---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Tue 12/27/11: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:20 AM - Re: Propeller diameter (Karl Heindl) 2. 05:57 AM - Thanks Bud (William Daniell) ________________________________ Message 1 _____________________________________ Time: 03:20:52 AM PST US From: Karl Heindl Subject: Europa-List: RE: Propeller diameter The recommended prop diameter maximum can be extended by replacing the nose gear shaft with a longer one. My propeller is 69 inches without any loss o f ground clearance. This clearance is vital when operating from a bumpy and /or soft field and should be at least 12 inches. Karl From: budyerly@msn.com Subject: Re: Europa-List: Will=2C Max prop diameter is still 64 inches recommended. This is based on the prop clearance of course. In the tri gear clearances are based on spring or bungee with the by the book cable stop dimensions per the build manual. This leaves nominally 10-11 inches from the prop tip to the ground (aircraft unloaded=2C nose tire inflated at 35 psi. and t he CG at 60 inches) in most of my aircraft. At full deflection of the gear at full gross weight=2C this gives 7-8 inches of clearance. (Yours may be different due to main gear installation.) FAA requirements for minimum propeller clearance: Sec. 25.925 Propeller clearance. Unless smaller clearances are substantiated=2C propeller clearances with the airplane at maximum weight=2C with the most adverse center of gravity=2C and with the propeller in the most adverse pitch position=2C may not be less than the following: (a) Ground clearance. There must be a clearance of at least seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with landing gear statically deflected and in the level takeoff=2C or taxiing attitude=2C whichever is most critical. In addition=2C there must be positive clearance between the propeller and the ground when in the level takeoff attitude with the critical [tire(s)] completely deflated and the corresponding landing gear strut bottomed. Europa nominal clearances: If installed by the book at 2 inches (full cable extension)=2C crossed properly so the cable cannot slip off=2C with a deflated nose gear tire=2C there is at least 4 inches of clearance on my new builds putting a full 300 pounds on the front of the engine. That will keep you from mowing the grass and or plowing a furrow with your 64 inch propeller if the nose gear tire fails on a rough landing or rough strip. 12 AY flew with the gear leg bolted solid in an attempt to install a longer prop. I don't recommend it. It's a bit harsh on a rough strip so to prevent fatigue I installed the springs shortly thereafter and shortened my cable stop to allow a total of 1 inch of movement until contact and a bit more on full extension. Longer answer on install and extended life operations notes: On installation=2C Chapter 29T says to pull the gear leg up (without springs or bungee) and swag the cable at two inches from the stop to the leg. I clamp (using a bolt type cable clamp) the cable at that distance with the gear leg pulled to check full tension on the cable. When satisfied=2C I then swag the cable. This gives 8 inches clearance as stated above. In the field=2C because the spring or bungee is attached normally=2C I use the one inch (two fingers) method to check if I need to re-swag the cable because of poor installation or cable stretch. I find the cable easy to pull down firmly from under the aircraft and check the distance. To check the springs I place my full body weight (180 lbs.) at the hub to deflect the springs the full amount for a quick check. When doing maintenance on other aircraft I have found that the cable will stretch a bit more than new which puts more strain on the springs. Occasionally I have seen on trigears which have operated extensively on grass=2C and the cable stop either was installed improperly or it had loosened and had not worked as advertised (it slipped off the lower leg) and this caused the springs to become weaker under severe grass strip operations. (Thirty pounds at the hub caused the springs to deflect which is unacceptable.) It is not fun to cut those springs off and replace them because they no longer hold the nose gear firmly on the stop. So it was a personal decision to go tighter than looser on the cable stop t o prevent this from happening. Regards=2C Bud Yerly Europa Tech Support 813 244-8354 ----- Original Message ----- From: William Daniell To: europa-list@matronics.com Sent: Tuesday=2C December 20=2C 2011 8:34 AM Subject: Europa-List: I am sure that this has been posted many time but to avoid having to hunt through the archives - what is the max prop diameter for a Trigear? Will href="http://www.aeroelectric.com">www.aeroelectric.com title=http://www.buildersbooks.com/ href="http://www.buildersbooks.com" >www.buildersbooks.com href="http://www.homebuilthelp.com">www.homebuilthelp.com href="http://www.matronics.com/contribution">http://www.matronics.com/chr ef="http://www.matronics.com/Navigator?Europa-List">http://www.matronhref ="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 2 _____________________________________ Time: 05:57:44 AM PST US From: "William Daniell" Subject: Europa-List: Thanks Bud Bud Thanks very much - as usual a very complete answer! Oh. and may I take the opportunity to wish you a very prosperous, successful and above all safe 2012. Yours Will From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Bud Yerly Sent: 26 December, 2011 17:19 Subject: Re: Europa-List: Will, Max prop diameter is still 64 inches recommended. This is based on the prop clearance of course. In the tri gear clearances are based on spring or bungee with the by the book cable stop dimensions per the build manual. This leaves nominally 10-11 inches from the prop tip to the ground (aircraft unloaded, nose tire inflated at 35 psi. and the CG at 60 inches) in most of my aircraft. At full deflection of the gear at full gross weight, this gives 7-8 inches of clearance. (Yours may be different due to main gear installation.) FAA requirements for minimum propeller clearance: Sec. 25.925 Propeller clearance. Unless smaller clearances are substantiated, propeller clearances with the airplane at maximum weight, with the most adverse center of gravity, and with the propeller in the most adverse pitch position, may not be less than the following: (a) Ground clearance. There must be a clearance of at least seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with landing gear statically deflected and in the level takeoff, or taxiing attitude, whichever is most critical. In addition, there must be positive clearance between the propeller and the ground when in the level takeoff attitude with the critical [tire(s)] completely deflated and the corresponding landing gear strut bottomed. Europa nominal clearances: If installed by the book at 2 inches (full cable extension), crossed properly so the cable cannot slip off, with a deflated nose gear tire, there is at least 4 inches of clearance on my new builds putting a full 300 pounds on the front of the engine. That will keep you from mowing the grass and or plowing a furrow with your 64 inch propeller if the nose gear tire fails on a rough landing or rough strip. 12 AY flew with the gear leg bolted solid in an attempt to install a longer prop. I don't recommend it. It's a bit harsh on a rough strip so to prevent fatigue I installed the springs shortly thereafter and shortened my cable stop to allow a total of 1 inch of movement until contact and a bit more on full extension. Longer answer on install and extended life operations notes: On installation, Chapter 29T says to pull the gear leg up (without springs or bungee) and swag the cable at two inches from the stop to the leg. I clamp (using a bolt type cable clamp) the cable at that distance with the gear leg pulled to check full tension on the cable. When satisfied, I then swag the cable. This gives 8 inches clearance as stated above. In the field, because the spring or bungee is attached normally, I use the one inch (two fingers) method to check if I need to re-swag the cable because of poor installation or cable stretch. I find the cable easy to pull down firmly from under the aircraft and check the distance. To check the springs I place my full body weight (180 lbs.) at the hub to deflect the springs the full amount for a quick check. When doing maintenance on other aircraft I have found that the cable will stretch a bit more than new which puts more strain on the springs. Occasionally I have seen on trigears which have operated extensively on grass, and the cable stop either was installed improperly or it had loosened and had not worked as advertised (it slipped off the lower leg) and this caused the springs to become weaker under severe grass strip operations. (Thirty pounds at the hub caused the springs to deflect which is unacceptable.) It is not fun to cut those springs off and replace them because they no longer hold the nose gear firmly on the stop. So it was a personal decision to go tighter than looser on the cable stop to prevent this from happening. Regards, Bud Yerly Europa Tech Support 813 244-8354 ----- Original Message ----- From: William Daniell Sent: Tuesday, December 20, 2011 8:34 AM Subject: Europa-List: I am sure that this has been posted many time but to avoid having to hunt through the archives - what is the max prop diameter for a Trigear? Will href="http://www.aeroelectric.com">www.aeroelectric.com title=http://www.buildersbooks.com/ href="http://www.buildersbooks.com">www.buildersbooks.com href="http://www.homebuilthelp.com">www.homebuilthelp.com href="http://www.matronics.com/contribution">http://www.matronics.com/chref "http://www.matronics.com/Navigator?Europa-List">http://www.matronhref="http ://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/europa-list Browse Digests http://www.matronics.com/digest/europa-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.