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because they do. if you catch a stall, just as it is occurring, with a goodly burst of thrust from a propeller you will pull forward out of the stall. Stall is about Angle of Attack, not speed. You can be a 10 knots (top of a loop) and not be stalled or 150 kts and be stalled (flick roll). |
a goodly burst of thrust from a propeller you will pull forward out of the stall Dr :8 |
Yep, FTDK and Old Acro,:ok:
It really shows how easy basic flying is!:E Some of the crap written here makes you wonder how some guys get from A to B without "plummeting" to Earth!:rolleyes: |
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if you catch a stall, just as it is occurring, with a goodly burst of thrust from a propeller you will pull forward out of the stall. This "Goodly Burst of Power" you speak of will more than likely result in a wing drop stall. The increased A of A on one wing due to the increased prop wash on it's own could cause a wingdrop, and if that doesn't induce a wing drop, the yaw from the increased slip stream probably will, as most pilots won't add sufficient rudder input to stop the yaw. |
I've seen a fairly benign stall turn in to a spin because a student applies power while holding the stick back on the stops. Most aeroplanes have a pitch up tendency associated with applying power, amplified by low airspeed and flaps, this can create a much deeper stall than a power off clean stall.
Anyone who says a stall recovery can be achieved with zero height loss has little appreciation for flight on the arse end of the drag curve! |
Quote:
if you catch a stall, just as it is occurring, with a goodly burst of thrust from a propeller you will pull forward out of the stall. Only if you push the stick forward first to fix the angle of attack...... |
because they do. if you catch a stall, just as it is occurring, with a goodly burst of thrust from a propeller you will pull forward out of the stall.
An interesting and novel thought .. Before you kill yourself one of these days .. you might like to read up on certification requirements .. CAM 3, FAA Order 8110-7 (if you can find a copy - if you do, please let me know what URL you visited to achieve that) or AC 23-8/8A/8B/8C should cover most of the aeroplanes you are likely to fly ... As an alternative to killing yourself (although that may still occur sequentially) you might pick up some experience of spins - erect or inverted as the particular aeroplane prefers to exhibit. For aeroplanes with larger engines, as Nomde plume observes, the normal prop force can give you a distinct lack of control over a rearing beast ... some aircraft require SAS to address this problem for the missed approach. Prior to the stall .. the power trick might be useful .. it was great fun powering out on the Electra at light weights ... And so it goes on ... doesn't anyone value conservatism these days ? |
john ....concentrate.
the subject is stalling a Cessna 172 at low level. my examples are from flying and observing aircraft in a similar league to the 172. ie light aeroplanes. your examples are way out of the scenario envisaged. in my Tailwind (lighter than a 172) you will immediately start flying again if power is applied right at the point of stall. ...but obviously not after the nose has dropped. |
john ....concentrate
Hopefully, even in my dotage .. I still can do that at least some of the time ... The references apply to certificated lighties ... the Electra is filed away in my memory archives .. wonderful time of my life. For the amateur builts etc., some can be considerably worse and the Regulator's TP/FTE have, over the years, spent much effort in endeavouring to convince folks out there busily building birds to emulate FAR 23 as a desirable goal .. your examples are way out of the scenario envisaged I suggest not ... the concerns are VERY real and well known to the flight test community. My only recollection of the Tailwind is from a flight with Peter Furlong about a million years ago .. he came along so I didn't kill myself ... does yours fly quite nicely with a huge yaw angle ? Quite interesting, I thought, at the time ... |
Most aeroplanes have a pitch up tendency associated with applying power, amplified by low airspeed and flaps, this can create a much deeper stall than a power off clean stall. |
Cuz, do you know anything about the RV10 with the pod?? It looks **** but haven't seen it before?
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And it probably stalls bad!
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Relative airflow
One 'stall' element, often poorly understood. Particularly when discussing the 'tail' being stalled rather than the 'mains'. Anyway, the link gets you back to the basics.
Relative Wind. All motion of an airplane that is relevant in aerodynamics is motion through the air. The air itself may be moving over the ground, and that is called wind. But the airplane does not experience wind. An airplane is like a fish swimming in a river, or lake, or ocean. If the water is moving the fish does not know that, it just drifts along with the current. The IFR navigation section of ProfessionalPilot.ca has some interesting simulations that further clarify this point. When a model airplane is placed in a wind tunnel a fan is used to blow air over the model. The model itself does not move. When an airplane flies through the sky the air as essentially a stationary gas (it is recommended that you completely forget about wind) through which the airplane moves. But from the airplane's perspective the situation is just like the wind tunnel. The air appears to flow over and around the airplane in EXACTLY the opposite direction and speed to the direction and speed of the airplane's motion. This apparent airflow is called the Relative Wind. All of aerodynamics depends on the relative wind. The relative wind is always equal to the true airspeed (TAS) but in the opposite direction. I have heard many amusing arguments as pilots try to convince each other that groundspeed is the proper measure of energy, but this is totally wrong. All energy measurements are relative to a frame of reference. When you drive a car the frame of reference is the earth, because it is the earth that supports the car and from which friction is used to move and stop it. We don't expect to have worse accidents if we crash going eastbound than westbound even though we could say we are driving backwards when eastbound, due to the earth's rotation. Similarly the airplane does not climb faster, or carry more weight with a headwind. It is an AIRplane, and as such its motion must be measured relative to the air. The only time groundspeed matters is for determining range, or when crashing (because at the moment of the crash the AIRplane stops flying, and becomes a GROUNDplane - so, don't ever crash with a tailwind.) In summary then: Relative wind is the airflow opposite to the direction of flight and equal in magnitude to the true airspeed. |
I went to that link LeadSled, but the author didn't convince me.
Flying a massive airliner with hundreds of people on board? No spin training required; By the late 1940′s, conventional wisdom was that the training itself was leading to more accidents than inadvertent spins occurring in the wild. I'd encourage anyone here to do aerobatics; it raised me from a poor pilot to an averagely competent one. (Dubbleyew eight - perhaps it might do the same for you... :E ) But throwing more mandatory exercises into an already tight syllabus isn't the answer IMO. Teaching the teachers how to teach stalling is a good starting point, and within CASA power. |
Lesson 2, primary and secondary effects of controls
Perhaps .. but I suspect that very few pilots have any idea of why in this case |
in my Tailwind (lighter than a 172) you will immediately start flying again if power is applied right at the point of stall. ...but obviously not after the nose has dropped. Many other light trainers with higher power engines, short rudder moment arm, will (yaw)roll over almost instantly if you are not spot on with the rudder. Throw in aircraft that don't have low speed design fixes like offset fin/engine mounting, washout, stall strips and differential/frise ailerons etc... and it makes for a fun day in the office when students come in thinking they can recover from a stall with zero height loss. The point of stall training foremost is to reinforce that all you have to do is lower the angle of attack, that is lower the nose/release back pressure, after that you are unstalled. What you do after that is dependent on the situation, if it yawed/rolled coordinate it back to level flight, if minimum height loss is desired then smoothly add power coordinate rudder and raise the nose back to a climbing attitude. Confusing the situation by adding too many things to do at once and the student will inevitably forget the main principle. Don't confuse this with a drill to recover from an unwanted stall warning indication in flight where by you recognise the approaching stall, smoothly add power whilst coordinating controls to maintain level flight. In this case you should be able to maintain level flight. All you are doing here is acknowledging you got to slow and use normal flight principles to go faster. |
Not really related but I love stalling in my BFR's, young instructor on board, I point that 172 up towards the sky with flaps on and by golly does it let go at the stall. I then raise my arms in the air, scream out then bear hug the instructor. Once they overcome the initial shock sometimes laughter follows. We've never flipped during my signature stall but I'll keep that in mind for my next BFR that is due shortly :cool:
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Oktas8,
Quite simply, the "conventional wisdom" of the day was wrong, it was never true that spin training caused more accidents than spins in normal operations. Ask any glider pilot about the value of spin and recovery training, and whether the training has a significant (or any) accident history. Tootle pip!! |
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