Stalling in Landing Configuration...?
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It's the FAA way of maintaining currency. In order to fly a SE aircraft you need to have done this specific checkride, called the biennual flight review (BFR), with an instructor in the last two years.
Thread Starter
Just a few words about this 'landing configuration'.. I have looked through my PPL course details, including the Pooleys Pilot's Work Book, and 'Landing Configuration' is not mentioned for Ex.10A Ex.10B or Ex11.
I also had an Instructor who asked for TTTT when approaching a Waypoint, which turned out he meant Transit, Turn, Trim, and Talk.
Where these terms come from I have no idea, maybe they are used in USA.
I have encountered the 'wing-flip' stall once when encountering my wake turbulence during a complete orbit, It flipped me out of the turn very quickly.
I also had an Instructor who asked for TTTT when approaching a Waypoint, which turned out he meant Transit, Turn, Trim, and Talk.
Where these terms come from I have no idea, maybe they are used in USA.
I have encountered the 'wing-flip' stall once when encountering my wake turbulence during a complete orbit, It flipped me out of the turn very quickly.
Moderator
While discussing the angry handling characteristics of certified GA aircraft, remember that they have, during certification, demonstrated that their handling characteristics, including stall recovery, can be accomplished without the need for unusual pilot skill and attention (FAR 23.143)
At certain amendment levels of 23.201 (stalls) power is not to be required during stall recovery (meaning you must be able to recover entirely power off). That said, nowhere in the requirements is there an objective to prevent altitude loss during a stall recovery. This notion seems to be a training thing. The idea that the application of power should be the first action to recover a stall worries me - what if the engine fails then?!
So the handling, and departure from controlled flight which may accompany an approach to stall, or actual stall in any configuration has been demonstrated during certification to comply with these requirements.
During certification stall testing, smooth air is desirable. If turbulent air is encountered during flight, including stalls, things can be very different.
In a Cessna 152/172/182/PA-28, landing configuration could be any configuration for which flight is possible (landing gear position as required, if applicable). The use of flaps, carb heat, propeller fine, cowl flaps are not required to accomplish a safe landing - just a good idea. Landing configuration need not be defined for a simple GA aircraft, it's about any configuration. If an instructor/examiner seeks a particular configuration, they should state it.
Yes, in a turning stall, the sudden application of lots of power can be destabilizing. This should be taught. If a pilot initiates a stall recovery at altitude, the application of a lot of power need not be necessary until the stall is recovered, as with lots of altitude, the pilot has some to spare to assure that stall recovery is less challenged. If the pilot has approached a stall at low altitude, and power is required during recovery, okay, the attempt should be made, but that pilot already has placed themselves into a precarious situation. Low altitude flight flight should not be out of control flight.
If a pilot wants to do a full stall in landing configuration, and they are well aligned with a suitable landing surface a few feet under them, very good!
....(b) It must be possible to make a smooth transition from one flight condition to another (including turns and slips) without exceptional piloting skill, alertness, or strength, and without danger of exceeding the limit load factor, under any probable operating condition ....
So the handling, and departure from controlled flight which may accompany an approach to stall, or actual stall in any configuration has been demonstrated during certification to comply with these requirements.
During certification stall testing, smooth air is desirable. If turbulent air is encountered during flight, including stalls, things can be very different.
In a Cessna 152/172/182/PA-28, landing configuration could be any configuration for which flight is possible (landing gear position as required, if applicable). The use of flaps, carb heat, propeller fine, cowl flaps are not required to accomplish a safe landing - just a good idea. Landing configuration need not be defined for a simple GA aircraft, it's about any configuration. If an instructor/examiner seeks a particular configuration, they should state it.
Yes, in a turning stall, the sudden application of lots of power can be destabilizing. This should be taught. If a pilot initiates a stall recovery at altitude, the application of a lot of power need not be necessary until the stall is recovered, as with lots of altitude, the pilot has some to spare to assure that stall recovery is less challenged. If the pilot has approached a stall at low altitude, and power is required during recovery, okay, the attempt should be made, but that pilot already has placed themselves into a precarious situation. Low altitude flight flight should not be out of control flight.
If a pilot wants to do a full stall in landing configuration, and they are well aligned with a suitable landing surface a few feet under them, very good!
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Stalls and recovery:
(i) clean stall;
(ii) approach to stall in descending turn with bank with approach configuration and power;
(iii) approach to stall in landing configuration and power;
(iv) approach to stall, climbing turn with take-off flap and climb power (single-engine aeroplane only)
(i) clean stall;
(ii) approach to stall in descending turn with bank with approach configuration and power;
(iii) approach to stall in landing configuration and power;
(iv) approach to stall, climbing turn with take-off flap and climb power (single-engine aeroplane only)
The TTTT thing has been going around for years and it gets perverted and changed, its not an official syllabus thing.
I think it was.
T turn
T time record the time you turned.
T forgotten that one might have been trim
T twist which was reset your DI so you didn't go off on some nonsense heading and get lost.
It might have been 5 t's, its bound to have come from some RAF CFS method and its raw form how it originally was worked a treat.
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Well, now the following is taught:
T T T
being
Turn
Time
Talk
In other words, at the waypoint, focus entirely on the threat and error management of your turn on to your new heading
Then note the time
Once stabilised on your new heading (gross error checks and a FREDA carried out) tell whoever you've been talking to on the radio
sorry about the thread drift.
TOO
T T T
being
Turn
Time
Talk
In other words, at the waypoint, focus entirely on the threat and error management of your turn on to your new heading
Then note the time
Once stabilised on your new heading (gross error checks and a FREDA carried out) tell whoever you've been talking to on the radio
sorry about the thread drift.
TOO
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Well, I don't know the examiner who would ask such a thing.
STALL means STALL = Loss of speed and control.
Holding 75 kts is not going to get you anywhere "near" stall in a C-172 unless you are willing to pull the wings off the thing. => High "G" load.
And then, with Flaps. . Come on . . . Max "G" load with flaps is 2 G.
Flaps + holding 75 kts? => You can fly the tanks dry without ever getting "ANYWHERE" close to stalling.
You are AT LEAST 15 kts ABOVE a possible stall.
Add some power to that and you are 20 kts ABOVE stalling.
We used to fly a C-172 right into the stall, add power, add more power till at FULL power and cruise along at 30 kts indicated.
With only 2 on board and light on fuel, we could get to 27 kts IAS. Yeah, yeah, that poor horn blaring like a stricken goat. LOL.
It' called flying on the back side of the stall speed. Transfer weight from the wing to the powerplant.
Less weight for the wing to carry and the stall speed drops off to ridiculous values.
BALL centered at ALL times. That's the only "must do".
STALL means STALL = Loss of speed and control.
Holding 75 kts is not going to get you anywhere "near" stall in a C-172 unless you are willing to pull the wings off the thing. => High "G" load.
And then, with Flaps. . Come on . . . Max "G" load with flaps is 2 G.
Flaps + holding 75 kts? => You can fly the tanks dry without ever getting "ANYWHERE" close to stalling.
You are AT LEAST 15 kts ABOVE a possible stall.
Add some power to that and you are 20 kts ABOVE stalling.
We used to fly a C-172 right into the stall, add power, add more power till at FULL power and cruise along at 30 kts indicated.
With only 2 on board and light on fuel, we could get to 27 kts IAS. Yeah, yeah, that poor horn blaring like a stricken goat. LOL.
It' called flying on the back side of the stall speed. Transfer weight from the wing to the powerplant.
Less weight for the wing to carry and the stall speed drops off to ridiculous values.
BALL centered at ALL times. That's the only "must do".
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My C 150, with a Horton STOL kit is capable of sustained flight, and 15 degree banked turns at 22 MPH indicated. However, when I installed a swiveling pitot head and second ASI, I found that the actual airspeed was 41 MPH. So that would be a case where the position error on the pitot tube was extreme, and the difference between IAS and CAS was huge. But, it's fun to look at 22 MPH, and think to one's self: "wow, that's slow!".
Careful doing that for sustained periods though, as the CHT gets hot, and could be damaging.
Careful doing that for sustained periods though, as the CHT gets hot, and could be damaging.
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There are threads on here and next door that have people getting very hot under the collar regarding the use of the words "stall" and "speed" in the same sentence.
Especially among those who like to be upside down a lot.
Having said that "landing configuration" is the determining factor here, which usually involves being straight and level, reduced power, some flaps, flying slower than cruise speeds etc. Trying to stretch the glide without increasing power seems to cause the problems, so is unlikely to result in maintaining 75 knots on a 172.
At 75 knots and decending at 700fpm is never going to stall because the "landing configuration" including airspeed and rate of decent are maintained.
The only way to stall that is to raise the nose, reducing the speed and increasing the angle of attack.
Or have I just stated the bleeding obvious again?
Especially among those who like to be upside down a lot.
Having said that "landing configuration" is the determining factor here, which usually involves being straight and level, reduced power, some flaps, flying slower than cruise speeds etc. Trying to stretch the glide without increasing power seems to cause the problems, so is unlikely to result in maintaining 75 knots on a 172.
At 75 knots and decending at 700fpm is never going to stall because the "landing configuration" including airspeed and rate of decent are maintained.
The only way to stall that is to raise the nose, reducing the speed and increasing the angle of attack.
Or have I just stated the bleeding obvious again?
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Crash one, trouble is the bleedn' obvious clearly isn't.
One of the big problems is that "landing configuration" is rarely if ever actually flown. First of all the starting point should be Vref, i.e 1.3 x Vso adjusted for aircraft weight. Most light aircraft final approaches are flown at way higher than 1.3 x Vso.
NS
One of the big problems is that "landing configuration" is rarely if ever actually flown. First of all the starting point should be Vref, i.e 1.3 x Vso adjusted for aircraft weight. Most light aircraft final approaches are flown at way higher than 1.3 x Vso.
NS
If we are in the game of stating the obvious, could I wade in and point out that configuration and speed are two different things.
In any given configuration, there are a range of speeds ay which the aeroplane may be flown.
G
In any given configuration, there are a range of speeds ay which the aeroplane may be flown.
G
I would like to point out that Vs0 is "stall speed in landing configuration" (at least on my side of the pond) which, in a 172, means full flap. That's the bottom of the white arc. You may, of course, actually land using less flap. I think most instructors teach full flap landings, except when wind conditons suggest otherwise. Certainly, short field landings are full flap.
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I was taught to deal with stalls in the landing configuration when turn from base to final. I usually have two stages of flap at that time and leave the final stage until on final (if I use it at all, depending on the wind). I guess the learning outcome is to deal with stalling during bank with flap.
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I think there is too much "airline jargon" applied to light aircraft ops.
If you have a 2000 metre runway and a 172, then "configuration" is not required.
With my Emeraude and 600 metres in a 10 knot wind, close the throttle and land.
As for 1.3 X Vso that amounts to 52 knots, I've had full control at 45 and don't have to backtrack quite so far.
Thread Starter
Hi Crash One... I don't see how the Approach speed has any connection with the distance of the Back-track. As long as you put the wheels on the tarmac, at the Piano Keys, at Vso, it doesn't matter two hoots what your speed was half a mile before.
There is one other anomaly, when we use the term 'speed over the fence'... It all depends upon where the fence is. For most of the airfields where I fly, the fence is 400 to 800 yards from the Threshold, plenty of space to loose many knots down to Vso. For pilots where the fence is at the threshold, they have to make some fiddle-factor adjustments.
.
There is one other anomaly, when we use the term 'speed over the fence'... It all depends upon where the fence is. For most of the airfields where I fly, the fence is 400 to 800 yards from the Threshold, plenty of space to loose many knots down to Vso. For pilots where the fence is at the threshold, they have to make some fiddle-factor adjustments.
.
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scifi "speed over the fence" is another airline term which is to do with landing performance.
Airliners are not mean to land on the numbers. The touchdown point is at a set distance down the runway with a nominated angled path down to it. When you are on this path then when you go over the threshold you will be at a specified height. This is referred to as the fence.
For departure there are also fences for take off performance which depend on if the runway is wet or not.
I have not on purpose given any hard numbers for these "fences". Like the 1.3 VSo which is also a airline reference speed number it isn't relevant to SEP aircraft.
It doesn't have anything to do with a physical fence on the airfield.
Airliners are not mean to land on the numbers. The touchdown point is at a set distance down the runway with a nominated angled path down to it. When you are on this path then when you go over the threshold you will be at a specified height. This is referred to as the fence.
For departure there are also fences for take off performance which depend on if the runway is wet or not.
I have not on purpose given any hard numbers for these "fences". Like the 1.3 VSo which is also a airline reference speed number it isn't relevant to SEP aircraft.
It doesn't have anything to do with a physical fence on the airfield.
Moderator
As long as you put the wheels on the tarmac, at the Piano Keys, at Vso, it doesn't matter two hoots what your speed was half a mile before.
I remember once, in very early days, landing a 182 on an 11,000 foot long runway. I allowed it to contact the ground much too fast (two hoots shortage on my part). What a bucking bronco ride that was! Now, for me, all tricycle type landings will be full or near stall at the time of surface contact.
My half mile back speed will be planned and executed. The place of landing and approach path may affect my decision, as well as the possibility (or reality) of engine failure, and the affect on other traffic of what could be a non standard approach.
On this landing, I was flying the approach to the knot, 1.1Vso, as I had only 40 more feet of runway length available than that required for the aircraft under those conditions.
Interesting points of view here. I wonder how many of the posters have actually stalled their aircraft in the configuration of the day, as it were? Independent of this thread, I spent an hour yesterday in a homebuilt, investigating behaviour at the stall in different configurations.
No flight manual, we are about half way through a fifteen hour program intended to give us the information we need to write one. I'm flying at a fairly light weight, between full and half tanks, solo in a two seat aircraft. Probably fairly representative of the use it will get. It's interesting to reflect on all the different possibilities there are. At this weight, Clean power off, clean at different power settings (1700 rpm, 2100 rpm, and 2450 rpm) Flaps 15 power off, 1700 rpm, and 2100 rpm. I'm not intending to try 2450 with any flap, we've set a flap limit speed based on similar types, and don't really want to bust it. Then there is Flaps 30, all the above, turns at different angles of bank with and without flap and power.
Then do it all again at different weights. I suspect all the DGAC really want is clean and
full flaps, but I'm having fun.
The hard part so far has been getting decent enough weather. The first flights were done in march, then we had three weeks waiting for the rain to stop and the runway to dry out.
I think I could easily spend all fifteen hours in upper air work and enjoy doing it. The speeds are actually predictable, once the clean stalling speed at a given weight is established. What is interesting is the way the aircraft signals that it is unhappy, and what happens at the point of stall. It's making my flying a lot crisper, for sure.
Does anyone know an easy way to measure takeoff distance to 15 metres? We are supposed to come up with that, at some point. At MAUW. Runway surface and wind not specified, which seems to make it a bit pointless, to my mind.
No flight manual, we are about half way through a fifteen hour program intended to give us the information we need to write one. I'm flying at a fairly light weight, between full and half tanks, solo in a two seat aircraft. Probably fairly representative of the use it will get. It's interesting to reflect on all the different possibilities there are. At this weight, Clean power off, clean at different power settings (1700 rpm, 2100 rpm, and 2450 rpm) Flaps 15 power off, 1700 rpm, and 2100 rpm. I'm not intending to try 2450 with any flap, we've set a flap limit speed based on similar types, and don't really want to bust it. Then there is Flaps 30, all the above, turns at different angles of bank with and without flap and power.
Then do it all again at different weights. I suspect all the DGAC really want is clean and
full flaps, but I'm having fun.
The hard part so far has been getting decent enough weather. The first flights were done in march, then we had three weeks waiting for the rain to stop and the runway to dry out.
I think I could easily spend all fifteen hours in upper air work and enjoy doing it. The speeds are actually predictable, once the clean stalling speed at a given weight is established. What is interesting is the way the aircraft signals that it is unhappy, and what happens at the point of stall. It's making my flying a lot crisper, for sure.
Does anyone know an easy way to measure takeoff distance to 15 metres? We are supposed to come up with that, at some point. At MAUW. Runway surface and wind not specified, which seems to make it a bit pointless, to my mind.
Piper - I don't know what your relevant experience is, nor what you're testing - but DAR and I have both spent significant portions of our lives doing that sort of testing for a living. I'm certainly very happy to share what wisdom I have, and I've never known him to be unwilling to open up and share his experience either.
Here's one way of doing take-off and landing distances, although nowadays we'd mostly use recording GPS...
http://bura.brunel.ac.uk/bitstream/2...oJ%20final.pdf
If you want to email be at boffin at engineer dot com, I'd be happy to set up a 3-way email conversation.
G
Here's one way of doing take-off and landing distances, although nowadays we'd mostly use recording GPS...
http://bura.brunel.ac.uk/bitstream/2...oJ%20final.pdf
If you want to email be at boffin at engineer dot com, I'd be happy to set up a 3-way email conversation.
G
Last edited by Genghis the Engineer; 18th Apr 2018 at 21:29.