Statistically, when is a stall more likely to happen?

[motzartmerv]

Yes, I understand. I worry when I read things like

 

What better situation is there - low AoA; fairly constant airflow.

When talking about an approach.

 

Its a common misconception that the angle of attack is low because the nose is down on the approach. Thats why I like the stick position emphasis.

 

 

[old man emu]

This is why I'm an emu and you are an eagle.

 

I've always felt very comfortable on the Base to Final part of the flight. I scare myself on climb out and turn to crosswind.

 

OME

 

 

[nong]

Looking at a range of stall accidents on youtube.com , it is a true STATISTIC that the most likely time for a stall to happen ( of the youtube sample) is when the elevator is positioned so as to make the wing stall.

 

In each case I viewed, it was a positive G stall with excess nose up elevator for the particular flight situation.

 

Some samples:

 

GLIGER PILOT turning final at dot feet and not having an appreciation of his situation, namely a 20kt tail component for landing. Pilot confuses ground speed with airspeed and fails to note clue offered by stick position.

 

BAD PLANNING/lack of pre-start assessment of a paddock take-off that appears to involve quite limited field length with obstackles to be cleared. This situation required the thinking to be done BEFORE getting into the aircraft. Instead, the pilot gives her the gun. Soon the elevator bites and the balance horn digs dirt! Then she flies...one wing drops, then a quick roll back the other way as the other one quits. Luckily, wing digs into ground and flight terminated. Full up elevator from go to whoa. Contributing factor: stress caused by airstrip limitations.

 

TWIN on short strip. Shortly into the take-off roll, pilot pulls in full nose up elevator. At lift-off only one wing flies and the other drags along ground until its over. Elevator position remains full nose up throughout. Causes: as per the previous accident.

 

It is clear to me that stall accidents arise when pilots, for whatever reason, fail to appreciate and keep track of the actual circumstances of their flight.

 

As a result of this failure, they sometimes get squeezed into a tight corner.

 

At this point they crash or not. What makes the difference?

 

STICK DISCIPLINE. Some people tough out or abandon (if possible) a tight situation whilst refusing to bring the stick back too far, often using indicators such as buffet.

 

OTHERS just go GA GA and haul on the stick.

 

 

[facthunter]

OME. How you feel is not enough. Try some steep gliding turns in a "draggy" aeroplane (with an instructor, and in a suitable plane) and you would be surprised how much nose down pitch you need to hold a safe airspeed. The safe airspeed has to be increased significantly from the lower bank angle turn, because your wings are dynamically loaded and have to provide much extra lift, so there is lots more drag to overcome. You will feel the "G" and the stick position for the stall will be the same, because (as we all know) stall is when we reach an angle with the relative airflow. The nose may be 25 degrees or more below the horizon and the speed still not enough to avoid stalling.. Nev

 

 

[ben87r]

Low, slow approach, overshoot the final turn and increase AOB is the recipe. Happen to be out of balance as well? That's not the recipe for a very interesting day

 

 

[motzartmerv]

Holding off bank in the final turn has killed more pilots than the spitfire!!!

 

 

[ayavner]

Probably a dumb question:

 

I think I understand the concept of the 'stick position' as relates to stalling, but would that translate to a particular 'yoke position' for those planes which have a yoke? if so, might be beneficial to take a red sharpie and draw a little line on the shaft as it reaches that point or a bit before?

 

**disclaimer: please no beard tearing about whether or not it would be dangerous to attempt to draw a line on my yoke while in a stall. i know. really, i do.

 

 

[motzartmerv]

Not only are you correct, it is something that lots of people do!!

 

An old 172 I used to fly would stall when the hole in the yoke pole, lined up with the hole for the control lock.., Was easy to see it coming.

 

I wont comment on my Instruictors trick of making it stall and putting the control lock IN to demonstrate how rudder instead of aileron was used..lol..Braver man then me!!

 

 

[ayavner]

cool, thanks that is good to know. One thing i did before my test was I had a good idea of how the instructor's yoke lined up wtih a particular spot on the door out of the corner of my eye. not completely scientific, but did help in seeing it coming.

 

would a piece of red pinstripe tape be a bad thing, or is the clearance through the hole such that it is likely to come off and gum up the works?

 

 

[facthunter]

Motz he's dumber than you ( I hope ) for your sake. I always thought the 172 needed ALL the back stick to stall it (including lifting the yoke to get all of it) if there is no one in the rear seat. Pretty docile plane. ( But not foolproof as fools constantly prove). Nev

 

 

[motzartmerv]

Yea, im pretty dumb sometimes. But im not the dumbest.

 

 

[facthunter]

The smart little animals don't get eaten. That strict liability law is onerous and we shouldn't have to operate under it. You have to operate your plane in the least hazardous manner if it comes to a decision. You MUST operate that way for your own sanity, as nothing else makes sense at all.. Rules are written as far as they go, to regulate behaviour, but often the court or some enquiry, will decide. It is worth considering how your action would stand up to being questioned by experts in a court situation, when you make the decision to go, if it is at all questionable as to it's legality...Nev

 

 

[Yenn]

Motza said. Skidding wont cause a stall. The ONLY reason its stalling, is because the stick is TOO FAR BACK.

 

You are beginning to sound like proffessor avius. It is possible to stall a plane without the stick being too far back. I know it is not common, but it has happened.

 

 

[Happyflyer]

Motza said. Skidding wont cause a stall. The ONLY reason its stalling, is because the stick is TOO FAR BACK.You are beginning to sound like proffessor avius. It is possible to stall a plane without the stick being too far back. I know it is not common, but it has happened.

Like C of G too far back, icing on the wings, trim too far back. But you can recover most of these by pushing the stick forward. So it must have been too far back in the first place!

 

 

[Bruce Robbins]

Hi Happy Flyer,

 

I can understand the icing, but how does C of G and trim affect the stall AofA ?

 

Or are you just referring to the stick position?

 

Regards, Bruce

 

 

[Roundsounds]

OME - I acknowledge this thread is asking about stat's on the most likely phase of flight to encounter a stall, however a stall could occur in any phase should the pilot allow it. Your best defence is to receive thorough training in the recognition of an impending stall and recovery at that stage. I am fortunate enough to instruct both RA-Aus and GA and often have the opportunity to train relatively high time pilots. I make a habit of reviewing their logbook before flying with them and often encounter people who's total stall training consists of a single flight of less than one hour. This is usually reflected in their ability to recover from a stall during the type training I do with them, conversely the pilots who have multiple stalling exercises during their initial training are usually quite competent in stall recovery. If you haven't received the proper instruction then please do yourself a favour and seek it. It would be difficult for pilots to judge whether their slow flight / stall recovery training was to a suitable standard, as a guide I have pasted an extract from the Flight Instructor's Manual below. If you don't t feel your training followed these guidelines, or you feel under confident, please do something about it. Stall awareness and ability to recover should be a skill equal to / better than to any other phase of flight.

 

09

 

STALLING AIM

 

To teach the student the feel and behaviour of the aeroplane at low speeds, the symptoms of the stall and how to recover with the minimum loss of height. INSTRUCTIONAL GUIDE

 

It should be emphasized that an inadvertent stall should never occur. The student must become proficient at recognizing the approach to the stall and taking immediate action to prevent it occurring. Although the student must be taught some method of entering the stall, it is emphasized that the method of entry is only incidental to the important task of recognizing the warnings of the impeding stall and the recovery from the developed stall. Even if the particular aeroplane normally does not ‘drop a wing’ during the stall the correct stall recovery technique should be taught from the start. The first demonstration of a stall should show the student that it is not in any way a frightening experience and should rid the pupil of any false ideas of danger and violent sensations. The first stall is best done at the end of the lesson preceding that on which stalling is to be dealt with in detail. Whilst no real instruction should be given during this demonstration, it is advisable to indicate the point of stall and the commencement of recovery. Obviously all the points raised cannot be taught during one flight but must be spread over several. Especially in the early stages watch for symptoms of air sickness and discontinue the exercise if necessary.

 

As you might have gathered, this is a bit of a pet subject of mine!

 

The CASA Flight Instructors Manual (available as a download from the CASA website) was developed from the RAAF WWII publication AP1732a. This manual was used in training pilots in high drag/low inertia aircraft like the Tiger Moth - so has relevance to RA-Aus types.

 

 

[Happyflyer]

Bruce, I was just referring to stick postiton that Yenn had brought up. Stalling angle should stay the same for the C of G and trim problems .

 

 

[Bruce Robbins]

Bruce, I was just referring to stick postiton that Yenn had brought up. Stalling angle should stay the same for the C of G and trim problems .

OK, thanks.

 

Lucky I checked before preaching to the converted.

 

 

[sfGnome]

During my last BFR, I took advantage of having a CFI on board and spent some time doing power-on, climbing, slipping stalls and power-on, climbing, skidding stalls. Apart from being lots of fun (with an instructor!!), it also clarified and confirmed lots of stuff I'd read about how the plane - and the pilot - should react.

 

 

[dutchroll]

Not only are you correct, it is something that lots of people do!!I wont comment on my Instruictors trick of making it stall and putting the control lock IN to demonstrate how rudder instead of aileron was used..lol..Braver man then me!!

I will. I think that's possibly up there with the poorest examples of instructional technique I've ever heard of.

He's not braver than you. Using bad instructional technique when demonstrating flight regimes involving partial or complete loss of control killed 3 pilot friends of mine in a single blow when they plunged 5000 ft into the ocean some years back. The mistake was only made once. You can't make it again when you're dead, but going to 3 funerals in a week was rather stressful.

 

 

[facthunter]

Putting a control lock in during flight is not really on. I recall a case of a DCA examiner switching the engine off but the keys came out and went on the floor somewhere. A Viscount went in flying below VMC(a) at Mangalore. Military DC 3's used to lift off below a speed where rudder control was sufficient to keep it straight if one engine went dead.. There are cases of aircraft taking of with gust locks engaged. You would have to wonder how this can happen but it's usually fatal. Nev

 

 

[motzartmerv]

Yea is not a technique I will be using.

 

I like to do jammed control training with pilots, but I simulate it by holding them myself.

 

 

[poteroo]

Putting a control lock in during flight is not really on. I recall a case of a DCA examiner switching the engine off but the keys came out and went on the floor somewhere. A Viscount went in flying below VMC(a) at Mangalore. Military DC 3's used to lift off below a speed where rudder control was sufficient to keep it straight if one engine went dead.. There are cases of aircraft taking of with gust locks engaged. You would have to wonder how this can happen but it's usually fatal. Nev

Agree with Nev here - but we're all human, and sometimes the situations can over-ride our training.

 

I do remember a G3 instructor taking off, (at an international airport complete with Tower), with a 'non-approved' control lock, (a bent nail), still in a C182. He successfully used power and trim to reland the 182 and only after shutting down did he discover the control 'lock'. Needless to say, he had his ticket lifted immediately and I never heard of him again. At worst - he lived to fly again.

 

The 2nd, and sadder story, was about a charter flight in a Baron to a country airport in WA. The pax returned very late,and the pilot,angry and apprehensive, prepared the Baron for takeoff in the dark. Now the Barons normally had the plastic throttle 'locks' connected to wires which threaded through a control column locking pin. Both had to be removed together. Unfortunately, in this Baron, the wires were not connected to the column lock pin - so both needed to be removed separately. In his haste, the pilot left the control lock pin still in place - started up the already pre-runup engines - rolled straight out onto the runway - and took off. The aircraft struck the ground a mile or so off the end of the runway and killed all 5 on board. This incident was featured in the old Aviation Safety Digest.

 

There are several points in the pre-takeoff procedures where a pilot should realise the control locks are still in. The best time is to remove, and stow, them as part of the pre-startup checks.

 

 

[BoxFat]

I have to wonder what happened to the ingrained habits in a case like the one which you relate with the Baron Poteroo. More specifically, that last check of "things that could kill me" just before lining up or opening the throttle e.g. Controls full and free, fuel on, trim set, engine instruments in the green canopy locked. Easy to miss something in a rush or when distracted during the prep, less so in that last quiet moment before "go". I wonder if the pax or radio was jabbering just then ?

 

With short term memory getting poorer with age (as it almost invariably does) I'm doing two things to try and keep myself safe in that phase of flight (a) back to printed checklists (b) putting a last item on the pre-take off list which is"clear the mind and wait 10 seconds, no matter what" before launching. On several occasions that has given my subconscious a chance to get a word in about something it has been screaming about for the last 5 mins without being heard. It can spook the pax if one closes the eyes and gives all zen Buddhist like but it's worth it.

 

Cheers

 

BF

 

 

[motzartmerv]

I think there's a reg that says you HAvE to check the controls for free correct movement immediatly before flight.