Landing and Wind

[LauraE51]

I've shared my story earlier about returning to flying after a 42 year pause. After beginning my BFR in late July, i was signed off after five lessons (eight hours). I continued to feel uncomfortable with my landings, though, and have appreciated the advice i received here on PoA.

Today, i again reserved a C172P with the intention of just practicing T&Gs. However, the winds at TCY were about 15kts with 19kt gusts. Since all of my previous landings were in winds less than 10Kts, i considered canceling my reservation, but fortunately the school had a CFI available if i could wait 30 minutes, which i did. I considered this a learning opportunity since i'd not flown in high winds since the 1970's.

The winds were from 320 on runway 30. While the crosswind component was not very high, i still wanted someone with me who could point out mistakes and advise me on best practices when landing in wind. It was a good decision. We stayed in the pattern the whole hour.

The first revelation was that my speed on final should be about 10kts higher than normal, in order to counteract the head/side winds. This i hadn't completely gotten, so first point to me for being smart to bring a CFI along. My landings in the past had tended on the fast side, so i hoped my landings today could focus on slowing things down on final. However, when flying gives you lemons, make lemonade.

So, here i am on the first final, carrying 75-80kts instead of 60-65kts and feeling strange. Still, i know that 15 of those kts are the winds, not me. Around 50ft, i reduce power to bring back my speed and round out, using left rudder and right aileron. Surprisingly to me, i landed fairly well with nose pointed mostly forward and my right wing slightly down into the wind.

Probably my best landing was my first. However, my other landings were all over the place, with me adding a little too much left rudder and then having to wiggle back and forth with the rudder to try to stay centered.

in all, i'm glad i brought a CFI along. i'm still a fairly low time pilot, with about 140 hours and just 13 hours since my return. I do plan to do this again the next time we have a windy day.

 

[F01LA]

The first revelation was that my speed on final should be about 10kts higher than normal, in order to counteract the head/side winds. This i hadn't completely gotten, so first point to me for being smart to bring a CFI along. My landings in the past had tended on the fast side, so i hoped my landings today could focus on slowing things down on final. However, when flying gives you lemons, make lemonade.

So, here i am on the first final, carrying 75-80kts instead of 60-65kts and feeling strange. Still, i know that 15 of those kts are the winds, not me.

I'm glad something clicked and your landing went well, but if this is what your CFI is telling you, I'd look for another CFI.

 

[LauraE51]

I'm glad something clicked and your landing went well, but if this is what your CFI is telling you, I'd look for another CFI.

How so? With the winds we had today, i could tell even during the first final that i needed more power to keep up my elevation. Without that extra speed, (and some landings i let the speed get down to 70kts), the winds ate my elevation for lunch. I had to power up to keep the plane on the right angle to land.

 

[F01LA]

Brush up on airspeed vs. ground speed. Also power vs. speed.

 

[CharlieTango]

Power adjustments can be extremely helpful when winds are volatile however your statement indicates an error in understanding relative wind.

15 of those kts are the winds, not me. with the exception of wind shear and by your post I can tell shear was present, still your plane flies in the relative wind so on approach all of those 75-80knts are you and not the wind.

A common approach is to increase your approach speed above 1.3 Vso by 1/2 the gust factor. The 4kt gust fact calls for a 2kt increase in your approach speed where you were using a 15kt increase when you wanted to try and limit your approach speeds.

 

[nosehair]

Don't listen to all them naysayers - you keep your speed up until you are comfortable with gust crosswinds .
THEN you can slow a bit. Once you have a good handle on the control response, you really don't need much extra speed, but until then, a few xtra its will give a few xtra seconds in the roundout to get aligned.

 

[NotEnough]

Carry 1/2 the gust component additional. Learning to land with too much airspeed will carry you off the end of a runway or porpoising one day. The 1.3 Vso you are using is probably for gross and already conservatively high.

 

[jesse]

I would not fly a single knot faster in those winds. The last time I landed with a bit of a breeze it was approaching 50 knots knots and I didn't apply a single knot of extra speed and landed with full flaps.

Extra speed does not make it easier, it makes it harder. We all of course have our own opinions

I have a different type of respect for the wind when I'm in the Flybaby. When it gets over 30 knots trying to taxi it to and from the runway is rather terrifying.

 

[jspilot]

Yeah get a new CFI! That's terrible advice to carry 15 knots extra speed in those kids of winds. I learned you can carry + half gust factor. Your gust factor was only about 3 knots considering the constant wind was 13 and gusts were 19. At most you should have been carrying 3-5 knots extra speed.

It seems to me like you and your CFI are totally confusing ground speed and air speed. Sure the wind will cause your ground speed to decrease but ground speed is not what you should be judging landings off of.

 

[FastEddieB]

It seems to me like you and your CFI are totally confusing ground speed and air speed.

I'll give the instructor the benefit of the doubt here and assume bbridges is misunderstanding and conflating airspeed with groundspeed.

I'll make my obligatory recommendation of Langeweisch's "Stick and Rudder" here. It was the first aviation book I ever read*, and I think it help set the foundation for my understanding of how planes fly relative to the air, not the ground.


*In turn, it was "The Whole Earth Catalog" that recommended it to me - though I suppose that dates me a bit!

 

[FlyingTiger]

Interesting, I just went through the same experience; getting current after a long layoff (22yrs) and my CFI and I agreed that the one thing that we should still do post sign-off, when the opportunity presented itself, was to conduct some more pattern work with a solid cross wind. Probably the most challenging thing to do after several years away.

You were smart to grab a CFI. Nothing wrong with bringing in some help from time-to-time to be safe and assist in becoming a better pilot. In regard to the specific advise, my CFI advised me to keep the airspeed a little higher and mentioned the half gust factor as a guide.

 

[James331]

Yup, just half the gust factor. Also if its just straight wind, i.e. no gusts, don't add any airspeed.

Keep in mind that those book aproach speeds are based on max gross, and are too fast if you're just solo in the plane.

If you have a heavy crosswind, use less flaps, in most aircraft, less flaps = higher max cross wind, some planes publish max demo crosswind for different flap settings.

Also your airspeed indicator will read realitive wind, your plane doesn't know or care about its speed over the ground, 50kt headwind, approach at 65, airplane thinks its still going 65 even though you're only tracking 15kts over the deck.

 

[skidoo]

How so? With the winds we had today, i could tell even during the first final that i needed more power to keep up my elevation. Without that extra speed, (and some landings i let the speed get down to 70kts), the winds ate my elevation for lunch. I had to power up to keep the plane on the right angle to land.

To me, it sounds like you are seeing the steeper descent due to the lower ground speed and therefore will need more power to shallow it out, or you need to plan ahead a bit better and turn base sooner.

Nothing wrong with a steeper descent. If the winds were say 50 kts steady on your 12 o'clock, and if your approach speed were 65-70 kts, your descent would indeed look very steep, but your descent rate would be the same for the same power level.

 

[MAKG1]

How so? With the winds we had today, i could tell even during the first final that i needed more power to keep up my elevation. Without that extra speed, (and some landings i let the speed get down to 70kts), the winds ate my elevation for lunch. I had to power up to keep the plane on the right angle to land.

More power is NOT more speed. You adjust speed with the yoke (and then trim), at least at the slow airspeeds used for approach.

Try this. Take the airplane up to altitude, trim for level flight at approach speed. Then pull the power to idle, hands off (keep the airplane level with rudder). What happens to the airspeed? What about the vertical speed?

FYI, 60 KIAS seems to be a nice approach speed for a 172 at max gross. Not 65, not 60-70. 60.

It's possible to increase speed with a combination of power and yoke, and it's appropriate to do that if you are slow on final. It is NOT HELPFUL, and actually rather dangerous, to just increase power if you're slow behind the power curve. Pushing down the nose is effective, but may be uncomfortable by itself if you are also low.

This is a really important lesson. When you are slow, you MUST get the nose down. Even if the ground is there. Controlled crashes are generally survivable. Stalls at low altitude are not.

 

[FastEddieB]

...(and some landings i let the speed get down to 70kts)...

Please clarify...

Are you talking about 70k approach speed, or actually landing at 70k?

 

[Timmer]

I see it common to confuse cross-winds and gusts. Gusts can be head on or not. You increase your speed to account for gusts. Cross-winds no... the plane doesn't care about cross-winds, just that you're trying to go a direction lined up with the ground not the winds so you'll angle the plane differently.

 

[Johann]

I've seen the advice to increase speed in a heavy cross wind. The reason being that at a faster airspeed the cross wind affects your track less (in other words, you need less of a crab angle). Also, at higher airspeed your control surfaces are more effective, so you should need less control inputs to do the side slip.

I'm not going to advice for or against it since I'm not a cross wind expert, but maybe that's where the confusion comes from.

 

[jesse]

I've seen the advice to increase speed in a heavy cross wind. The reason being that at a faster airspeed the cross wind affects your track less (in other words, you need less of a crab angle). Also, at higher airspeed your control surfaces are more effective, so you should need less control inputs to do the side slip.

I'm not going to advice for or against it since I'm not a cross wind expert, but maybe that's where the confusion comes from.

The problem with the above logic is that you still need to slow down to actually land the airplane. So you just sit there, down low, floating, close to the ground, too fast, fighting the winds, trying to slow the plane down, which makes things much harder than it would be had you flown the proper speed in the first place.

 

[nosehair]

The problem with the above logic is that you still need to slow down to actually land the airplane. So you just sit there, down low, floating, close to the ground, too fast, fighting the winds, trying to slow the plane down, which makes things much harder than it would be had you flown the proper speed in the first place.

And to the beginner, it is during this "sitting there floating and fighting", that the new or inexperienced pilot can get the feel and control.
As he/she catches up to the airplane during this roundout with crosswinds, the student can begin to slow the approach speed like everyone is saying.
Like slowflying down the runway.
Which is also a great technique in crosswinds.

 

[Henning]

You don't want to be faster, you want to be steeper or control you descent with more throttle if you're on a glide slope. The 1.3 Vso speed to trim for applies regardless the wind.

 

[LauraE51]

Please clarify...

Are you talking about 70k approach speed, or actually landing at 70k?

the CFI shared that once we were at the 50ft mark, it was ok to cut power to slow us down. it's amazing how slow my ground speed was, even though the ASI showed 70, but then that's the wind pushing us back. round out was about the same as without wind, at 60kts. The effects of 15kt winds really shows on final. however, reducing flaps to 20 instead of my usual 30 did help a bit.

 

[FastEddieB]

it's amazing how slow my ground speed was, even though the ASI showed 70, but then that's the wind pushing us back.

I have an alarm that goes off when I sense a "Stick and Rudder*" moment.

It just went off.

I suspect you're missing something basic here, though it may just be a communication problem.

Remember, a plane in flight knows no wind (barring gusts and shear). It is simply flying in an air mass which is itself moving.

Thought exercise: Suppose you were approaching to land into a 70k headwind, using 70k IAS.

Could it be accomplished power off, and if so, how?

Also I wonder about...

"the CFI shared that once we were at the 50ft mark, it was ok to cut power to slow us down."

While I like to be at idle in most small planes by 50', I don't like the implication that power is used to control airspeed on final. It CAN be done, but is not how I learned nor how I taught. Since power should already be at a low setting, better to use pitch for airspeed - though that can open a whole can of worms!

* That's the seminal book by Wolfgang Langeweische that I think should be required reading.

 

[MAKG1]

I have an alarm that goes off when I sense a "Stick and Rudder*" moment.

It just went off.

Mine as well.

Ground speed is relevant for the length of the ground roll and the aircraft's behaviors while on the ground. It is not relevant for the aircraft's behavior in the air. The airplane will fly the same at 60 KIAS whether it is in a 1000 MPH headwind or no wind. Its ground track will change, obviously, but the airplane will fly exactly the same. In particular, it will stop flying at the same airspeed. In a 172P, that's 40 knots indicated, flaps down. It's a whole lot less than 60.

Speeds on approach are a function of AIR speed.

If you're reading ground speed, there is probably a GPS in the plane. Turn it off. Same deal if you're reading DME. If you're in a glass panel, cover the GS display or turn the panel off and use the standby instruments.

This does appear to be a basic misunderstanding. Take sharp aim at it, and the "aha" moment will come. Your landings will be a whole lot better.

It's actually much easier to land in a moderate steady wind than in "calm" winds, as long as you don't get confused about the air and ground speeds.

 

[petrolero]

I have an alarm that goes off when I sense a "Stick and Rudder*" moment.

It just went off.

I suspect you're missing something basic here, though it may just be a communication problem.

Remember, a plane in flight knows no wind (barring gusts and shear). It is simply flying in an air mass which is itself moving.

Thought exercise: Suppose you were approaching to land into a 70k headwind, using 70k IAS.

Could it be accomplished power off, and if so, how?

Also I wonder about...

"the CFI shared that once we were at the 50ft mark, it was ok to cut power to slow us down."

While I like to be at idle in most small planes by 50', I don't like the implication that power is used to control airspeed on final. It CAN be done, but is not how I learned nor how I taught. Since power should already be at a low setting, better to use pitch for airspeed - though that can open a whole can of worms!

* That's the seminal book by Wolfgang Langeweische that I think should be required reading.

I understand why your alarm went off but I read this a little differently.

I think the word "that's" in his sentence could be referring back to the slow groundspeed, not the ASI showing 70. If that is how he meant it, then it makes sense and his understanding may be OK. He could be saying that they were getting slow ground speed even though ASI showed 70 and that that is because of the wind. That would be correct.

But it is ambiguous and hopefully the OP will be along to let us know what he meant.

 

[FastEddieB]

But it is ambiguous and hopefully the OP will be along to let us know what he meant.

Sometimes I do get "false alarms", which is why I proposed it might be communication problems.

 

[CharlieTango]

My alarm went off as well. Plane's fly in the relative wind and this concept is hard for some to grasp at least for a while.

 

[MAKG1]

My alarm went off as well. Plane's fly in the relative wind and this concept is hard for some to grasp at least for a while.

Most people do get it eventually.

It's really important for where you fly. High altitude means the ground speed should be faster, but the indicated airspeed should not.

 

[Silvaire]

This may not be completely relevant but we often have pretty good winds at my home airport which is just a few miles north of the OP's airport and I mean mid 20 to low 30 knot range. They are normally right down or very closely aligned with one of the runways however and when I approach with my Champ in these conditions, which cruises at about 85 mph, I will normally just fly it at cruise power right down to the numbers, pull the throttle back and land. There is a bit of float in the flare but with a ground speed of 12 knots it's not much of an issue. If I didn't do it this way I'd probably have to pack an extra snack to eat while I'm on final.

 

[MAKG1]

The OP is at Tracy. Where are there regular 30 knot winds anywhere near there?

Even Byron doesn't often get much over 20.

I don't understand the numbers. 85 MPH is a bit over 70 knots. If you're doing 12 knot ground speed, that means the headwind is 58 knots.

 

[petrolero]

I have an alarm that goes off when I sense a "Stick and Rudder*" moment.

It just went off.

I suspect you're missing something basic here, though it may just be a communication problem.

Remember, a plane in flight knows no wind (barring gusts and shear). It is simply flying in an air mass which is itself moving.

Thought exercise: Suppose you were approaching to land into a 70k headwind, using 70k IAS.

Could it be accomplished power off, and if so, how?

Also I wonder about...

"the CFI shared that once we were at the 50ft mark, it was ok to cut power to slow us down."

While I like to be at idle in most small planes by 50', I don't like the implication that power is used to control airspeed on final. It CAN be done, but is not how I learned nor how I taught. Since power should already be at a low setting, better to use pitch for airspeed - though that can open a whole can of worms!

* That's the seminal book by Wolfgang Langeweische that I think should be required reading.

The OP is at Tracy. Where are there regular 30 knot winds anywhere near there?

Even Byron doesn't often get much over 20.

I don't understand the numbers. 85 MPH is a bit over 70 knots. If you're doing 12 knot ground speed, that means the headwind is 58 knots.

He's talking about the flare at that point so his airspeed is no longer 70 knots I imagine. If he lands at, say, 40 knots then that would be only a 28 knot wind.

 

[FastEddieB]

I think my "alarm" had started to go off from something in the original post:

"So, here i am on the first final, carrying 75-80kts instead of 60-65kts and feeling strange. Still, i know that 15 of those kts are the winds, not me. Around 50ft, i reduce power to bring back my speed..."

It's still hard for me to discern what "15 of those kts are the winds, not me" means.

And when my students are taught to come back to idle by at least 50', it's in no way to slow down. Their speed should be about right already, and if anything they will control their airspeed with pitch, pitching down slightly so as not to lose airspeed with the power reduction.

Again I may be losing something in the translation!

 

[Silvaire]

...Even Byron doesn't often get much over 20...

My guess is you don't "often" visit Byron, especially mid summer late afternoons. They didn't put all those windmills up on the hills there for no reason.

...I don't understand the numbers. 85 MPH is a bit over 70 knots. If you're doing 12 knot ground speed, that means the headwind is 58 knots.

Landing speed is around 40 mph but really, there's just supposed to be some humor in this, you don't need to pick nits out of it.

 

[LauraE51]

My guess is you don't "often" visit Byron, especially mid summer late afternoons. They didn't put all those windmills up on the hills there for no reason.



Landing speed is around 40 mph but really, there's just supposed to be some humor in this, you don't need to pick nits out of it.

oh, i've flown around Byron a few times, but rarely over it because of the parachuting and glider activity.

While i feel totally comfortable in most aspects of flying, i still feel a bit of a novice when landing which is why i keep practicing landings to find the sweet spot. I was a bit taken aback when the CFI recommended flying so fast on base and downwind. He explained his formula and then asked another CFI in the room for confirmation.

Regarding the comment that if my IAS was 70kts and the winds were also 70kts, i'd be standing still in relation to the ground. i'd essentially be little different than a helecopter as i floated straight down. No, i get that i should carry a little extra speed just in case the winds cut out.

Say i was aiming for 55kts for my final leg and given that Vso on the 172 is 33kts, that's probably ok. If i was facing a 20kt headwind that suddenly cut out, my airspeed would instantly be 35kts. it makes sense to me to carry the extra speed until we get closer to the runway.

But then, i'm getting enough conflicting advice here, and from my CFI, that i'm not sure what's best except to take a different CFI up next time it's a really windy day.

I do appreciate all of you chiming in, though. I love PoA and appreciate what i learn here every day.

Brian

 

[CharlieTango]

Its debatable whether or not you should add 1/2 the gust factor. Adding speed for a wind that might cut out would fall under that 1/2 the gust factor rule.

You want to adjust for negative wind shear just because there is wind, there should be an indication of shear and then you can use 1/2 of the gust factor which is more likely a few knots.

 

[MAKG1]

Having once had a 15 knot "steady" wind stop suddenly over the fence, I agree it's not fun.

But you're trading it for floating down the runway for 1000 feet and fighting gusts the whole way.

The lesson I got from my experience was to feel the gusts. In retrospect, I had a lot of warning, just not from the windsock nor from ATIS. I even asked tower for a wind check on downwind, and they repeated 300@15, 'cause it felt bumpy.

I probably should have added half the gust factor there, but 5 knots would have done it. Not routinely, but rather because I felt the gusts.