Stalls, and turning.

[corvairkr]

I see many pilots and students looking inside the turn, chasing the runway onto final- in doing so they fail to maintain a constant bank angle, tightening up the turn as you say, or skid it with rudder or lose the correct horizon reference attitude(airspeed) any one of these will contribute to bringing you closer to the stall; and clearly at a very dangerous point in the circuit!Correct turning vigilence is one of my hobby horses, and "dirty" unco-ordinated turns show poor piloting. This may be a contributor IMHO.

The turn will finish when it finishes- forcing it can be fatal.

These points above are exactly what was drummed into me..

I also have this video saved on the computer which i often watch

 

https://www.youtube.com/watch?v=xwrfEsCiltc

 

jason

 

 

[coljones]

That sounds like a recipe for disaster, how on earth are they allowed to do that ?

Today I flew at YSBK. One part of the fight was departure and arrivals on 29R using 132.8 and later crossing over to circuits on 29L on 123.6. 29Centre was also in operation. The radio traffic was quite heavy and I had to abort my approach on arrival at the reporting point as I was getting too close to the CTR without clearance as I could not get a break in radio traffic (maybe I am too timid). Without separate frequencies for circuits and departures/arrivals it would have been a total schmozzle. In this case strict adherence to approach and departure heights and tracking alignment is essential so that traffic at YSBK can be optimised (for our enjoyment and sanity) and for the sanity of ATC people.

 

 

[M61A1]

I think that what Tomo was trying to point out was, as also a point of the Brandon notes, the increase of wing loading in a tighter turn, increase of AoA and stall speed. From memory, a 30deg increase Vs to 1.07, but tighten that turn up to 60deg(for whatever reason) and Vs is now 1.41. So if you're on approach at 1.3 Vs, things just got ugly because you forgot you needed some more airspeed up your sleeve to do that. It's all we and good to talk about AoA being the deciding factor (and it is) but how many of our aircraft have an AoA indicator? Who doesn't have an ASI?

 

In short, if you want to tighten your turn, best have some more airspeed, if you can't get the airspeed, you can't afford to tighten that turn(assuming you're fond of living).

 

 

[nong]

I was going to ask a question some time ago but couldn't find a relavant thread to ask it in.In relation to tommos numbers about angle of bank in a turn and incresed stall speed, is a wing level skidding turn a

real option (ie no increase in stall speed)? i bear in mind the recipe for spin = stalled + yawing so this would be one problem with my idea.

You don't seem to be getting the answer to your quite reasonable question, so here goes.

A flat turn with wings level is pretty do-able and aerobatic pilots muck around with unco-ordinated stuff of this ilk quite frequently. Do it up high if you want to play.

 

Considerations.... 1) You or your passenger might be flung overboard if not strapped in. This is a major risk, aircraft doors are too flimsy to be an effective secondary restraint. Passengers sometimes quietly undo their belts.

 

2) It will likely be perceived as feeling bloody 'orrible, like taking a bend in a car. The load is no longer vertical through your spine.

 

3) Fuselage and vertical tail structures are not neccessarily up to the job. An Airbus lost its vertical surfaces and crashed disasterously because the pilots used the rudder aggressively at LOW speed. Bloody amazing. So much for certification. What are you flying?

 

4) If you use the unco turn technique during any turn near the ground you are taking an increased risk because the angle of attack is almost certainly high because of the modest airspeed. You may think that the flat turn enables a lesser angle of attack.....good theory....but there is likely some wing blanketing happening. This reduces total lift and will have to be made up by, you guessed it, increasing the angle of attack!

 

5) If you stall near the ground with the controls crossed for a flat turn..... you're gone, man. No way will you catch it. It will flick inverted to the inside of the turn so fast it will catch your breath, your last one, in fact.

 

 

[M61A1]

3) Fuselage and vertical tail structures are not neccessarily up to the job. An Airbus lost its vertical surfaces and crashed disasterously because the pilots used the rudder aggressively at LOW speed. Bloody amazing. So much for certification. What are you flying?

For the record, the Airbus with the vertical stabiliser failure, was due to a series of large, rapid rudder inputs and reversals causing (if I understand correctly) resonance and snapping it off.

[Gnarly Gnu]

In short, if you want to tighten your turn, best have some more airspeed, if you can't get the airspeed, you can't afford to tighten that turn(assuming you're fond of living).

Unless you unload the wing right? (not applicable at 100 feet of course)

 

 

[M61A1]

Unless you unload the wing right? (not applicable at 100 feet of course)

Can't unload the wing AND tighten the turn.

 

 

[ben87r]

That sounds like a recipe for disaster, how on earth are they allowed to do that ?

Gunersy beat me to the point about the parallel ops but, it works fine. For instance f 03 is in use 03L on 118.7 is for departures and 03R124.6 is for circuits. So it is quite important to make sure your on cl on approach and it has all been drilled into us NOT to use more then 30* of bank onto final and if it was needed its to be an unstable approach.

 

 

[Gnarly Gnu]

Can't unload the wing AND tighten the turn.

Why, what are you flying? Seems to work in a Jab (good EMT practise). But maybe I am misunderstanding you?

 

 

[M61A1]

Why, what are you flying? Seems to work in a Jab (good EMT practise). But maybe I am misunderstanding you?

I think we are misunderstanding. Increasing bank angle, which is necessary to tighten the turn, will increase wing loading. To unload the wing, bank angle needs to decrease (less bank & less backstick) which will open up your turn.

 

 

[boingk]

...while maintaining level flight.

 

- boingk

 

 

[M61A1]

...while maintaining level flight.- boingk

I though that this whole thread was in regard to stalling on the base turn to final.

 

 

[boingk]

True. But if you initiate a descent and increase the bank then you can technically unload the wing. Most of the G and other flight figures people have been quoting for the entire thread are based on level flight.

 

Personally, I stand by just flying ahead of yourself - forsee problems before they happen and avoid them where possible. Where not possible, take actions to negate and danger.

 

In a teacup... don't f*** up.

 

- boingk

 

 

[Gnarly Gnu]

Yeah, no problem doing a 60 - 75 degree power off banked turn in a Jab at slow speed M61A1, just have to unload the wing or it won't work. For anyone reading don't practise this at low level!

 

 

[rtfm]

forsee problems before they happen and avoid them where possible. Where not possible, take actions to negate and danger.

But that's exactly the point... IF the unexpected and potentially catestrophic happens, WHAT ARE YOU TO DO?

Duncan

 

 

[M61A1]

Yeah, no problem doing a 60 - 75 degree power off banked turn in a Jab at slow speed M61A1, just have to unload the wing or it won't work. For anyone reading don't practise this at low level!

Could someone explain the physics of this please.

 

 

[dazza 38]

Dont make things to complicated. Peeps, just make gentle turns when low to the ground and make balance turns with rudder and don't pull the stick back to tighten the turn. Feel what the aircraft is telling you.

 

 

[Billzilla]

It's all we and good to talk about AoA being the deciding factor (and it is) but how many of our aircraft have an AoA indicator?

FWIW the Citation 2 I used to fly had one and it was brilliant. I used to fly it back in the 90's mainly on freight runs and after takeoff at V2 + 10 kts we got 0.6 on the AoA meter. if we had 0.61 that meant the loaders had given us a bit more than they showed on the manifest. ;)

 

You could also fly a surprisingly accurate approach with it and not look at the ASI at all.

 

 

[M61A1]

Dont make things to complicated. Peeps, just make gentle turns when low to the ground and make balance turns with rudder and don't pull the stick back to tighten the turn. Feel what the aircraft is telling you.

I certainly agree with "feel what the aircraft is telling you", as for "don't complicate things", I've just been told that someone can do something I thought not possible, I want to know how.

 

 

[turboplanner]

BS flows freely on forums.

 

I just looked up my Jab notes for safe operations in a circuit - which I was expected to be able to demonstrate.

 

Turning crosswind after climbout - 15 degrees

 

Turning from crosswind to downwind - 30 degrees

 

Turning from downwind to base - 30 degrees

 

Turning from base to final - 30 degrees

 

Do that and you'll have a good safe margin

 

Training for steep turns (45 degrees) was conducted above 3000 feet in GA, and there was no training for or suggestion of more than that. Even steep descending turn training was at 45 degrees.

 

At 60 degrees in the circuit the AOB is 100% above what it should be and you're very close to a spin or spiral dive and if your recency is the same as most, you'll be lucky to pick it up after the slightest lapse in concentration or gust of wind.

 

The risk factor of a spin is exponential according to Angle of Bank, so by conduction the turns at 30%, your risk factor is not just half, but a fraction of half.

 

 

[turboplanner]

I tried to post a link to the above post in the thread http://www.recreationalflying.com/threads/fatal-incident-at-parafield.59915/, for Compulsion but it's been locked. Why we do this when there are lessons to be learnt I'll never know.

 

Compulsion, I had the feeling you were questioning your own safety in your own aircraft, and the post above should give you some considerable reassurance of the huge safety margin you have if you follow safe circuit practice with 15/30 degree turns as against 60 degrees.

 

I would be stunned to find any RA/GA instructor departing from these standards, but there are dozens of public reports which tell be it could be going on.

 

 

[dazza 38]

BS flows freely on forums.I just looked up my Jab notes for safe operations in a circuit - which I was expected to be able to demonstrate.

 

Turning crosswind after climbout - 15 degrees

 

Turning from crosswind to downwind - 30 degrees

 

Turning from downwind to base - 30 degrees

 

Turning from base to final - 30 degrees

 

Do that and you'll have a good safe margin

 

Training for steep turns (45 degrees) was conducted above 3000 feet in GA, and there was no training for or suggestion of more than that. Even steep descending turn training was at 45 degrees.

 

At 60 degrees in the circuit the AOB is 100% above what it should be and you're very close to a spin or spiral dive and if your recency is the same as most, you'll be lucky to pick it up after the slightest lapse in concentration or gust of wind.

 

The risk factor of a spin is exponential according to Angle of Bank, so by conduction the turns at 30%, your risk factor is not just half, but a fraction of half.

I agree Turbo, I don't think I have ever gone passed 30 degrees bank at circuit height or at low level. No need for it.When I want to have fun & do steep turns, I always do them with plenty of height.

 

 

[M61A1]

I had a BFR some years ago now, where, while in the circuit, the instructor pulled the power, roughly level with the downwind threshold on the downwind leg. I was wondering where he intended me to go, because I figured that there was no way I would get back to the strip, he then reminded me that as long as I have xx kts airspeed, I can bank up to 60deg, so get the nose down even further. This allowed me to carry out a tight dogleg between large gum trees, which put me back on the strip downwind (a low wind day too), rounding out as I levelled the wings. At best glide speed I would have had no hope.

 

In short, I think training and refreshing such procedures are helpful, so that in an emergency ( I have had it happen for real), the situation is not unfamiliar, and because it is familiar, you will recognise when things aren't right.

 

 

[turboplanner]

I suppose we are trained at the base level as recreational or occasional flyers.

 

For what you just referred to relating to 60 deg. there are calculations - charts of them giving the various combinations.

 

So if you were going on to an environment where there would be a copilot and time, then that knowledge could come in handy at some time in the future.

 

I notice you didn't quote the speed, and that's that's achilles heel of getting too complicated too soon in a profession. At our level as non professionals we never achieve the recency levels to remember all those minute details or put them into use. The problem comes when someone is in an emergency, and pulls the angle on, forgetting the essential proviso and dumps a perfectly good aircraft nose first into the ground when he may have survives with a few dents.

 

 

[M61A1]

The problem comes when someone is in an emergency, and pulls the angle on, forgetting the essential proviso and dumps a perfectly good aircraft nose first into the ground when he may have survives with a few dents.

That's why I think learning it in the first place then refreshing/praticing is a good thing. Make it instinctive.I didn't quote the speed because it is aircraft and weight specific. With the lighter aircraft I fly though, I think that you can afford to use your MTOW numbers when considering such events. I'd rather carry a little excess speed on the landing roll than not enough in the turn.