francisg Posted June 27, 2020 Report Share Posted June 27, 2020 To the Vintage Mooney Experts, I have a 63 M20C and would like to use Torx head stainless screws of the appropriate sizes. Is there any rule preventing from making the change? I am tired of chewed up and damaged Philipps head screws. Any input would be appreciated. FrancisG Quote Link to comment Share on other sites More sharing options...
RLCarter Posted June 27, 2020 Report Share Posted June 27, 2020 3 minutes ago, francisg said: I am tired of chewed up and damaged Philipps head screws For clarification are you talking about inspection panels? No idea on the regs but I can say this, A good quality screwdriver of proper size will eliminate a lot issues, also not over torquing them will make life easier 2 Quote Link to comment Share on other sites More sharing options...
47U Posted June 27, 2020 Report Share Posted June 27, 2020 Are you talking just the sheet metal screws on the cowling and (some) belly panels? Or the countersunk screws on the wing oval and rectangular panels, also? The wing access panels are structural. Finding conformance data on them might prove to be a hurdle too far. I have begun painting a thin stripe of anti-seize on the machine screws before I put them back in. I’ll run them up with a ‘yankee’ screwdriver and then tighten by hand. Use a new good quality #2 apex bit when you remove the screws and 99.9% of your stripped screw problems will disappear. tom Quote Link to comment Share on other sites More sharing options...
ShuRugal Posted June 27, 2020 Report Share Posted June 27, 2020 (edited) https://www.law.cornell.edu/cfr/text/14/appendix-A_to_part_43 Quote Preventive maintenance. Preventive maintenance is limited to the following work, provided it does not involve complex assembly operations: (12) Making small simple repairs to fairings, nonstructural cover plates, cowlings, and small patches and reinforcements not changing the contour so as to interfere with proper air flow. (26) Replacement or adjustment of nonstructural standard fasteners incidental to operations. [/Quote] additionally: https://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations/data/interps/2009/Coleal - (2009) Legal Interpretation.pdf Quote Even though the introductory text of [Appendix A] subparagraph states that “[p]reventive maintenance is limited to the following work… (emphasis added), in view of the broader definition of preventive maintenance in section 1.1, we believe that such limitation is not controlling. Similarly, for the same reason, we also believe that the following sentence in Advisory Circular 43-12A…is overly restrictive. That sentence…states: ‘If a task or maintenance function does not appear in the list, it is not preventive maintenance.’ As with the other paragraphs of Appendix A (i.e., on major repairs and major alterations), the lists are better viewed as examples of the tasks in each category—they cannot be considered all-inclusive EDIT: why is this website so freaking unusable? can i please have a plain-text edit mode? having two separate quotation blocks in one post should NOT cause the thing to freak out like this.... Edited June 27, 2020 by ShuRugal Quote Link to comment Share on other sites More sharing options...
Hank Posted June 27, 2020 Report Share Posted June 27, 2020 I bought teflon washers from Aircraft Spruce to put under inspection panel screws. It helps. Don't just use hardware store screws, the countersink angle on aviation screws is different 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted June 27, 2020 Report Share Posted June 27, 2020 I throw all the screws in a Dixie Cup (should I just call them cups?) and spray them with lube before you put them back In. They never stick. You can even use @Piloto favorite WD-40 1 2 Quote Link to comment Share on other sites More sharing options...
Jim Peace Posted June 27, 2020 Report Share Posted June 27, 2020 1 hour ago, N201MKTurbo said: I throw all the screws in a Dixie Cup (should I just call them cups?) I am offended....moderators please fine this person....... how about this? https://www.tmz.com/2020/06/26/master-bedroom-canceled-houston-realtors-texas-slavery-connotation-primary-bedroom/ 2 Quote Link to comment Share on other sites More sharing options...
Ross Taylor Posted June 27, 2020 Report Share Posted June 27, 2020 4 minutes ago, Jim Peace said: I am offended....moderators please fine this person....... Oh great... it just means biggest or best. Now what are fishing crews going to call the best baiter? Quote Link to comment Share on other sites More sharing options...
francisg Posted June 27, 2020 Author Report Share Posted June 27, 2020 To all well meaning Experts, i am talking in reference to all inspection panels, properly fastened with stainless Philips head screws. And yes, torqued to the required amount, coated with anti-seize and possibly with nylon or teflon washers (those are mostly effective in protecting the paint, not the “mangling of the Phillips head). Bottom line, i am still not sure i can use Torx. head stainless screws. Thanks to all for your input. FrancisG Quote Link to comment Share on other sites More sharing options...
Ross Taylor Posted June 27, 2020 Report Share Posted June 27, 2020 Sorry @francisg - we got a bit giddy and off topic. I think @ShuRugal was posting the owner maintenance rules as an indication that it’s okay...or I’m wrong. Quote Link to comment Share on other sites More sharing options...
ShuRugal Posted June 27, 2020 Report Share Posted June 27, 2020 Sorry [mention=9712]francisg[/mention] - we got a bit giddy and off topic. I think [mention=16465]ShuRugal[/mention] was posting the owner maintenance rules as an indication that it’s okay...or I’m wrong. That's my read.As long as the screws are not structural, part of control surfaces, or part of controls, there's nothing saying owner pilot can't replace them (provided the plane is only used for part 91 flights) 1 Quote Link to comment Share on other sites More sharing options...
francisg Posted June 27, 2020 Author Report Share Posted June 27, 2020 To all the well meaning contributors, I am only trying to keep my vintage "C" up in the air as best as i can do, and afford. I have been a long time follower of Mooneyspace and all it offers, maybe my desire to switch to Torx screws, teflon or nylonwashers, and antiseize, will not only help me, but anyone doing owner assist annuals, without having to fight the few striped and overtorqued screws from previous inspections. Once again i thank the Experts for all their wisdom. respectfully, FrancisG Quote Link to comment Share on other sites More sharing options...
Skates97 Posted June 27, 2020 Report Share Posted June 27, 2020 4 hours ago, Hank said: Don't just use hardware store screws, the countersink angle on aviation screws is different Don't miss the point Hank is making here. The challenge might be finding torx head screws with the correct countersink angle. Quote Link to comment Share on other sites More sharing options...
francisg Posted June 27, 2020 Author Report Share Posted June 27, 2020 To all the well meaning contributors, I agree that countersunk angle is a concern, but many of my cowling and belly panels use button heads. Finding the right countersink angle may be a problem, but having access to SoCal aerospace fastener manufacturrers may be helpful . respectfully, FrancisG Quote Link to comment Share on other sites More sharing options...
kortopates Posted June 27, 2020 Report Share Posted June 27, 2020 To all the well meaning contributors, I agree that countersunk angle is a concern, but many of my cowling and belly panels use button heads. Finding the right countersink angle may be a problem, but having access to SoCal aerospace fastener manufacturrers may be helpful . respectfully, FrancisG Although a pilot/owner is allowed to remove and replace screws under preventative maintenance as mentioned above, recognize the only approved replacement parts/hardware is listed in your IPC. Anything else is considered a alteration or modification. A minor modification can be approved by an A&P but not under preventative maintenance. Thus its best to seek the guidance of your IA performing your annuals before making modifications to avoid surprises later.Sent from my iPhone using Tapatalk 4 2 Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 27, 2020 Report Share Posted June 27, 2020 Francis, The coolest thing about certified airplanes... They have reliable results... There are thousands of M20Cs that continue to fly safely each year... All the documented parts have documented success... To start swapping things around for various reasons... opens things up to what will fail if I do this.... Essentially trading things out with something that sounds better... starts going down the path of the experimental world... Maybe you are a fastener expert, and know better... there is a simple process for that... Maybe you are a machine builder... read up on the FAA rules for that... If you are not sure what fasteners belong in your plane... they are listed in the manuals... Somebody put them there for a reason, and documented it... Are you familiar with truss head bolts? Why they are chosen? Simple question? What makes you want to go down this path? Lots of work with so little to gain... PP thoughts only... Best regards, -a- 3 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted June 27, 2020 Report Share Posted June 27, 2020 There are several issues with stripped screws. Stainless steel screws tend to bind in the plate nuts, cadmium plated steel screws don’t. The addition friction of driving stainless steel screws increases the wear rate of the Phillips drive. Worn and ill fitting screw drivers make turning screws against the additional friction difficult. Diamond Aircraft use 3mm stainless steel Allen drive screws on some airframes, they wear out for the same reason. Clarence Quote Link to comment Share on other sites More sharing options...
Mooneymite Posted June 27, 2020 Report Share Posted June 27, 2020 In my experience the best way to avoid hard-to-remove panel screws (and consequentially stripped heads), is to remove them every year and keep your plane in a hangar. The first annual on my plane virtually every panel screw posed a problem. I can only surmise that these panel screws hadn't been removed in years. Subsequent annuals had virtually no problem screws, (stainless, or cad). I also heartily endorse Hank's use of nylon washers in most places. Quote Link to comment Share on other sites More sharing options...
rbridges Posted June 27, 2020 Report Share Posted June 27, 2020 2 hours ago, M20Doc said: There are several issues with stripped screws. Stainless steel screws tend to bind in the plate nuts, cadmium plated steel screws don’t. The addition friction of driving stainless steel screws increases the wear rate of the Phillips drive. I did not know that. Quote Link to comment Share on other sites More sharing options...
Ross Taylor Posted June 27, 2020 Report Share Posted June 27, 2020 I have no idea if this is the case here...but in my most recent career, in wind turbine tech work, we found that stainless fasteners and nuts were more susceptible to galling (seizing) when driven in/on with motorized drivers. When spun on by hand, stainless nuts would go on normally...but when an electric driver or impact was used we'd get a high frequency of seized fasteners. The same happened with stainless bolts and screws. Anti-seize compound helped, but was not a 100% cure. We developed guidance for the installers that discouraged the use of drivers. But...like I said...I have no idea if that translates to a potential problem using a screwgun on the panel screws. PP thoughts only...not a professional torquerator (a tribute to -a-) 2 Quote Link to comment Share on other sites More sharing options...
Hank Posted June 27, 2020 Report Share Posted June 27, 2020 ^^^^ This is why I bought a fancy double-ratcheting screwdriver at Lowe's Christmas sale. Panel screws go in and out much faster. It's only part if why I strongly prefer owner-assisted annuals--not only do things get done in accordance with my desires, proper methods and FARs, but I see the condition of everything and am on hand if something unexpected pops up. I also keep screws and teflon washers on hand and replace any that are worn, stripped, cross-threaded or just hard to turn. It's a good thing when screws come out and go in easily! 1 Quote Link to comment Share on other sites More sharing options...
MB65E Posted June 27, 2020 Report Share Posted June 27, 2020 Stainless will Gall if you get them hot with a screw gun. My wing is all structural CAD screws. As an IA I would compare the strength of the screw listed for both the IPC screw and the ones you want to install. Citation switched to structural Stainless #10 torque countersunk screws in most of their airframes. I never stripped a single one, as long as I had a good bit. Genuine aircraft hardware has the best description and source for most fancy hardware. Cessnas screws actually had a Cessna PN. -Matt Quote Link to comment Share on other sites More sharing options...
cctsurf Posted June 27, 2020 Report Share Posted June 27, 2020 54 minutes ago, Hank said: fancy double-ratcheting screwdriver at Lowe's Christmas sale My IA suggested exactly this screwdriver for maintenance on my flying pile of screws (was just musing the other day with another pilot on how much all the screws on a mooney weigh). My wife bought the Lowes screwdriver for me pretty soon after the suggestion and I LOVE it. I'm a little disappointed when I get into an area I can't use it. To the OP's point, I would suggest cadmium plated screws over the stainless (as others have noted), but I think going to torx or something different would just interfere with maintenance (I understand the impulse, I love using torx when I get to in other situations). The Philips head screw is ubiquitous in the aviation business. You may find shops not equipped to work on your plane if you change to torx. I recently had a car battery fail next to an airport shop, when I begged the IA for tools to help with the replacement, he had no metric tools...I ended up using a pliers... I expect that very few shops are equipped to deal with torx. Just my $.02 Quote Link to comment Share on other sites More sharing options...
carusoam Posted June 27, 2020 Report Share Posted June 27, 2020 Buy lots of extra screws... Buy lots of extra driver bits... Toss driver bits and screws at first hint of trouble... PP thoughts only... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Hank Posted June 27, 2020 Report Share Posted June 27, 2020 42 minutes ago, carusoam said: Buy lots of extra screws...toss at first hint of trouble... This works well for me. 1 Quote Link to comment Share on other sites More sharing options...
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