Statistically, when is a stall more likely to happen?

[old man emu]

Elsewhere we are discussing someone's dissertation on the how to instruct students about stalls.

 

I wandered off the track and as I recalled my stall training, I wondered if anyone had actually thought of what part of a flight was an airplane more at risk of stalling. I think the riskiest time is climb-out from the runway.

 

My training mostly involved power-off stalls. I suppose these were meant to replicate the Base turn/ Finals part of the flight. What scares me most is the possibility of stalling on climb-out after take off. Pretty much full power; raised nose, and a climbing turn. Yet I was never shown what happens when too much back-stick is applied at this stage.

 

I am probably wrong in what I do, but my technique is to monitor the airspeed and try to pin it at Best Climb. But how am I going to handle Best Rate, or Obstacle Clearance?

 

From Buddy Holley and the Big Bopper to now, how many take-offs have resulted in otherwise mechanically sound airplanes becoming scrap a couple of hundred yards off the end of a runway?

 

Old Man Emu

 

 

[Guest ozzie]

Initial climb out until a positive rate of climb is established and the base to finals turn. Always seem to find the burning wreck about 1/4 to 1/2 mile of either thresh hold.

 

 

[spacesailor]

Touch-down, Lots of bent Undercarriages, engine on tickover low airspeed, THEN pull back the joystick to flare, oooops a tad too high, air speed zero! wing not lifting, no control, to put nose down attitude. Drops like a brick.

 

spacesailor

 

 

[rgmwa]

Base to final turn seems to have the worst track record.

 

rgmwa

 

 

[DonRamsay]

When doing ab initio, I used to find downwind to base was a risk. In those early days very busy with downwind checks, slowing the aircraft getting some flap out radio call and turning to base. Easy to forget with all that going on to have a quick glance at the IAS. Turn onto final should be a non event. Have a look around and continue with descending turn.

 

 

[Downunder]

Late final. Max weight. A bit of head wind that drops off.......numbers can get mighty close to a stall in a high drag aircraft very quickly.

 

I don't see climb or takeoff as a problem......

 

 

[Guest Howard Hughes]

Anytime you are at low level and low speed and get distracted from the task at hand.

 

 

[Jabiru Phil]

On late downwind, speed, flaps, check list.

 

Then full concentration can be given to radio calls, speed and altitude.

 

Full attention is the only way to stop a stall using this criteria. IMHO.

 

Phil

 

 

[Yenn]

The question was when "statisticly" it was most likely to happen.

 

I doubt that there are statistics for stalling, only when the stall has caused an incident.

 

That seems to be mostly in the base, final stages of a circuit, but I bet there are alot of takeoff stalls out there.

 

Really it doesn't matter much unless you are close to the ground.

 

 

[Marty_d]

Statistically, probably just as the main wheels touch the runway. (Yeah I know I'm a smartass...)

 

 

[rgmwa]

Statistically, probably just as the main wheels touch the runway. (Yeah I know I'm a smartass...)

Would that be the first, second or third touch, Marty? Just curious.

 

rgmwa

 

 

[Guest Howard Hughes]

This probably answers your question, NTSB press conference regarding Phenom 100 crash in Maryland yesterday. Pilots qualifications and experience at 5' 30" makes for very interesting listening.

 

 

 

[Ultralights]

One thing i have seen spending time with an Aerobatic flying school, that hours in the air account for zip most of the time... we have seen 10,000 Hour airline pilots fail to recognise stalls, and really struggle to grasp advanced manoeuvres, yet low time PPL's pick it up real quick and can win aerobatic competitions with only a few hundred hours. or in some cases, before they even finish their PPL.

 

even the worlds highest time B747 captain admits himself, from his book, he doesnt have 30,000Hours flying experience, he has the same hour, 30,000 times.

 

Its the High time pilots that come in looking to do an aerobatic endorsement, bragging that this will be easy as they have so many 1000 hours in whatever, are the ones who make the biggest mistakes.

 

as for the question, When is a stall more likely to happen? the correct answer should be.... "when i make it happen"

 

 

[Marty_d]

Would that be the first, second or third touch, Marty? Just curious.rgmwa

Everyone aspires to make it the first, but in my case, probably the tenth!

 

 

[rgmwa]

Everyone aspires to make it the first, but in my case, probably the tenth!

Sounds like my landings, but I blame it on the speedhumps in the runway.

 

rgmwa

 

 

[Guest ozzie]

Most of the high time jet jocks have a hard time keeping a C150 straight on take off.

 

 

[old man emu]

Base to final turn seems to have the worst track record. rgmwa

I've been pondering this opinion all day. I can't argue whether the statistics show if it is right or wrong, but I'm truly baffled as to how an airplane on a descending flight path and turning into wind can stall. (I'm assuming here that the turn is relatively gentle - not a pirouette around a wingtip.) What better situation is there - low AoA; fairly constant airflow. The only reason I can see for a stall in this phase of the flight is the pilot trying to correct an undershoot with the elevator [ raising the nose and increasing AoA] and not the throttle [halting the rate of descent with Power until the airplane intersects the correct descent path].

 

Old Man Emu

 

 

[motzartmerv]

OME.

 

I think you need to look a little deeper into the relationship between speed and angle of attack.

 

The reason the stall turning final (or base ) is so prevalent in the stats is for a couple of reasons.

 

Not least of these is the basic fact of aerodynamics that a'low speed can be associated with a high angle of attack'

 

In the cruise you have the aeroplane flying with a low angle of attack (generally) When you start to slow down for your approcah, you MUSt increase angle of attack to produce the extra lift needed.

 

As your speed is reduced, angle of attack MUSt be increased to keep the aeroplane flying. So while it feels rather docile and safe, the true indicator , as always, is WHERE IS THE STICK, or the control column.

 

Take note next time your on approach, you will have the stick much further back then at any other phase of the flight. This is why the turn is so deadly.

 

If you are ALREADY close to the stalling angle (stick position) and you roll on bank and come back FURTHER on the stick (as you do in a turn) you can put the angle of attack through the stalling angle. Your nose may be down, below the horizon, easily. No worries, it doesnt have to be high to stall, thats one idea I cant stress enough.

 

 

[corvairkr]

I've been pondering this opinion all day. I can't argue whether the statistics show if it is right or wrong, but I'm truly baffled as to how an airplane on a descending flight path and turning into wind can stall. (I'm assuming here that the turn is relatively gentle - not a pirouette around a wingtip.) What better situation is there - low AoA; fairly constant airflow. The only reason I can see for a stall in this phase of the flight is the pilot trying to correct an undershoot with the elevator [ raising the nose and increasing AoA] and not the throttle [halting the rate of descent with Power until the airplane intersects the correct descent path].Old Man Emu

Check this video out OME I watch it often and it reinforces the need to keep coordinated and watch your angle of attack

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

 

Jason

 

 

[rgmwa]

I've been pondering this opinion all day. I can't argue whether the statistics show if it is right or wrong, but I'm truly baffled as to how an airplane on a descending flight path and turning into wind can stall. (I'm assuming here that the turn is relatively gentle - not a pirouette around a wingtip.) What better situation is there - low AoA; fairly constant airflow. The only reason I can see for a stall in this phase of the flight is the pilot trying to correct an undershoot with the elevator [ raising the nose and increasing AoA] and not the throttle [halting the rate of descent with Power until the airplane intersects the correct descent path].Old Man Emu

No problem if speed is OK and the turn is balanced. It only becomes a problem if the turn is misjudged and efforts to get back on track result in an unintentional slip or skid and attitude change that causes a wing to stall at too low an altitude to recover before you hit the ground.

 

rgmwa

 

 

[motzartmerv]

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

 

 

[rgmwa]

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

Yes, you're right Motz. I didn't explain it too well. I probably should have said that trying to correct the attitude in a misjudged turn by pulling back on the stick and consequently increasing the angle of attack is what causes the stall.

rgmwa

 

 

[facthunter]

Stick position is a useful concept. It's not universal. Where you have a trim adjustable horizontal stabiliser, the stick (hands off )stays in the mid position when trimmed out at any speed and configuration.

 

Having a rearward C of G can mask stick position being an absolute indicator of likelihood of stall. It's also variable with configuration and C of G position. But STALL stick position IS a very useful concept.

 

However one thing is true. Generally , (nearly ALWAYS)the pilot stalls the plane. A lot of the normal trained reactions lead him/her to pull the stick back if in strife. It becomes a natural reaction.

 

The way we teach stalls is deficient. We set up the plane in steady level flight and close the throttle and maintain height with slow and steady back stick till eventually the plane shakes a bit and the nose drops, at a low indicated speed WOW I've just stalled and I didn't die.. Piece of cake that. Got stalls signed off now..

 

Do we teach stalls (and recovery) in steep turns? NO. There are reasons for that. Our aircraft are not designed for it.

 

Does that mean we will never stall a plane in a steep turn.. NO, it doesn't..

 

Slip or skid will ensure the stall is assymetric. ie One wing stalls before the other. It may even flick over on it's back if you pull the stick back rapidly, and this will complicate your day if you don't know how to deal with it.. If you know how to deal with it, perhaps you won't EVER get into the position? Perhaps not. You know, familiarity and overconfidence.?

 

Distraction is a factor, and it's happened to experienced pilots as well as ab initio. The lower your altitude the more serious a stall event is. SOMEONE, MUST be FLYING the plane regardless of the apparent distractions /LOAD.

 

I don't know where the stats indicate but I believe turning onto final, if you run through centre line and pull the turn tighter and apply a bit of bottom rudder, It's all set to happen for you.

 

Engine failure on initial climb and turn back under pressure, often results in the aircraft stalling and going out of control. The primary need is to maintain control. Nev

 

 

[motzartmerv]

Where you have a trim adjustable horizontal stabiliser, the stick (hands off )stays in the mid position when trimmed out at any speed and configuration.

Not many RAA aircraft have this design feature. I know the 73 has this, but it also has a stick shaker!

 

 

[facthunter]

I think the Pacers might have it, and it was on some STOL thing which was RAAus registered, that I had a bit to do with years ago... With U/L' s a lot of hi tech features can appear, out of the blue. SOME instructors don't go with the stall/stick relationship concept, and I'm not sure why..\

 

I'm with YOU on it, Merv, BUT you know how careful you have to be HERE or you get shot down in flames Nev.