Avoiding the Base-to-Final Stall/Spin

[Head in the clouds]

I came across an excellent video that may help some with understanding of the dynamics of the Base-to-Final Stall/Spin scenario, and it offers some ideas and methods that may help to avoid ending up there in the first place, or save the day in those critical moments if someone gets a bit untidy and needs to react correctly in an instant.

 

Some may recall my method for identifying which rudder to press because I often find it hard to be sure in the heat of the moment, which way I'm spinning. I press the rudder which is following the rotation of the earth below - if I'm spinning to the right the earth appears to be going from right to left of the windshield, so I press left rudder and v.v.). In this video the author has another good method, press on the wing that is high to bring it back down again ...

 

 

 

 

 

[kgwilson]

Good video. I was taught "Opposite Rudder" & it just seems instinctive to me, but whatever floats your boat & works for you is the best.

 

 

[Thruster88]

Regular practice of the falling leaf works for me.

 

 

[facthunter]

Pretty good coverage., but a fair bit there if you are just getting started. The pilot puts the plane into a spin, not the plane.  Most pilots are $#1T scared of stalls. That's fair enough but till you can recognize them and suitably react you are not a good or safe pilot, so you need plenty of practice and the right technique. The way we are generally taught is not good enough. It's too predictable , It's set-up and makes you think you only stall when the nose attitude is high and that's not true. You can stall when the nose is well below the horizon as when pulling out of a dive, or in a turn. There's one common feature of a stall. . Unless the plane is very tail heavy or trimmed  wrong  you will be applying a lot of back stick, consciously or not. The elevator determines the wing's AoA  (The angle at which the wing meets the RELATIVE airflow). and that causes the stall, when it exceeds about 14 degrees...

 

      In a balanced steep turn , if you pull the stick back either wing may stall first, usually depending on the riggers angle of incidence, or some slight bias in the planes rigging or power setting. The rudder bias is only correct for one speed and engine power. A change of power needs a change of rudder input, unless the engine thrust line is offset sideways a fair bit.  Pilots of U/L's should be active rudder type pilots and conscious of flying unbalanced/ balanced, at all times, and going into a turn either add power or be prepared to lose height (intentionally) to stop speed bleeding away when it needs to be increased. Nev

 

 

[Kyle Communications]

That was a good video...I always remember when I first started flying in gliders almost 35 years ago. My instructor said the one thing that has always stuck with me and that is "aileron will kill you...rudder will save you" . I am always thankful for starting flying in gliders as it taught me the use of rudder and how valuable it is. I see so many power pilots who really dont use rudder except for steering on the ground

 

 

[skippydiesel]

Great Video - in all the years I have been flying I have never entered a spin. Might be time to talk to my local RAA CFI about spin recognition/recovery. The alternative, is to go GA and do that unusual attitude recovery (aerobatic) program.

 

 

[Thruster88]

 

 

 

This is a great video from a no bullshit guy that has 20 years of real flying expirennce.

 

 

[Head in the clouds]

This is a great video from a no bullshit guy that has 20 years of real flying expirennce.

 

Yup, couldn't agree more, thanks for reposting it!

 

 

[Old Koreelah]

I've come across too many pilots who focus on flying a circuit with neat, square turns. I suspect this emphasis has led to a few stall/spins. Many students find it difficult to assimilate the whole package that instructors try to teach and may neglect some aspects of their lessons in favour of others.

 

Perhaps they should give priority to keeping the ball in the middle.

 

 

[facthunter]

 Give priority to being situationally aware. No good hitting someone with the ball in the centre. . Never fixate on any ONE thing. You can't concentrate on the ball in the centre during the flare in a x -wind.  The so called "Seat of the Pants" flying implies an awareness of skidding  or flying out of balance.... Feeling what the plane is doing. Ignore only when in IMC and you are not supposed to be THERE...Nev

 

 

[Kyle Communications]

My base to final turns are usually always circular. I have never liked the square turns. Probably a hangover from my gliding days. I have found it to be far more accurate to do the round turn as it is easily adjusted for overshoot or undershoot 

 

 

[Kyle Communications]

oh and easier to keep the bloody ball in the centre ?

 

 

[skippydiesel]

I think one of the aspects of converting from GA - RAA that I found most difficult, was the gut (as apposed to intellectual) understanding of how a low inertia aircraft behaves in the circuit particularly on the turn to final.

 

When your speed "over the fence"  is about 40 knots and your aircraft is about 300 kg you have to pay attention to airspeed on that last turn. So easy to stall in the turn. I try to make my base leg no lower than 60 knots, use minimal aileron and lower the nose (can always bleed off any undesirable air speed).

 

Something I have to be very aware of :  I usually fly alone, so when I have a passenger it makes a big big difference to how my little beauty handles in the landing phase. I must confess. despite trying to allow for the extra weight, my landings with passengers are not always a thing of grace & beauty. 

 

 

[kgwilson]

My base to final turns are usually always circular. I have never liked the square turns. Probably a hangover from my gliding days. I have found it to be far more accurate to do the round turn as it is easily adjusted for overshoot or undershoot 

Agreed. With my aircraft, 1000 foot circuits are way smaller than when I was flying GA Cessnas & Pipers so my turn on to base is a descending wide 180 degree turn to line up on final at 4-500 feet with power back to idle on a light wind day so basically a glide approach. High wind day, same approach but may need a bit of power if my circuit is not tightened up quite enough. Usually though I have excess height so a sideslip sorts that out.

 

 

[facthunter]

 Jets use the circular pattern usually but probably training in U/L's the squared off pattern is easier to learn where you don't take flap and gear  while in a turn. Early on you keep it simple, and do one thing at a time. Extending flap on some aircraft  requires a corresponding  significant nose down pitch or added power or the speed may wash off surprisingly fast.. Turns need extra speed to have the same % margin of stall reserve. Practicing figure 8's adding and reducing power as you enter and leave the turn is the way to get this right. The plane won't fly itself through a turn. YOU must know and achieve the right technique, or you risk being a statistic when you put yourself under a bit of pressure. Practice entering medium gliding turns till you get it neat . Also 180 degree gliding reversals with positive speed control. It should be second nature.  ADD Bank, add power or lower the nose. and consider traffic when turning always.  Nev

 

 

[Old Koreelah]

My base to final turns are usually always circular. I have never liked the square turns...

Me too Mark. Why not a neat semicircle from downwind to final? The only valid reason I've heard was that during a slow, constant turn, another aircraft might be obscured by a window post or strut; "square" turns avoids this.

 

 

[pmccarthy]

I agree re circular turn, works in a low wing ok re visibility. 

 

 

[kaz3g]

My base to final turns are usually always circular. I have never liked the square turns. Probably a hangover from my gliding days. I have found it to be far more accurate to do the round turn as it is easily adjusted for overshoot or undershoot 

And easier to see where you ate in relation to the runway when you have a high instrument board and a nose high landing attitude.

 

kaz

 

 

[skippydiesel]

As I see it, the angular/squared off circuit pattern, is a method for instilling  a disciplined/by the numbers approach to landing.

 

Personally I like the challenge of doing it this way - the environment is always changing, ( aircraft load, pressure altitude, wind,, perspective, terrain, even runway width) so there is no such thing as a perfect landing every time no matter how good/experienced the pilot is.

 

A wee bit contradictory - the only time I am inclined to do a curved approach is when I am nonpracticing an engine out - I nearly always have to "slip" to bleed of excess hight.

 

Other factors for consideration/debate:

 

• The aircraft waiting to line up - a curved approach gives the waiting pilot less opportunity to see/pick up an aircraft on final.
   
   
  
• When does the curvy pilot make his/her call "on final"
   
   
  

 

 

 

[facthunter]

 Let me assure you that in practice these problems are not an issue. with the Racecourse Pattern  I also stress that with initial training taking flap while  entering or in a turn while bleeding speed back to target speed is a bit more complex than taking flap on downwind  prior to turning or on final in a straight line. A stable approach must ideally be achieved at some point( Height) related to the type of aircraft, and type of operation.  One adverse aspect is "sighting" another plane  which is on a straight in approach when you are in a constant turn. Most of this procedure is done at Primary airports where separation is applied by the controller but visual  still plays a part even there. Nev

 

 

[BirdDog]

Interesting how we all do things slightly different.

 

I was taught to drop power to idle right at the downwind/base turn.  Maintain 70 (in my bird anyway) all the way through the downwind/base turn.  Depending on height etc, deploy a stage of flap either on base, or on final, right after the base/final turn.  I was taught to again maintain 70 (again in my bird) right the way through the base/final turn (way above stall speed) . It was hammered into me as the most important turn of the circuit.  Then once on final, maintain 60 and deploy flap or side slip if the height is wrong.  Worse case, go around.  Was also taught to lower the nose right before flap deployment. 

 

Have practiced the crap out of 3 stage flap with side slip, and she can get down pretty bloody fast!

 

Lastly, was taught to "never chase final"  In other words, if I overshoot the base/final turn, don't chase to get back on centre line.  If it's too bad, go around.  

 

 

[turboplanner]

Me too Mark. Why not a neat semicircle from downwind to final? The only valid reason I've heard was that during a slow, constant turn, another aircraft might be obscured by a window post or strut; "square" turns avoids this.

Country flyer idea. One afternoon, I was No5 on final at Moorabbin; only three of us got in, but the last one could see the first one rolling for the runway exit. 

 

Try handling that in a quarter circle.

 

There were probably another 2 or 3 on base, the last one at least being able to see everyone in the line turning final.

 

Try handling that in potentially (from the above) 8 different semi circles.

 

However, no one had invited any novel patterns or anything other than the three legal heights above ground level.

 

You'll find it in the VFG.

 

 

[Student Pilot]

Turboplanner, I don't think anybody was suggesting to do a circular circuits at places like Moorabin, horses for courses

 

 

[octave]

Here is an interesting article https://www.flyer.co.uk/rectangle-or-oval-circuits-which-is-better/

 

 

[turboplanner]

Turboplanner, I don't think anybody was suggesting to do a circular circuits at places like Moorabin, horses for courses

I haven’t looked up the legislation but I’ve never seen a list of the airfields where this might be permitted.