Proper Airfoil for Horizontal Stab ?


Former Gyro know it all
I can't push the blades into the tail on my Dominator even trying. They can come really close to the ground though if I push them to the stops and the gyro is on the tailwheel.


No aircraft is perfect - they are all compromises and have good points and bad points.

As Jim has reported teeter stops are standard on the Sparrowhawk, so the blade through the rudder issue is sorted (btw the rotor on my single seater, or any other UK single seater, doesn't pass through the rudder. The same is true for the VPM as far as I know).

I'm pleased to hear that other people haven't found the same problem with the nosewheel steering. It might have been specific to the aircraft I was in, or may have been fixed in later iterations of the upgrade kit. Anyway, we need to keep these things in perspective - heavy steering is a small price to pay for an aircraft which is so much safer than a standard RAF 2000.


Paul B,I too am supprised at how much teeter is built into some rotorheads.Neither of my machines blades will come close to the rudder or the ground.[wot is the ruel of thumb minimum teeter alowable?????]

But as someone said before in another way,if you'v got your hand on the wrong stick,your go'n to damage sumth'n.


A reforming stirrer!!!!!
Birdy, teeter is not built into the rotor head. Maximum pitch control movement is, and should be around 18 degrees.

Teeter is made up of teeter bolt height in the teeter towers and the undersling of the rotor.

With a pre rotator you can get away with as low as probably 10 degrees maybe less, but slowing the rotors down on a windy day can end up with rotor flap. Without a pre rotator you need approx 18 degrees to get the blades over the first hump.

Aussie Paul.:)

Aussie Paul.


I thought the amount of teeter was how many degrees the hub bar could hinge between the stops.

But your right,it can be a barsted to catch the blades in a gail.Never thought of that.
Good thing I got a well set stick lock ay.


Senior Member
Paul, are you talking about +/- 9 degrees on the teeter or a total of 18 degrees in pitch?


Gold Member
Birdy, you asked: "wot is the ruel of thumb minimum teeter alowable?"

The "normal" teeter is 9 degrees down and 9 degrees up for a total of 18 degrees. Also the rotorhead torque tube tilts 9 degrees forward and 9 degrees back for a total of 18 degrees (also left and right). So, the rotor blades can be 18 degrees forward down to 18 degrees read down, making a 36 degree total maximum allowable tilt.

This does not answer your question as to "minimum", but it should not be too much less than the "normal".

Brian Jackson

Platinum Member
Thanks, Ken, for the teeter/head angular info.
Little by little I'm cataloging bits of useful information in a series of Gyro-related text files... more of a copy-&-paste thing, but since there's no official "Gyro Design College" I guess I earn my degree here!

Brian Jackson


A reforming stirrer!!!!!
Both Don. At the moment I am running 14 total teeter with my rotors. The reason for this is that I had some towers that fitted and I ended up with 14*.

I always like a total of 18 or 20 degrees in rotor head pitch movement. I like 18 back and 1 or 2 degrees negative with full forward stick. This helps to slow the rotors down if you cannot get the wind behind you. If you have too much negative and you go to full forward stick after landing with considerable rrpm the rotor can pull you along and off the runway if the stick is not central.

Is that the info you were after?
Aussie Paul.:)


Thanx Ken.
It's just that I see a big vairiation in different desigens and wundered why.Both my machines have very little teeter but they'v never hit the stops in flight[not that I'm aware of anyway].I'll put the bubbleometer on them later and check wot they read.


A reforming stirrer!!!!!
If the teeter stops hit Birdy, you would know about it for sure!!!!!!!!

If the teeter stops hit Birdy, you would know about it for sure!!!!!!!!

You probably would not be posting. The other day I was testing some Jack allan wide chord blades set to a little over 3 degrees on the pitch blocks. The blades are 25' and the machine an ea-81 with a belt drive and a 70" 3 blade W/drive.

The day was bowing over 10 kts and boy did we whae a battle hand start them!!!!!! On the take off run after gently allowing the blades to get up to quite a blurr I opened the tap and the blades just started to hi speed flap!!!! (Hit the teeter stops.) I was quick enough to reduce power as I was very on the ball all week testing Dewies machine. We had adjusted the blade pitch with the rotors on the machine, and thought that we only tweeked a line width. When I came back after a circuit we removed the blades and measured 3 degrees!!!!!!!!!!!

We have them now set at 2.1 degrees at the moment, and they are going reasonable. As I have always believed, they are great blades for carrying heavy loads at a slow speed.

Mceagle Tim might comment on his findings of these blades, over the years.

This machine of Dewies was obviously built by someone who knew veryy little about gyros. This someone had rolled it twice. I certainly did not have time to make a mug of coffee on the first take off!!!!!! :eek: :eek:

I will start another threat with the weeks progress.

Aussie Paul. :)


I reckon your right Paul.
I'v only ever flaped 3 times on takeoff,all three were try'n to take off too short with a dead battery.
It's just that sometimes when I turn hard ,starting from behind the curve and using more rudder than stick ,I tend to git alot of feed back [side kick]through the stick.
Was think'n maybe I'm out run'n me slow turning rotors and they tap on the stops.