Turns at low IAS

[facthunter]

Look I don't want to be hard on anyone either and I worry about weird ideas getting about that might bring someone to grief at some stage in the future I "read it somewhere" is often said.  so at times a get a bit to the point for some's liking. People are not often who they appear to be  on line. I don't like pulling rank. The argument should run on it's own validity and merit but I can't control what interpretation some choose to put on it. No one likes lengthy posts either and they skim it or may switch off.

 I knew a Ken with a Glassair and I've flown it. He's not with us anymore.. I flew at a time that will never be with us again . Planes were pretty unsafe and unreliable. The training in them was downright dangerous. I don't care if it's big, little or basic. You just adjust and allow for it s mass, power or lack of either.. Instructing has taught me so much. It's one thing to fly a plane and handle it and it's something else to  adapt to each student and cope with what they might do in some situation so your ability to pull a rabbit out of a hat must be fully functioning. Also every student is different.. You don't know WHAT their knowledge base is, so YOU must expose yourself to a big learning process and be adaptable or you won't survive.

   Airline Pilots?  Flown with 1,000s including a lot of WW2 People.  Originally I thought they were Gods and I found out they were just people. Human and fallible like the rest of us.  The training is what makes the difference between them and a Drifter pilot. Some have had millions of dollars invested in their training. It's done a lot cheaper these days. Not all good.

 If someone prangs because of something I didn't explain well or even teach that's a cross I didn't want to carry .  I think there's work to be done but I'm wondering IF it will ever happen. . . Nev

 

[bull]

1 hour ago, facthunter said:

And LOW flying can't be taught for the majority of RAAus pilots. I've always thought that is WRONG.. Landing, taking off and going around is LOW flying and subject to well know illusions. OUR stall training is minimal and not related to REAL situations, either.  Nev

Totally agree with you Nev, I was flying around when WE where not ALLOWED higher then 300ft,,,,lol

[facthunter]

 Me too. That didn't add to safety either.  Nev

[bull]

5 minutes ago, facthunter said:

 Me too. That didn't add to safety either.  Nev    ps. i have had two full engine failures and one was successfully gained and then takeoff made after repairs , but walked away second time made it down and on roll out at 30kts hit a little ditch that liked my undercarriage more then me and pinched it ,,lol

But Nev, in those days after the wheels leave the turf yours and my head would have been swiveling around and sussing out the ground ahead whilst in climb etc.  My pucker valve did not close properly until i was at1000 ft,,,,lol

Edited January 10, 2021 by bull

[facthunter]

I think the initial  climb to about 50 feet is the most critical part. I had mates who had severe back injuries from low height engine failures. I tried to cover that by overspeeding the climb a bit. Overspeed it too much and you don't climb.The plane was a brand new 2 seater (tight  Fabric) with pull start engine. It actually flew the best by far of any  I've flown since.  Nev

[spacesailor]

" If someone prangs because of something I didn't explain well or even teach "

virgin galactic rocket plane disintegrated, because the crew were Not told of the consequences of doing something when at speed.

the wing rotating lock was pulled too early, to give the pilots more time for the next job .

with all their training it happened.

spacesailor

[RossK]

answering OMEs orignal question, where I'm least comfortable in the circuit is turning downwind from crosswind on a windy day.

Typically I'm still climbing  or have just reached circuit height, so still slow and doing a climbing turn.

The wind gives the sensation of trying to pick up the upwind wing and flip the plane whilst the crosswind on the tail seems to slow the rate of turn, so I feel like I want to kick in a bit of left rudder, but the ball says I don't need it.

I feel I could easily end up overbanked in a skidding turn if not paying attention.

 

Ross

[old man emu]

Who ordered pilots to fly circuits with strict 90 degree turns? Go watch a warbird doing a circuit. There are no crisp 90 degree turns for it. Crosswind and Base are simply 180 degree co-ordinated turns. Watch this simulation of the circuit flown by a Bf109 and see how it makes these turns.

 

I know that someone will come back to say that these aircraft fly this type of circuit due to their high landing speeds, which if they didn't cut corners the wouldn't be able to stay reasonably close to the airfield. I'd agree. But just because your speed in the circuit is a sedate 50 to 80 kts, why must you risk a stall/spin just to show that you can fly with precision?

 

Here's another question. At what sort of landing places do these stall/spin incident occur? Is it the airfield where there is a lot of traffic in the circuit, or the quiet strip that maybe only sees one or two movements per day or week? Landing on a farm strip, or landing at the town strip? 

[Jabiru7252]

I've done a lot of work at various RAAF bases around Australia. I noticed the F18s never did 'standard' circuits as we (LSA) pilots understand them. The F18's scream into the circuit and fly perfect constant rate turns from downwind to finals. Apparently it's a tactic that minimizes time in the circuit. Somebody may correct me but that's how it was explained to me by a RAAF pilot.

[facthunter]

Ross, generally you are operating in a moving airmass but there is always the likelihood moreso at lower levels to get some windshear. You can even have both windsocks disagreeing. Sheds and lines of trees can  cause issues downwind of them..  In thermals the outer wing gets tugged down if you get to the edge of it. If it feels funny increase your speed  a bit first but keep controls balanced and avoid large aileron inputs and sudden control  and pitch changes till you sort out what's happening if you are worried.  . Nev

[RossK]

4 minutes ago, facthunter said:

Ross, generally you are operating in a moving airmass but there is always the likelihood moreso at lower levels to get some windshear. You can even have both windsocks disagreeing. Sheds and lines of trees can  cause issues downwind of them..  In thermals the outer wing gets tugged down if you get to the edge of it. If it feels funny increase your speed  a bit first but keep controls balanced and avoid large aileron inputs and sudden control  and pitch changes till you sort out what's happening if you are worried.  . Nev

Yeah, it's just one of those situation where your senses are lying to you, particularly when still climbing, ie still full power, so still require some right rudder.

Trying to turn left, raise the right wing and then feel like I'm trying to hold it down so it doesn't overbank.

The sensation is I'm putting in a little right aileron down, and still on the right rudder (just), but trying to turn left 😬. 

The brain and the senses are saying this is all wrong, but the instruments confirm I'm turning left a balanced turn.

 

[facthunter]

Ross, Your senses developed when your ancestors had their feet on the ground. Blame the semicircular canals in your middle ear for most of that..  IF you can't see an horizon it gets worse..  Nev

[facthunter]

OME  the long nose makes a curved final a good thing so you can see more. Turn radius is very dependent on forward speed especially if bank angle limited.

   Teaching  someone to fly you don't have them turning and adding flap  dropping gear and changing power etc at the same time. Early on you'll extend flap on downwind and then turn base or turn base and then drop flap..  AND you try to be stabilised  on final at a certain height for whatever plane you fly. (whatever the POH says). "Over quickly" 90 degree turns are much simpler. It's "done with" quicker.

   A wide radius turn of 180 degrees  with hardly any bank angle is a bit of a pain to do on your slow Bugsmasher Mk 2 especially on days with some thermal activity.

   Commercial and military Jets do racecourse circuits but can be vectored onto any of the 4 circuit positions. It's pretty flexible and no big  deal either way.

   In answer to "where do these things happen most" I would say at Airshows where the area to operate is restricted for various reasons .Like you are not permitted over crowds, you might be landing into the sun, communications with the tower intrude due to the nature of the "show". Co ordinating previous or following events, people can get "rushed"  There's a lot of pressure on at such times.   Often the pilots are very  experienced. Nev

[old man emu]

2 hours ago, facthunter said:

"where do these things happen most" I would say at Airshows

Then that implies that since most of us aren't airshow performers, we don't need wot worry about this dangerous situation. 

 

But my question still stands unanswered: Who ordered pilots to fly circuits with strict 90 degree turns?

 

Jab7252's observation mentions constant rate turns. A standard rate turn is defined as a 3° per second turn, which completes a 360° turn in 2 minutes. During a constant-bank level turn, increasing airspeed decreases the rate of turn, and increases the turn radius. A rate half turn (1.5° per second) is normally used when flying faster than 250 kn. The term rate two turn (6° per second) is used on some low speed aircraft.

 

A formula to work out the angle of bank in your head for a Rate One Turn is {TAS/10} + 7.  For airspeeds up to 120kts TAS  the angle of bank is up to 20 degrees. Working out the radius of a turn os a tad more complicated as the formula contains the value of tan for the angle of bank.

Or in feet (where velocity is given in knots):

 

The value if tan from zero to 20 degrees ranges from 0 at zero to 0.364 at 20 degrees, so the bottom line ranges from zero to 4.

[facthunter]

You're just WRONG on the turn  radius thing . Any one who's done a dogfight knows that and I qualified it further by using  equal limit bank (of 30 degrees)  ' Why would you say we don't have to worry if it's more likely to happen at airshows with experienced pilots.  If experienced pilots have a problem we could expect to have  it also. The ISSUE is probably related to pressure and distraction which can apply to most of us. Pilots in unusual situations ( for them) stuff it up more. That happens all the time.

       Re the circuit. It's done to prepare for landing or practice. I don't know if it had to be ordered or just evolved. The rectangular form suits ab initio in slow planes. and anyone in slow planes. If you wish to do the racecourse thing you'd have to be close in on downwind  as you might be if the engine failed. Nev

Edited January 11, 2021 by facthunter
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[Old Koreelah]

5 hours ago, old man emu said:

Who ordered pilots to fly circuits with strict 90 degree turns?

Good point, OME. I know the reasons for them but I also know new pilots who seem to have been taught to overemphasize the squareness of their turns at the risk of ignoring other, more crucial aspects of their flying.

[old man emu]

46 minutes ago, facthunter said:

Why would you say we don't have to worry if it's more likely to happen at airshows with experienced pilots. 

Did you miss the emoticon  ?

 

When I was a lad, doing my circuits and bumps in a C-150, it took 10 minutes to do a circuit. Plenty of time to go through pre-landing checks so they were out of the way so I could concentrate on the landing and doing nice tight circuits at Bankstown, where, back in the dim dark past, there were often tow other aircraft in each leg of the circuit. What I'm saying is that if you arrive overhead at a private, or quiet country town strip, and do a proper entry from the dead side, then putter along downwind, why do you have to fly a rectangular path the the threshold when you could just as safely do a descending turn?

11 minutes ago, Old Koreelah said:

I know the reasons for them 

Well, lad. Out with them!

[spacesailor]

who ordered 90d turns ?.

The instructors of course. " make your turn when the  end of the runway is 45d ".

What don,t you do all at once !, " BUMFISH ".

spacesailor

 

[Garfly]

We've been round this circuit a few times before ... so we have a ready supply of answers:

 

 

[skippydiesel]

I am a supporter of the angular (90 degree) turns especially for students;

 

• A large part of learning and continuing to fly is discipline. In fact aviating should be viewed as a discipline, we all aspire to perfect. In this case it is the ability to conduct all of the relevant maneuvers, communication, aircraft configuration, at the appropriate time/point all the while making small adjustments for wind speed/direction and glide slope - to arrive at a successful touch down.
• The angular pattern helps the pilot, especially the new one, to gauge distance , hight & target speeds for the variose stages - not so easy if you are conducting a 3/4 arc, or part thereof, approach.
• Once mastered, the angular pattern can be modified to suit the circumstances that present themselves to the pilot - this may include the curved/arc approach (which I have nothing against if the pilot knows what he/she are doing.)

[aro]

5 hours ago, old man emu said:

But my question still stands unanswered: Who ordered pilots to fly circuits with strict 90 degree turns?

CASA is the obvious answer.

 

The main purpose of flying a circuit is to be predictable, and to observe and be observed by other traffic. On base leg, you you should be looking for traffic flying a straight in approach, and also possible other traffic that might have turned base from e.g. a closer downwind. Many aircraft have blind spots in a turn that would make that difficult. Straight legs of the circuit allow you to see traffic that is obscured in the turn.

 

Additionally, AIP calls for a straight final approach beginning at least 500' AGL. The purpose is to allow you to check for traffic on the runway, and to make a stable approach.

 

My understanding of the military initial and pitch is that it helps fast aircraft slow down, and creates separation for landing between multiple aircraft in a formation. It does not seem to be a good solution where you need to fit in with other unrelated aircraft in the circuit.

[old man emu]

1 hour ago, Garfly said:

We've been round this circuit a few times before ... so we have a ready supply of answers:

I don't think we have "answers". From reading those earlier posts, the argument is not resolved, and is never likely to be - it's all subjective, it seems.

[aro]

A standard circuit is pretty clearly defined in AIP. If you're looking for a particular person, I don't know. I suspect it predates WWII.

[Garfly]

5 minutes ago, old man emu said:

I don't think we have "answers". From reading those earlier posts, the argument is not resolved, and is never likely to be - it's all subjective, it seems.

I thought that you were complaining that your questions were going 'unanswered'.  No pleasing some folks.

[pmccarthy]

No square corners in my circuits. I keep them smooth and continuously banked until lined up for final. Just works for me.