Flying in Gusting Winds (How too?)

[poteroo]

A comment on the Cessna 210 's Va and turbulence. When the very first 210's appeared in Australia in 1960, they were to all intents a straight back C182,with r/g and 260HP up front. The Va was 113 Kias - same as the 182C/D models. My recollection is that at least 2 of the early 210's broke up in flight - having been pushed through rough summer storm situations way above Va. When negotiating potentially rough situations in the bigger Cessnas, (especially C210 and C182RG), I slow down to < 120KIAS. Dropping the gear in rough air helps stabilise the aircraft and you can use a bit more power for improved control response.

 

Rudder! HH was on the money with respect to rudder. Employing more rudder to level your wings in rough air allows for a smoother,straighter approach. This allows you to concentrate on getting the approach angle right - for the wind situation of the day. You learnt this under 'further effects of rudder'.

 

Speeds? I find it easier to hold an angle of approach than slavishly chasing a target IAS. More h/w - use more power, (and maybe less flap), to 'flatten' the approach angle so that it's the 'same' as in nil wind. Faster IAS to hold approx the same ground speed seems to work well. Of course, there's a limit to watch, and that's Vfe. Take a J160 with 83 Vfe, and a usual Vref of 60 - you have over 20kts to add as needed to approach speed to achieve your 'learned' approach angle - and still be able to use flap. If you are out there in >23 kts hwc, then maybe flapless is preferable.

 

happy days,

 

 

[Yenn]

landmann.

 

If you use the GPS to work out your landing and approach speeds I would advise extreme care. What airspeed gives you the required ground speed. What if the wind is on the nose at 30kts, do you use a GS of 50mph and would that give you an airspeed of 73 knots?

 

 

[Guest High Plains Drifter]

Re climbs -

 

I use the airspeed indicator as my primary reference, not attitude. Many a time I've had an aircraft in a [full power] climb 'attitude' and had a decaying airspeed - theres only one way to fix decaying airspeed.. nose down.

 

IMHO, attitude flying is a foundation skill, airspeed flying is the day to day survival skill.

 

 

[Guest landmann]

Unfortunately that's the case. Because of the hills and trade winds the wind can go from 25 knots to 5 knots in about 5 seconds and change 90 degrees. I have actually had it do a 180 from 20 knots head to five knots tail while I was on a 700 ft final. My approach is a plateau with a rather steep (but landable) 100 ft high incline. I level off just a bit low and drag it on for the last 500 ft with flaps down power on and nose level When I had this wind shear I was coming in with a real comfortable "airspeed" I had to add power and lots of it real quick like. That's when I came to the conclusion that regardless of the wind, if I have 50mph ground speed and this happens again I am still left with 45mph airspeed and my stall speed is 35mph. Just at the brink of the plateau I raise the nose a bit to set down on top of the hill and get stopped in about 200 ft. If the wind is a woooffing I just get stopped a quick as possible, raise my flaps and sit there a few minutes till it dies down and then do a 180 and toodle off to the tie down. If I wind up landing with no wind I can still get stopped in 300 ft so with my 600 ft strip I have always managed to land in less than half.

 

Martin

 

 

[Guest High Plains Drifter]

That "ground speed" flying your doing on approch worries me a little landmann.

 

Re landing approchs, ground speed is relavent to the landing speed (varies with wind and altitude) though I carnt see the relavence of it to your approch indicated airspeed - IMHO, trying to fly the two speeds on the approch may cause confusion and a prang. I may very well have miss-understood your post though :big_grin:

 

...I am a bit alarmed though, about the dragging it in 500' for what sounds like a pinicle landing - wouldnt a steep, power off, full flaped or slipped approch be better ?

 

 

[Guest landmann]

It's very easy to fly a Savannah ADV a foot or so from the ground. Any flap setting any speed or wind condition. Just be prudent with the throttle, stick and rudder. I have a two mile runway in Hilo to practice on and fly it with flaps up at 100mph airspeed and flaps down at 40mph airspeed and everything in between. I usually limit my direct crosswind practice in the trades from 12 gusts to 19 and then I am glad to maintain 10 to 20 ft. My goal is to fly the full length at one to two feet without touching down. I seldom succeed and usually touch or float up. All you have to do to land is trhottle back a little and it will sink down. The easier you throttle down the softer the touch. So coming in to land on top of a hill with 100 ft below you (landable) and a 600 ft run to stop is as easy as it gets. Kind of like an aircraft carrier I guess. For practice I come in and skim along the runway do a touch and go and come around again. If you are going to do a power off,full flap approach and flare....you better be damn good.... because you have to pull that flare from 5 to 10 feet agl from 10 degrees nose down to just slightly nose up. Most Savannah drivers will agree that the only reason to do such a landing is to show off. The new Savannah's without the front slat and VG's apparently float a lot better and are much easier to land as you suggest.

 

 

[Guest High Plains Drifter]

Apoligies landmann, I miss-understood your previous posts about the sort of operation you were conducting. Sounds like you have a lot of fun there :thumb_up:

 

 

[Yenn]

From your description of a plateau with a steep incline, I can see all sorts of problems. If the wind is straight down the strip I would expect very rough turbulence at the edge of the plateau with big downdraughts. That would lead me to come in steeply to try to be above the worst of the turbulence. Of course it is impossible to say from here how to land in Hawaii, but you must be doing something right to still be alive. I think I would rather gamble in the casino.

 

 

[Guest pelorus32]

Unfortunately that's the case. Because of the hills and trade winds the wind can go from 25 knots to 5 knots in about 5 seconds and change 90 degrees. I have actually had it do a 180 from 20 knots head to five knots tail while I was on a 700 ft final. My approach is a plateau with a rather steep (but landable) 100 ft high incline. I level off just a bit low and drag it on for the last 500 ft with flaps down power on and nose level When I had this wind shear I was coming in with a real comfortable "airspeed" I had to add power and lots of it real quick like. That's when I came to the conclusion that regardless of the wind, if I have 50mph ground speed and this happens again I am still left with 45mph airspeed and my stall speed is 35mph. Just at the brink of the plateau I raise the nose a bit to set down on top of the hill and get stopped in about 200 ft. If the wind is a woooffing I just get stopped a quick as possible, raise my flaps and sit there a few minutes till it dies down and then do a 180 and toodle off to the tie down. If I wind up landing with no wind I can still get stopped in 300 ft so with my 600 ft strip I have always managed to land in less than half.Martin

I think that it's worth you working this issue through with your friendly local instructor. Here's why, try this little scenario.

 

Light headwind of 5 knots, ground speed of 50mph = airspeed of 55mph. Then it suddenly turns to a tailwind of 20 mph. You now have an airspeed of 30mph with your groundspeed moving to 70mph as the aircraft regains equilibrium. The question is will it get there quick enough or will your groundspeed become vertical as you stall? I think the latter is very likely if you are working off ground speed.

 

The guys flying the heavy iron use a combination of groundspeed and airspeed indications in wind shear situations, but their margins over the stall are much greater than we are talking about here.

 

I think that ground speed flying on approach in our types of aircraft is similar to approaching a difficult strip with your eyes closed.

 

Kind regards

 

Mike

 

 

[Guest landmann]

The thing to remember is that I am flying with a nose level attitude. Altitude is controlled 99.999 percent with throttle. If the wind decreases I do not stall but rather start to sink. To arrest the sink I add power which picks up ground speed and I do a rather speedy touch and go. A real concern on landing on a short strip is ground speed. Once you touch down it becomes EVERYTHING. I do not want to try to do a full stop with more than 50mph on grass. That is why I check the ground speed as I come over the fence. 50mph is the max. It's got nothing to do with keeping afloat and all to do with getting stopped. If the windsock is pointing the right way and fully erect, with 50mph groundspeed there is airspeed up the yingyang. When do you suppose is the last time any vfr pilot in a light plane has ever actually looked at an airpseed indicator or anything else in the cockpit for that matter during the last few seconds of touchdown.

 

Martin:loopy:

 

 

[farri]

Anyone trying to land a recreational aircraft,in gusty conditions, using ground speed as a reference,is in my opinion, ( Nuts ).

 

Frank.

 

 

[farri]

Whoops........... I wasn`t very diplomatic was I?

 

I mean very optimistic.

 

Cheers.

 

Frank.

 

 

[Yenn]

No you were not farri, but I am in agreement. Anyone who lands a Savannah at 50mph could be put in the same category, but this is happening in Hawaii, part of the "funny country"

 

 

[farri]

Relative Airflow.

 

The thing to remember is that I am flying with a nose level attitude. Altitude is controlled 99.999 percent with throttle. If the wind decreases I do not stall but rather start to sink. To arrest the sink I add power which picks up ground speed and I do a rather speedy touch and go. A real concern on landing on a short strip is ground speed.Martin:loopy:

Howdy,Landmann,

 

Can you please tell me,where you think the " Relative Airflow " is coming from, when the wind decreases and the aircraft starts to sink.

 

Frank.

 

 

[Guest High Plains Drifter]

landmann, after reading the other posters assessment of your operations, I'm beginning to lean back to my first impression of what you are doing.

 

I'm wondering if you dont mind giving us a "google earth" lat/long of your airfield so we can get a better idea of what you are describing ? I dont mean to pry, though I'm a little concerned about your ops (as are other posters) ... more then likely though, we have just miss-understood your posts :)

 

 

[motzartmerv]

Dude.. How are you still alive??.. The science doesn't care what your groundspeed is...its completly irellivant.. Your airfoil needs airflow, a level attitude doesn't mean airflow is at a low "relative angle".. its relative remember..Your eyes should be able to tell you if your GS is too hot..

 

Hope ypur still around to respond:thumb_up:

 

 

[eastmeg2]

Anyone trying to land a recreational aircraft,in gusty conditions, using ground speed as a reference,is in my opinion, ( Nuts ).Frank.

Hi Frank,

 

With gusting headwinds on final I tend to use GPS ground speed as a reference by keeping ground speed above stall speed even if it means I have the trike (Airborne Streak-III) doing 70-80 kts IAS. Is that nuts? Remember that the headwind could disappear at any moment and ground speed is still no greater than for a still air landing, possibly a few knots less. . .

 

Rgds,

 

Glen

 

 

[farri]

Hi Frank,With gusting headwinds on final I tend to use GPS ground speed as a reference by keeping ground speed above stall speed even if it means I have the trike (Airborne Streak-III) doing 70-80 kts IAS. Is that nuts? Remember that the headwind could disappear at any moment and ground speed is still no greater than for a still air landing, possibly a few knots less. . .

 

Rgds,

 

Glen

Hi Glen,

 

I regret using the term (nuts),it was a spur of the moment thing.

 

I would appreciate it if you would explain to me why you use ground speed,as a reference,so that I can understand a little better.

 

Regards,

 

Frank.

 

 

[farri]

Dude.. How are you still alive??.. The science doesn't care what your groundspeed is...its completly irellivant.. Your airfoil needs airflow, a level attitude doesn't mean airflow is at a low "relative angle".. its relative remember..Your eyes should be able to tell you if your GS is too hot..Hope ypur still around to respond:thumb_up:

Hi Merv,

 

Relative airflow is the airflow directly opposite the flight path of the aircraft.

 

When the aircraft starts to sink as Landman has said the relative airflow is now coming from a lower point relative to the chordline and therefore the angle of attack is increasing and the AC is getting closer to the stall angle.

 

Applying power does reduce or arrest the sink rate however it is important that relative airflow is well understood.

 

Regards,

 

Frank.

 

 

[motzartmerv]

G'day Farri.. Yes mate, thats exactly what i was saying.. He is holding a level nose attitude while the acft sinks, that was my concern. Thats why i said " a level attitde doesn't mean you have a low relative angle"..

 

 

[bushpilot]

Some interesting points are getting made - and questioned, here..

 

I have to say I wonder about the sense in relying on a GPS for GS, when the refresh rate on some can be a bit slow..and it's another in-the-office distraction..

 

But I also wonder about the "normal" approach to instructing, where for short landing roll practice in say a Jab160, the instructors insist on 65Kts on late final, using power if needed to make the keys.. I get nervous about getting under 70Kts until just before the flare (and over the threshold), as with my trike experience I have regularly found sudden sink on final. I know its not as likely in "heavy" RA-Aus a/c, but a reasonable margin over stall seems sensible to me..

 

 

[motzartmerv]

Bushpilot.. Yes, this subject has been the source of much discussion at our school.. Our Jab ops manual says to approach at 60 kts with full flap.. To do that you need a lot of power and timeing the flare and power chop is crucial.. Some (including me) think this is a dangerous practise to be teaching students..

 

The VS with full flap is under 50 kts, and with power this is lowered a bit more, but when the power comes off the sink rate is heavy.. Touching down with some power on is probably the best way, but the manual says nothing about this..

 

I have been teaching to approach as normal, but approaching the fence reduce the speed to 65 and leave some power on untill after touchdown..60 kts in my mind is to fluffy.

 

 

[farri]

Bushpilot.. Yes, this subject has been the source of much discussion at our school.. Our Jab ops manual says to approach at 60 kts with full flap.. To do that you need a lot of power and timeing the flare and power chop is crucial.. Some (including me) think this is a dangerous practise to be teaching students..

Merv,

 

I instruced in an Austflight Drifter and I would show students how to do short field landings, because it was part of the syllabus, but I always felt that at those low hours they didn`t have enough experience or skill to be capable of doing them safely.

 

I also thought and still think that it is dangerous for anyone with low hours to be doing short field landings in anything other than perfect conditions.

 

Frank.

 

 

[motzartmerv]

Absolutely.. And imagine how dangerous that could be if a lowtimer was to read this thread and think it a good idea to use a gps GS for the approach..

 

 

[Guest pelorus32]

Hi Frank,With gusting headwinds on final I tend to use GPS ground speed as a reference by keeping ground speed above stall speed even if it means I have the trike (Airborne Streak-III) doing 70-80 kts IAS. Is that nuts? Remember that the headwind could disappear at any moment and ground speed is still no greater than for a still air landing, possibly a few knots less. . .

 

Rgds,

 

Glen

G'day Glen,

 

You've set out the exception that proves the rule! This is the one case where flying GS will not reliably kill you. It still might kill you because gusting headwinds can become non-gusting no wind or worse still gusting tail wind. Your system in a steady headwind leads to a GS that looks like your normal IAS and therefore an IAS well above the usual IAS for approach. This approach (pun intended) of course will not work for a/c which use flaps and have narrow flap limitations - you will exceed your Vfe.

 

Having said that it is not a method that I would use in any circumstance. If you are flying into a headwind - gusty or otherwise you simply monitor your airspeed - as long as it is sufficient then you are fine - you will keep flying. If you need more speed for "penetration" - ie you're flying backwards or standing still - then you've got to wonder whether you should be flying today and of course it may be valid to increase your IAS to get there.

 

Commenting on the thread generally:

 

In the other circumstance of a tail wind you have to ask "What's most important? Approaching with sufficient airspeed to keep the a/c flying or having too much GS to land safely on the strip?" The answer is of course airspeed. If that means that you are carrying too much GS then you always have the option of getting the heck out of Dodge - you can GO AROUND - the two most important words in any pilot's vocab.

 

Of course if it is a one way strip then you need to be very clear of your go/no go decision criteria early on so that you don't commit to something that is unlikely to come off. To quote Dirty Harry "How lucky are you feeling punk? Do you want to fall out of the air on approach or run of the end of the strip after you've landed? What's your choice?" The answer of course is neither.

 

Regards

 

Mike