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-   -   Why do many "Airline" training organisations insist on flying such wide circuits? (https://www.pprune.org/pacific-general-aviation-questions/402019-why-do-many-airline-training-organisations-insist-flying-such-wide-circuits.html)

Ando1Bar 17th Jan 2010 01:52

Trent, thanks for the backup based on your A380/QF experience.

To clarify what is being taught - turn crosswind 10-15 deg AoB depending on wind, wings level momentarily at 90 deg to check for traffic and runway alignment, then continue the turn. This gives the 'racecourse' crosswind turn. Of course given the speed we are flying we are going to be no where near as far away from the field as a jet on downwind.

On base a more square leg is used allowing more visual contact with the runway on approach. The circuit really isn't much different to what you would all be flying.


Why would you teach an airline procedure to a basic student not flying an airliner?
We're trying to teach skill sets from the beginning they will use throughout their career and introduce the concept of standard operating procedures. Of course this is adapted to the aeroplane and common sense applies. This allows us to, as Zoomy puts it:


...fly the bloody aircraft as per the POH and the DAY VFR syllabus not like the space shuttle.
As mentioned on a previous thread, if you have a real interest in wanting to know what is taught, don't post snide remarks - PM me. If the pilots in the white planes at YBAF are holding you up or doing silly things PM me - I'll speak to the pilots involved (it is part of my job to).

Slight thread drift, I read a post a couple of years ago by an instructor explaining how they teach landings. Every approach was basically a glide approach so the student would be able to land just in case he had an engine failure. Well, that's one way to tighten the circuit, but the student is in big trouble later in their career when it comes to flying a stablised approach with good aim point and speed control.

MCKES 17th Jan 2010 02:56

Ando I know your position and I respect your comments. But Zoomy is 100% correct in saying that a Cessna 172 Is not a space shuttle. Sure there is a small - very small percentage of your students that will go straight into an aircraft above 5700 but the majority wont. Fly a 172 how it is meant to be flown. :ok:

Cap'n Arrr 17th Jan 2010 03:18

My favourite was always:

"ABC request clearance to leave and re-enter the GAAP zone on downwind"

Tower: "Why do you need that?"

ABC: "Cause I'm going to need it if you want me to stay number 2 to XYZ ahead"

Tower: "Ahhh, XYZ tighten up your circuits mate":D

eocvictim 17th Jan 2010 03:51

Ando1bar, I can understand teaching a stabilised approach but at 318ft/nm (3deg) in a 172 at 1.57nm at 500ft thats a ROD of 344/min. That seems very shallow, surely it would be better to do the norm and aim for 1 at 500 and go down at 542. That is the essence of a stabilised approach, teach 3deg profile when its required during instrument approach.

I dunno, that's just my thoughts, I dont know the training organisations over all goals but from the outside seems a little arse about.

I think answering the above, with an unquoted explanation from the ops manual, will finally put a rest to this argument. This is now essentially all it has come down to, your final position.

edit/might as well be accurate.

Trent 972 17th Jan 2010 03:53

MCKES and eoc, I spoke a little while ago with the fellow who does a lot of the Qf interview sim checks and he said that he was disappointed with the majority of candidates inability to fly a 3 deg approach whilst maintaing an aim point, 'on' speed. He didn't care if they flew 172's or space shuttles.
Those 3 abilities are a must in Qf. Anyone who can't display that in the sim check has lessened their chances in a very competitive interview process. Ando has already pointed out the nm required to achieve a 3 degree path. There are a great many ways to fly a 172, but only one way will impress the interviewer. I think Ando is on the enlightened path, grasshopper.

eocvictim 17th Jan 2010 04:11

I was basing my figures before on a 172 app speed of 65 kts, I guess you could fly it faster or drag it in on the prop, either way is undesirable but as you said possible. I guess with minimal hours picking what the strip should look like at 3deg is pretty important. Though a couple of hours in a Hi-Po piston or basic turbine would solve this too.

Trent out of curriosity what is the ROD for 3deg in the 380 I'd imagine it'd be close to 716ft/min? I'm assuming its about 135kts? Too slow?

3deg is easy once you work out the key number is 318ft/nm. Did my head in before then... idiot.:ugh:

Trent 972 17th Jan 2010 04:28

Pretty spot on eoc. @ a normalish landing weight of 380 tonnes, ISA conditions = 141 knots. Which includes a 5 knot addition to Vls (velocity lowest selectable). RoD = 750fpm. I don't wish to tell anyone how to fly a 172 at all, just that if you want to get into Qantas, then you should probably consider this aspect. As Ando is obviously involved in an Airline Training School, he would be a fool to teach other than what the clients require.
As for the other CFI, cynical speaks of. He is obviously very good at what he does as well, but like I said earlier if you want to impress at a Qantas sim check..... Try diving at the runway in a Qf sim check and I'd bet that would be the last time you ever get to see inside a Qantas simulator.
The only other observation I've made is that the people who fly a stabilised approach (3 degree or whatever) make the transition to night circuits a lot better than those who are 'up and down like a brides nighty'.

Good luck to all (if that's what you want)

Veruka Salt 17th Jan 2010 04:35

QF circuits ...
 
Guys,

Not sure about the A380 as I haven't flown it, but have flown the 744 and 767 with QF, and A330/340 with another carrier and in all cases downwind is flown with approx 2.5nm spacing and a curved base leg. Doubt whether the A380 is any different.

Cheers,
VS.

Keg 17th Jan 2010 04:50

Veruka, 767 oval base? Really? The diagram I'm looking at, whilst not particularly clear, implies a 'square' base. Given the speeds on crosswind and the turn to downwind (as opposed to the speed coming across base and then F30 prior to the turn onto final, I'm not sure how you can fly an oval base unless using a very small angle of bank all the way around. Remember the old trick with the trend vector being a 1/3 of the way the final approach? You can't do that on an oval base.

I'll leave the discussion as to whether a C172 should be flown the same way to other people.

Veruka Salt 17th Jan 2010 04:56

Keg,

I know the 'base training' circuit diagram you refer to, however I never flew square base either on the line or in the sim.

20 deg AoB xwind turn (nil wind), adjust tracking on downwind, 15 deg AoB on base (initially), adjusted as necessary for headwind/tailwind. Airbus similar except more like 15 deg AoB xwind, 10 deg on base.

Definitely not a square base unless I'd stuffed it! :{

VS.

Trent 972 17th Jan 2010 04:59

Greetings Veruka, I haven't flown the 76, so I'll leave that to Keg, but I also have flown 330 and 744 and quoting from the 744 FCTM...

......Turning base leg, adjust thrust as required while descending at approximately 600-700fpm. Extend landing flaps prior to turning final.....
I guess I must be intepreting it differently.
*No probs Veruka. I only quoted that part of the text because it talks of a base turn and a turn to final, inferring a base leg, if you wish.
**Airbus A380 FCTM/Normal Operations/Visual Approach/Intermediate-Final Approach = Square Base Leg (diagram) Also A330 FCTM 02.140 square base...That pretty much covers 380/330/744 (in theory).

Veruka Salt 17th Jan 2010 05:05

Trent,

Not disagreeing with rates of descent or selecting landing flap etc .... rather, the only times I've ever flown a square base are when I'd used too large an AoB turning base, or had a strong headwind, or been too wide on downwind and not corrected it prior to turning base ....

Current teaching where I work now is to use constant bank all around base, particularly in poor vis (common in our part of the world).

VS.

MCKES 17th Jan 2010 05:35

If they want to see what the runway looks like when on slope just teach them to use the PAPI's or T-VASIS when they go into YBCG, YBMC, and all the other places. There they can see it, not when practicing circuits in busy airspace with varying performance aircraft in the same circuit including twins and high performance pistons.

Keg 17th Jan 2010 06:37

Veruka, fair enough. I've always used 20 degrees AoB and flown a square base leg. No one has ever chipped me for it.

Ando1Bar 17th Jan 2010 07:13


Ando1bar, I can understand teaching a stabilised approach but at 318ft/nm (3deg) in a 172 at 1.57nm at 500ft thats a ROD of 344/min. That seems very shallow, surely it would be better to do the norm and aim for 1 at 500 and go down at 542.
Agreed


Ando I know your position and I respect your comments. But Zoomy is 100% correct in saying that a Cessna 172 Is not a space shuttle. Sure there is a small - very small percentage of your students that will go straight into an aircraft above 5700 but the majority wont. Fly a 172 how it is meant to be flown.
Agreed also.

Which I why I have said in previous posts in this thread:


We're trying to teach skill sets from the beginning they will use throughout their career and introduce the concept of standard operating procedures. Of course this is adapted to the aeroplane and common sense applies.
We're not doing anything ground breaking in a C172. In fact someone flying our planes a page or two back posted an image of what is flown. I also mentioned:


Given the busy training environment we don't end up as far as 1.57 from the aim point turning final, more likely a bit over a mile. This still allows a good approach angle while maintaining a bit of power to control the speed. The aim of the game is to prevent a low power, fast, steep descent to land - if the student does this on their flight test they will fail.
Ecovictim, you asked:

I think answering the above, with an unquoted explanation from the ops manual, will finally put a rest to this argument. This is now essentially all it has come down to, your final position.
Here you go:



An approach is stabilized when the aircraft is:
a lined up with the landing runway
b established on 3° glidepath
c in the landing configuration at Vref +5 / - 0kts
d descending at less than 500fpm


eocvictim 17th Jan 2010 08:09

Thanks Ando1bar, clears it all up and should put a stop to it all. The ops manual wants it, then thats how you fly it.

Checkboard 17th Jan 2010 09:40


Also it is quite rare to fly a 'circuit' in an airliner, but it is a square base, just like the littlies. On the 380 it is a square base leg until .9nm xtrk deviation then turn final.
I would imagine it is quite rare to fly a circuit in a 380! ;)

In Ansett, based in Perth, we flew to 60 odd destinations throughout the north and west of Australia, and only three or four of them were ILS's. All of the rest were circuits. Three jet types, a lot of circuits, and not one of them had a square base (at least, not a planned one!). In Europe, on the odd occasion I fly a circuit, it is an oval base.


I read a post a couple of years ago by an instructor explaining how they teach landings. Every approach was basically a glide approach so the student would be able to land just in case he had an engine failure.
Silly idea, I agree. the aircraft eventually has to leave the circuit - that's why we teach PFL and Prec Search - the tiny amount of time in the circuit makes no difference. The only glide approaches I taught were to complete the PFL exercise (the bit below 500', where you introduce the skills for a glide touch-down)


Remember the old trick with the trend vector being a 1/3 of the way the final approach? You can't do that on an oval base.
Trend vector? Oh yeah - got one of those now. :}


......Turning base leg, adjust thrust as required while descending at approximately 600-700fpm. Extend landing flaps prior to turning final.....
Doesn't say or even imply that the base leg is square. A curved base occurs before final, just as a square base does.


An approach is stabilized when the aircraft is:
a lined up with the landing runway
b established on 3° glidepath
c in the landing configuration at Vref +5 / - 0kts
d descending at less than 500fpm
I don't know where that's from, but it isn't a very good definition. There are many approaches around the world which require greater than a 3º approach to the runway. :cool:

Back Seat Driver 17th Jan 2010 10:11

Checkboard said

In Ansett, based in Perth, we flew to 60 odd destinations throughout the north and west of Australia
60 I bet you couldn't name more than 40 of them. Unless we're talking the 1960's but then that wouldn't have been AN.
ps
All you blowhards who carry on about curved bases and other crap, are full of it.
Easiest picture I could find of a standard circuit is here
God help the poor newbies who listen to all this sooking about curved this and curved that. There are 5 legs to a standard circuit pattern and they are all straight and perpendicular to the previous leg. How you fly it is your business.

Ando1Bar 17th Jan 2010 11:01


Quote:
An approach is stabilized when the aircraft is:
a lined up with the landing runway
b established on 3° glidepath
c in the landing configuration at Vref +5 / - 0kts
d descending at less than 500fpm



I don't know where that's from, but it isn't a very good definition. There are many approaches around the world which require greater than a 3º approach to the runway.
It was from our ops manual, the question was raised where it said such an approach had to be flown.

Checkboard 17th Jan 2010 11:16

It was a guess, I admit. Hmmm ...

Perth, Kalgoorlie, Newman, Geraldton, Meekatharra, Cocos Is, Christmas Is, Bali, Barrow Is, Port Hedland, Argyle Mine, Karratha, Broome, Derby, Kununurra, Darwin, Gove, Groote Is, Weipa, Cairns, Hamilton Is, Townsville, Mt. Isa, Alice Springs, Ayers Rock, Sydney, Melbourne, Adelaide.

... Ok - not 60 :O

Still a lot of circuits, though. ;)


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