Fly with doors on

[Whirlydog]

I have read numerous times of people with enclosed machines such as the RAF and UFO ect. that can't or won't fly with thier doors on.  I thought that was the whole idea of an enclosed cabin is so that you can fly inside out of the wheather and in comfort.  What is the big difference with flying with and without them? What do you think cuases this problem? what design changes are need to correct this problem?  When I start building my own gyro I want an enclosed cabin and I want it to be as just as stable with the doors on as without.

 

[Udi]

Re: Fly with doors on

WhirlyDog,<br><br>It would be nice if you signed your real name at the bottom of the post or at least in your profile.<br><br>The machines that you are talking about have too much side surface in front of the aircraft CG and not enough vertical stabilizer to compensate for that.  Their yaw stability with the doors on is very poor.  A simple way to fix the problem is to size the vertical stabilizer properly, as is the case with the SparrowHawk, which flies stable with the doors on.<br><br>Udi-<br>

 

[Whirlydog]

Re: Fly with doors on

Udi, thanks for the reply.  I quess that answers my question.<br><br> My real name is Shawn Rowland.   In the profile section it doesnt give you the option of both handle and real name.  I can sign all my post with no problem.  It is also there in my signature line. <br><br>Shawn

 

[Whirlydog]

Re: Fly with doors on

Next question.  Is there formula or something that can help in determaining the size and placement for the vertical tail.  ie. a smaller tail set further back having the same effect as a larger on up close?  I am thinking of how a lever works.  I hope I am on the right track.<br><br>Shawn

 

[Aussie_Paul]

Re: Fly with doors on

Shawn, when we put the gearbox instead of a crankshaft breaking belt drive on Hybrid, the prop went the other way, so we had to make a new tail with opposite offset.<br><br>As the Raf was a "foot full" with the doors on we made the tail for Hybrid 30% larger and Hybrid will fly feet free with the doors on during gusty crosswind touring.<br><br>Aussie Paul.

 

[John_wilkinson]

Re: Fly with doors on

8)can verify that,bean in it and don that.

 

[StanFoster]

Re:Fly with doors on

Shawn: I seemed to have missed this thread as I know I would have read it closely. I bought my RAF with the full intent of flying with the doors on after I flew it this year accumulating experience. I have the Parham stab with the winglets.

I was told by several pilots that I would not have much trouble with the doors on with that stab. I talked to Ron Menzie over the phone and he told me the same. He trains students with the doors on and no problems.

So...I have from day one flew with the doors on and feel very comfortable with it ..even flying perpendicular to the wind on fairly windy days. I am as yet only taking off and landing with moderate sidewinds while I am getting accustomed to my RAF's limits. But...so far I am very pleased with it.

 

[Aussie_Paul]

Re:Fly with doors on

Guys, and MJ, the stab that were are developing for the UK market, but have put on hold untill Firebird is up and running, had the fins on the ends of the stabs to inprove the efficiency of the stab and help the poms fly comfortably with the doors on in their colder climate.

I understand what you are saying Stan.

Aussie Paul.

 

[mceagle]

Re:Fly with doors on

Stan,

"I have from day one flew with the doors on and feel very comfortable with it ..even flying perpendicular to the wind on fairly windy days."

You may be "tracking" perpendicular to the wind but the Gyro should always be flying directly or straight into the wind. It should be no different to flying in zero wind. The drift string should always point straight back.

 

[Aussie_Paul]

Re:Fly with doors on

Tim, I think this is maybe what Stan was getting at.

Flying with a gusty cross wind in a stock Raf with the doors on the gust moves the cabin because the tail is too small, so you are dancing on the pedals at times to keep the string in the center.

With the doors off most of the gust goes through the cabin, and life is easier.

With my Hybrid, which has a 30% larger tail than the stock Raf, it does not matter.

On a stock Raf the extra vertical area, as with my pictured stab and other stabs like the Parham etc, greatly helps the problem.

Aussie Paul.

 

[StanFoster]

Re:Fly with doors on

Tim: What I meant to say is what Paul said better. I am talking about gusty days,,,and flying perpendicular to those gusts. I can recall my Air Command with its pod yawing a little...but not too bad,.

My RAF doesnt even concern me so far. I was flying today in some pretty stiff variable winds and no problems.

Paul: That looks like a nice stab you have. Obviously, the more vertical tail area you have,,,and the farther back...the more stable it will be.

 

[ventana7]

Re:Fly with doors on

A week ago I was flying the Sparrowhawk in some fairly gusty winds with the doors off. With its large tail there is a noticable yaw effect when the gust hits the tail but basically goes thru the open cabin. It did not require any particular rudder pedal work but each gust brought with it a momentary yaw which straightened itself out as soon as the gust passed.

Rob

 

[Aussie_Paul]

Re:Fly with doors on

Rob, everything seems to be a compromise. With the larger fin and rudder on Hybrid we get more yawing with the doors off than we did with the doors ON a Raf!!!

There is a balance, fin and rudder area, at which are aiming for, that gives the best of both worlds.

Aussie Paul.

 

[mceagle]

Re:Fly with doors on

You must also remember that when you increase the fin area with the addition of winglets then you must increase the rudder area proportionly to have the same rudder response. If you get too much fin area you can get to the stage where you have not got enough rudder to land in a crosswind.

 

[Aussie_Paul]

Re:Fly with doors on

Correct Tim, I should have mentioned that.

Aussie Paul.

 

[StanFoster]

Re:Fly with doors on

Tim: That is a good point about the rudder being less effective in cross winds. As I am training myself in my RAF...I am sneaking up on the cross wind experience. I am making sure I still have rudder effect.

I just figure I may have to land a tad faster if I have a good crosswind...of course one can point it right into the wind too.. ;D

 

[Larry Boyer]

Re:Fly with doors on

Last week I finished my new stabs from Larry Martin and installed them. They look nice! It was windy/gusty with a dead cross wind. It was a beautiful day and I did want to fly the new Ultimate stab in the wind. I rolled out the Raf that was dormant since the end of December and fired her up. It purred like a kitten and I thought what the heck, this is supposed to be a superior stab to anything else out there, so lets do it. I taxied down the runway and turned around and started my prerotation. When I got 150rpm, I applied power. At 45, it wanted to fly so I left it. I had the rotors trimed for the old Larry Martin stab. I had to hold hard forward stick to let it climb at 60. It was really gusty, yet I felt no pitching at all, and I believe I would have with the old stab. I trimed it out to 65 and I got hit with gusts that actually turned me almost 180. Yet it corrected itself faster than I thought to with rudder. The large vertical parts of the stab really work well. I turned into the wind and it was very smooth. I felt the gusts, but it did not pitch up or want to pitch down.
Now I am going to peeve some of you. You can say that I am only feeling the stability, well I was in conditions that I normally would have hesitated to fly in because I would have had my hands full. The RAF flew stable with no adverse tendencies what so ever. I have always held the contention that the RAF is not for the new guy. Well whith this stab, I think the PPO issue will be greatly deminished on a RAF and other HTL machines. When Larry Martin first announced this stab and it's tests by Ron Menzie, a couple people said Larry had exagerated his claims. Ron had used Gremminigers outline for stability to determine the effectiveness and said he liked it very much to the point Ron M was training students in windy conditions with success., and yet the RAF haters said it couldn't be so. I think Larry M has a winner here. If Raf owners are on the fence concerning the AAI change, or are flying without a stab, or have a old style stab, then call Larry Martin and get yourself this finely designed stab.I think you will love!( maybe this is one of two fixes for the RAF high thrust line!)

 

[StanFoster]

Re:Fly with doors on

Larry: Good post. I have talked to several that have told me that the stab you have and my Parham stab are really nice handling.

I was up flying yesterday and the winds were 25- 35 and gusty. I flew for an hour and was very relaxed. Right on take off my stupid yaw string desides to get tangled up...so I thought this would be interesting. I soon discovered that it flew better with me just letting the rudders go by themselves. I am like you and feel very confident in my RAF. It felt so good from day one that as long as I was very comfortable...I would continue with my self training. I have 25 hours in it now....and am ecstatic about the way it flies. There has been way too much anti RAF hype....in my opinion.

 

[Harry_S.]

Re:Fly with doors on

Stan and Larry;

You're both right. People who bad-mouth the RAF do not fly the RAF, 1 or 2 do but most don't. With an effective stab, it is a most enjoyable machine to fly. An inexperienced pilot should not attempt to even taxi it without an instructor sitting along side. It is a big heavy machine.

I flew mine for 90 hrs. before I installed a Ken J. stab. Without a stab there's quite a workload to fly in windy and gusty conditions, I must say, but with a stab it can handle anything. I am not foolhardy and will not attempt to fly in say 50 mph winds, altho, I do fly when most of the FW's stay on the ground at my airport.

I'm pushing 400 hrs. on the Hobbs and looking for another 400, here in central Florida.

 

[Harry_S.]

Re:Fly with doors on

Addendum to the above post:

I never installed doors on my machine so I have no yaw problems. Don't need doors in this area.