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FlyingKiwi_73 19th September 2011 19:58

Crosswind Flaps
 
Hi all, been away from the forum for a while, actually flying!

I have searched for threads on this, which i thought would be a hot topic here but all i can find is biz jet techniques,.. a little outside of my price range!

I was flying a nice 172N on the weekend in slight crosswind that stiffened as i continued my familiarisation circuits (hadn't flown the 172 in a while).

Now i must be out of practice in crosswinds because i made a few what can be described as alarming landings. At first i thought it was the extra speed on the aproach so i slowed to 65 KIAS this helped some what but the touch downs were still very hard and my directional control was still hopeless.

I'm using the sideslip trick i was taught nose into wind kick straight at the flare, into wind wing down, that wheel to touch first.

I'm wondering if it was my use of 20-30 deg flap on the approach???
I tried a flapless as i do practice these every now and then and that approach was better and the roll out much more straight.

What i found i was having trouble was is the touchdown, it was always fairly 'positive' (the flare being nearly forgotten keeping the right wing down) and i had a real job keeping the aircraft on the center line, or infact vaguely in the middle... i got pretty close to the edge on one circuit and a dab of right brake brought the nose down alarmingly, so much so i was worried about a prop strike.

I was using RWY 16 wind was 20-30 deg off the nose and not more than 10-15 knts which to my mind is a xwind of 6ish knots.

Any advice is helpful especially on the use of partial or full approach flap.

Yes i have booked to go out next weekend with an instructor. i think i need it.

paulthornton 19th September 2011 21:36

I was taught, assuming the runway length was sufficient, to not use full flap when there was a significant crosswind. This technique has worked well for me as the airports I use typically have long runways for the type I fly, so use half flap in these conditions.

The main thing to bear in mind is that the landing roll will be longer - and human factors being what they are you can end up focussing on the crosswind and how best to deal with it and overlook runway length / the fact that the aircraft will float longer if not using usual landing flaps.

Paul.

Mark1234 19th September 2011 22:26

Flyingkiwi, there are arguments for and against using reduced flap, it can tend towards a holy war.. however: Given a crosswind component you quote at 6kts, you really shouldn't need to be considering less flap. I would suggest it's just a handling hiccup that will most easily be fixed with a little assistance from someone on board who can watch what you're doing.

For my part, I wouldn't recommend sorting out the cross control during the flare - I either get into the slip before the flare, or flare and use slip as required during the hold off. That might be a matter of terminology.

Pilot DAR 19th September 2011 22:34

Kiwi,

The 172 was certified to wording like this:

Directional stability and control.

(a) There may be no uncontrollable ground or water looping tendency in 90 degree cross winds, up to a wind velocity of 0.2 VS0, at any speed at which the airplane may be expected to be operated on the ground or water.
(b) A landplane must be satisfactorily controllable, without exceptional piloting skill or alertness, in power-off landings at normal landing speed, without using brakes or engine power to maintain a straight path.
(c) The airplane must have adequate directional control during taxiing.


You'll notice first of all that there is no reference there to flap position. Therefore the technique required to achieve this requirement can be specified, and commonly manufacturers seem to suggest lesser flap settings for crosswinds, but with no numbers attached to the recommendation. However, unless the Flight Manual makes a reference to "avoid", "not approved", "prohibited", "maximum" etc. with respect to flap use, it's pretty well up to your preference.

I have previously posted here that my personal preference in every aircraft other than a Twin Otter, is full flaps for every landing, unless you've had a flap system failure. My personal preference may not be right for everyone, and that's fine. Though, if it were my plane, a pilot who could not demonstrate a full flap landing in the "demonstrated" crosswind value for the plane, would not be taking it solo.

When I flight test a plane with an external modification (often tail booms), I am specifically looking for a weathervaning affect that the mod might have on the crosswind capability. I will fly in the maximum appropriate crosswind I can manage, and always use the maximum recommended flap setting. I have never had a problem. I do agree that taildraggers are more challenging in this regard, and I do shy away from high crosswinds when flying taildraggers.

The most extreme tests I have done like this were in two different Cessna Grand Caravans, one in a direct crosswind of 19 gusting 25 knots, the other in 35 gusting to 40 knots, 45 degrees off the runway heading. Both mods introduced more tail aft of the C of G, so more weathervaning was likely. Though I did have to apply and hold full rudder a few times to keep straight, there was no problem maintaining control in either test.

Interestingly, the Caravan flight testing required me to also demonstrate zero flap landings (wind not a factor) last week. The touchdown speed was about 30 knots higher (full flare not possible, 'cause of mod), and a bit alarming, compared to full flap landings.

I encourage you to just keep practicing crosswind landings, and keep using the greatest flap settings you can feel comfortable with. You'll find that your confidence grows faster than you'd expect. You'll only get better if you push yourself a bit. Know that the aircraft can do it, when you apply the skill. A 172 will land nicely in at least 10 knot direct crosswind, with full flaps, quite happily.

Personally, and a bit like a "fraidy cat", I would simply rather be going more slowly should something bad happen, and the more flap I have out, the slower I'm going!

Big Pistons Forever 19th September 2011 23:31

I think part of the problem with flight training is "one size fits all" pronouncements.

The characteristics of the aircraft have a large effect on the handling and so the amount of flap used should reflect both the aircraft and the conditions. Cessna's, particularly ones with 40 deg of flap, and loaded towards the front of the CG envelope tend to want to adopt a flat attitude in flare until they get quite slow and need a lot of up elevator to get a satisfactory nose high touchdown. If the wind is gusty they trying to transition into the nose high attitude without ballooning and while managing the drift can be hard for new pilots. Assuming a reasonably long runway, my experience teaching has been that using 10 deg of flaps makes it much easier for the student. The naturally more nose high attitude makes the flare easier to judge, the extra 5 to 10 knots makes the controls more responsive, and as soon as the wheels touch the nose can be lowered and you get a good transfer of weight from the wings to the wheels.

However this is for Cessna's. For Grummans I teach full flap for every landing as the flaps are relatively ineffective and the landings work just as well as partial flap ones.

For Pipers I teach full flap except for crosswinds that are near, at, or over the POH demonstrated max crosswind component value, where I recommend 2nd stage flaps.

All airplanes are different and for some more extreme examples like a forward CG C182 with 40 deg flaps or a Comanche/Twin Comanche, I would say a max flap max crosswind landing is demonstrating potentially poor pilot decision
making by not respecting the handling peculiarities of the aircraft.

Tarq57 20th September 2011 02:23

Couple of factors. Flap down reduces landing speed by a few knots. Those few knots reduce control effectiveness, albeit only slightly. This matters when the wind is gusty and/or near the limit of what you can handle as a crosswind.
Flap down also moves the centre of lift (in a spanwise context) more toward the fuselage. Maybe a few inches. The area of the wing with the flap down produces more lift (and drag, but that's beside the point) as the outer wing section. This has the effect of slightly reducing aileron effectiveness.

All this should not matter for a x/w of 6 knots in a 172. If the crosswind was above the demonstrated component, or very gusty up to that component, then it starts to matter. (And then available length/performance considerations need to be made.)

The most important thing is to keep flying the aircraft until it's below minimum flying speed. If the x/w is of variable strength, that means that during the hold-off you are continuously altering the bank angle and required rudder to keep the aligned with the runway and not drifting off to one side or another. At the same time you need to keep flying the aircraft, holding off for a reasonably smooth touchdown at close to normal landing speed. It's a busy time. It's tempting to try and put the aircraft down at the earliest opportunity. Don't. Once the aircraft has touched down, it's tempting to lower the nose, as it's been trained into a lot of pilots that "that's what you do in a crosswind". Don't. Keep the controls positioned to let the nose come down when it's ready. Keep the aileron and rudder inputs as they would need to be for handling the crosswind, as though you were still airborne.

That's how the instructor who kindly corrected my initially poorly learned crosswind technique* taught me, and it's served me rather well since.

My 2p.

(Flare and kick it straight just prior to touchdown, wings level, put the nose down. This technique will bust a nosewheel, sooner or later.)

172_driver 20th September 2011 03:58

Me myself I tend to use full flaps for C172 x-wind unless the crosswind is stiff. I don't think the flap setting would have had much influence on the 6 kts x-wind landing the OP asked for advice about. Simply, x-wind requires that you are current in the technique, something that is quickly lost with too long time on the ground. So just keeping practicing and it will get back to you.

I remember one particular instance though when the crosswind was right at, or even above, the demonstrated. I was using F30 and did feel I was running out rudder authority during the late part of the flare. Perhaps taken by a sudden gust, but felt like I couldn't push the nose fully aligned. Since then I use lesser flap settings when it's a good breeze across.

To each their own…

FlyingKiwi_73 20th September 2011 04:13

Hi Tarq57,

just so i'm clear your saying the crab and kick approach is not the best?

I was taught fly nose into the wind kick it straight as you round out, flare, wing down into wind. easier said than done for me at the moment, it is indeed a busy time.
I found that a moment of 'head in the cockpit' doing 50+ down the runway and cleaning up the flaps was enough to nearly cause a prop meets tarmac issue

I'd also like to point out i'm slightly new to tarmac runways too and their unforgiving nature, which obviously didn't help.

Tarq57 20th September 2011 05:45

No, the crab, then kick and wing down with the kick technique is the better one. I believe it is the mostly taught (and probably best) one, too.

I was taught to keep the wings level and just rely on the timing of the kick a nanosecond before touchdown to align the a/c with the runway. (Which is fine if you always know exactly when touchdown is imminent; it only takes a gust to ruin the landing.)

The "other" historical way was sideslipping all the way down final, staying aligned with the runway from a long way out.

The current method is a combination of those two. The timing of when to kick it straight doesn't need to be precise. I found it seemed to be best when done at the same time as the round-out was commenced, or maybe just prior.

If you're busy during touchdown, that is not the time to be faffing around with flaps.
Don't worry, it will come with practice. You'll get to relish it. Maybe even love it. Few things are as rewarding as a crosswind landing done well in adverse conditions. And some days you can be on top of your game and just the way the wind gusts/swings, end up with a thumper.

mad_jock 20th September 2011 06:08

The kick it straight in the flare sets you up for some interesting arrivals if your not spot on.

But the again taking the drift off at 500ft isn't the best plan either.

Personally I would start easing the crab out at about 50ft so that I am cross controls as I begin to flare.

On the subject of what stage of flaps to use I have always used the full lot right up to the demonstrated xwind without an issue.

Fuji Abound 20th September 2011 07:10

Frankly flyingkiwi that is hardly a cosswind and whatever technique you use flapless or not is irrelevant as you should be able to produce a reasonable landing in any of these configurations.

Sorry to be harsh but i suspect you are either a little rusty with landings in a little cross wind or just need more time on type.

Whopity 20th September 2011 07:25


I'm using the sideslip trick i was taught nose into wind kick straight at the flare,
If you are sideslipping, i.e. wing down, the aircraft should already be straight! If you are crabbing, with the nose into wind there is no side-slip, the difference between track and heading being drift.

kick straight at the flare
You should not kick anything, maintain directional control with the rudder, you only need to align the wheels with the runway just before they touch it.

If you have a strong X wind (not 6 kts) the last thing you want is the aircraft drifting sideways over the runway before you touch down, full or land flap is put there to provide additional drag at that critical moment to minimise the time spent floating sideways, why throw it away by reducing flap settings and increasing the landing distance.

scotbill 20th September 2011 07:31

This is a shortened version of a paper I once wrote for professional airline pilots. It is based on painful experience gained in the north of Scotland where operations in winds of 60+ knots were not uncommon

An immense amount of harm has been done to pilot confidence for decades by training establishments of the RAF and some commercial schools which continue to teach the so-called "kick off drift" method of crosswind landing. For those of us steeped in the technique at a formative stage it may be difficult to accept - but this was a blind alley in the history of aviation.
It is understandable that crosswind landing finesse need not command a high priority in military aircraft, but the method gained respectability in commercial aviation in the heyday of such aircraft as the Viscount when it was considered that there was a risk of touching the inboard prop in a wing-down situation.

Leaving aside the use of the word 'kick' (which should have little place in the vocabulary of a professional airline pilot ) this technique requires a measure of fine judgement often acquired at the cost of some heart-stopping moments along the way. Its most notable drawback is that, if misjudged, it leaves the aircraft drifting downwind in a highly vulnerable state. Once the line of inertia departs from runway centre-line, the possible consequences on a slippery surface are obvious.

There is a better way!

Skilled exponents of the Kick-off-Drift system apply into-wind aileron simultaneously with the rudder input. The Controlled-Slip technique merely moves the timing of this crossing of the controls further back along the approach path. The B757/767 autopilot (which is capable of a very polished demonstration) initiates the side-slip at 500' radio. However, it should be remembered that side-slip involves a performance penalty - and there may well be windshear below 500'. It can be easier for the human pilot to stabilise the situation approaching the threshold - when the wind is more representative of that on the runway.

The Full Programme :-

1) Ensure the aircraft is tracking along extended runway centre-line. Thus, even if the pilot takes no corrective action at all, the wreckage of a tricycle undercarriage aeroplane will continue to track along line of inertia (i.e. down runway centre-line). Clearly last-minute attempts to get on centre-line cause the line of inertia to deviate from runway heading with possible serious consequences.
(If Kick-Off-Drift goes wrong and the nose is pushed down in a desperate attempt to retrieve the situation, a nosewheel-first landing will almost inevitably cause damage to large aircraft)
2) Remember that strong winds do not necessarily require more power than normal. In the 90 degree crosswind situation there may even be a tail-wind on finals. Use normal flap settings.

3) If landing from an instrument approach, resist the temptation to align the aircraft with the runway on going visual. The consequent rapid downwind drift makes it extremely difficult to accomplish step 1) above.

4) On short finals, smoothly co-ordinate an application of into-wind aileron with downwind rudder. Once the aileron input is made, this becomes a new datum position. See-sawing of the ailerons must be avoided at all costs as this is known to have given rise to go-arounds in the past.
Notice that the control inputs required are modest - and (because of the secondary effect of opposite rudder) the ensuing bank is even more modest. Thus the technique is more correctly described as ‘aileron-into-wind’ rather than 'wing-down'.

5) Having achieved a stabilised crossed-controls flight regime, a normal landing technique becomes possible. Flare as usual and close the throttle(s) smoothly. Even if the aircraft does not touch down immediately, the crossed controls ensure that it continues to track centre-line.

This is the greatest advantage of the technique.

6) A common fault is to centralise the ailerons in the flare. On swept-wing aircraft in particular this allows the upwind wing to lift. For the reasons stated above, into-wind aileron must be maintained right through the flare and landing run - particularly if the runway is wet and/or limiting.


Finally :-

It must be recognised that this technique is not instinctive. Do not rely on playing it by ear close to the ground in conditions which may change rapidly. Remind yourself beforehand of the specific aileron and rudder inputs required on the day.

But - although this was written with the swept-wing B767/757 in mind - the method works for any aircraft from the Tiger Moth upwards. (Airbuses require adaptation). Tailwheel aircraft should be landed on mainwheels only with a gradual lowering of the tailwheel/skid - but the technique permits tricycle-geared aircraft to make a normal flare - thereby removing the risk of vulnerable propellers touching the ground or nosewheels being damaged.
In aircraft without lift-dump the flaps can be retracted on touchdown to kill lift and curb any tendency to become partially airborne again!


Crosswinds can be fun !

mad_jock 20th September 2011 07:47

turn of phrase whopity.

In stead of easing the crab out gradually its a more positive alignment to the runway track.

As said previously this can go round and round in circles.

Some aircraft seem to prefer decrabing and flying crossed controls and others seem to prefer kicking,easing,applying rudder just before touch down. Just like some its better to pitch for airspeed instead of point and power.

All the light aircraft I have flown seem to work well with taking the crab out just before the flare. The just before touch down in my experence does work but has a much higher chance of folk not quite getting it right. The set the rudder and hold it and control the slip with roll seems to have better results. I don't like those that say that the plane should be flown all down the approach cross controls which is just plane stupid.

The main problem with most tricycle pilots is that they don't use the rudder enough in all stages of flight and when they do use it they don't have the same controlled touch that they do with the stick. The taildragger/glider pilots don't seem to have the same problems and seem to be much more coordinated with thier control inputs.

Fuji Abound 20th September 2011 10:31

I still cant believe a 6 k xwind is producing reams of discussion about correct technique and in depth debate (as interesting at that might be, and not that I care about a little thread drift).

However I do think (and really meant in the best spirit) while the posts will undoubtedly stand you in good stead in stronger xwinds if the OP is struggling with 6 k the best advice, is the advice they have already taken - go and do a few flights with an instructor.

6 k of cross wind is not a cross wind and should be a non event.

:)

Pull what 20th September 2011 12:22


Leaving aside the use of the word 'kick' (which should have little place in the vocabulary of a professional airline pilot )
Nor indeed in the vocabulary of a professional flying instructor-arses are for kicking, not rudder pedals.


(Airbuses require adaptation)
The 318 & 321 certainly didnt, very easy even in max xwind-Airbus technology doesnt suit pilots who over control, as U tube vdeos shew!


Don't. Keep the controls positioned to let the nose come down when it's ready.
Ouch no! Get some forward elevator on and get the nosewheel on straight away and dump flap straight away(essential in high wing a/c) in a light aircraft esp in high winds. xwinds generally produce more localised gusty conditions over the runway as they blow over the obstructions to the side of the runway. The crosswind landing is the one landing where you havent finished landing until you clear the runway.


6 k of cross wind is not a cross wind and should be a non event.
Not mentioned so far but wind is measured at 10 metres agl, a 6 knot crosswind is only going to be about 3-4 knots on the runway.


A common fault is to centralise the ailerons in the flare. On swept-wing aircraft in particular this allows the upwind wing to lift. For the reasons stated above, into-wind aileron must be maintained right through the flare and landing run
Bad technique in a light a/c in strong croswind-wind on max into wind aileron once the noswheel is on.

scotbill 20th September 2011 13:17

Quote:
A common fault is to centralise the ailerons in the flare. On swept-wing aircraft in particular this allows the upwind wing to lift. For the reasons stated above, into-wind aileron must be maintained right through the flare and landing run

Bad technique in a light a/c in strong croswind-wind on max into wind aileron once the noswheel is on.


There you were supporting my thesis and you go and spoil it! Are you suggesting that the ailerons should be centralised in the flare? Even on a light a/c that would allow the upwind wing to lift and also defeat the purpose of ensuring adhesion to the tarmac on the upwind side - and build in bad habits for the future.
As I indicated in the earlier post, have demonstrated this technique on a variety of light aircraft. In particular those which have the most Xwind problems - the taildragggers (due to the innate weather-cocking tendency allied to blanking of the rudder as the tail comes down).

Piltdown Man 20th September 2011 14:32

There is more than one way to skin a cat. But before we go on to skin another cat, answer this one, was the landing OK? If it was just firm, that will do just fine as long as it was in the right place at the right speed.

For a 172, I used to muck about a fair but on crosswinds but eventually settled for a standard, drift corrected approach and shortly before landing used to apply aileron onto wind and a squeeze of rudder to maintain the centreline. This should mean that the aircraft is banked slightly into wind. Then when flaring, keep bank the applied as you land the first wheel and the aircraft tracking correctly with the rudder. Eventually the other main wheel will land followed by the nose. Just take your time and fly the speeds. From recollection a typical approach speed was something like (43 x 1.3 + 1/2 wind) which would have given you a speed of just under 65 kts. But the the secret is to look out of the window. That will give you all the clues you need for tracking and flaring.

Don't mess about with flaps and throwing the nosewheel on the ground. If you have allowed the aircraft to land properly and hold the ailerons into wind you'll find it just won't want to fly.

PM

Pilot DAR 20th September 2011 16:16

With my cats now safely in the house....

To support what piltdown has said, Cessnas have lots of control available to land and hold the plane on only one mainwheel with the wing lowered into a crosswind. This control remains available to to point where the wing will no longer carry the weight, and the plane settles on on its own.

My nosewheel is not lowered to the ground until the full up elevator control can no longer hold it off - ever. As long as the elevator is able to hold the nose off, the rudder is effective enough to control direction, and more so, than the nosewheel.

The following photo was taken with about a 15 knots crosswind carefully chosen to be about 60 degrees off the nose to the left. Full flaps used. The aircraft was being held stable in this attitude, at about 45 MPH. Were it to be on pavement, there would be some mainwheel chirping, as the mainwheel is also sideslipping across the surface. I'm certainly not suggeting that this degree of wing low is necessary, but it is possible in a 150/172

http://i381.photobucket.com/albums/o...t/IMG_2465.jpg

Pace 20th September 2011 16:41


The most important thing is to keep flying the aircraft until it's below minimum flying speed.
Why would you want to be flying an aircraft above the runway waiting for the speed to drop below its minimum flying speed in strong, gusty winds with shear?

Landing an aircraft has NOTHING to do with stall speed. Landing an aircraft at the slowest speed possible does.

In certain wind conditions the last thing you may want is to be anywhere near the stall speed landing.

On days with windshear approaching the flair you may want more control authority, more speed and less drag.

You can use less flap taking a higher stall speed and higher speeds.
As stated landing has nothing to do with stall speed! An aircraft can be flown on and in certain situations flying on is better than sinking on near the stall!

Pace

BackPacker 20th September 2011 17:29

Pace, i don't think that's what he meant. What I understood from the post is simple: After the plane has touched down (at whatever speed) the landing is not over. You should still apply proper control inputs until the aircraft has slowed down to well below minimum flying speed.

Or, arguably, until the plane is back in the hangar with the hangar doors closed.

Pace 20th September 2011 18:15


The most important thing is to keep flying the aircraft until it's below minimum flying speed. If the x/w is of variable strength, that means that during the hold-off you are continuously altering the bank angle and required rudder to keep the aligned with the runway and not drifting off to one side or another. At the same time you need to keep flying the aircraft, holding off for a reasonably smooth touchdown at close to normal landing speed. It's a busy time. It's tempting to try and put the aircraft down at the earliest opportunity. Don't. Once the aircraft has touched down, it's tempting to lower the nose, as it's been trained into a lot of pilots that "that's what you do in a crosswind". Don't. Keep the controls positioned to let the nose come down when it's ready. Keep the aileron and rudder inputs as they would need to be for handling the crosswind, as though you were still airborne.
Backpacker

I totally agree with what you say but am slightly concerned with some of the above?
Firstly one pilots impression of strong winds might not be anothers.
I have landed at Gatwick with winds 40 gusting 65 kts and the wind 20-30 degrees off.
In very high winds the biggest danger is shear and huge variations on the ASI
OK that was in a Citation! The 737 landing behind was one foot over planting his one wing into the runway.
Not the sort of conditions you would want to be holding ANYTHING OFF.
I have had similar sort of conditions at brize, Manchester and Dundee.
Ok not the sort of conditions that Joe Bloggs is likely to be flying around in a 172 but even that is possible!
There are occasions in light aircraft where you will want to plant it down, Where you wont want full flap if for nothing else than you dont want drag should you need instant speed.
I am purely highlighting the point that landing has nothing to do with stall and on occasions you may want to land quite a lot above the stall.
If I have misread the above my apologies to the Author.

Pace

Pull what 20th September 2011 18:34

I get the distinct impression that some of of the contributors to this thread have never landed in strong gusty crosswind.

If you were to taxy down a runway at 10 knots with a strong crosswind with no tailwind component would you use full into wind aileron in a high wing aircraft.

Would you prefer to taxy down the same runway with flaps up

Would you taxy down the same runway with the CC slightly forward of neutral.

If the answer to all the above is yes, as it should be, why would you want to land at 50 kts and leave flaps down of keep the nosewheel off for longer than necessary or not use full into wind aileron?

If your not convinced try your technique on a wet runway with a 30 knot crosswind.

Pilot DAR 20th September 2011 19:11

When flying a nosewheel Cessna, or most other nosewheel types, unless directed otherwise:


If you were to taxy down a runway at 10 knots with a strong crosswind with no tailwind component would you use full into wind aileron in a high wing aircraft.
Always, and for landing and takeoff as well.


Would you prefer to taxy down the same runway with flaps up
No, I usually taxi with some flaps extended in a 100 series Cessna, as it improves the downwash over the stabilizer, and makes the elevator more effective than no flaps. I prefer the more effective elevator, with which to keep the nose light. When I'm taxiing, it is not the final stage of a landing, for which I would have used full flaps.


Would you taxy down the same runway with the CC slightly forward of neutral.
Never, unless the conditions were a wailing tailwind. Were the wind that strong, and I was flying a 100 series Cessna, I would be really thinking hard about how badly I needed to fly (or taxi) at all.


why would you want to land at 50 kts and leave flaps down of keep the nosewheel off for longer than necessary
Simply preference, based upon experience. In Cessnas, the rather expensive nosewheel assembly, and in 172's in particular, the attachment to the firewall, is not quite as robust, or durable as some might wish. I have repaired quite a few of them (struts and firewalls). If the nosewheel is being held off, or light, it is very much less likely to be damaged. If conditions (meaning not a really strong tailwind) permit, I will certainly taxi a long backtrack holding the nosewheel completely off the runway. Agreed, that a strong or gusty wind will make this impossible, but you can still hold it light. When you start operating off rough runways, keeping weight off the nosewheel becomes even more vital. When operating off loose runways, propeller care makes it vital.

If nothing else is varied during taxiing a 172, simply holding the controls all the way back will bring the nose an inch or two higher. That's an extra inch or two of propeller clearance, and oleo stroke available.

I once had to taxi a 172 from the hanger, to the runway about 500 feet away, through a field which had been lightly plowed up (by mistake - forgot the plane was in the hanger). Two heavy guys in the back for ballast, 15 degrees of flap, lots of power. The nosewheel came right off, and I picked my way through at a walking pace, on the mains only. The plane did not seem to mind a bit.

Other than for a strong tailwind, the intensity of the wind would not otherwise affect my taxiing technique, or choice of flap position much. I will admit that I have never landed any aircraft in a direct 30 knot crosswind. I don't believe any aircraft I have flown has a demonstrated crosswind capability approaching that. That would be an aircraft which the design standards might suggest had a 150 knot stalling speed, and that's way out of my league!

FlyingKiwi_73 20th September 2011 20:05

Hah it always worries me starting a thread here:

A) It exposes my lack of pilot skill
B) Runs away into long diatribes of technique and counter technique, which of course i love to read.

Fuji is right it was a light xwind and i was surprised i had trouble too, i think i am new to the type, new to tarmac and was having a not so hot day in the cockpit,.. perfect storm.

I realised what was going on, i did a full stop and gave the Aero club back the keys... rather than push it further, i will get more practice and some more instruction on type.

I also don't have my terminology correct either it seems.... as far as crab vs sideslip.

Thanks as always for the useful advice.

KF_73

Pace 20th September 2011 20:20


Other than for a strong tailwind, the intensity of the wind would not otherwise affect my taxiing technique, or choice of flap position much. I will admit that I have never landed any aircraft in a direct 30 knot crosswind. I don't believe any aircraft I have flown has a demonstrated crosswind capability approaching that. That would be an aircraft which the design standards might suggest had a 150 knot stalling speed, and that's way out of my league!
Pilot Dar

Demonstrated is no more or less than its description and does not refer to the limit which could be twice the demonstrated.
I have over 2000 hrs in Seneca fives and have landed the aircraft at over twice its demonstrated limit with 90 degrees crosswind.
Reading your posts which I always love I am sure you are equally or even more capable than I ;)

Pace

Pace

Vilters 20th September 2011 21:10

The special 172
 
Yes the 172 is special.
A C-150 has 40° of flap.
The next version: the C-152 has "only" 30° of flaps.
Back to the C-172 that has 40°. And big doors they are.

As mentioned before, and I fully agree, every landing is a FULL FLAP landing.
But the C-172 is special. This baby has too much flap, and never got the C-150 to C-152 FLAP angle REDUCTION.

What would I do?
If confident and pretty sure of the landing? Land FULL Flap; All 40° of them.
If bumpy, uncertain, (not every day is the same, better safe then sorry) I would fly short finals at 30°, ready for a go around if needed. (as per C-152)

Short finals? NOT in crab. Certainly, and in this situation CERTAINLY NOT in crab.

From 1000ft, I would go in the wind Wing down, and opposite rudder.

If you can hold a plane on runway centerline, at Approach speed, Wing down, opposite rudder? You can salefy land.

If you run out of rudder? Go someplace else to land. => VERY simple.

So you come to short final, on centerline, Full flaps, on speed, wing down, opposite rudder, very stable position;
All what is left to do is flare and land on the upwind wheel.
MAINTAIN the X-wind aileron and rudder, let the second wheel touch, and let the nose come down when she wants to.
If the nose is still UP, and you run out of rudder? You CAN gently use a (one) brake to amintain direction.
it will help the steering, help the nose come down, and slow you down.
Be G E N T L E .

During roll out; MAINTAIN aileron input into wind, and use nosewheel and rudder action to stay on centerline.

NEVER stop flying the plane till at the hangar.

Tarq57 20th September 2011 21:37


Originally Posted by Pace
Quote:
The most important thing is to keep flying the aircraft until it's below minimum flying speed.
Why would you want to be flying an aircraft above the runway waiting for the speed to drop below its minimum flying speed in strong, gusty winds with shear?


Originally Posted by BackPacker
Pace, i don't think that's what he meant. What I understood from the post is simple: After the plane has touched down (at whatever speed) the landing is not over. You should still apply proper control inputs until the aircraft has slowed down to well below minimum flying speed.

This.^^
Sorry for the confusion. That is exactly what I meant.


Originally Posted by Pace
I totally agree with what you say but am slightly concerned with some of the above?
Firstly one pilots impression of strong winds might not be anothers.
I have landed at Gatwick with winds 40 gusting 65 kts and the wind 20-30 degrees off.
In very high winds the biggest danger is shear and huge variations on the ASI
OK that was in a Citation! The 737 landing behind was one foot over planting his one wing into the runway.
Not the sort of conditions you would want to be holding ANYTHING OFF.
I have had similar sort of conditions at brize, Manchester and Dundee.
Ok not the sort of conditions that Joe Bloggs is likely to be flying around in a 172 but even that is possible!
There are occasions in light aircraft where you will want to plant it down, Where you wont want full flap if for nothing else than you dont want drag should you need instant speed.
I am purely highlighting the point that landing has nothing to do with stall and on occasions you may want to land quite a lot above the stall.
If I have misread the above my apologies to the Author.

True. The comment was intended to be taken in the context of landing a light a/c, esp the 172, in light crosswinds, as per the OP. Personally I've flown a 172 in 50+ kt winds. Was able to come to zero g/s on final. (It was smooth; no shear.) The most difficult part of operating this a/c in that wind is, of course, ground handling. The most crosswind I recall landing the 172 in was about 24. That was a zero-flap landing, and the nose was allowed down with the elevator in a slightly aft of neutral position, rather than the normal full aft. It was certainly a higher touchdown speed than normal; required because a higher rudder authority was needed than that available at normal landing speed.

FlyingKiwi_73 20th September 2011 23:56

Just on Flaps in the AC i was flying, it has a reduction in the flap setting to a MAX of 30 deg travel, i think this is due to a mod needed to increase the MAUW with the introduction of the long range tanks.???

This is ZK-KAS for those NZ posters

On the actual flap selector it actually looks more like 25 Deg.

I revised my Cross wind calculation to a blistering 9knts xwind.

Did i mention i've only just broken 100 hours??

Pilot DAR 21st September 2011 02:08


Reading your posts which I always love I am sure you are equally or even more capable than I
I'm not so sure Pace... I'm a jack of some planes, and a master of none! Reading your posts gives me something to aspire to, like flying those Cessnas with no propellers! Fortunately for me, many of the planes I fly don't have to be landed in a 30 knot crosswind, as in winds of that intensity, the runways just get shorter, but very much wider! ('got in trouble for that once though...)

You and I, and others here, are capable enough, that we should be inspiring newer pilots to carefully and safely challenge their own skills.


Did i mention i've only just broken 100 hours??
I don't think so, but I'd give you my best advice in any case!


it has a reduction in the flap setting to a MAX of 30 deg travel
The reduction of flap travel is explained very well in the book "Cessna Wings for the World" by Thompson. He explains that "pitch pumping" in flaps down sideslips was reduced when the flap travel was limited. This is associated with the "Avoid slips with flaps extended" placard. The 40 to 30 change began with the C-172Q (around 1981). The text of the book downplays this as being much a problem at all in the later 40 flap 172's, but perhaps Cessna just lacked the desire to build aircraft capable of landing into runways so short, that they could not take off! I highly recommend the aforementioned book.

As explained to me today by my very experienced test pilot mentor, the reduced flaps setting for crosswinds is mostly a factor of crab angle required. The faster you fly forward, in the same speed crosswind, the lesser the required crab angle will be required. Less flap out = faster, so less crabbing required. If you are comfortable with the greater crab angle, go right ahead. This is why (as Pace correctly points out) the "demonstrate" crosswind capability is not limiting. There is a minimum requirements to be demonstrated of 0.2 Vs, but what's the incentive for manufacturers to publish higher (or actual) crosswind speeds in their flight manuals. Someone will try it, go off the runway, and, well... you know the rest of the sad legal story.

Though I have never flown a Seneca, or Citation, I am very willing to believe that they can handle these high crosswinds. The 100 series Cessnas are a little less capable. My personal record in the 150 is 37 gusting to 43 knots, 30 degrees off the nose. It was a search, or I would not have tried it at all. It worked out okay, though I could not land back at home, and had to land elsewhere, and park in the lee of a hanger, before I could shut down and stop flying!

A truly startling experience is to arrive to the destination, when flying an Ercoupe with no rudder pedals, and find that you have a 12 knot direct crosswind. Somehowe the plane handles it just fine, though I to this day have not figured out how!

Pace 21st September 2011 07:52

depending on the aircraft I prefer part flap for strong wind flying. The last thing I would want would be to have to abandon a landing in wind shear and turbulence.

Hanging on the prop 15 feet up with every bit of drag hanging out and a low powered engine isnt my idea of fun.

I would tend to use the flap setting on a particular aircraft which gives most lift for least drag especially in light, draggy, low powered aircraft where the poor engine needs as much help from not having drag in the event of windshear and downdraghts.

There was an arguement of not taking full flap till assured of landing. In strong winds and turbulence with a large cross factor and shear you never really are assured of landing.

At the end of the day what works for one doesnt for another and every situation is different.

Remember too that with a strong headwind component your landing distance will be much shorter so going for minimal landing speed is not so critical but being near the stall in shear/ lift and crosswind is!!!

Pilot Dar


You and I, and others here, are capable enough, that we should be inspiring newer pilots to carefully and safely challenge their own skills.
Totally agree but I also dont think students should only have a blinkered view! I love to watch the Red Bull Air Racing and see what the pilots and aircraft are capable of. That doesnt mean I am going to emulate them :E

If your ever over in the UK a Citation Ride is on as would love to meet you as I have done with quite a few on the forums now.



Pace

Pilot DAR 21st September 2011 11:38


That doesnt mean I am going to emulate them
Aw, c'mon... I bet you could just touch the Citation wingtip to the water, as you go around a pylon!

I'll be looking you up before too long....


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