INSTALLATIONS AND INSTRUCTIONS MANUAL. BWS-BASIC Manual Bug Wiper System

Transcription

1 BWS Pirker & Storka Bug Wiper Systems - Mückenputzer INSTALLATIONS AND INSTRUCTIONS MANUAL BWS-BASIC Manual Bug Wiper System - 1 -

2 BWS (Bug Wiper System) BASIC is a manually operated device for removing bugs, flies, beetles and debris from the wing of gliders and motor gliders during flight. WARNING To avoid collisions and other hazardous situations during the whole cleaning procedure, don t forget to keep an eye on other gliders and planes in your environment. Remember, the operation of the device is always done at your own risk and responsibility. For proper and safe use read the operations and installations manual carefully. Perform the cleaning in straight flight only at an air speed of approximately 120 km/h. Avoid turbulent air, also abrupt deflections of rudder and ailerons. Any stall might cause the wipers to fall off from the wing. Make sure that the retrieval cable of the device cannot get hung up by any parts of the wings like covers, zigzag tape, gap between ailerons and flaps, wheels at the wing tips etc. Cable deflectors and other protecting means might have to be installed! Check the quality of the retrieval cable before each take off and renew it, if you detect any wear or damage. Change it before each season. If the cable is made out of stranded metal wire, don t kink it. Be aware that damaged or worn out cables might break. Although the blades are light, fly in such a manner that in case of a down falling BUG WIPER it may not hit any other glider or plane. Be sure that the BUG WIPER is able to move freely on the wing leading edge up to the end of the unwound retrieval cable. Knobs or wheels near the wing tip might be a hindrance. Before take-off, test also by moving and pressing the BUG WIPER on the wing leading edge that the cleaning filaments (nylon strings) don t get caught at the gaps between the wing root and fuselage or between the outer and inner wing parts. The gaps might not have been sealed properly by a stiff plastic stripe or film underneath the adhesive tape. Don t repair the device BWS BASIC by yourself. This shall be done only by the producers or authorized persons. Inflictions on this, as well as any un-authorized modification of the BWS BASIC cause loss of warranty

3 General notes and remarks: Please, pay further attention to the following: The installation and operation of the BWS BASIC is done at your own risk and responsibility. We, the producers, don't take any liability for any damages caused by faulty installation or inadequate operation. Study the operations and installations manual carefully. Get familiar with the cleaning procedure. Improper operation might damage the BUG WIPER, the glider and might break the retrieval cable. If you operate the BUG WIPER system on ground by pulling out the BUG WIPER by hand, take care that if you wind up the cable again, it is never loose. Take care during up-winding that the cable is always under tension, otherwise you tangle the cable, get a cable mess and the reels might get stuck. In case of bad luck, you probably will have to renew the cables. The retrieval cable has a tensile strength of about 30 lb (15 kp). Exceeding this value will inevitably break the retrieval cable, causing the loss of the BUG WIPER blades. Do not overstress the metal BUG WIPER blades by pulling them too strong towards the fuselage, by flying too fast, dropping them on the floor, stepping on them accidentally or by bending them in any other careless action. Deformed BUG WIPER blades don t work properly and may need a careful re-bending or replacement. BUG WIPERS made out of carbon fibre are somewhat stronger and more resistant against rough treatment. Before you start with the installation, please read the complete instructions thoroughly and accurately

4 Explosion drawing of the hand wheel: Supporting frame Fixing screw for shaft Casing of the manual reel wheels Fixing screw for casing Fixing screw for the support of grip Manual reel Reel nipple Shaft Brake pressure plate Sinter bronze bearing, maintenance-free Brake pressure plate Washer protection against torsion Locking button Support for the grip Grip Nut Saefty screw Spring 1) List of parts and components: The manual system BWS BASIC comprises the following parts: 2 x Bug Wipers with cleaning filaments (nylon), one for the left and one for the right wing 2 x Manual Retrieval Cable Reels with Reel Locking Thumbscrew, one for each Bug Wiper 1 x Supporting Frame for attaching the Reels to the cockpit side rail 2 x Bowden Cables for guiding the Retrieval Cable 2 x stranded steel or DINEMA Retrieval Cables of about 30 lb (15 kp) tensile strength, length according to wing span 2 x brass or aluminum Cable Duct Nipples for the holes in the fuselage 4 x Cable Fasteners for the bowden cable - 4 -

5 BUG WIPER for the right wing Locking thumbscrew Supporting frame Nipple Retrieval cable Cable duct nipple for fuselage hole Manual retrieval cable reel Bowden cable Bowden cable fastener Cable duct nipple for fuselage hole Cleaning filament (nylon) Cable guide eyelets in the driving frame of the bug wiper Retrieval cable Cable guide eyelets in the stabilizing frame BUG WIPER for the left wing 2) Layout, position of the parts: 2.1) Layout of the retrieval cable: Depending on the span and type of glider the retrieval cable may be led and connected to the BUG WIPER above or below the wing. To position the retrieval cable on the upper side of the wing has the advantage that in case of gliders with large wing span the cable will not get caught so easily by the gap between the ailerons and the flaps or by the zigzag tape at the underside of the wing as the cable will be well above the wing during the cleaning process

6 Especially gliders from Schleicher tend to catch the retrieval cable at the underside of the wing in the aileron. The mounting of the retrieval cable on the upper side of the wing is therefore favoured for some of these gliders. For all other gliders the retrieval cable is located under the wing. 2.1) The retrieval cable under the wing Bug wiper for the right wing Manual reels with locking button and supporting frame Retrieval cable under the wing Bowden cable Retrieval cable under the wing Cleaning nylon Bug wiper for the left wing - 6 -

7 2.2) The retrieval cable above the wing Bug wiper for the right wing Cable reels with locking thumbscrew and supporting frame Cleaning nylon Retrieval cable above the wing Bowden cable Retrieval cable above the wing Bug wiper for the left wing 3) Installation of the Bug Wiper System 3.1) Mounting the Cable Reels: Attach and fix the Cable Reels with the supporting frame to the right cockpit wall by using in dependence of the type of glider: structural adhesive, 2 minutes epoxy adhesive, pick up closure, 3M hook & loop reclosable fastener tapes, 3M pressure sensitive tapes, simple screws or door tie screws etc. Before mounting get into the glider and find out for yourself the proper position of the cable reels. Take care that the operation of the various control levers and knobs in the cockpit is not compromised

8 Examples for mounting the cable reels Fixing with 2 minutes epoxy adhesive or hook & loop fastener tapes: Canopy Hook & loop fastener tape or pressure sensitive tape or 2 minutes epoxy adhesive etc. Pik 20D ASW 20 ASW 24 ASW 27 ASW 22 ASW28 ASH 25 Screw on: Canopy Flat head screw Hook & loop or doublesided adhesive tape as a safeguard against twisting Ventus Discus Nimbus 3 Nimbus 4 Mini-Nimbus Jantar Jantar 2B SZD 55 Screw on: Canopy Canopy DG 100 DG 300 DG 400 DG 600 DG 800 DG 1000 LS 3 LS 4 LS 8 LS 10 Supporting plate (is not part of any delivered bug wiper set) Flat head screw with plate and nut. Gate volume screw with plate and nut

9 Note direction of rotation! Unwind counter clockwise, wind up clockwise! Wind up clockwise Unwind counter clockwise Supporting frame Casing of the manual reel wheels grip Manual reel Locking button Reel nipple Bowden cable Spare threaded holes for screws are provided in case an additional mounting plate has to be screwed to the supporting frame Supporting frame - 9 -

10 3.2) Drilling a hole in the fuselage wall for the aluminum cable duct nipples: To be able to lead the retrieval cable from the manually operated reels inside the fuselage out to the BUG WIPERS at the wing roots you have to drill a hole at each side of the fuselage with a diameter of 5 mm. Proceed as follows: 1) Rig the glider 2) Seal the gap between the fuselage and the wing root by a tape. 3) Mark the location of the hole: According to the following figures fold up the BUG WIPER and place it on the wing in retract position. Push the BUG WIPER up to the fuselage and use a scriber, a thin long pencil lead or a thin drill to mark the location of the hole on the fuselage. To do this, the scriber, lead or drill has to be stuck through the cable guide eyelets of the BUG WIPER. The gap between the wing leading edge and the BUG WIPER should be about 0,5 to 2 cm, but not less to prevent squeezing of the BUG WIPER in the retract position. During the marking the wing-fuselage gap has to be sealed by an adhesive tape. 4) Remove the BUG WIPER and drill a hole with a diameter of 5 mm at the marked position. Take care not to damage the wing by the drilling machine. To be on the safe side dismount the glider. 5) At gliders with double board walls, like Ventus or Discus, drill the holes of the outer and inner wall in one operation, drilling in the proper direction. Then enlarge the hole of the inner wall by drilling it up to 17 mm so that you are able to stick the cable duct nipple through it from inside the cockpit into the hole of the outer fuselage wall where you fix it with an epoxy resin adhesive. Retrieval cable below the wing A Schnitt A-A Detail X A

11 Retrieval cable above the wing A Schnitt A-A Detail X A Detail X for the retrieval cable below the wing Underside of the wing Wing Gap space between fuselage and wing root Tape Lead pencil or thin drill Mark the hole here Fuselage Wing BUG WIPER Mark the hole here 0,5 2 cm Distance depends on the type of the glider

12 Detail X for retrieval cable above of the wing Top side of the wing cable guide eyelets for the retrieval cable in the driving frame and stabilizing frame of the BUG WIPER. Mark the hole here Tape Wing Space between fuselage and wing root Fuselage Mark the hole here Distance depends on the type of glider 0,5 2 cm Wing BUGWIPER

13 3.3) Mounting the fuselage cable duct nipples: 3.1) for gliders with a single cockpit and fuselage wall : e.g.: LS 3, 4, 6, 7, ASW 20, 22, 24, Pik 20 E, Jantar 2, 2b, Nimbus 2, 3, 3D, DG 300, 400, DG500, 600. Saw off the cable duct nipple to the correct length and smooth the rim of the nipples hole with a triangular scraper or sharp knife carefully. Stick the nipple into the fuselage hole and glue it with a 2 minutes epoxy adhesive. 3.2) For gliders with a double cockpit wall e.g.: Ventus, Discus Stick the bowden cable nipple from inside through the 17 mm diameter hole into the 5 mm hole from the outer wall and like for the gliders with a single wall cut off any exceeding length of the nipple after marking and rounding off the inner border or rim of the nipples hole. Glue in the nipple by quick hardening epoxy adhesive. 3.4) Installation of the bowden cable: Lay the bowden cable from the fuselage nipple to the nipple at the retrieval reel. Cut the bowden cable to appropriate length. Fix the bowden cable on suitable places in the cockpit with the enclosed fastening adhesives. AQvoid any S- loops or any other superfluous loops or bending. bad bad good

14 Procedure in detail: Shorten the bowden cable to the right length with a cutting tool. Prepare the ends of the bowden cable before sticking them into the cable duct nipples. Make sure that the Teflon tube inside the bowden cable is not crushed or squeezed. If necessary open the end of the tube with a tapered or sharpened nail. Cut the bowden cable with a cutting tool Trim the bowden wire. Remove sharp edges totally!! Bowden wire Sharpened nail black plastic coat Teflon tube Starting from the fuselage cable duct nipples fix both bowden cables by the use of cable fasteners to the cockpit wall according to the following examples:

15 Some examples for the Installation of the bowden cable. Nimbus 2, Nimbus 3, Nimbus 3D, Nimbus 4D, DG 200, DG 300, DG 400, DG 500, DG 800, DG 1000 ASW 20, ASW 27, ASW 28, ASW 22, ASH 25, ASH 26, Rear wall Bowden cable without S-bows Back rest Wing leading edge Bowden cable fastener Cockpit Double board in the fuselage (only Nimbus, Ventus etc.) ASW 24: On the right side of the fuselage you will have to drill a little bit upwards with a slope or inclination of about 30. Drill in such a manner that the bowden cable still goes a little bit through the driving work cover. Drill on the left side like for ASW 20 etc. ASW 20, ASW 27, ASH 25 Driving work cover

16 Discus and Ventus oblong hole Bowden cable fastener LS 3, LS 4, LS 6, LS 7, LS 8 Bowden cable fastener 3.5) Drawing the retrieval cable into the bowden cable 1) If the retrieval cable is already wound up on the reels: Push the end of the retrieval cable by hand through the cable duct nipple at the reels and the bowden cable until it comes out from the fuselage hole at the wing

17 2) In case the retrieval cable is not previously wound up on the reels it is better to push the retrieval cable from outside through the hole at the fuselage into the bowden cable and then to tie it to the cable reels according to the figures below. 3.6) Tying the retrieval cable to the reel: According to the figure knot a self contracting sling around the cross-piece between the two holes of the reel. NOTE: an improper knot might reduce the tensile strength of the retrieval cable by about the half (!!). Therefore, test by an appropriate device (for instance: spring balance) the tensile strength of the cable with and without a knotted loop and make sure that the cable plus knot provides a minimum tensile strength of about 30 lb (15 kp). Example of a suitable knot 3.7) Cutting the retrieval cable to length Take the end of the retrieval cable and draw it to the wing tip until the whole cable is wound off from the reel and tensioned. Cut now the retrieval cable so that the cable end does not reach beyond the wing tip - or that the BUG WIPER when attached to the cable can not come closer to the wing tip than approximately 20 cm. ca. 10 cm The bug wiper shall not come closer to the wing tip than 20 cm

18 3.8) Forming a loop at the end of the retrieval cable. To be able to secure the retrieval cable to the BUG WIPER a loop has to be made at the end of the cable. Form the loop and fix it by a knot. If the retrieval cable is made of a steel stranded wire which is coated by plastic then you can fix the loop by melting the coating together by using the fire of a pocket lighter. However take care that the plastic melts only and does not burn. Should the retrieval cable be of stranded steel wire without any coating, then the loop can be soldered with soft plumb line (electronic solder). retrieval cable Form a loop and make a knot 3.9) Securing the retrieval cable to the BUG WIPER (applies to all types). Insert the loop of the retrieval cable into the eyelet of the small stabilizing frame, then pass it onwards through the corresponding eyelet on the big driving frame, then through the adjacent eyelet and finally hang the loop on to the hook. Then tighten the cable a little bit. BUG WIPER Driving frame Stabilizing frame Eyelet of the stabilizing frame Retrieval cable Eyelet of the driving frame, opposite to the stabilizing frame Hook Critical place for cable wear. Adjacent eyelet in the driving frame

19 3.10) Fixing the BUG WIPER to the fuselage in the retracted and collapsed position After having secured the retrieval cable to the BUG WIPER, ask somebody to hold the BUG WIPER and to tension the retrieval cable, while you operate the manual reels to up wind the cable and to pull the BUG WIPER to the fuselage until it collapses and comes to a stand still at the retracted position. Then lock the reel by rotating the locking thumbscrew to prevent any reverse movement. NOTE: Be sure that the cable is always tensioned during the up winding and retracting to the fuselage. NOTE: Take care not to exceed the tensile strength of the retrieval cable (30lb, 15 kp) with your hand force! 3.11) Replacing the nylon cleaning filament by a new one: If the cleaning nylon should break, then install a new one by the following steps: According to the figure below draw in a new nylon filament of 0.2 mm diameter and 3 4 kp tensile strength through the appropriate eyelets to form an endless loop. To adjust for the proper length place the BUG WIPER on the wing about 20 cm away from the wing tip. There, the profile is the thinnest. Now, knot the nylon filament in such a way that by pressing the BUG WIPER against the wing leading edge only the filaments and NOT the drive frame comes into touch with the wing leading edge, otherwise the filaments would not be able to shear off the bugs from the wing

20 Retrieval cable below the wing 4 knots, bind filament also to the stabilizing frame Cleaning nylon Wing leading edge retrieval cable under the wing Distance between driving frame and wing leading edge shall not be less than 5mm (measure near the wing tip). (There will be no cleaning effect if the bug wiper slides on the driving frame and not on the cleaning filaments.) Retrieval cable above the wing 4 knots Retrieval cable above the wing and cleaning filaments Wing leading edge Distance between driving frame and wing leading edge shall not be less than 5mm at the thinnest part of the wing near the wing tip

21 Cleaning nylon Wing 5 mm BUG WIPER The distance between driving frame and leading edge shall not be less than about 5 mm at the thinnest part of the wing. 3.12) Tapeing the gap between the inner and outer wing To avoid that the filaments might get caught in the gap between the outer and inner wing of open class gliders etc. you have to bridge this gap in the right manner. Use a stripe of about cm length you might cut out from an overhead foil, from a film or the plastic cover of a folder and put it over the gap in the front area of the wing. Then cover this area with a thin adhesive folio or with thin adhesive tapes you are using normally. NOTE: It is Important to test the tapeing by simulating the cleaning procedure by pressing the BUG WIPER on to the wing leading edge and by sliding it over the taped area. The filaments should pass without getting caught. It might be also beneficial to cut a horizontal V at each side of the tape at the wing leading edge so that the filaments which run rectangular to the cut get heaved over the tapes. broad tape thin tape Gap between two wing parts stiff foil, film, stiff plastic tape or strip which prevents the falling in of the more softer tapes Perhaps cut a horizontal V into the tapes

22 4) Pay increased attention to the following points: 4.1) If you install the bowden cable take care that the bowden cable is as short as possible and does not have any S-bows. The bowden wire could add unnecessary drag during operation. 4.2) If the retrieval cable is of stranded steel, greasing with Vaseline helps to reduce the drag. 4.3) Before each launch examine the retrieval cable against wear, especially in the region of the BUG WIPER. If the cable is damaged replace it by a new one. 4.5) Change the retrieval cable each season to avoid unexpected cable break and loss of the BUG WIPER. 4.6) Warranty cannot be given for the retrieval cable. So be careful not to vulnerate the cable. Examine that there are no sharp edges anywhere in the system which might scratch or cut the cable apart. 4.7) Operate the BUG WIPERS carefully and keep in mind that with your hand power you can easily exceed the tensile strength of the cable of about 30lb (15 kp), especially when the BUG WIPER folds up at the end of the cleaning procedure. Also if the BUG WIPER should get stuck on the wing whatever reason might be the cause don t just tear on the reels and try to pull the BUG WIPER in by force. The cable will inevitable break and the BUG WIPER gets lost. For this reason warranty for the retrieval cable cannot be given!! - Also not for the lost BUG WIPER, in such a case. 4.8) Take care that by replacing the cleaning filaments (nylon) the filaments are not too long, because then they would run on the frames and not on the filaments. On the other hand, don t make them too short as the BUG WIPERS might not slide so well on the wing and the elastic nylon filaments might get overstrained at high flying speeds and therefore might break. If the filaments have the right length, at high speeds the BUG WIPERS not only run on the filaments, but also on the drive frame which in this case is a safeguard against over tensioning 4.9) During the cleaning procedure don t stall or spin, otherwise you loose your BUG WIPER. 4.10) If the BUG WIPER falls off the wing during the cleaning procedure and trails behind the aircraft, then use the reels to retrieve the BUG WIPER, reel them to the wing root / fuselage junction until it collapses there and gets fixed. Leave it there until you land. The flight does not have to be aborted in this case. After landing, put the BUG WIPER on its correct place again

23 5) OPERATIONS INSTRUCTIONS 5.1) Before take off: 5.1.1) Check the retrieval cable: The retrieval cable is a part which is subject to wear: NOTE: Therefore, it is evident that if the cable breaks and the BUG WIPER gets lost, that this is considered to be a faulty operation of the BUG WIPER system. The manufacturers in this case will not replace the lost BUG WIPER by a new one without charging it (!!). For this reason, the cable has to be checked prior to every flight. An early wear results from the following: 1) inferior installation of the bowden cable, 2) sharp edges at the ends of the bowden cable, 3) wrong cranking direction of the reels to wind up or wind off the retrieval cable. The retrieval cable should only be wound up by turning the reels in the clock wise direction and wound off in the anti clockwise direction - otherwise the cable might be not in line with the bowden cable and nipple and therefore might scratch at the edge of them. How to check the retrieval cable: Take the end of the retrieval cable, pull it out until the whole cable is wound off from the reel. Examine the cable thoroughly. If the cable is in a bad state: change it! Especially critical is the region near the BUG WIPER where the collapsing process causes the greatest stress. If the last part of the retrieval cable in the region of the BUG WIPER is affected only, then it is sufficient to shorten the cable in the following manner: cut off the inferior end of the cable, form a new loop and hook it again to the BUG WIPER ) Mounting of the BUG WIPERS: In case the BUG WIPERS are not mounted yet: For each BUG WIPER: pass the loop of the retrieval cable through the proper eyelet of the stabilizing frame (see figures on page 20 and 21), then onwards through the corresponding eyelet of the opposing driving frame, and finally through another eyelet of the driving frame back to the inner side of the driving frame to hook the loop of the cable to the clip on the inner side of the driving frame

24 The BUG WIPER must be set on the wing in such a manner that the smaller of the two folding frames, the stabilizing frame, is adjacent to the fuselage. Up wind the retrieval cable by cranking the reel until the BUG WIPER has collapsed completely. NOTE: Do not apply unnecessary high tensions and hand forces, because the cable has only a tensile strength of about 30 lb or 15 kp. If you exceed this limit the cable might break. So take care. Lock the reel by rotating the locking thumbscrew ) Improving the cleaning efficiency: To improve the cleaning efficiency of the BUG WIPER System be sure that the wings at the wing leading edge are as slippy as possible. For this reason treat the wings with polish and wax which may also contain Teflon to close the pores of the surface. This hinders the bugs to stick too much to the wing surface. If you don t do this, there might be some tough bugs which clinch really fast to the wings and the BUG WIPERS will tend to smear them along the surface. But if you have prepared the wings properly the bugs will just fall off easily when the BUG WIPERS pass by on their cleaning journey. 5.2) During flight: 1) Select the side which you want to clean. 2) Clean in straight flight. 3) Fly with approximately 120 km/h. 4) Operate the corresponding reel (for the right or left wing). 5) Unlock the reel by rotating the locking thumbscrew. 6) After unlocking the reel hold the crank of the reel to avoid uncontrolled movement of the BUG WIPER. 7) By cranking the reel move the BUG WIPER along the wing leading edge to the wing tip. 8) Then reverse the cranking direction to pull in the BUG WIPER until it folds up again completely at the wing root. 9) Turn the reel a little bit further to apply a modest amount of tension to the retrieval cable. 10) Lock the reel by rotating the locking thumbscrew in the right direction

25 NOTE: Very important: If you let the reel unwind itself the BUG WIPER might move out to the wing tip with high speed. In this case take care to stop the movement before the retrieval cable has unwound itself completely (some meters before the BUG WIPER reaches the wing tip) otherwise the cable will break by the sudden jerk at the end of the unwinding and the BUG WIPER will be lost!! To slow down in time you can grip the rim of the cable drum with your fingers to apply appropriate friction to it. To avoid this risky situation unwind the cable in a controlled manner by cranking the reels with your hand. NOTE: During cleaning, take care not to stall the wing, especially in turbulent weather. The BUG WIPER might fall off the wing. In case this happens, with some luck, by winding up the retrieval cable you might bring it back to the fuselage where it folds up and gets fixed by the cable. After landing you can set it back into its correct position. Mostly, the cable will rupture and the BUG WIPER gets lost. NOTE: Avoid big and abrupt deflections of the ailerons and the rudder. They have a big influence on the movement of the BUG WIPER and the sag of the cable. Always keep an eye on the BUG WIPER during the cleaning process. NOTE: Be sure that the BUG WIPER slides on the cleaning filaments and not on the drive frame, except at high speed, where the BUG WIPER slides on both due to the elastic nylon filaments and the high pressure. NOTE: If for some reason the BUG WIPER moves too slow to tension the retrieval cable properly, the cable might get blown behind the wing. Problems may arise from this if there is a gap between the flaps and the ailerons or if there are some extensions on the wing: The cable might get stuck on the wing. If you try to reel them in without any success, don t get nervous, just keep cool: DON T try to retrieve the BUG WIPER with too much hand power otherwise the cable will break and the BUG WIPER gets lost. The BUG WIPER may stay there on the wing till you land. Afterwards, you can put it on its right place again. Take actions to prevent another hang up of the cable. In other words: NOTE: Take care that proper precautions have been taken to prevent the cable to get stuck in gaps between aileron and flaps (seal them), or loose zigzag-tapes (be sure that they are not loose, tape them on the rear side) or covers of steering elements (add appropriate cable deflectors) or at any other extension on the wing. 5.3) After flight: 1) To avoid damages to the BUG WIPERS on ground, in the hangar, during derigging of the glider, it is advantageous to unhook the BUG WIPER from the retrieval cable and to store it in a safe place. 2) Stick a match or safety pin into the loop at the end of the cable to prevent that the cable slips into the bowden cable. Tighten the cable by turning and locking the cable reel

26 3) If you don t want to detach the cable from the BUG WIPER, you can also store the BUG WIPER in the cockpit with the cable attached to them. Close the canopy carefully and pay attention not to squeeze the cable. 6) MAINTENANCE: 6.1) Retrieval cable: Check the retrieval cable before each flight. If you notice any wear or damage then replace it. Depending on flying hours renew it from time to time or at least each season. 6.2) Manual reels: The reels comprise bearings made out of sinter bronze which are maintenance-free. However, it is not bad to lubricate them after each season with a drop of sewing lubricating oil. 6.3) BUG WIPERS Normally don t need any maintenance. Clean them from time to time, apply some wax and perhaps a drop of oil on its opening spring. Take care not to bend or deform the metal BUG WIPERS. In case this has happened a careful re-bending to its original form has to be made to enable proper operating again. BUG WIPERS made of carbon are somewhat more robust and in spite of rough treatment tend to keep their shape. The cleaning filaments might break (rather seldom) and then would have to be replaced by new once (see page 19)

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