8/9/2019 EASA M6 Study Notes

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Threads

- Buttress thread can bear unidirectional load- One complete turn of a single start thread moves the bolt 1 further - Tapering of a tapered pin is 1:48- Unified Thread (B ! is mar"ed #ith ( ooo !- $ heli-coil insert fits tightl% to the hole- $&' (B ! is a pan head scre#- )oc"#ire is set at 4 degrees to the fastener

- *ith a pre-load indicating #asher (+),! a boltcan be tightened to a pre-determined tor ue

.ivets

- )/0 aluminum B rivet has blac" anodic color #ith ( , ! mar"ing- $ll rivets come pre-lubricated b% the manufacturer - onel rivets are used for nic"el allo% sheet fastening- .ivet pitch depends on rivet diameter - The rivet head mar"ing indicates the rivet material t%pe- &'42' 4-4 is used for fastening & 3 ' '/& material

+iping

- 5lares are not used #ith rigid heav% load tubes- 6igh pressure hoses have smooth surface finish- 5le3ible hoses are measured from the outermost part of the nipple- /7/& is the minimum clearance bet#een the piping

*ood

- The moisture nominal in #ood structures is around 1&- ealing of #ood is critical- 9asein adhesive trac"s must be scraped off completel% before ne# adhesive is

applied- +henol-formaldeh%de resin cannot be used for structural #ood repair - pacing bet#een t#o splices or bet#een a splice and a reinforcing palte should be

no less than / times the length of the longer splice- ample oint destructive testing is carried out after actual oint adhesion

5abric

- ,nspection rings are installed onl% on the bottom #ing part unless installed on the

top b% the manufacturer - ;rain holes should be cut onl% #ith small blade "nives- +ol%ester cover lasts around &'-/' %ears- $ll overlapped and doped seams shall be made onl% over underl%ing support

structures e3tending bac"ing the full #idth of the seam- +ol%ester is the most light#eight cloth

prings

8/9/2019 EASA M6 Study Notes

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- Belleville springs are cone #asher springs #ith short a3ial length- Overheating ruins the spring- pecial rig test is used for spring testing- pring inde3 is the ratio of mean coil diameter to #ire diameter < 9=;7d

Bearings

- pherical roller bearings resist high radial and moderate a3ial loads- Thrust bearings resist a3ial loads onl%- Thrust bearings cannot be used high speed rotational loads- 9ontrol cables use sealed bearings- >eedle bearings resist high radial loads- Tapered roller bearings are used in #heel hubs

Transmissions

- +lanetar% gears align input and output shafts- $ pattern determines the mating of gears- )ash and pattern are crucial for correct gear operation- >o load pattern is ideall% in the middle- The smaller gear tooth end is called ?toe:

9ontrol cables

- 9able direction change is obtained #ith pulle%s- 9ontrol cables are cut onl% #ith chisel@ anvil and hammer

Alectrical cables and connections

- $* $)0 is the smallest aluminum #ire gauge in use- $ stone "e% is used for correct mating of plugs and soc"ets- ;esign number is never put on the bac" shell- *ires are bundled together according to function- Bac" shell is put to ensure a good connection- 9rimping soc"et to #ire distance is 1710