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Slow flying


Yenn

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On other threads in this forum there is quite a bit of concern about low slow flying and stalling in the turn to final. I just wonder if any of you practice slow flight with a view to finding how it feels at the edge of the stall.

 

I thoroughly enjoy pulling up alongside a Thruster and trying to match his speed. Unfortunately some of the locals are wise to my tricks and they slow the Thruster down, 55kts in a Corby and you are pointing to the heavens and the controls feel a little on the soft side.

 

 

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Just remember - the stall speed increases at the square root of the wing loading [s&L] - SOME RA and SOME GA PPLs that I have met are not aware and this is importent when doing steep turns at low speed.

 

Simply put the wing loading in a 60 degree turn is 2 so the stall speed increases by 1.414 - close enough to half for mental maths.

 

So a stall speed of 40kts S&L increases to 60 kts at 60 degree angle of bank - You can do your own maths about smaller angles of bank but important info to keep in the back of your mind.

 

I don't want to start an arguement but I think this is relevant info. if someone is not already aware of it.

 

Frank

 

 

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On other threads in this forum there is quite a bit of concern about low slow flying and stalling in the turn to final. I just wonder if any of you practice slow flight with a view to finding how it feels at the edge of the stall.

I have always found this interesting because the training sylabus puts a lot of emphasis on stalls in a climbing turn or stalls with a wing drop.

 

The place where most come unstuck is a stall in a descending (gliding) turn but it is not a requirement for a licence. Sort of a 'we know it happens but don't go there' approach.

 

 

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I have always found this interesting because the training sylabus puts a lot of emphasis on stalls in a climbing turn or stalls with a wing drop. The place where most come unstuck is a stall in a descending (gliding) turn but it is not a requirement for a licence. Sort of a 'we know it happens but don't go there' approach.

When the aircraft is pulling G's (usually associated with speed) the weight theoretically increases... and thus the stall speed.

 

Scary really... I guess by the time you feel the G's increase the aircraft is stalled... The Red Bull air race was good for seeing this in effect.

 

 

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Guest davidh10
On other threads in this forum there is quite a bit of concern about low slow flying and stalling in the turn to final. I just wonder if any of you practice slow flight with a view to finding how it feels at the edge of the stall. .

Yes. I sometimes fly in company with a friend who has a "Cruise" wing, so have to trim back to about 48kn. That's ok till I hit some turbulence, when a few more knots make it much more comfortable.

Needless to say I don't bank steeply at this speed. In straight and level flight, I can pull it back to about 43kn in calm air without stalling, but it wallows, so is not a useful attitude.

 

I don't think steep turns are scary, but as with any manoeuvre you have to think about it first. Steep "s" turns are the way to lose altitude quickly in a weight shift aircraft, as you cannot side slip in one. The time you want to use this is when practicing engine failures and you are approaching the runway on glide too high. So, as others have mentioned, understanding the effect of the increased wing loading on stall speed when doing steep turns below circuit height is very important.

 

 

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I just wonder if any of you practice slow flight with a view to finding how it feels at the edge of the stall. QUOTE]Absolutely.......Been flying my Drifter for a long time and know all of it`s habits but still enjoy putting it on the edge and through stalls.......Keeps me up to speed.

 

Frank.

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On other threads in this forum there is quite a bit of concern about low slow flying and stalling in the turn to final.

Hi Yenn

 

Just a thought... stalls at low altitude aren't good anywhere in the circuit but the one that seems to be the real killer happens during the turn downwind, not onto final.

 

kaz

 

 

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Just remember - the stall speed increases at the square root of the wing loading [s&L] - SOME RA and SOME GA PPLs that I have met are not aware and this is importent when doing steep turns at low speed.Simply put the wing loading in a 60 degree turn is 2 so the stall speed increases by 1.414 - close enough to half for mental maths.

 

So a stall speed of 40kts S&L increases to 60 kts at 60 degree angle of bank - You can do your own maths about smaller angles of bank but important info to keep in the back of your mind.

 

I don't want to start an arguement but I think this is relevant info. if someone is not already aware of it.

 

Frank

Which is why, when in a situation where a spin would be unrecoverable due to height, the speed should be not less than 1.5 times the stall speed of the aircraft. This includes all of the circuit.

 

 

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Guest davidh10
Which is why, when in a situation where a spin would be unrecoverable due to height, the speed should be not less than 1.5 times the stall speed of the aircraft. This includes all of the circuit.

In a 60 degree turn at 1.5Vs with gusty wind and or turbulence there is still a possibility of a stall, so rather than just using rules of thumb, always be aware of the basis of the rule and its shortcomings.

 

 

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1.5 times the stall speed would mean the speed is much higher in most types then the best rate of climb speed and therefore useless. Keeping the turns shallow and adding a few kts on the approach as CFIcare has suggested is an easy way to minimise risk.

 

 

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Hazards of stalling.

 

All this commentary on stalling and slow flight and no mention of "stall stick POSITION?

 

You can practice stalling safely at the end of your circuit when the wheels are one inch off the ground. (as long as the wind is not gusting). Nev

 

 

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From all the posts here, I see that David10 and Farri do slow flight, I am not sure what it is like slow flying an Edge as I have a total of about 30mins in that type of plane. Farri I would expect to know what he is doing. To all those who have given their theoretical views, how about giving it a try. I cruise at 100kts and can quite capably slow fly at 60% of that, how does that equate to the speeds of a Savanah?

 

Go on I dare you, but do it at a safe height and approach it at a alowly reducing speed, no need for turns,steep or flat for a start, but you will probably learn more about how your plane handles.

 

 

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Farri I would expect to know what he is doing. QUOTE]Yen,rightly so,I should know what I`m doing.

 

The reason I put my two bobs worth in, is to show that I still enjoy practising slow flying and stalls and doing all the manuevers that I`m capable of,this keeps my skills honed, I`m also hoping to encourage others to do the same.

 

Regardless of catogory or type flown,the fact that a pilot has been flying for a long time,is no reason to stop practising stalls or any other manuever,this helps to keep reflexes sharp and remain familiar with the behavior of the AC .

 

Frank.

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Over the past two years there have been 4 serious crashes out here in SW QLD involving aircraft flying low and slow. The first was an x-air cattle spotting, stall and spin, crashed throuh trees, pilot suffered a serious broken leg. The 2nd on the 15 May 2010 a C172 where the pilot was also cattle spotting, and struck a tree before nosing in, suffering a serious broken leg. The third on 22nd of Sep 2010 was a Tecnam with 2pob also spotting cattle, crashed into trees and the passenger suffered a seriously broken leg and the pilot other internals.

 

The latest was a C172 looking for horses which crashed resulting in the loss of both the pilot and passenger. This is currently under investigation by the ATSB. I attended all these incidents and I can tell you I have a new appreciation for low flying and full awareness of the environment.

 

If you are going to practice slow flying, as mentioned do it at a safe height, but do it. Get used to your a/c and how it handles at slow speeds and turning. I have and have learnt a lot. Also stress to your friends who fly on properties, these recent incidents and the need for discipline when looking for/mustering stock.

 

 

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Learn how to manage minimum radius turns - in balance - and you won't be worrying as much about 1.4 and the other numbers. If you don't load your wing up - it's unlikely to stall - as Nev notes in regards to 'stall stick position'

 

The probable cause of lots of those LL accidents is likely the 'mustering' stall, where the lower wing is raised with rudder while in a steep turn - so the target isn't lost behind the wing. In Canada & Alaska it's known as the 'moose' stall - where the wing is lifted by rudder so a pic can be taken.

 

If you do a proper LL course, you should learn how to make a variable angle of bank turn at low speed so that the target stays in view while the aircraft is in balance and not near the stall.

 

happy days,

 

 

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Low and slow can be dangerous and it isn`t a smart way to fly

 

so what is low and slow?

 

In my opinion,low is the height where, if the aircraft stalls there is no chance of recovery.

 

Slow is the speed at which the aircraft can stall due to the human factor or wind shear.

 

We need to keep in mind that this is also type dependent.

 

If practising, get sufficient altitude to allow plenty of height for recovery if things go wrong, sky above is of no value.

 

Frank.

 

 

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The probable cause of lots of those LL accidents is likely the 'mustering' stall, where the lower wing is raised with rudder while in a steep turn - so the target isn't lost behind the wing. In Canada & Alaska it's known as the 'moose' stall - where the wing is lifted by rudder so a pic can be taken. QUOTE]

Just in case I'm not the only one that was scratching my head as to why lifting a wing with rudder was the culprit, here's another explanation found on a US site;

 

"

 

A typical "moose stall" or "wolf stall" scenario is as follows: A pilot is circling at low altitude above an object on the ground with his/her attention focused on that object (instead of on flying the aircraft). Airspeed is slow and bank is steep in a effort to stay in close proximity to the object and keep it in sight. Due to the steep turn the nose tends to drop, which the pilot then subconsciously tries to raise with top rudder (opposite the turn direction). When the critical angle of attack is reached, the airplane stalls abruptly and rolls over the top (in a direction opposite the turn) into a spin entry. This condition can be complicated by winds frequently encountered close to abrupt terrain. A gust could contribute to causing an inadvertent stall, or down drafts could exceed the airplane's climb performance in a turn. The pilot's inattention, the abruptness of the stall, and the low altitude combine to give insufficient warning or time for recovery."

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More on the "moose stall": some aeroplane types, when passing through their own wake at low speed (specific configurations of flap & power) will cause the horizontal stabilizer to stall resulting in a sudden nose down pitch.

 

Learn how to manage minimum radius turns - in balance - ...

Minimum radius turn is achieved at a fairly high speed and high load factor. I rarely encounter anyone who knows how to do a minimum radius turn.Add another consideration such as maintaining level flight with full power or turning with minimum height loss with power off drastically changes the parameters for discussion.

 

 

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Making it clearer

 

Some general comments.

 

It would be an advantage to everyone and I would appreciate it if everyone would define the aircraft under consideration when making statements of performance and stall recovery.

 

I can assure everyone that my WB Drifter doesn`t need anywhere near 1000`AGL to recover from stalls,not to say that it isn`t safer above that height.

 

To have a meaningfull discussion,we have to accept that there are still many basic RAA aircraft and the performances vary greatly,broad statements trying to cover all AC types,can in fact be totaly incorrect and confusing.

 

For example......There`s no point in trying to compare what a Cessna does or requires,to a WB Drifter,an XAir or even a Zenith 701 and I could go on,I`m familiar with quite a few of them.

 

Frank.

 

 

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Hi Back when I learnt to fly scout mk3 in the 80's here was a saying " if you fly low and slow your life will go " they also had another saying to "if the fan stops the pilot sweats " I think they both still stand today . You only die hitting the ground so the further you are away from it the safer and better you will be !! Dan

 

 

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