crabbing on take-off

[lopeznoel]

Pardon me if this is a stupid question...
I have 7 hours training in a Sparrowhawk(Steve McGowen and Terry Brandt) and have been thinking a lot about this.

When taking off in a strong cross-wind (like can occur in Buckeye, Az), the rudder is used to keep you parallel to the center line. My question is: if you are blown off center line and are still parallel to centerline, do you use the cyclic to ease you back to centerline or do you overcorrect with rudder to get back to center and then get parallel again?

I tried asking Terry Brandt this question but he wanted me to "feel it" and then answer my own question. Unfortunately, I can't get out there enough and this question has really been bugging me since there are no good computer simulations of gyros. The reason I ask is because I flew in such a situation and was able to get off the ground but I fought really hard to stay on the runway. I thought Terry helped me but he complimented me on the take off.

What are your comments?

[Chopper Reid]

Well,you should not be blown off the centre line as you use rudder to keep straight and the 'cyclic' [stick] should be tilted into the wind. As long as you have plenty of runway on the short side, there should be no reason why the takeoff cant be continued. Terry is correct, you need to be able to 'feel' what is needed.

I for one would question training with a 7 hour student in cross winds that strong to blow you of centrer line .

PS. I'm not an instructor.

[dragonflyerthom]

Terry

I would say use your cyclic to stay on the center line but allow the rudder to stay neutral and the cabine to windmill into the wind naturally. Now this is for take off. If you are landing then what Brian explained is applicable.


Thom

I also am not an instructor

[Gyro-nut]

I've been up in some pretty stiff wind the past couple weekends. My advice is to always use the stick to 'tilt' into the wind and keep the nose straight down the runway. If something happens to your engine mid take-off and your 'crabbed', prepare to shell out some big bucks.

[Aussie_Paul]

During take off and landing you must use the stick for drift and the rudder for yaw. In other words, tilt the rotor disc into the wind and keep the airframe aligned with the runway/direction of travel with the rudder.

In cross wind conditions you have the aircraft unbalanced, so if the nose wheel touches the ground and the machine has no self aligning qualities, there could be trouble.

I am an instructor and probably a poor one at that!!!

Aussie Paul. :)

[enewbold]

From FAA 8083-21, page 20-4: CROSSWIND TAKEOFF

A crosswind takeoff is much like a normal takeoff, except that you have to use the flight controls to compensate for the crosswind component. The term crosswind component refers to that part of the wind which acts at right angles to the takeoff path. Before attempting any crosswind takeoff, refer to the flight manual, if available, or the manufacturer’s recommendations for any limitations.

Begin the maneuver by aligning the gyroplane into the wind as much as possible. At airports with wide runways, you might be able to angle your takeoff roll down the runway to take advantage of as much headwind as you can.

As airspeed increases, gradually tilt the rotor into the wind and use rudder pressure to maintain runway heading. In most cases, you should accelerate to a speed slightly faster than normal liftoff speed. As you reach takeoff speed, the downwind wheel lifts off the ground first, followed by the upwind wheel.

Once airborne, remove the cross-control inputs and establish a crab, if runway heading is to be maintained. Due to the maneuverability of the gyroplane, an immediate turn into the wind after lift off can be safely executed, if this does not cause a conflict with existing traffic.

-------------------------------------------------------------------

Does this help?

=Ed Newbold=

[Harry_S.]

From FAA 8083-21, page 20-4: CROSSWIND TAKEOFF

Once airborne, remove the cross-control inputs and establish a crab, if runway heading is to be maintained.



Thank you Ed.

I picked out this portion of your post because this is what most people fail to mention...the "CRAB" into the wind on takeoff.

I guess my machine does it automatically, or, I unconciously pressure the controls to assume the "CRAB" into the wind?!

I presume that most are concerned with the takeoff roll with a crosswind rather than the takeoff roll AND the runway heading after liftoff?!


Cheers :)

[Mike Jackson]

I personally find the techniques the same with RW or FW and is quite fun and natural. The xwind control discussion is great - keeping the gnd track basically rwy heading. Just as the upwind wheel (supposed to be the last thing on earth, sts) breaks ground the gyro yaws into the wind. Now it's cyclic and rudder to keep whatever ground track you like. My goal is to make the transition from a gnd run to a takeoff seemless. I don't always accomplish that, especially if the winds are gusty. Playing in the wind with a conservative build up approach is very fun.

Once airborne the aircraft doesn't care where the rwy is. The rest is technique wrt to how you want to fly your gnd track for upcoming surprises - like power out.

[Aussie_Paul]

Thank you Ed.

I picked out this portion of your post because this is what most people fail to mention...the "CRAB" into the wind on takeoff.

I guess my machine does it automatically, or, I unconciously pressure the controls to assume the "CRAB" into the wind?!

I presume that most are concerned with the takeoff roll with a crosswind rather than the takeoff roll AND the runway heading after liftoff?!


Cheers :)

Harry, after lift off if you have the string on the middle then the machine will climb out balanced in crabbing along flight as should happen.

Aussie Paul. :)

[Chopper Reid]

Thats right Paul, string in the middle BUT maintain runway heading as well.

The original post actually asks a bit difernent question[ I think] this fellow has been blown off the runway centre and wants to know how to return to the centre line or if indeed, should he need to do so.

I thought that provided he had plenty of runway on the side, then continue takeoff. What do the experts say ?

Just as a matter of interest, I find really strong X wind takeoff's, one of the most danger fraught manourvers one can do and to be avoided at all costs.

[Aussie_Paul]

Thats right Paul, string in the middle BUT maintain runway heading as well.

The original post actually asks a bit difernent question[ I think] this fellow has been blown off the runway centre and wants to know how to return to the centre line or if indeed, should he need to do so.

I thought that provided he had plenty of runway on the side, then continue takeoff. What do the experts say ?

Just as a matter of interest, I find really strong X wind takeoff's, one of the most danger fraught manourvers one can do and to be avoided at all costs.

If you have the room just stay parallel, If not use both the stick and the rudder to bring you back.

Brian, maintain runway tracking not heading as you will be pointed in a different direction to what you are traveling. heading and track made good are different with a cross wind.

Aussie Paul. :)

[Chopper Reid]

:) wrong word I used there Paul, tracking looks better !!

[Steve McGowan]

If ya gotta think about it,, Your too Late....

You don't get into a gyro,,,,,,,Ya WEAR IT !!

[Rick Whittridge]

That`s it you Wear it! Feet,Hands,Eyes,throttle, JUST DO IT!

[Harry_S.]

I've never used a *string* so I can't go that route, I guess.:D


Cheers :)

[Chopper Reid]

The 'string ' is a very important part Harry.

[Aussie_Paul]

What do you use for balancing the aircraft Harry?

Aussie Paul. :)

[Harry_S.]

What do you use for balancing the aircraft Harry?

Aussie Paul. :)





:confused: :confused:


Cheers:)

[ferranrosello]

A superb explanation, Ed Newbold. The crosswind take off is the most difficult thing to do flying gyros. Flying with crosswind cannot be performed by procedure, lopeznoel. You must drive (fly) the gyro. Use the pedals to control where you are pointing (the runway heading). Use the stick to maintain your gyro in the centerline.

Once airborne, your gyro will want to yaw into wind. Let the gyro do it, getting a crab. But maintain the edge with the stick. In this way you will take off safely and avoiding the drag penalty of the uncoordinated flights. And don't worry, taking off with cross wind is very difficult.

Ferràn.

[lopeznoel]

I thank everyone for their comments. Everything that was said was what I expected and it helped me solidify my understanding of crosswind takeoffs. I understand the general consensus that I have to practice to "feel" the situation but I need to understand what I am doing. The reason I ask is that I also had a misconception on the use of the rudder on crosswind landings that Terry helped me correct.

[Aussie_Paul]

:confused: :confused:


Cheers:)

Harry, most aircraft have the "bat and ball" type slip/skid indicator to balance the aircraft from slipping or skidding. The gyro world seem to mostly use the "string" to trim for balance. Gliders us the string a lot.

I have heard that in Helos, when they are first tested for balanced flight, use the string to set up the "bat and ball" instrument. The "bat and ball" may not be square in the instument panel in a Helo.

I hope I have explained that slightly clearer than mud!! :)

Aussie Paul. :)

[Harry_S.]

Once airborne, your gyro will want to yaw into wind. Let the gyro do it, getting a crab. But maintain the edge with the stick. In this way you will take off safely and avoiding the drag penalty of the uncoordinated flights. And don't worry, taking off with cross wind is very difficult.



Ferran;

I was going along with your post until I got to your last sentence. I do believe you omitted a critical word...NOT...between *is and very*...as in, "taking off with a cross wind is NOT very difficult."

You might scare a bunch of pilots otherwise.:eek:


Cheers :)

[Harry_S.]

Harry, most aircraft have the "bat and ball" type slip/skid indicator to balance the aircraft from slipping or skidding. The gyro world seem to mostly use the "string" to trim for balance. Gliders us the string a lot

Aussie Paul. :)



I follow you now, Paul. I have a mental block right now, but I don't think we called it a "bat and ball" way back when I learned to fly.

I learned to fly in a J-3 Cub and used that ball to co-ordinate my turns. And that *feeling* of co-ordination stayed with me. So consequently, in later years I found myself relying on the *seat of the pants* feeling in my recreational flying. True, my feeling may be off somewhat...but I'm flying VFR for my fun time. So if I'm a bit un-coordinated...so what?!

So, like I said...I've never used a string and if I'm a bit un-coordinated...so what?! I really don't think I'm too un-coordinated. When I'm flying, I don't think I would be looking at that *string*, anyway.


Cheers :)

[ferranrosello]

Harry, flying is the easiest thing to do, but the most difficult thing to learn...

I'm answering to a flying student. When you really know how to do it, it is very easy to fly with cross winds. But the take off alone, is a very difficult manouver to learn by anybody flying autogyros. If, in addition, you have cross wind it is still harder.

Ferràn Roselló

[ferranrosello]

I have some good ideas about the coordinated flight, the bat and ball and the string.

What we need to do is fly straight in the air. If not we will have a drag penalty. This penalty is very important in the take off.

The ball is an indicator of the balance between the forces acting on your aircraft. If the forces are very small the ball is not going to indicate any thing.

At very low speeds (like in take off) it is posible to fly sideways in the air with the ball centered (because the inbalance between the forces is very small).

The strip is going to show you if you are flying straight in the air or not. It will indicate a sideway flight when it happens, including very low speeds. So it is a much more acurate indicator for straight fly than the ball.

Ferràn Roselló

[Harry_S.]

Ferran;

I agree with your two posts above. In my previous post I should have made reference to the new and the more experienced pilots, as regards crosswind takeoffs.

Crosswind landings would be a little testy as well...even for the experienced pilot.


Cheers :)

[Aussie_Paul]

I have some good ideas about the coordinated flight, the bat and ball and the string.


The ball is an indicator of the balance between the forces acting on your aircraft. If the forces are very small the ball is not going to indicate any thing.


The string is going to show you if you are flying straight in the air or not. It will indicate a sideway flight when it happens, including very low speeds. So it is a much more acurate indicator for straight fly than the ball.

Ferràn Roselló

Absolutely. Nicely explained Ferran.

Aussie Paul. :)

[mceagle]

The Ball is a "bubbleometer" or spirit level that is fixed to the dash and indicates when the fuselarge is level laterally. In a fixed wing, the wings are fixed to the fuselarge so the fuselarge level = wings level = coordinated flight.
In a gyro the rotors are not fixed to the airframe and even if they were, the airframe is rarely level, even in coordinated flight, = ball useless.
You cannot get anything more accurate (or cheaper) than a drift string

[Aussie_Paul]

The Ball is a "bubbleometer" or spirit level that is fixed to the dash and indicates when the fuselarge is level laterally. In a fixed wing, the wings are fixed to the fuselarge so the fuselarge level = wings level = coordinated flight.
In a gyro the rotors are not fixed to the airframe and even if they were, the airframe is rarely level, even in coordinated flight, = ball useless.
You cannot get anything more accurate (or cheaper) than a drift string

Spot on Tim.

Aussie Paul. :)

[Chopper Reid]

Harry, you dont actually "look" at the string, the string is like other things that you see but do not focus on entirely. My string is located halfway up my UHF aerial and this is right in front of me so its easy to see.

The string is a great instrument in very windy conditions when having to do say X wind takeoffs or the odd landings, you can see exactly what force the wind is having on the gyro.

[Harry_S.]

Harry, you dont actually "look" at the string, the string is like other things that you see but do not focus on entirely. My string is located halfway up my UHF aerial and this is right in front of me so its easy to see.

The string is a great instrument in very windy conditions when having to do say X wind takeoffs or the odd landings, you can see exactly what force the wind is having on the gyro.



Brian;

Your point as well the others, regarding the string are well taken. The string is a dependable, educational flight indicator...and cheap too. I think it a must for the trainee. I have nothing against using the string at all.

I just made mention that I, do not use a string. If I had used a string in my initial F/W training, many years ago I might add, I could probably still be using one.


Cheers :)

[Aussie_Paul]

Harry, do you fly with the doors on much?

Aussie Paul. :)

[Harry_S.]

Harry, do you fly with the doors on much?

Aussie Paul. :)



Now Paul...you surprise me. I pay attention to your posts but apparently you don't read my posts too well?!:twitch:

I've never flown my machine with doors on, nor have I flown any other RAF with the doors on.

The reason I don't fly my machine with the doors on, is that...I HAVE NEVER INSTALLED THE DOORS ON MY MACHINE. I believe I have mentioned that fact at least a dozen times in years past. I mean no offense towards you , Paul. I know you're concerned with your project.

Living in Florida, I saw no need to install the doors. I do have the doors and the installation hardware still in the boxes in the event I sell my machine and the new owner would like to add the doors. I do have the doors trimmed to fit and are ready to install.

I still see no need for me personally, to use a string. I don't need to have one. Okay?!


Cheers :)

[Aussie_Paul]

Now Paul...you surprise me. I pay attention to your posts but apparently you don't read my posts too well?!:twitch:

I've never flown my machine with doors on, nor have I flown any other RAF with the doors on.

The reason I don't fly my machine with the doors on, is that...I HAVE NEVER INSTALLED THE DOORS ON MY MACHINE. I believe I have mentioned that fact at least a dozen times in years past. I mean no offense towards you , Paul. I know you're concerned with your project.

Living in Florida, I saw no need to install the doors. I do have the doors and the installation hardware still in the boxes in the event I sell my machine and the new owner would like to add the doors. I do have the doors trimmed to fit and are ready to install.

I still see no need for me personally, to use a string. I don't need to have one. Okay?!


Cheers :)

That's fine Harry. Sorry to surprise you. :wave: I thought I remembered something like that but too busy or LAZY to do a search.:D

I would not need a string flying a Raf without the doors. I certainly need one with the doors on!!! :lol:

Aussie Paul. :)

[Chopper Reid]

Lets get the issue of strings straight, a string is not a no go item and anyone can fly a gyro safely without one and if you are like Harry and never had one, then you would never miss it.
However, I feel it is a worthwhile investment and it could help you save the bacon one day.

[dragonflyerthom]

Yes and almost free is cost effective also. Just tye it on an antenna or go cut yourself a coat hanger and mount it.


Thom

[Steve Osborne]

Make sure you get a certified airworthy string. It will work better & be more dependable according to the FAA and it should only cost around $500 .....LOL

[mceagle]

Some seem to be missing the point of the string here. The string is a very accurate drift indicator and as such informs the pilot when he is in uncoordinated flight (inefficient). An experienced pilot uses rudder as required and in most cases he doesn't even know he is doing it. Visual ques are a very powerful thing and a pilot can easily be bluffed into uncoordinated flight, especially when flying along a ground reference like a road or fence line, with a cross wind.
If the rudder is not properly trimmed for feet off coordinated flight, then it is impossible to tell if you are in coordinated flight or not, no matter how good a pilot you think you are.

[dragonflyerthom]

Tim

Do you fly with a GPS? It is amazing how to go from point A to B that the heading you fly is not the heading you will be going to. My GPS does a really good job of it. Alot easier than the old flight puter.

Thom

[Harry_S.]

I don't believe anyone is poo-poo'n the use of the string. I personally endorse its use for the new or low time gyro pilot...and any other pilot that wants to use the string.

But, I do have a question...how un-coordinated or inefficient would an experienced gyroplane pilot become, by not using the string? When an experienced gyro pilot is up, putt puttin' around the countryside for a relaxing hour or so, taking in the sights and sites...why would or should he be concerned about a bit of un-coordinated or inefficiency that went un-noticed, anyway?! I wouldn't.

I'll tell you what I do, do and it's more or less a subconcious thing, which comes by way of experience.

As you know, I don't fly my RAF with doors. Other than when I scan the panel, my eyes are outside the cabin, scanning for traffic and/or looking at the ground activities.

When I sense a change in wind hitting on my arms...a steady wind change...I give a bit of rudder pressure to that side, ie, an increase on my right side, I give a bit of right rudder and vv. I do believe the string would indicate the same correction needed to co-ordinate, but I sensed it on my arms.

Again; I endorse the use of the string, it's just that I don't use nor do I need one.


Cheers :)

[ferranrosello]

It is possible to fly a gyro without a string reasonably well. In cruise flight a good and well trimmed gyro flies coordinated by itself. The pilot can use other cues in order to coordinate his flight, in an open frame gyro is easy to feel the wind in yor face..., or to hear the noise of drift in the intercomm.

But the string is the most acurate drift indicator I know. So all the gliders (which are the more sensitive aircraft to drift) use the string. And the same thing happens with lots of helicopters. And when you need to perform a short take off with cross wind the string is very helpful not only for beginners but for experienced pilots.

Ferràn

[dragonflyerthom]

The string is helpful when the doors are on and you don't have your arms out the doors.

I put the doors on my little bird this week. I can't believe how much it dressed her up. She is b e a u t i f u l and looks GREAT. I know that it increases drag on the cabin and effects yaw but she sure looks good. I guess I will use the string more huh.


Thom

[Aussie_Paul]

The string is helpful when the doors are on and you don't have your arms out the doors.

I put the doors on my little bird this week. I can't believe how much it dressed her up. She is b e a u t i f u l and looks GREAT. I know that it increases drag on the cabin and effects yaw but she sure looks good. I guess I will use the string more huh.


Thom

Actually Thom the doors reduce drag and increase the airspeed, BUT they make the Raf very yaw unstable.

Aussie Paul. :)

[dragonflyerthom]

Gday PB

Hows tricks? Have you made it to NZ yet? We have two Universities here in Arkadelphia and the Baptist Univ has a couple of Professors fro NZ. They have a granddaughter that lives with em also. Very dark complexion . \

I can hardly wait to see what you are doing on your project. Red is a pretty color.

Post more pics please.

[Brent Drake]

I'll tell you guys. I fly with the string all the time. I've noticed that when I fly by GPS with a crosswind then use rudder to fly with the string. Flying with the string will gain me 3 to 7 mph depending on the crosswind conditions.
So flying around the airport I do not use the string, but cross country, it does make a difference. I cannot see where experience of any kind, could make your sensesfly the sraight string when one is not there.

[birdy]

Iv never had a string on the ferel, or an accurate ASI for that matter, and with my lousey efforts in flyn, i gess it speaks volumes:)

I used a string on the wasa once, only to set the trim tab on the rudder.
A few weeks later i noticed it wasnt there, and had no idea wen it dissapeared.

[Harry_S.]

Uh, Uh, Oh Birdy.

Some people are going to insist that we are flyin' around the sky in an un-coordinated condition, being as we don't have a drift string to tell us when to apply rudder.:help:

Maybe we best re-consider using a string?!:D


Cheers :)