Hangar Flying

Excellent Advice from Waiter and Dan.

Something is reaching natural frequency at these speeds. Possibly due to air motion, engine motion, loose part motion or any combination. Things that move in the airstream, wings, rudder, canard etc look for changes.

Things that are removed from the airstream (closer to the cowling ) may reach or are induced into a resonance by something innoculous like worn bushings on the engine mounts, the baffling chaffing the cowls etc.

The engine is a natural source of vibration that can also induce other vibrations.

Higher or lower frequencies of the noises should also offer clues. Hi pitched noise generally means lighter items vibrating real fast. This is opposed to lower frequencies and bigger parts but this is not a hard fast rule.

Borrow a set of ANR headsets and see if the frequency changes or disappears altogether might be another idea. if you're already using an ANR set, change the batteries. This may sound strange but I endured a flight back to the airport with a low frequency "thumping" all the way back.
When I shut down the radios and the engine, the thumping was still there. It was coming from some  feed back loop caused by low batteries.

I took a second look at the images. From the top left the 2nd & 3rd shots are interesting.

The 2nd shows a large smudge on the front surface but the scratches are not following the rotation of the blade.

In the third shot, take a close look at the wood fibers. They are all straight.

If you strike something that fast with woodand it breaks, wouldn't you expect the fibers to be bent toward the clockwise direction. ( The prop is rotating CCW from this view)

Maybe it's just me, but the wood just looks old. Anybody else notice this?

Rick

Jesus Eddie, your pucker factor must have been off the scale.

Both blades as well. Both blades at about the same point.

I have to agree with Drew though. I had a bird renting out apartment space on top of the engine and decided to leave only after  I was crusing at 120 Kts.

It scared the hell out of me for what was a only few onces of blackbird. The engine shook bad until I cut power, then the vibration went away so I returned to the airport.

I can't imagine anything big enough to do this. I had blood all over the back of the blade and cowls in small droplets.

But once the blade strikes the bird, it throws it off ie it would not be there by the time the other blade comes around.

Maybe the blade broke free and the second one came around and hit the first one.

If is was a bird especially one big enough to do this, you will have lots of blood evidence.

Note: All the blood on mine was on the back side of the blade and on the lower cowl- I would not have expect blood droplets to go forward-go figure.

The pictures were well documented.

Thanks for sharing this with us & glad you got home safely

Rick

The weight, altitude and passenger is not unusual. Should have gotten off
better.

Tire pressure, winds down the runway and lift off speed are among many factors. Try this when your by yourself. Pull the nose off gently at 55 kts (it reduces ground friction a little less than a third)

I tried this and it works but I have to admit that normally I pull back at about 60 to 70 kts.

Rick

Dave

Opps, sorry !

I did not mean to imply that I had the catto Prop. Nice thought though.

Radio works, intercom works, all new wiring etc.

I'm off next week and will redo some of these numbers.

Can't see how you get 161 Kts out of a O-235 But If our friend in Europe says so then OK

Rick

Hi Dave

Interesting numbers. Even more amazing. Account for variances in
drag, tach error differences, airspeed indicators and a small bit to altitude, we are only 5 kts apart with the same plane, same prop, same engine and exactly the same time on the engines.

If you think about it, the spread between your high and low end RPM and mine are about the same. One of us could have a 150 rpm error in the tach.

I would imagine this is pretty typical for us Long Ez's drivers with 0-235 L2Cs

167 mph burning less than 7 gallons and hour on less than 120 Hp-not bad

Opps, almost forgot 860 lbs empty with the big Prestolite starter

Rick[/img]

Are the plans really copywritten.

I checked out the US Copyright web site and they have an interesting search engine.

There is nothing on RAF or Rutan, Burt but there is something registered under Rutan, Dick

Check it out

http://www.copyright.gov/records/cohd.html

Main site is

http://www.copyright.gov/

Under FAQ's there are two areas dealing with plans or instructions

How do I protect my recipe?

Does copyright protect architecture?

You may want to check out the systems at Superflight.

They have a filler/primer, two part that is non-hydroscopic. After I removed all the featherfill, I got in touch with the boys at Superflight and discussed what I was doing. They were very helpful.

The filler I bought was outstanding, easy to apply, sanded easy compared to Epoxy & Micro. It builds up well. You may not find it on the site but if you call, they will help. I later shot the rest of the plane with Imron directly over the superfill.

I you stop and think about, structurally, the weave in cloth is very much like the weave with fiberglass-both have to be filled.

http://www.superflite.com/Index.asp