Aircraft Rigging

[irishfield]

Just wanted to share something with the masses. I see way too may guys running for a hunk of aluminum and riveting a big ass trim tab on the rudder as a quick fix, instead of just figuring out what is causing the need for some rudder in the first place. Is it the fact that you have one rudder pedal spring stronger or tighter than the other? Can it simply be fixed there or with some other simple, none drag causing means?

Today I test flew IWH on her new amphib floats. As most of you have seen I did a video of it flying on wheels, flying around with my feet flat on the floor and hand off the stick. I did this for almost 1/2 an hour using nothing but body shift to turn when I wanted to.

I test flew her today on the amphibs. She flew with about 3/8ths of a ball out the right side and needed a bit of right rudder. Now the quick thing to do would have been to come back and land and just bend that stupid trim tab that the last guy riveted to the rudder. Issue with that...you go back to wheels and then what, bend it back??

The obvious issue is something slightly off on the floats, so why play with the airplane? Sure it's a lot more work to unwrap that safety wire off a turnbuckle than bending that tab but hell... that's what I did. 5 turns tighter on the right water rudder to air rudder cable and it once again flies ball centered, feet on the floor and hand off the stick. Nothing needs to be touched at change overs and I think I could fall asleep going cross country in this one.

And it still cruises at 118 MPH @ 2500 RPM and lands like a dream with the floats at 3.5* throat angle. Take off solo and 25 gallons of fuel (1600 lbs) less than 7 seconds. I think this engine is pulling more than it's spec'd 160 HP and it's having no issues turning that -58 sensenich up to 2550 climbing out at 1200 FPM!

Here's the very first water landing.. camera just sitting on the dash with noting holding it but friction and gravity. Think I landed her pretty well...

https://www.facebook.com/wayne.oshea.3/ ... 6452389136

[Walter Klatt]

Yeah, I bent one of my float rudders one time when backing it against a dock, and didn't realize it until I took off again. I noticed it immediately as I went into cruise and was really wondering what was going on for a while with a slight shift in rudder pressure. I flew slower and carefully until I got home, as was worried something worse might be wrong causing some kind of drag on one side. I was quite relieved when I saw it was just a slightly bent float rudder and easily straightened out again.

Re performance, that is pretty good indeed. Are you sure it is a 58 pitch? My 150 hp 320 would do 1200 fpm with the 54 pitch, but less with the 56,... never tried a 58. What is your static rpm? That will tell me actual hp if it is indeed a 58 pitch. Did you do a top speed run? Maybe it had the extra high compression 165 hp pistons? I think they were 9 or 9.5:1.

[bgeorgen]

Was the 58 pitch prop a Sensenich? It didn't look like it from the video. I have a 150HP 0320 with a 54 pitch Sensenich prop and I would have to agree with Walter. I started with a 56 pitch on wheels but had it bent to 54 for better performance on floats, but I don't get anything like the numbers you described.

[irishfield]

Yes Bruce... bought factory direct.. 225 hours total time 74DM7-0-58. Never repitched.

Holding the brakes in the grass prior to take off I see almost 2500 rpm and about 2550 climbing out. From the first flight when I brought this airplane home, 6 years ago, I noted that this thing really motors along!

Unfortunately, I only have the engine log and no work report to know what they stuffed inside of it. Log simply states "Engine Rebuilt by Gilbert Custom Aircraft Ltd". Was a first overhaul on a 1507 hour engine.

[Walter Klatt]

Yeah, if you are getting 2500 rpm static with a 58 pitch Sensenich that is 165+ hp. The normal 160 hp does 2500 with a 56 pitch and 2550 with the 54. My old 150 hp did 2500 static with the 54 pitch and about 2570 in climb out and up to 1200 fpm (solo and 1/2 fuel). But what was really interesting is that my 150 hp got off the water faster, out climbed and had higher top speed than the 160 hp with the 56 pitch.

I bet you would see even better performance (incl top speed) with a 56 pitch on that engine. And it should do better than 1200 fpm with 165 hp.

[bgeorgen]

Wayne, what's the empty wieght on floats? Mine is 1185 lb. not fuel or gear.

[irishfield]

I wasn't trying to make it climb... that was just it's leisurely pace leaving the field here! :thumbup:

If it performs this well as is, and shows that it works well fully loaded (when I get to that stage), the prop will be left as is. That way it works for wheels and floats and skips the two props nonsense.

Now back to what this post was about... correct the riggin issue, do not Band-Aid it with something else!

[irishfield]

What did you strip off your airplane to get that weight Bruce? :shh:

Engine full of oil, ready to fly other than fuel, 1249 lbs.

[Walter Klatt]

1200 for mine, and didn't change with the 360. I flight plan for 1250 though because of my survival kit and all the junk I haul around. I do think the speed cowl saves a few pounds if done right, and not having to reglass the bottom exit 4 times like I did on my old one.

And think you should change the thread subject... :wave:

[bgeorgen]

Really? Maybe I should weigh mine again... it's been 11 plus years. I think I used borrowed scales. Funny you mentioned having to use right rudder after float installation. I had the same issue and just put up with it for years until I added a rudder tab. I never thought of adjusting the spring with a few turns of the turnbuckle. Now I feel like a claude twice today.