On Mon, Dec 26, 2011 at 4:18 PM, Bud Yerly <budyerly@msn.com> wrote:
>
> Will,
> Max prop diameter is still 64 inches recommended. This is based on the prop
> clearance of course. In the tri gearclearances are based onspring or
> bungee with the by the book cable stop dimensions per the build
> manual.This leaves nominally10-11 inches from the prop tip to the ground
> (aircraft unloaded, nose tire inflated at 35 psi. and the CGat 60
> inches)in most of my aircraft. At full deflectionof the gear at full
> gross weight, thisgives 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 cableextension), crossed
> properly sothe cablecannot slip off, with adeflated 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 propellerif 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 bitharsh 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 inchof 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 gearleg 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 thatdistance with the
> gear legpulled to check full tension on the cable. When satisfied,
> Ithenswag the cable. This gives 8 inches clearance as stated above.
>
> In the field, because the spring or bungeeis 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 placemy full body weight (180 lbs.)at the hubto deflect the
> springs the full amount for a quick check. When doing maintenance on other
> aircraft I have found thatthe cable willstretch a bit morethan 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 wasinstalled
> improperly or it had loosened and had not worked as advertised (it slipped
> off the lower leg) and this caused the springs to becomeweaker 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
> To: europa-list@matronics.com
> 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
>
>
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