oil orgrease goes where it is meant to go.of gliders, the moving parts are all slow- You can do a good deal ofharm by allowingmoving, and fOr this purpose the best oil or grease to get into places where itlubricant is a good quality grease. Un- should not be. Therefore take great carefortunately most manufacturers are rather that no lubricants get into the wrong places.stingy in the matter offitting grease nipples, These are as follows:-which enable grease to be pwnped in with a I. On to any timber. If left, the timbergrease gun. Unless this can be done, it is will soak up the oil and eventuallyextremely difficult to get the grease into a become rotten.bearing, and no amount of grease slapped 2. On to any fabric. The same ,willon the outside of a bearing dOes any good happen.at all. Probably the best method may be 3. On to any cables. The result of this issaid to be: "take it apart, grease it, and put that the oil, or grease, will collect gritit together again." - and form a grinding compound whichThere is a good deal to be said for the use will wear away the cable where itof heavy oil, about SAE 140, for control passes over pulleys, or through fairsystems, particularly for control surface leads.hinges. Where the latter are of the usual 4. On to any rubber. If left, the rubberpin-and-split pin type, the only satisfactory will dissolve into a horrid sticky mess.way to get grease into them is by taking If you should accidentally spill a little o~them apart. Slapping grease on the outside in any of these places, wipe it up at once; Itonly seems to result in a frightful-looking will save you a lot of work in the end.-126-