Gazelle crosswind landing

[Admin]

Just thought that after reading another post I would say one thing that I feel I can do better in a Gazelle then any other aircraft that I have flown.

 

We all know there are two ways to come in on final in a crosswind - either crab her in or come in with a wing down. Now irrespective of what your instructor taught you to do or entering into a debate on which method is better, I find that with the Gazelle I can crab her in better.

 

The Gazelle, to me, crabs in really nice and then just before I flare I give her a bit of rudder to straighten her up and plonk on the runway she just comfortably goes. To me the Gazelle seems to just really nicely responds to this type of landing when there is a crosswind. In other aircraft I have flown when I stick the rudder in during a crab at flare they seem to act differently each time whereas the Gazelle seems to just go to the straight and lined up position - it's as if she knows.

 

Just thought I would mention this - any comments from other Gazelle flyers?

 

 

[Guest brentc]

My comment on that would be that I found that the crab technique worked really well as it does in most aircraft, however you will find that in a strong crosswind approaching the documented aircraft maximum that you will run out of rudder. One way to overcome this is to apply power when the rudder is applied to assist in yawing the aircraft back onto the centreline, or alternatively if the wing is stronger, to lower the into-wind wing. If the Gazelle has bent rudder horns which many of them do you will be lacking rudder authority and these techniques may help. That being said it took me many hours in a Gazelle to master the crosswind landing technique to the point that I could land in nearly anything. One day the crosswind was so strong after I had landed the aircraft ground-looped! and yes, it has a nosewheel!

 

 

[Admin]

One way to overcome this is to apply power when the rudder is applied to assist in yawing the aircraft back onto the centreline

VERY DANGEROUS - In my opinion do not do this as this will only work one way because if you are already crabing to the left applying power will make you yaw even further to the left causing you to go sideways - if you are crabing to the right a different story

 

 

[hihosland]

For me,

 

crab all the way down

 

then an abrupt yaw to align with the centreline

 

and plant the up wind wheel.

 

I'd be very cautions about that burst of power

 

to boost the rudder efficacy, things could get

 

really interesting really quickly.

 

If the cross wind is so strong that it cannot be

 

yawed straight you could almost land across

 

the runway or on the taxiway.

 

Davidh

 

 

[Yenn]

I have found that the crabbing approach works well with an aircraft which doesn't float a lot. For an aircraft which floats I prefer the slipping method.

 

 

[Barefootpilot]

Ian I'm a little confused by your warning. This method does work only because the increase in power in-turn increases air flow over the rudder giving it more authority it doesn't matter what way the rudder it pointed (It also increase lift over the inboard sections of the wing but thats beside the point. NOTE: Lift only increases for aircraft that have the engine up the front!)

 

The best way to keep from having to do this is know your and the aircrafts limits! Remeber if you roll your aircraft into a ball and its above the cross wind limit or even the demostrated cross wind your insurance agent will probably laugh and walk away!

 

Adam.

 

 

[Guest brentc]

You are correct Adam. The extra airflow over the rudder surface will result in increased rudder authority.

 

If you have experienced a crosswind close to or above the limits of the aircraft will have found that at low engine power settings you will simply run out of rudder.

 

A similar thing can happen in 6 cylinder Jabiru's on takeoff with a left cross-wind. You may run out of right rudder and as a result power is required to get the aircraft tracking straight. It only usually poses a problem if the nose of the aircraft is lifted off too early in the takeoff roll. The Gazelle has a large tailplane / rudder surface so this method will definitely assist in successfully handling a crosswind.

 

 

[Admin]

Firstly I have moved this thread from the Gazelle Usergroup forum to the General Discussion forum as it may be an interesting thread.

 

Now I may stand corrected - I have a great deal of respect of you and your comments Adam - but these are my thoughts.

 

The scenario put forward is that you are landing in a severe crosswind to the point that you have run out of rudder (your right pedal is all the way down) but you still are not lined up straight to the runway with the aircraft still yawing to the left. Assuming that at this point you are on idle as you are either short final or close to point of flare.

 

This means that your aircraft is being flown beyond it's safe operating limits and you are in fact "unstable".

 

A sudden burst of power as put forward will:

 

a) Cause a sudden yaw to the left - under normal circumstances requiring some more right pedal but you are already at full deflection - the aircraft will yaw further left.

 

b) An increase of air flow caused by the burst of power will cause extra air flow pass the rudder but will also cause extra lift causing the aircraft to become even further unstable in severe crosswind - and we don't want lift when trying to land as this makes us even more vulnerable to the uncertainty of the wind.

 

c) The net effect is that you are trying to land a very unstable aircraft that you are flying far beyond its safe operating limits.

 

d) Full rudder with power and close to the ground - YOU HAVE NOTHING LEFT for that sudden gust or whatever

 

This is why I believe that if you are to increase power there is only one thing you must do to minimise the danger level of your situation:

 

- Completely change your mindset from one of trying to land to one of trying to Go Around - if you don't do this then in my opinion only you are suffering from the same as "Got to get their itis" - and that is DANGEROUS

 

My point is - run out of rudder - go around!

 

These are my thoughts!

 

(Disclaimer - I am not an instructor with 000's of hours experience and neither most other pilots flying recreational aircraft so we don't need to put ourselves into dangerous situations)

 

 

[Guest pelorus32]

I'm with Ian on this. I think the evidence is there for his contention that the best action is go around! If you look at the ATSB reports for crosswind landing accidents - there was a reasonably recent one of a Cessna in the Torres Strait area - the aircraft departs the UPWIND side of the runway.

 

Now it is probably right that the burst of power aids controllability to some extent and because we are still at or about flying speed we might get away with it. However if the pedal is already to the metal then the increase in airflow over the rudder will only arrive after a yaw of indeterminate size to the left. That may be all it takes.

 

In any event why dice with it? A go around is probably the way to go. However a go around means that we go to full power and...yaw to the left because we have run out of rudder. That's fine in the climb - we will be maintaining runway centreline:), the problem is if we've made the decision basically in the flare then we are heading left at a great rate and had better hope that we are really flying and not just trying to fly.

 

The other thing is that as the aircraft slows down in the flare and roll out it will have a greater tendency to weathercock into the crosswind. That bears some thinking about too.

 

Great topic.

 

Same caveat as Ian - I'm no instructor, just like thinking about this stuff:;)3:

 

Regards

 

Mike

 

 

[Guest Fred Bear]

It is a good topic and just my 2 cents. Re the Jabiru, be careful with the Jab (if you have low hrs on the a/c and don't know it) because in a good strong x-wind the little Jab runs out of little rudder real quick. I am sure there are many techniques but I (personally) prefer the go-around approach.I always say "You go around, you get to fly another day". Anywhere in any airport go-arounds are conducted when the pilot in command is simply not happy with the events unfolding before him.No harm done either (except the circuit may cost you an extra 5 bucks)

 

 

[Barefootpilot]

Hello again,

 

Ian I agree with your thoughts I just put the example out there so if one day someone needs it for some reason they have at least thought about it. In the situation described it would be best to go around and find another place with less crosswind to land.

 

I would just like to clear up a few points (just the terminology is a bit confusing to me)

 

You say "The scenario put forward is that you are landing in a severe crosswind to the point that you have run out of rudder (your right pedal is all the way down) but you still are not lined up straight to the runway with the aircraft still yawing to the left."

 

The aircraft won't be yawing it will be tracking or skidding left across the ground. The aircraft is actually being yawed to the right as Yaw is a function of rudder and only effects the aircraft on its axis.

 

A sudden burst of power as put forward will:

 

a) Cause a sudden yaw to the left - under normal circumstances requiring some more right pedal but you are already at full deflection - the aircraft will yaw further left.

 

This yaw left would be from the increase in torque and would be minimal compared to the increase in rudder authority.

 

b) An increase of air flow caused by the burst of power will cause extra air flow pass the rudder but will also cause extra lift causing the aircraft to become even further unstable in severe crosswind - and we don't want lift when trying to land as this makes us even more vulnerable to the uncertainty of the wind.

 

Yes this is true but the short burst of power would only create a small increase that would be barely noticable although as very good point.

 

c) The net effect is that you are trying to land a very unstable aircraft that you are flying far beyond its safe operating limits.

 

d) Full rudder with power and close to the ground - YOU HAVE NOTHING LEFT for that sudden gust or whatever

 

Absolutly true!

 

All in all I agree with you completly you are risking alot just to prove a point and its probably not worth it! But if you get stuck and don't have a choice one day this may get you out of a pickle.

 

Just to open another can of worms!

 

Another way you can over come lack of rudder in a cross wind if you have differntal brakes is to land on the down wind main gear first and use brake to aline yourself with the runway. As you slow down you are probably going to be weathercocked into wind with a possible ground loop if you are not lucky but again if its a choice of crashing or ground looping!

 

Warning!! I don't not recommend this technique unless you are very confident with aircraft and even better you own it so if you bend it, you only have yourself to blame!!!

 

Adam.

 

 

[facthunter]

X-Wind handling.

 

Some of you fella's have got me real worried here.

 

What are we doing in the air with full rudder on at low ( approach )speed ?

 

If you are crabbing at a steady drift angle, with wings level the rudder pedals are even height, the ball is in the centre. The cross wind has nothing to do with it, any more than when you lay off drift on any other leg of the circuit. If you have full rudder on, You are crossed up, even during the landing roll where you should be crossed up, trying to make sure that the into wind wing doesn't lift, but NEVER in the air, unless deliberately trying to SPIN the aircraft, OR PERFORM A SIDESLIP. I think we can discuss technique once this has been considered. C'mon Nev...

 

 

[Guest Fred Bear]

Nev,

 

I for one cannot stand side-slipping. It is putting the aircraft through a little more stress (in certain aircraft) and I believe in the J160 a little more stress than need be on the tail empanage. It's (sideslipping) not natural (to me anyway). If you have botched up a landing that much that you are that high and need to slide slip you should start practising your landing techniques again. But hey, that's just me. I'm a straight in approach, do it nicely kind of flier. I know there's lots out there that like to put on a show for those on the ground showing their side slipping techniques off until they encounter a fence/tree or something breaks off the a/c due to it being over stressed. I have heard many a/c 'whistling' during some pretty severe side slips I have seen 'Crabbing' is a different story.

 

 

[facthunter]

Sideslipping.

 

Yes , there is some stress on the fin, at slower speeds it is not as bad as you might think, but at slow speeds it is more dangerous from the spin -inducing consideration. It feels pretty ordinary with the side loads in the cockpit on the occupant. Often the procedure is not performed well, the aircraft should first be banked over & then top rudder applied to stop (or reduce) the turn. I don't want to get sidetracked at the moment .I'd like some responses to my previous post because some serious safety issues are there. Nev...

 

 

[Guest Fred Bear]

http://www.geocities.com/cfidarren/r-crosswind.htm

[Guest brentc]

A couple of points.

 

Be wary of saying that the aircraft will 'yaw' to the 'left' with power. This is not always the case, subject to the engine/aircraft type and propellor rotation, it may yaw to the right.

 

Sometimes, if it is windy, you might HAVE to land. Going around is not always an option. Whilst it is an option to go around, you may need to eventally land and you will need to be able to handle the landing eventually. You can't always rely on the forecast and there can always be sudden changes in the weather. Remember that you can always combine the rudder technique and the lowering of the wing to get better results. There are many aircraft where the one technique alone is not adequate.

 

If you are slow in airspeed and struggling to maintain directional control due to running out of rudder, the obvious solution is to increase power. Not only does this increase rudder effectiveness due to the increased airflow, but increased speed which creates more airflow which results in increased control effectiveness. I made the comment "One way to overcome this is to apply power when the rudder is applied to assist in yawing the aircraft back onto the centreline" - I didn't suggest a 'burst' of , but, that being said, this is still a valid technique.

 

Applying power does not necessarily make an aircraft pitch up. Climbing and descending is controlled by the pitch which is the primary effect of the elevator. Whilst some aircraft may pitch up with the application of power, not all will. This is an important thing to consider in a discussion such as this because you are all talking about completely different aircraft, some with flaps and some without. We have in this thread a Jabiru, Tecnam and Gazelle to start with which are all very different.

 

Adam, the differential braking comes into effect in an aircraft with a castoring nose-wheel. The Cirrus SR20 that I fly has a fully castoring nosewheel. If you are taking off in a strong crosswind you may need to apply full rudder AND brake on the one side to keep the aircraft aligned for takeoff. Same goes with landing. Once the aircraft slows to a speed in the landing at which the rudder ceases to be of further directional control, braking will be required to keep the aircraft straight. If you had a brake failure in a Cirrus with even a slight crosswind you are destined for pain and damage as there is no way to control the aircraft. The only solution might be to land on a bitumen runway and put one main wheel on the grass to the side to use that as a break, and then combine this braking with the other brake. Cirrus have since fitted overheating flags on their brakes so that during the pre-flight you can tell if the guy before you braked too hard.

 

 

[Guest pelorus32]

Hi Nev,

 

I took it like this:

 

You've crabbed down final as you should - in this situation the aircraft is not crossed up and the rudder will be neutral - the aircraft is simply on a heading not aligned with runway centreline in order that the track is aligned with runway centreline. This is analagous to laying off drift as you fly cross country.

 

As you come into the flare you transition from a heading not aligned with runway c/l to a heading aligned with runway centreline in order to ensure that there are no side loads on the gear as you touch down. It is at this moment as you yaw the aircraft right (we have a left xwind) and put the left wing down that I took it that Ian had run out of rudder.

 

When all is stable again you will still have right rudder in (but hopefully less) and left wing down to ensure that you are not sliding to the right as you float. That is you will be side slipping to the left the exact same amount as the wind is blowing you right. Now you are tracking and heading straight down the centreline. If you run out of rudder because of the amount of left wing down that you have then you are in a hell of a sideslip and in trouble.

 

Obviously if your touch and timing is good the aircraft touches down at just the moment that you have got it facing straight down the strip - the B737 story - as you dare not lower a wing.

 

In our case however where we have the wing lowered and some right rudder in, the aircraft may well still be trying to weathercock into wind, requiring more right rudder (over and above that required by the simple side slip) whilst we wait for it to settle (first on the upwind wheel).

 

Regards

 

Mike

 

 

[Barefootpilot]

Hi Nev,

 

Mike got it spot on we are not talking about side slipping the whole approach just the as you flare you line her up with the centre line with rudder. Sorry if any of my post indicated otherwise.

 

Brent, Yep you got it the aircraft I fly mostly, only has castering nose wheels so all ground control is by diff breaking however I was thinking more along the lines of Cessna 180's with the one wheel breaking idea.

 

Some of these idea's are suitable for some aircraft but some will just plain not work in others so if in doubt ask someone with time on type.

 

Adam.

 

 

[facthunter]

Crab or Slip.

 

Good website darrenmasters. Why do we have to do one technique or the other? A combination works fine.

 

One thing that I have always emphasised is that if you use the crab method, you must not let the into wind wing rise above horizontal, as you would be crabbing into wind & slipping downwind at the same time. Clearly ridiculous, but you will see it happen .

 

Obviously, the problem with the crab method is that if you are a bit fast, (airspeed) and you kick it straight, if the float is prolonged, you start to drift off centreline, and contact with the runway will impose side loads on the undercarriage, which can tend to tip the A/C,etc

 

The Gazelle doesn't normally float far ,so that makes it more easily managed.(plus the ailerons and rudder keep working ).

 

It makes you think you can fly, when maybe you're not that good. ...Nev.....

 

 

[facthunter]

Gazelle X-wind landings.

 

Thanks Mike & Adam. I'm a little wary of misunderstandings not being corrected,& and I don't want to talk LIMIT flying here although it interests me (IN Principle) I worry about the example set .Ive seen people crash planes in the most inexplicable way as a result of a wrongly interpreted discussion , So I just wanted to be sure that we are all on the same wavelength I' ll get back to you later.. N..

 

 

[Yenn]

The way I see it is that on the descent you keep lined up with the runway by either method, or even both combined. You don't have a problem until the instant you touch down. Kick straight with rudder as you touch and the landing is done but the fun starts on the rollout, the side wind pushes the ineffective rudder downwind causing you to travel across the runway.

 

If you have no alternative to landing then land as close as you can to the downwind edge of the runway and enjoy the ride.

 

For those who don't like slipping I say "give it a go". It isn't difficult and gives great control over glide slope, with the only proviso being don't do it if the designer says it is a no no. Some of us don't have flaps and the slip is the only way to control glide slope without an engine and we should be able to land safely without the engine.

 

 

[Admin]

I thought this would start some healthy conversation ;)

 

But lets get this into perspective! The first post was made by myself and was simply stating that I felt the Gazelle when being crabed in seems to easily straighten up with some rudder as she seems to know how to do this herself. Other aircraft I have flown behave differently each time. That was all!

 

Post 2 came in saying that in a severe crosswind and you have full rudder deflection to just apply power.

 

Now if the thread stopped there and a student pilot was reading that he/she would have gone away thinking - great, no problem, if I ever run out of rudder and I am not straight on the runway all I have to do is just simply apply power.

 

I think we have an obligation to all those that read these posts to ensure the reader is fully aware of the consequences of what we have said - we need to be so careful on what we say and how we say it to ensure our fellow recreational flying friends don't take any unnecessary risks and get themselves killed because of something we said.

 

The next post was mine saying that applying power in that situation is dangerous.

 

The posts that flowed on have been really great in discussing the pros and cons of different methods and outcomes and this IS what these forums are all about without any one thinking they know it all and most importantly I think this thread, although moved away from the theme of the initial post, has clarified/is clarifying the pros and cons of the situation and sending a great message(s) to anyone that reads this thread - well done guys

 

 

[Guest Decca]

Despite the intention of the first post of this thread, this inexperienced wanna-be has a few stupid questions for you many experienced pilots. So far I’ve enjoyed the read, but just wondering;

 

ALL aircraft have operational limitations, right?

 

DOES that include a CROSS WIND limitation?

 

IF SO we all know our operational limitations, correct? And we would never knowingly exceed any of these limitations of course!

 

Now if we’re at an aerodrome with an ATIS, do we need to calculate the crosswind from the provided data? How is the crosswind worked out?

 

At any other airport how accurately can the crosswind be determined by looking at the windsock?

 

Now would any aircraft manufacturer allow their aircraft to run out of rudder authority at max crosswind?

 

There is an airworthiness notification for the Skyfox/Gazelle rudder horns (base of rudder leading edge spar) to be inspected before next flight, for bending due to rudder pedal pressure being applied when at max travel (rudder stops being in contact with horn/s). This would jeopardize rudder throw to something less than the nominal 30deg +/-1 each way, therefore reduce authority.

 

Regards, Decca

 

 

[Guest Fred Bear]

ALL aircraft have operational limitations, right?

Yes.

 

DOES that include a CROSS WIND limitation?

Yes.

 

IF SO we all know our operational limitations, correct? And we would never knowingly exceed any of these limitations of course!

Most of us Decca that want to live another day would not but people do.If a cross wind limit of an a/c is 12kt people will land them in 20kt.

 

Now if we’re at an aerodrome with an ATIS, do we need to calculate the crosswind from the provided data? How is the crosswind worked out?

Cross wind at aerodromes is worked out by either an observer or an AWS (automatic weather station).It will give a crosswind mean and crosswind max component.

 

At any other airport how accurately can the crosswind be determined by looking at the windsock?

Quite accurately if you know how to read a wind sock.

 

Now would any aircraft manufacturer allow their aircraft to run out of rudder authority at max crosswind?

Not sure.Probably not though as the max component should 'give or take' a few extra kts should this situation be encountered.Pylon 500 would know more.

Hope that helps some.

 

 

[Guest John Mac]

It all about planning your arrival.

 

Wing down into wind and keep it straight down the centre line with rudder.

 

Here we have max Xwind with gusts -- Look well ahead and keep those feet relaxed and moving.