• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

EDO Float Fittings - limit for elongation of bolt holes

SEFYK

PATRON
Germany
The holes in my EDO float fittings (rear fitting at the aircraft P/N 69747) where the pins for the flying wires go through are worn out. On one side the hole is nearly double as long as it is wide. On the other side it is less.
Are there any limits for the elongation of these holes? How much material must be left between the hole and the end of the fitting?
Since new fittings are $$$ from Kenmore (and they do not sell the inner plate separately, only the whole fitting) I want to keep mine as long as possible.
 
The fact of owning an airplane is that you need to replace worn out components. Replace the fitting. If it fails it will cost a whole lot more.
 
I'd replace something that worn. That's going to permit movement, followed by sudden stop of that bolt, and sooner or later will cause a failure.

There are a few outfits that stock used parts as well. Doug Ronan and Eddie Peck come to mind.

MTV
 
The holes in my EDO float fittings (rear fitting at the aircraft P/N 69747) where the pins for the flying wires go through are worn out. On one side the hole is nearly double as long as it is wide. On the other side it is less.
Are there any limits for the elongation of these holes? How much material must be left between the hole and the end of the fitting?
Since new fittings are $$$ from Kenmore (and they do not sell the inner plate separately, only the whole fitting) I want to keep mine as long as possible.

The hole is work hardening and is very dangerous. Your floats have had extensive wear BE CAREEFUL and insepct them closely. A work harden fitting for that configuration should be changed before flight. Please order serviceable hardware for all work harden structural fittings.

BTW:
* Do you have pictures?
* Total Time on STC'd floats attached to aircraft(s)?
 
I ordered a set of fittings from Stoddards today, my old ones are far from being servicable any more.
Question was how the limit is for the wear of the wholes.
 
I bought the plane with the fittings. I am currently putting it again on floats for the first time and inspected the fittings and found the wear.
 
Any detectable relative movement means unserviceable part(s). The standard hole elongation tolerance is measured in thousands with a hole gauge. No dia. can be more than the upper limit of the hole dia. the Dwg. calls for. If no upper limit specd, then it's the Dwg. tolerance added to the specd. dia.
 
At least for normal bolt holes this is correct and the normal tolerances apply, but this hole is a bit special. The pin (not bolt) which goes through it is only loaded in one direkton - the flying wires are pre-loaded by tightening and they can not carry any load in the opposite direction. By the nature of the construction: a steal pin through an aluminium hole, and the vibration in the system the hole is worn out over time in the dirction of the load. I do not think that this unique to my airplane (have seen other fittings with the same form of hole elongation). As long as there is enough material left between hole and the end of the fitting to carry the safe design load from the flying wires there should be no failure. But how much is "enough"?
I attach a picture to illustrate the problem:

holes.jpg
 

Attachments

  • holes.jpg
    holes.jpg
    71.4 KB · Views: 195
....
I attach a picture to illustrate the problem:

View attachment 6319

from your earlier description, you made it sound WAY wobbled out..... that don't look too bad for a job that's only in tension, and only clamped to air frame with a couple tiny bent bolts anyway,(that hole is not the weakest link in setup...)..... clean it check for cracks and go....
 
Standard for edge distance is 1 1/2 times the diameter of the bolt or pin in this case. I agree with Mike

John
 
The picture does not look like it was described in the first post. Next time you post meassure X, Y, Z of hole, and edge distance. Plus, picture(s) and total time on the part.

Tip: Get a blast cabinet with glass beads (or similiar media used for aluminum) to clean and inspect ALL fittings. You will find the seaplane world takes a lot of common sense that is unwritten. Being intuative is paramount.

NOTE:

You said -> "...where the pins for the flying wires go through are worn out. On one side the hole is nearly double as long as it is wide...."
I Say -> Your statement said "worn out". Generally in the USA that means not serviceable buy your own conclusion.
------------------------------------------------------------------
You said -> "...nearly double as long as it wide..."
I say -> ...Is not going to pass any inspection no matter what the edge distance.
-------------------------------------------------------------------
 
But, remember blasting/cleaning with abrassive can hide flaws too! Cracks can be "closed up" with to much air pressure for the media or using a hard media like garnet stone on aluminum.
 
Bushing on fly-wires may not be a good idea, due to vibration and popping the bushing out? The part could be fabricated with a bandsaw and a bending brake?
 
That fitting is made of steel. It can be welded and hole redrilled. Bushing repair would also work. Press fit bushing. There is something in AC43.13 on bushing repairs but i don't recall the section without looking for it.
 
Someone said "in the seaplane world there is a lot of common sense that is unwritten" I agree, so use it.
 
I just hope that the bolt on fittings for my, 73 year old, EDO 1140's look that good!
 
Thanks for all the answers. The picture is not from my original fittings, but from an other set - I should have mentioned that. I only posted it to show which hole I mean. I will take pictures of mine as soon as I come back to the airplane and post them.
The 1 1/2 edge distance is a good limit.
What material for a (press-in) bushing would be best, brass or steel?
 
If it was me I'd weld and re-drill it, but a steel bushing would be appropriate. i would not use brass.

John
 
Sorry guys, I apologize. That float bracket is aluminum like SEFYK stated. It's been a long time since I've seen one. I stand corrected. I did some research since his post and it is made from 7075-T6 Al. Therefore its unweldable. You would have to put a bushing in it. I would make a bushing out of the same material.

John
 
EDO Fitting.jpgHere is the picture of my fitting. Notice the elongated hole.
 

Attachments

  • EDO Fitting.jpg
    EDO Fitting.jpg
    111.3 KB · Views: 169
Here is the picture of my fitting. Notice the elongated hole.

That looks like a stretched hole! I see a little filiform corrosion too on the other surfaces. The outline of the end fork has also left a scar (I enlarged the photo). The edge distance looks OK for a rework.

I did a FAA SDR search for EDO float fittings P/N 69747) found no hits.

Thank you for the picture. How are the other parts of your project progressing?
 
Since I change from the old EDO 2000's to new Wipline 2100A the other parts of the float installation are new.
 
Since I change from the old EDO 2000's to new Wipline 2100A the other parts of the float installation are new.
Since you have new Wipline 2100A floats those fittings should have come with the new floats. That fitting is part of a float installation kit which comes from the respective float manufacturer with the floats.
 
Back
Top