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Stalling in Landing Configuration...?
During one Bi-annual check-ride, the instructor asked for a 'Stall in the Landing Configuration'. I explained that this was a Cessna 172 and that it hadn't ever done stalls in the landing configuration. However he asked for me to set up the airplane, which I did... 75 knots, two stages of flap, and about 700ft/m rate of descent. I said my previous instructors had done 'Stalls with Flaps', but had never mentioned Landing Configuration.
Anyway we tried, but as long as we held 75knots / -700ft/m, there was no way the C172 was ever going to stall. We even tried 60 degree banked turns, but still no stalls...... We then went on to do some other exercises. . |
Try it in something which bites next time...
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Well the only thing you can take from that is that you never managed to get over the critical angle of attack.
There is a exercise to which you should have done which is recover from an incipient stall in the landing configuration which is set up as you say then pitch up gradually maintaining a shallow decent until the stall warner goes of and then recover from there. Its not mean to be a fully developed stall or have a constant airspeed. It meant to simulate you pitching up on approach without adding power because you are low and not noticing your airspeed is decreasing. The other one is a turn with partial configuration and again recover with the stall warner. Its not the best idea of intentionally trying to get a fully developed stall in a steep turn, you can quite easily manage to stall one wing and not the other and get thrown over the top in either direction into a fully developed spin in a mode which may never have been looked at in the certification flight tests and may not be recoverable using the POH technique. |
scifi,
Try a similar exercise, using full-flap and full-power. ;) As an aside, 75 kts is a very high speed to be using for approach. Vso is 53-55 kts (depending on the model year). A 55 kt approach speed will give you an easier flare and shorter landing. I routinely use this speed, with 50 kts over the fence, in a C182. |
Stall in landing configuration or approach configuration is essentially the same thing.
Many different ways you can practice a stall and it’s recovery and you should try them all under guidance: - Wings level, maintaining altitude. Landing config and power to idle and try and maintain altitude till the aircraft stalls. Attempt minimum altitude loss in the recovery without a secondary stall. - Wings level, descending. Landing config, power idle and trim for approach speed. Then slowly raise the nose while still continuing the descent as if you are trying to extend the glide on final. - Banking, maintaining altitude. Landing config or approach config. Power idle and you’re mimicking a turn in the circuit. - Banking, descending. Landing config, power idle. Mimicking a descending turn in the pattern. Now do all of the above with different flap settings from UP to FULL down. Purpose of all these excercises is multiple. Develop muscle memory for the recovery. Steer away from the ‘mental’ picture that the aircraft can only stall in one attitude in one configuration. Honestly you’ve been done a disservice in your pilot training if you haven’t been taught all of the above plus all the ‘power-on’ variations. |
Scifi, Think of a "configuration" as not including a specific speed or power setting. "Configuration" is flap setting (in degrees on a Cessna, not "stages"), landing gear is already down for you, the prop is probably already fine, and you're not worrying about cowl flaps. With the configuration set, you're approaching the stall as the flight manual says: Slow deceleration. If you are maintaining the speed (75 knots is way too fast), to approach stall, you'll have to cause a change in something else, like increasing G. This is a massive deviation from a landing configuration type of flying.
A 172 will stall delightfully with any flap setting, and within 45 degrees of wings level, if approached with steady flight and slow deceleration. Yes, huge variations in power setting may also be used, and it is good to be familiar with the differences in how this affects a stall, however, I suggest that you perfect this all at low or no power first, and with your good technique refined, then start to repeat with greater power settings. Early in section 5 of the later 172 flight manual, you will find the stall speed per flap setting and angle of bank. 75KIAS does not appear for any approved combination of these variables, so one could assume that you cannot safely make the 172 stall with any flap setting and 60 degrees bank. I am relaxed with the idea that in general, 172s, like many other GA types, are stalled in landing configuration, mere inches above the runway, during landings. |
Stalling in landing config is one of the most important things to practice, especially being able to anticipate it.
As India 42 comments you could be at a much slower speed and the ability to feel the approach of a stall in this state is vital, it can happen (from personal experience). Can't understand it not being part of your training. |
Not disagreeing with my learned colleagues, particularly my friend DAR, but...
Originally Posted by scifi
(Post 10118158)
During one Bi-annual check-ride, the instructor asked for a 'Stall in the Landing Configuration'. I explained that this was a Cessna 172 and that it hadn't ever done stalls in the landing configuration.
Stalling in the landing configuration is certainly here in Britain, quite often flown in aeroplane checkouts. However he asked for me to set up the airplane, which I did... 75 knots, two stages of flap, and about 700ft/m rate of descent. I said my previous instructors had done 'Stalls with Flaps', but had never mentioned Landing Configuration. Anyway we tried, but as long as we held 75knots / -700ft/m, there was no way the C172 was ever going to stall. We even tried 60 degree banked turns, but still no stalls...... We then went on to do some other exercises. Sec. 23.201 Wings level stall. (a) It must be possible to produce and to correct roll by unreversed use of the rolling control and to produce and to correct yaw by unreversed use of the directional control, up to the time the airplane stalls. (b) The wings level stall characteristics must be demonstrated in flight as follows. Starting from a speed at least 10 knots above the stall speed, the elevator control must be pulled back so that the rate of speed reduction will not exceed one knot per second until a stall is produced, as shown by either: (1) An uncontrollable downward pitching motion of the airplane; (2) A downward pitching motion of the airplane that results from the activation of a stall avoidance device (for example, stick pusher); or (3) The control reaching the stop. (c) Normal use of elevator control for recovery is allowed after the downward pitching motion of paragraphs (b)(1) or (b)(2) of this section has unmistakably been produced, or after the control has been held against the stop for not less than the longer of two seconds or the time employed in the minimum steady slight speed determination of Sec. 23.49. (d) During the entry into and the recovery from the maneuver, it must be possible to prevent more than 15 degrees of roll or yaw by the normal use of controls. (e) Compliance with the requirements of this section must be shown under the following conditions: (1) Wing flaps. Retracted, fully extended, and each intermediate normal operating position. (2) Landing gear. Retracted and extended. (3) Cowl flaps. Appropriate to configuration. (4) Power: (i) Power off; and (ii) 75 percent of maximum continuous power. However, if the power- to-weight ratio at 75 percent of maximum continuous power result in extreme nose-up attitudes, the test may be carried out with the power required for level flight in the landing configuration at maximum landing weight and a speed of 1.4 V<INF>SO</INF>, except that the power may not be less than 50 percent of maximum continuous power. (5) Trim. The airplane trimmed at a speed as near 1.5 V<INF>S1</INF> as practicable. (6) Propeller. Full increase r.p.m. position for the power off condition. I think that, just possibly, the instructor might have known more than you did chap. Also, if you're nervous of stalling a C172 with full flap, I'd suggest never ever even contemplating flying a PA38 without a grown up sat next to you! G |
Quite easy, if a C172 ever stalls in fully developed landing configuration and slowed down - it does have a rigging problem. It is one standard I do first when renting out a 172. If it is rigged correct it will go to parachuting, not stall.
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Hi Funfly, I've done stalls in all sorts of ways, Accelerated, Power On, Power Off, Banked, Flaps and Flapless, but had never used the terminology 'in the Landing Configuration'.
There was no way I could stall the C172, and remain on the simulated glide path, maintaining the Landing Configuration... We used up a good 3000ft of airspace, and even pulled some fancy spiral dives trying... . As for the speed being high, my Checklist says... Normal Approach 65-75 KIAS. which I take to mean 75 on approach, and 65 over the fence. . |
Hi Genghis, thanks for the details from FAR-24 Sec 23-201... So they say it is stalled if we hold the stick back for at least 2 seconds... Well I suppose I did that, but nothing happened in the same way that a PA38 would have responded.
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There was no way I could stall the C172, and remain on the simulated glide path, maintaining the Landing Configuration You cannot safely stall a 172 at 75KIAS (refer to stall speed table in FM), so you're going to have to slow down to get the plane to safely stall in any configuration. If high speed stalls are in your plan, the aircraft should be equipped with a G meter. (As an aside, I find it amusing/alarming that the G limits are pilot limitations, which aside from a coordinated banked turn, the pilot cannot determine). Landing configuration in a 172 will be any configuration in which you can land (flaps up or flaps down). There really are no variables which take a 172 out of landing configuration. If you have too much power, or too much speed, it won't land, otherwise, you're in landing configuration if you allow it to slow (hopefully over a suitable landing surface). The actual C of G position will affect the stall indication to the pilot, between controls full back, descending, or nose drops while controls held well back - either is a stall. Happily, a 172 is very docile, and no matter how you stall it, will be recoverable with no excitement with adequate altitude. Stalls conducted with angles of bank exceeding 60 degrees, or G loading exceeding the limitations are unsafe, but certainly are nothing near flight from which a landing could easily be made. There are some types (Ercoupe, for example) which are pitch control limited, to provide a stall barrier to the pilot. You can hold the controls full back, and the nose will not drop (though the plane may be going down!). This makes those types poor primary trainers - pilots need to learn to stall and recover. |
Originally Posted by scifi
(Post 10118437)
. As for the speed being high, my Checklist says... Normal Approach 65-75 KIAS. which I take to mean 75 on approach, and 65 over the fence. . I've a fair few hundred hours on the 172/182. For me it's a little steeper than the three degrees I often see, and 55 all the way down final. A few knots more if it's particularly gusty. 75 is just plain silly. 65 is still ten too much.:= |
Hi Flyingmac, what you need is an Extra 300, then you can practice Prop-Hanging correctly.
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then you can practice Prop-Hanging correctly In general, 172's could be happily flown on a power on full flap landing approach at 60KIAS, and a gliding approach at 65-70KIAS. More speed is generally not helpful. |
If you want to fly an approach at an absurd and totally pointless 75 kts then fill your boots. But please don’t cry about floating, using all tbe runway available or going through the far hedge. But I digress. The stall in landing configuration is achieved by reducing speed (at one knot per second) until the stall, not by holding your approach speed.
PM ps. Where did you get your checklist? Wherever it was, don’t go back. The POH has all the information you really need. No more and no less. |
One of the killers in flying is the turn from base leg on to approach stall. So I think as an exercise set it up with 30 of flap, 1500rpm, flying straight and level just hold altitude and wait. Min altitude 4000 agl and an instructor.
Due to the spiralling airflow of the prop normally one wing will stall first. The objective to correct with less than 500ft of height loss, because if not, your dead on a real approach. The idea is to teach how to recover and keep the speed up in the circuit add 4 kt for the turns. The first time I did this in a 150 the instructor never told me what would happen and I lost 1500 ft but only 150ft on the next try. Spin entry to the right over corrected spin entry to the left, while winding up the flaps and closing the throttle. So I think it is an important exercise and teaches even the 152/172 can bit. Note in a 172 with passengers in the back, it may not be so much of a pussy cat, pushes the CG back and ups the weight, which affects stall speeds and pitch sensitivity. |
Originally Posted by scifi
(Post 10118437)
..... but had never used the terminology 'in the Landing Configuration'.
Originally Posted by scifi
(Post 10118437)
There was no way I could stall the C172, and remain on the simulated glide path, maintaining the Landing Configuration...
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Originally Posted by Flyingmac
(Post 10118545)
I've a fair few hundred hours on the 172/182. For me it's a little steeper than the three degrees I often see, and 55 all the way down final. A few knots more if it's particularly gusty. 75 is just plain silly. 65 is still ten too much.:=
For a C172 or C182 speed down final should be from initially around 75 slowing to 55 at the threshold. |
Originally Posted by scifi
(Post 10118158)
Anyway we tried, but as long as we held 75knots / -700ft/m, there was no way the C172 was ever going to stall. We even tried 60 degree banked turns, but still no stalls...... We then went on to do some other exercises. . There is no reason to do this and the POH is clear that spins are prohibited with the flaps down. If you did get it to stall with 60 deg of bank and lots of power you are going to be in for an interesting ride. In any case the whole point of the landing configuration stall is to show the student that the airplane will be in only a slightly nose up pitch attitude when it stalls, unlike the introductory stalls where the aircraft will be in quite a nose high attitude. Therefore it is a good demonstration of the importance of maintaining the correct pitch attitude to maintain airspeed on final. I always teach this exercise as if when on final, finding yourself low you raise the nose to try to get to the end of the runway instead of adding power. |
as long as we held 75knots / -700ft/m, there was no way the C172 was ever going to stall. Are you being serious? Of course the thing isn't going to stall if you're just sitting there simulating an approach :ugh:. I don't know who I find more ridiculous; you for doing such a thing or your instructor for watching you and not asking, "what the hell are you doing?" It's stalling in the approach CONFIGURATION i.e. with the gear, prop pitch and flaps set up as if you're landing........and then you stall the aircraft in that CONFIGURATION, just like you'd stall any other time. To properly simulate the configuration, you leave some power on and then just fly level or slightly nose up to avoid being there all day (you can pretend to be stretching the approach), let it stall and recover. You don't let it descend at 700 feet per minute or guess what doesn't happen. You can call it 'stalling with flap' if you like because you're not (normally) going to be altering the gear or prop pitch in a 172 but it's still in the approach configuration and is a term so often used I find it very difficult to believe you've never heard of it before. Yes, a spade is called a spade. |
Sci-Fi has been 'outed' as a troll on at least two previous occasions.
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Originally Posted by scifi
(Post 10118463)
Hi Genghis, thanks for the details from FAR-24 Sec 23-201... So they say it is stalled if we hold the stick back for at least 2 seconds... Well I suppose I did that, but nothing happened in the same way that a PA38 would have responded.
. Over the years I've seen stall defined by... - Full back stick and high rate of descent - Pitch break - Incipient spin with no warning - Pitch break with wing drop - Roll inverted (that was somewhat unacceptable and we did have to do something about that). - Increasing amplitude wing rock All of those I'm happy to have defined as "the stall", the levels of acceptability did vary somewhat. It just happens that the C172 in most configuration / CG combinations does the first. Which, incidentally is one of the reasons I rate the C172 as one of the worst training aeroplanes readily available - a training aeroplane should teach rather more respect for the aircraft, and particularly the low speed range than the 172 does. You may recall FAA, EASA and CAA half a dozen years ago evangelising about how schools should NOT be teaching powering out of a stall without pitch inputs. That was, in my opinion, significantly because they were teaching in one of two types (the tapered wing PA28s being the other) which are so benign you can get away with that. G |
Originally Posted by Heston
(Post 10118825)
Sci-Fi has been 'outed' as a troll on at least two previous occasions.
G |
This can happen, don’t get complacenent.
I was attemting to land at Ashcroft many years ag and did a low level flight over the runway to have a look. In practice I was flying slower and slower, although I didn’t stall, i realised I was not far off. Can happen to anyone, be prepared |
scfi As I said before this is an important exercise but approach speed is 1.3xStall which changes with load and flap setting. Not some number plucked out of the air. I think 75knts is higher than the best climb speed. So to fast. But for this exercise it is not about speed it's about stalling in the landing configuration. 30 of flap 14 to 1600 rpm and trying to fly level with speed bleeding off. The point is this will be almost straight and level flight, looks normal not some nose high configuration and when it stalls she will suddenly drop a wing. Another config that can bit is in a sideslip adding full power some Cessnas will roll on their back so fast difficult to catch always return to balanced flight before adding power. The other one not practised very often is in a nose high full power climb chopping the power the nose hast to be lowered very quickly or it will stall.
So the point is visual clues do not always warn you and speed bleeds of very quickly with the extra drag of flaps. It happens most in the final turn when the nose is not dropped a little for extra speed and the up going wing stalls. I remember an accident at Shoreham a student pilot in the circiut was distracted by other traffic, as in landing config speed decayed quickly and he spun in, so an important exercise. |
I remember an accident at Shoreham a student pilot in the circiut was distracted by other traffic, as in landing config speed decayed quickly and he spun in, so an important exercise. https://www.gov.uk/aaib-reports/cess...b-19-july-2006 I'd argue that whilst flying the *correct* approach speed is important in both types, they have markedly different aLSS and stall characteristics. G |
Hi Genghis it was back around 73 I nearly did the same thing myself in an Aerobat doing solo circuits had 40 of flap on and distracted it was only the sloppy controls that caused me to go to full power.
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I did some testing in the same C150 variant myself after Southend. We showed a pull force to stall with the trimmer fully nose-down, in the full flap / full power combination in the order of half a pound.
G |
30 of flap 14 to 1600 rpm and trying to fly level If a strut braced Cessna is dropping a wing, or otherwise not stalling wings level, it's worth reporting this to the maintainer. It is likely that the wing cams are not properly set. In addition to adjusting the angle of incidence of each wing, the adjustment of the cams also has a slight, though perceptible effect to sweep a wing forward or aft. It could be the case that one wing is swept slightly forward, and the other aft, which will affect handling at low speed. |
Originally Posted by horizon flyer
(Post 10119617)
Hi Genghis it was back around 73 I nearly did the same thing myself in an Aerobat doing solo circuits had 40 of flap on and distracted it was only the sloppy controls that caused me to go to full power.
All because I had told him about torque effects on a P51 I had been flying in America. During my course at Oxford Air Training school in the depths of history we did the same exercise in PA28's. They were far more benign, but the exercise was thoroughly drummed home, stalling in a turn in the landing configuration can be evil if the recovery is mis-handled. One of the witnesses to this https://www.gov.uk/aaib-reports/soca...-december-2003 told me that it looked like a torque roll and certainly later models of the aircraft have had serious modifications to minimise the torque effect from a sharp increase of power. For the OP, if this was new to you I'd be asking why I wasn't taught about it during my PPL course. Its' probably not part of the PPL sylabus, but it should be, many aircraft will seriously bite in landing configuration. SND |
Not quite its intended purpose, but there's a paper here where a team of researchers stalled 14 different aeroplane types - including the C172 in both cruise and landing configurations and flew a range of different recoveries.
https://www.aerosociety.com/Assets/D...urnal/3965.pdf G |
Originally Posted by Heston
(Post 10118825)
Sci-Fi has been 'outed' as a troll on at least two previous occasions.
That distinction is important. When you're in the landing configuration that's usually because you're landing (duh), and thus happen to be close to the ground (duh). So you need to recognise the early signs of a stall and act upon it immediately. You can't let the stall develop, because you don't have the height to recover. So every time I've done this exercise, the exercise briefing always included "recovery on the first sign of the stall". Which were: - Stall warner - Sloppy controls - Buffet - ASI at the lower end of the white band Recovery is standard: pitch down sufficient to break the stall, full power, establish climb, clean up the aircraft and climb away (go around). But do NOT sink any further: The whole exercise should be done without height loss. |
Plenty of us have performed, or taught, stalls in the landing configuration.
Just because the most common exercise with students is "recovery from the first symptom of the stall" doesn't mean that one can't, or shouldn't, actually stall it sometimes. G |
If you stall a small Cessna with landing flap and some power, especially from a right hand turn, you WILL roll off to the left, probably quicker than you think!
This is not a miss rigging, and I have seen this on many individual aircraft. It is a great shame that some instructors only teach up to the approach to the stall. Stalls in themeselves are not dangerous, I like to show students what happens when you DONT recover straight away! ;) |
This day and age unfortunately anything outside the syllabus of your training organisation and your exposing yourself.
If your syllabus gives you the option and its been approved by the powers that be then there is no problem. If the syllabus tells you its only incipient you should take it too then that's what you have to do. Outside a formal course structure fill your boots. My FIC had all the stalls in it until stall as exercises that I had to take control and recover from the RHS while the FII put the aircraft into them. But it was not a pattering exercise it was pure recovery handling and I wasn't expected to teach them to a PPL. And it was documented in the FIC syllabus. |
Originally Posted by Genghis the Engineer
(Post 10120016)
Plenty of us have performed, or taught, stalls in the landing configuration.
Just because the most common exercise with students is "recovery from the first symptom of the stall" doesn't mean that one can't, or shouldn't, actually stall it sometimes. G One tiny thing about stalling in the landing configuration though is that quite a few aircraft have lower G loading limits with flaps down (typically only 2G). If you stall in the landing configuration, get into a wingdip and then mess up the initial recovery, you may end up getting pretty near, or even over that limit. Not saying it can't be done. Just saying it's something to consider when you do this exercise. |
Originally Posted by 27/09
(Post 10118660)
55 all the way down final is also plain silly. A really good way to piss off any aircraft following behind you.
Only if I flew Bomber circuits. I tend to turn final at around 400ft and less than a half mile out. Don't you? |
"But the OP question was specifically about the biannual checkride."
What is that? |
Despite this thread being kicked off by a troll, the reminders about care in adding power while turning in landing configuration are very useful.
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