Turns at low IAS

[Student Pilot]

I think I have done maybe 10 good landings. By good landings I mean one where the wheels just start spinning up and you can't feel the aircraft contact the runway. Aircraft also has to be on the centreline and touchdown in the perfect spot where you just roll through to the taxiway without excessive braking. Every time I land I try to do better.

[Garfly]

3 minutes ago, Student Pilot said:

I think I have done maybe 10 good landings. By good landings I mean one where the wheels just start spinning up and you can't feel the aircraft contact the runway. Aircraft also has to be on the centreline and touchdown in the perfect spot where you just roll through to the taxiway without excessive braking. Every time I land I try to do better.

And that's from someone with over 26,000 (hands on) hours and maybe 200,000 landings under his wheels.

[Student Pilot]

You exaggerate Captain Gaz, only approaching 25 in my log book! 

[phantomphixer]

I’m with pmccarthy on this. Smooth gentle turn from mid base leg. Eyes outside but lots of glances at airspeed and the ball, keeping it all coordinated hopefully.

[Kyle Communications]

I was taught in RAA back 10 years ago that the slow curved constant turn from base to final is the best and also this gives you time to line up. Once lined up you mainly use throttle and rudder for the approach and landing. Ailerons to be used as minimal as possible. In crosswinds I do pretty much exactly the same but keep the into wind wing low as required. Works very well. When i was doing GA in the mid 90's they only taught crab...I hated it. I much prefer this method as there is very little chance of slipping the final turn. I have landed in a 30kt crosswind using the wing down method and it was surprisingly easy..just need to keep your speed up a little over the fence.

 

[skippydiesel]

21 minutes ago, Kyle Communications said:

I was taught in RAA back 10 years ago that the slow curved constant turn from base to final is the best and also this gives you time to line up. Once lined up you mainly use throttle and rudder for the approach and landing. Ailerons to be used as minimal as possible. In crosswinds I do pretty much exactly the same but keep the into wind wing low as required. Works very well. When i was doing GA in the mid 90's they only taught crab...I hated it. I much prefer this method as there is very little chance of slipping the final turn. I have landed in a 30kt crosswind using the wing down method and it was surprisingly easy..just need to keep your speed up a little over the fence.

 

Well everyone has their training & pet theory's - as a supporter of the angular approach, as my preferred way, with weathercocking on final, straightening/aligning with the centre line just befor touch down.

 

HOWEVER I also advocate fitting your technique to the conditions of the hour/minute/second - this may be a curved approach, with a slip into wind, whatever suits - I try for  proficiency in both and can mix/match as required (this came with time/practice after becoming reasonably proficient on the former).

 

Those that rigidly stick to one system, will find themselves discombobulated, when they dont fit/suit the circumstances they face in the moment. 

 

Once again I advocate the angular approach for students, as this offers a more disciplined method, with points of reference (relative to the active runway) ,for all of the actions required from long down wind, base, final, to touch down. I can not see how the curved approach offers (to the student) similar reference points.

[Yenn]

I think the advice pmcarthy was given is good.use the rudder on short final, but also use the ailerons to keep the ball in the centre, unless you want it elsewhere due to slipping. One thing I have found is that a long gliding turn to final is better for visibility purposes that straight legs with sharp turns. The plane is easier to see during a turn because the wing is inclined. I once met someone doing a right circuit in a slightly slower plane than mine. I hadn't seen him in the circuit, because I was not expecting a plane there. I saw him when he was about 200m ahead of me and at right angles to me. I just swerved to my right, overtook him and landed really long on a 2km long strip. The pilot was the owner of the strip and his radio was faulty. He was doing right circuits to keep away from skydivers using another strip and hadn't notified anyone else. It is quite impressive to have a slow high wing STOL type float across in front of you.

[Kyle Communications]

The slower curved turn to final from base there is much less chance of slipping. its easier to keep the aircraft in balance all the time...nothhing too abrupt in the landing phase. Most spin in of the final turn are caused by harsh angular approaches and pushing to get the aircraft around. I can do that too and do sometimes but my preferred approach is also the curved one..and yes always better visibility

 

[Jase T]

I was taught and Always flew oval CCTS in the defence force.. Especially at low level!!! A constant rate turn from base to final was the go but then again my final patter went like this.. Attitude, Aimpoint, airspeed closure rate (closure rate was kept at a fast walking pace all the way to a 3 foot hover...). For the record in a fixed wing I teach square CCTS at normal height to allow students time to sort out the aircraft. Make configuration changes when not turning as I want your eyes outside in a turn and look at the airspeed before you do anything (flap, turns, power changes etc etc if you are going to do anything you look at the airspeed first). BUT low level or bad weather circuits are flown as oval downwind to final. Otherwise you are too far away from the runway on downwind and risk losing sight of it in the rain! for low level circuits configure the aircraft on downwind and fly a constant level turn to intercept final keeping the airspeed at the front of your scan. For my money on a VFR flight you are most likely to stall the aircraft shortly after going inadvertent IMC!!!

 

Edited January 13, 2021 by Jase T

[skippydiesel]

Kyle et al : Do you have any response to my comment ? - 

 

"........... I advocate the angular approach for students, as this offers a more disciplined method, with points of reference (relative to the active runway) ,for all of the actions required from long down wind, base, final, to touch down. I can not see how the curved approach offers (to the student) similar reference points."

[Kyle Communications]

My reference point even when I was doing GA back then is your shoulder when coming on downwind..then it doesnt really matter does it...I never pick reference points other than where the end of the strip is and what terrain is around in front of my path. I find doing angular approaches in windy conditions is far worse than my curved approach. I also get the centreline of the runway much easier. Dont get me wrong sometimes you have to do the angular approach but why do it when you dont have to. its much less stressfull. So long as you CAN do it and practice it occasionally...who cares..whatever floats your boat..none of them is right or wrong its just a different method. I think if you are trying to get someone to learn isnt it easier to show them the simpler way first then work on the problematic ones

 

[Kyle Communications]

Mind you thinking about it my approach was no different when I learnt to fly gliders in the mid 1980's...always a curved approach to final...I just think its easier and simpler to do it that way. Aiming points and references were the same..use your shoulder on downwind and depending on the aircraft it would depend on how far you went downwind. I find I pull the throttle back to idle at the end of the runway then continue on until my height drops and do my curverd turn and line up and I am at the perfect height for a snodger of a landing...sometimes 🙂 ....its just what I do

 

[Garfly]

 

From the teaching point of view pylon500 commented on this in one of the earlier threads:

 

 

[Yenn]

I don't know what you mean by "use your shoulder" but I always adjust the start of my turn from downwind according to the wind direction. A strong cross wind will either extend my downwind if it is going to be a tailwind on base, or reduce my downwind if it will be a headwind on base. If I am going like a rocket on downwind I will start the turn early, so that I don't undershoot.

[RFguy]

In any sort of strong wind, my circuits are usually rounded parallelograms / squashed circles/ irregular shapes. 

 

I use the shoulder view to establish a nil-wind benchmark for the base turn.  

[skippydiesel]

21 minutes ago, Yenn said:

I don't know what you mean by "use your shoulder" but I always adjust the start of my turn from downwind according to the wind direction. A strong cross wind will either extend my downwind if it is going to be a tailwind on base, or reduce my downwind if it will be a headwind on base. If I am going like a rocket on downwind I will start the turn early, so that I don't undershoot.

I think they are referring to the instruction to students, that your turn onto base, should be start when your aircraft is about 45 degrees relative to the threshold/landing point - this can be estimated by looking back "over your shoulder".

 

This is an estimate that should vary according to conditions, with further  corrections for wind speed & direction done on  base/final

[Kyle Communications]

Exactly..my shoulder is the reference I use for any airstrip to get me at the right distance out for downwind and of course the conditions dictate where I turn base and final..again though I tend to use my should as the fixed reference and adjust my look angle..hope that makes sense. All I know is it works for me. Maybe not others but it was taught to me in my glider days which was my first 80 hrs of flying fullsize aircraft..its sort of stuck throgh GA and RAA because it just works...for me

 

 

[old man emu]

I need some numbers, please.

1.  Circuit leg speeds for the aircraft you fly (book speeds if possible)

2. Typical angle of bank for turns onto Base and Finals

3. Typical weights for a 2-seater RAAus aircraft. MTOW, MT weight, fuel remaining from full after 30 minutes cruise flying.

 

I have to specify that fuel has been used after a period of flying because the mere act of flying a circuit will reduce the fuel load from full capacity.

 

Anyone have strong objections to using 95 kgs as the weights for pilot and passenger as a sort of average?

 

I want to use these figures to do some "lift reduction in turn" calculations.

[Thruster88]

I think you are over complicating it OME. Every pilot already knows that in a 30° bank turn the load factor is 1.15 and the stall speed is 1.07 times greater than S&L configuration regardless of aircraft type or wieght.

[Garfly]

And we learn that unloading the wing in a turn (allowing the nose to drop while staying balanced) should forestall a stall, somewhat.

 

Well, for anyone with enough curiosity and time on their hands, this thread on the Pilots of America forum 'Low altitude steep descending turns...'

goes into that topic at length and with a fair amount of heat to go along with the light.

 

https://www.pilotsofamerica.com/community/threads/low-altitude-steep-descending-turns.90484/

Edited January 16, 2021 by Garfly

[RFguy]

I see people writing  about turning  low on base-final and 'suddenly' ending up with a tailwind, and losing all airspeed suddenly 

 

This doesn't suddenly happen in a turn that takes 10-15 seconds  (unless there is some sort of shear) 
 

You don't "SUDDENLY" turn into a tail wind and loose all your airspeed "suddenly" . It takes TIME to get around the turn, and meanwhile IF you are watching your airspeed, you'll notice the IAS dropping and you will take action  to maintain airspeed.

 

If you are not looking at your ASI often enough , then yeah, you might go from 60 to 30 KIAS in the turn, then you are F___cked- but you should have been watching your  ASI  AND OR feeling what the plane is doing....

 

the other day I did an simulated EP and did a tight steep descending 180 deg turn  at < 500'. Instructor wasn't concerned he said  because  I was keeping the airspeed up . and it was only  a 20 to 30 deg turn. 

best glide is about 62 kts ish, clean stall ~ 45 kias,  nill wind . 

-  I continued to hold  the best glide through the 180 deg turn .  then stopped the turn, then flaps out (when assured of making the chosen landing area) .

If there had been a strong wind  I might have added a bit more airspeed- but if I turned into a tailwind, and airspeed would have dropped  and I  would have just pushed the nose down maybe moderated the turn  and there fore reducing AoA and increasing airspeed simultaneously (required). no issue with height.. Sure, you cannot do that at 50 feet, but you wouldn't anyway.

 

Edited January 16, 2021 by RFguy

[old man emu]

2 hours ago, Thruster88 said:

think you are over complicating it OME

My request for that information is to satisfy my own curiosity. Whether I post anything arising from it, or not, is a different matter.

[Garfly]

25 minutes ago, RFguy said:

but if I turned into a tailwind, and airspeed would have dropped  and I  would have just pushed the nose down 

 

Wind-shear aside,  if we take it that we're flying within a moving parcel of air, then, is 'turning into a tailwind' really a thing, up-there, as it is, on the ground, say, while taxiing? 

Of course, when we're manoeuvering at low level, the perception of ground-speed plays a big part but does the wing know or care about that?

Edited January 16, 2021 by Garfly

[RFguy]

yes we are flying within a parcel of air sure, but my point is (without a shear etc) the airplane does not go instantaneously from a headwind to a tailwind . turning the aircraft takes time, and as long as you know your airspeed often enough (by looking at the ASI or feeling it through your hair) , you wont be caught out.  if you are  S&L 10 kts about the stall with a 30 kt headwind, and turn 180 "instantly" and are flying S&L   then now you are 20kts below the stall speed. But it wont happen that way on a 30 deg AOB turn at base/final speeds of rec aircraft.

 

and yes, I agree  the wing is relatively unloaded in a moderate speed steep descending < 30 deg turn. Not much required of the wing...  very different to the high AoA / flow separation stall condition. wing will be at low AoA for high flying descent rates.

  

[old man emu]

The biggest hassles with a tailwind if you have to land with one are firstly, you will be moved towards the runway as you are flying your Base leg. That'll put you higher than you are used to as you turn onto Finals. Then the tailwind will carry you further down the runway as you try to get the wheels on the ground. Once that happens you'll be travelling along the ground faster than usual.