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View Full Version : 50 hour evalution of the RAF


StanFoster
04-26-2004, 05:30 PM
I have logged over 50 hours in my RAF since the issuance of its airworthiness certificate Feb. 29th. I thought I would condense what I have said over various threads that I have posted in exuberance over my experiences so far. I am doing this mainly because I would have loved to have read this while I was making my decisions on buying my RAF in the first place.

I transitioned from my Air Command with very little problems at all. It seems the only problems I have had were being too cautious while experiencing for myself what this machine feels like.

My intitial plan was to just taxi and balance on the mains for awhile and then go see Ron Menzie for some lessons. I talked to him on the phone a few times and his comments gave me a lot of assurance that I would do fine with my RAF after getting some lessons. Well...my balancing on the mains seemed no problem...so as long as I was comfortable...I proceeded with more power and some crow hops. This continued for quite awhile as I was getting the feel of this machine and the reflexes to control it. I felt very relaxed and that point I feel is the main problem learning to fly...if you arent relaxed...the reflexes arent going to be as smooth and as quick.

Soon the RAF was flying the runway and I felt very comfortable in it. Pattern work followed with different approach speeds being conservatively checked out. I found for myself that the recommended 60 mph approach was too fast and had to much float...so I went to 55 mph approaches.....then to 50 mph approaches. For myself. 50 mph with the throttle back works best for me...this approach is more engine out like and thats what I practice for.

I have had no problem with lack of rudder....except in a good crosswind...then I just leave on a little more throttle. A strong crosswind..I just turn into it squarely anyway.

I had read many times that there would be problems flying with the doors on. I find this totally untrue with my Parham stab. I have flown in very high variable winds and for hours at a time and wasnt the least bit uncomfortable. I bought this machine to fly year round...but had read so much negative stuff...that my initial intentions were to fly all this year without the doors..and then experiment with them when it gets cold this fall. Well..the crow hops and short flights down the runway indicated no problems,,and I ended up not even experiencing flying with the doors off until it got hot one day. I cant really say I can tell the difference except for the noise level and you can feel the air when you are crabbing. Ron Menzie told me that his students have no problem with the doors on..and I place a lot of confidence in what that guy says.

The rotor seems to have more reserve energy for flaring compared to my Air Command. It took me a little bit of time to get used to this extra kinetic energy....especially with my earlier higher appoach speeds. Now that I land slower with a steeper power off descent, I find the flare to be easy to execute with less float.

My rotor is fairly smooth...I do have a little cabin hop..not bad enough to cause me to put it on my priority list...but still is in the back of my mind to tinker with later on. Otherwise...I am content if I dont improve it a bit. Ken J's probably has gone to more effort to fix the rotor problem he was having than anyone..and his excellent post have probably saved me a bunch of waisted time. I believe his final solution of getting SC blades was his correct way to go with all the problems he was having...as they are very consistent in their construction..and if Ken says they are smooth....I would bet my life that they are smooth. :)

I will stop the ranting in this post with this last comment. I am very satisfied with my RAF and I intend to fly it for a long time as I feel I really have my machine I have been dreaming about for years. If I would have known what I know now...I would have bought one years ago. But I have no regrets in approaching my decision with caution. My biggest surprise with this whole experience is that there havent been ANY surprises at all.

Honest as I can be.....Stan

mcbirdman
04-26-2004, 07:01 PM
If I would have known what I know now...I would have bought one years ago. But I have no regrets in approaching my decision with caution. My biggest surprise with this whole experience is that there havent been ANY surprises at all.
Stan if you did buy years ago, we may not have been reading your post, that is honest also. I am glad things have improved since then and a lot of people are finally starting to learn from these past experiences by taking them seriously. It doesn't get more serious than this.

Glad you are enjoying your dream, a dream that is the same for many of us.... jtm

KenSandyEggo
04-26-2004, 11:06 PM
Stan, I don't recall, but have you changed out the rod-end bearings in the control-rod system? That would be 8 total ends and the 2 smaller ones at each end of the "mixer-box." If I can think of only one thing to recommend, it would be this. The kit-supplied ones were shown to be impurity filled and prone to cracking. Jim Mayfield had them analyzed by a metalurgical lab and they were not of the best quality. If one of these cracks in flight and let go, it would be very critical. I believe that changing these out and the addition of a stab are the 2 most critical first moves for any RAF owner.

StanFoster
04-27-2004, 02:31 AM
Ken: I havent changed those rod ends...I was aware of some problems with them but now my awareness has been heightened somewhat by your post. Thanks and I will be ordering these asap.

Stan

CLS447
04-27-2004, 03:11 AM
Speaking of rod ends.... How do we know the quality of any of them? I can't find any markings to prove. I know that my KB has different looking ones than my AC's.

I have one3/8" rod end that holds the top of my tall tail on my new machine & I believe it to be the "WEAKEST LINK" to keep my tail on.

I am gonna order one from JEGS. Super strong chromoly with chromed hardened ball & Kevlar & teflon race. Strongest they offer . Used for racing steering links & such. How do you think these compare to "Aircraft Grade" ?

KenSandyEggo
04-27-2004, 07:05 AM
I would at least go with Heim bearings from a well-known source. Your odds go up astronomically from the ones that come with the kit. I don't know how the "racing" and "aircraft" grades would compare, but either sounds a lot safer than the originals. I took a cracked one of mine to a bearing house here in San Diego, and after the tech looked at it, he said it was "junk" and he would never sell a grade as that one. He showed me the impurities that were visible to the eye. He said he could get them for less than $2 per bearing, but he wouldn't even dream of selling them to his customers. The lack of quality was verified by the metalurgical lab in Salt Lake City that Jim Mayfield sent one of his cracked bearings to. It cracked when an attempt was made to loosen the lock-nut from the threaded shaft with a wrench. That was scary.

steveb
04-27-2004, 01:25 PM
Here's a report from the UK AAIB on an RAF rod-end which broke in flight (fortunately the aircraft was only a few feet off the ground at the time):

http://www.dft.gov.uk/stellent/groups/dft_avsafety/documents/page/dft_avsafety_027262.hcsp

The key part is:

"The metallurgical report found that the eye end of the control rod had fractured by overload in bending, as previously thought. The surface appearance and distortion of the fitting suggested, at the most, a few load cycles to final fracture. The eye end was a commercial part closely resembling an aerospace quality component in appearance. The main difference however was that the body of the fitting was manufactured from a free-machining low carbon steel with a tensile strength of around 34 tons/in2. In an aerospace application, a low alloy steel of around 50-60 tons/in2 would be expected, however there was no requirement to use an approved part in this application. Furthermore, the steel used had a high concentration of manganese sulphide 'stringers' which were able to significantly further reduce the expected bending strength and stiffness."

GyroRon
04-27-2004, 04:01 PM
in other words they were junk that shouldn't be trusted.

StanFoster
04-27-2004, 05:26 PM
I should have condensed my condensed evaluation to....just a very easy and comfortable machine to fly somewhere in. :)

Stan

rgraffeo
04-27-2004, 06:42 PM
Stan,
Glad to hear you are having so much fun.
I noticed when I installed my Parham stab that my RAF floats more in the landing flare. I learned to fly without a stab & added it after 80hrs.
I'm going to try your approach & lower the landing speed some to see what happens.

Aussie_Paul
04-27-2004, 07:07 PM
I notice that the Parham stab has very little dihedral. We found that a total of 20 degrees, 10 each side, allowed the air to spill out and not hold the tail a little high with the cushion of air.

Aussie Paul.

StanFoster
04-27-2004, 07:07 PM
Rudy: I am really enjoying this thing. It feels like it is a part of me now.

The 50 mph approaches are just right for me with the engine at idle. The descent is steep..the flare is quick and short...no float.

If I am landing in a fairly good wind..I will increase my approach to 55 as the landing is still next to nothing.

GyroRon
04-27-2004, 07:51 PM
I was refering to the rod ends not the machine as a whole

mcbirdman
04-27-2004, 08:35 PM
Hey Stan - Just a Warning - watch your Wallet.

- First Ken J will get your rod end problem fixed and then who knows, the alternator/bracket, the ignition module, the blades and who knows .... an 800.00 order from a little company named Whelen...... (lol) Sometimes he claims he is just doing his part to help the economy..... Luckily you got a start on his list when you got a stab...

(but he is right)

Glad you're havin fun, jtm

StanFoster
04-28-2004, 02:38 AM
James: I will hang on to the wallet :eek:

Stairs keep me in the air :D

Stan :)

CLS447
04-28-2004, 03:09 AM
Stan, I would love to see some of your Spiral work.

Mike Hook
04-28-2004, 03:09 AM
Ken J

Maybe in your spare time you could post a list of your prefered changes for a RAF to make it safe. I know you have some pet items that you have changed out.

Mike

Gary_in_Orygun
04-28-2004, 08:20 AM
I have put some of the RAF topics of interest on:

http://home.att.net/~raf2000owners/

I haven't done a whole lot to this site lately. If anyone sees something they would like to add or needs changing, let me know.

KenSandyEggo
04-28-2004, 08:22 AM
Mike, I have done that before, but it was on the old forum. I'll make up a list of what I think is important to make an RAF safer to fly, less going to CLT.

StanFoster
04-28-2004, 03:06 PM
Chris: I will post one picture of that spiral you requested. My main work is the large curved stairways...these spirals are something I build once in awhile. If you would like to see some curved stairways..I would be more than happy to e-mail you some. I dont want to clutter up this fine rotorcraft site with stairways. :eek:

Stan

StanFoster
04-28-2004, 04:47 PM
Steve: Thanks....it made my gyro purchase. :D

asmuzsr
04-28-2004, 08:17 PM
Your son know he's in the picture? Check the mirror.

Tony
N267A
N352P

CLS447
04-29-2004, 03:16 AM
Wow Stan, That is REALLY nice! You build these from scratch?!? I'm sure you have more pics so don't forget about the OFF TOPIC thread ! How about the one in the mansion near you?

mcbirdman
04-29-2004, 06:58 AM
Stan, If you ever decided to switch powerplants and thought maybe you would build your own powerplant..... - does turbines come to mind? I'd think you would be able to whip something out.......

jtm

StanFoster
04-29-2004, 11:54 AM
James: I love turbines ...the application in a gyro isnt to good with the constant speed they run at. You would have to have a variable speed prop that I am not aware of exists and the things are fuel hungry.

StanFoster
04-29-2004, 12:03 PM
Chris: Thanks.....I build all my stairways from scratch. That spiral is the smallest stairway I build. Most of my stairways take 8-10 guys to screw them through the front door.

I would post pictures ...but I would rather do it on a site they belong. I am on the Fine Homebuilding site a lot where everyone posts pictures of their projects.


Stan

PW_Plack
04-29-2004, 04:04 PM
Stan,

ATP (which stands for Affordable Turbine Power) is releasing a 200-pound, 240 HP turbine to the Experimental market this summer at Oshkosh. The output of the redrive spins at about 3000 RPM max, and it uses the NSI variable-pitch prop. It's a neat-looking setup, but the performance chart says it makes only 600 pounds of static thrust at 240 HP, or about what a stock Subaru 2.5 can do.

The Subaru will drink about 7 gallons per hour at 100 per cent power...the ATP burns more than twice as much:

www.wimpy-yet-thirsty.com (http://www.atpcoinc.com/Pages/Products.html)

Maybe it compares better at higher speeds and altitudes, and it certainly would sound cool to hear your gyro spooling up...