8
$\begingroup$

Original Question: Is it okay to purposely stall a small single-engine aircraft just before touch down to get a good flare?

At the time of asking this question, I didn't know a myriad of things about actual flying that I do today, and this question branched out from confusions due to lack of knowledge. However, I think that the main question about the onset of the stall horn remains valid (regardless of the impractical manoeuver through which I got to it). So I sought to edit this post to make it less nonsensical to future readers rather than deleting it.




I'm still learning ground theory and have only flown in simulators (P3D v3 Academic). For a long time, I've been trying to properly flare single engine aircraft but have mostly failed. I even watched a video on youtube made by a certain flight instructor that said that the smaller airplanes like a Cessna 172 and Mooney acclaim don't flare - they "transition" just to make sure the rear gears touch down first.

What I did to flare better in the SIM was: as I approached the threshold, I gradually started pulling the throttle and pitching up. In that condition, the airplane would tend to sink rather than go up and since the aircraft's height wasn't much above the ground, the impact from a "fall", I thought, would not be fatal.

However, I thought that I was essentially stalling the aircraft (purposely) as I even got a stall warning (though it lasted for about 2 secs). What I was trying to do here is making sure that the nose wheel was higher so the mains would touch down first.

As far as I know, a stall situation is usually a bad one. However, I was thinking that it might be okay if the pilot knew what they were doing and still had control while (kind of) stalling the aircraft. But I'm confused since I haven't flown a real bird yet.

So, my question is, Is it okay to hear the stall horn on a small aircraft while flaring?

$\endgroup$
5
  • 1
    $\begingroup$ Related: What is the best method to time your round out or flare in Cessna 172? $\endgroup$
    – Bianfable
    Commented Sep 27, 2019 at 9:02
  • 1
    $\begingroup$ @papamike99 You may wish to invest the time flying with an instructor. There are "short field" techniques, coming in slower (and more nose high). However, gusts and wind gradients can make doing this extremely dangerous. "Rounding out" involves pulling the elevator, which can stall the aircraft (and crash it). Much safer to (for example) approach 65 knots, round at 65 knots (10-15 feet off runway), flare down to 50 knots (stall warning comes on), settle onto runway. You don't have to stall to settle, just reduce AOA (pitch) slightly. $\endgroup$ Commented Sep 27, 2019 at 12:22
  • 1
    $\begingroup$ Anecdotally, I often hear the stall warner just before touchdown in a PA28 or C172. Its not really much to worry about in those sort of trainer aircraft. The horn goes off a good few knots before the wings actually stall and the nose drops. $\endgroup$
    – Jamiec
    Commented Sep 27, 2019 at 12:35
  • $\begingroup$ @RobertDiGiovanni Thank you for the helpful words. I will soon go to a flight school and, at present, am simply trying to make sense of what I learned theoretically, in the simulator. $\endgroup$
    – PapaMike99
    Commented Sep 27, 2019 at 13:45
  • $\begingroup$ I do prefer not to hear the stall warning on takeoff though, especially when I am not the PIC. Makes me a bit nervous every time it happens. $\endgroup$ Commented Aug 11, 2022 at 0:21

6 Answers 6

11
$\begingroup$

"To get a good flare". Never heard of pilots talking about "wow, I had a great flare on that landing!", although a very famous test pilot really had a beauty landing the XF-92A, reducing landing speed from around 160 to 67 mph.

So why do we flare? What is a flare?

"Flaring" is increasing AOA to MAINTAIN lift as the plane slows down.

Why do we slow down as much as possible before landing?

Too fast and the plane will "bounce". Bouncing is not a major problem if it is on the main gear (and not too hard). Bouncing the nose gear can be disasterous. Since you have a lower AOA for the same lift when faster, risk of bouncing the nose gear is greater. For taildragger, the risk is prop strike.

So you flare to increase AOA after rounding out and prior to touchdown, reducing speed and increasing AOA.

Do you need to stall to get a good flare? NO!

Does the stall warning mean I'm stalled? Try it at altitude first. Generally they are set a few knots ABOVE stall, and it is normal to hear it as you touch down. Know your plane.

Finally, "round out" at approach speed (you don't want to stall here), then reduce throttle and pitch up (flare). The trick is to hold it a few feet off the runway as speed decreases and AOA increases. You are now flaring!

Actually landing, well, everyone has their own ideas. In a 172, I could just start to feel the seat of my pants drop. At that point, back pressure on the yoke was relaxed just a tiny bit (slightly reducing AOA and lift), and the plane would settle onto the runway.

Flaring is all about speed control. Keep it safe.

$\endgroup$
7
  • $\begingroup$ Thank you for the answer, Robert. I see that the priority is not to get a good looking flare but to have a steady approach and touch down (and making sure the rear gears touch down first). Just one thing though: what exactly do you mean by "round out"? $\endgroup$
    – PapaMike99
    Commented Sep 27, 2019 at 10:25
  • 1
    $\begingroup$ "Round out" is bringing the plane level (stopping your descent) a few feet over the runway, prior to flaring and landing. $\endgroup$ Commented Sep 27, 2019 at 10:30
  • $\begingroup$ To prop strike a taildragger you have to be going really really fast. When flying TDs I prefer to "wheel land" them, tail high, and when you do that you actually fly down to a foot or so above the surface, applying just enough pitch to stop the descent, then instead of holding the nose up with increasing elevator, you PUSH to plant the mains, and keep pushing to hold the tail up until you slow down. This affords way more control in gusty conditions and xwinds. $\endgroup$
    – John K
    Commented Sep 27, 2019 at 12:32
  • $\begingroup$ No mention made of relationship between ground speed in excess of stall speed, and landing roll distance. This is probably the most significant reason we try to slow down as close to the stall speed as possible before landing. Done right, this happens as close to the approach end of the runway as is safely controllable, so that we have the maximum amount of runway remaining to stop. $\endgroup$ Commented Aug 11, 2022 at 0:11
  • $\begingroup$ @CharlesBretana not always a good idea, especially in wind. This question is from a student who may benefit from not trying for short field perfection at that stage of training. Flaring at a safe approach speed provides precious seconds to set up a good landing. This is why learning with a lot of excess runway is very helpful. $\endgroup$ Commented Aug 11, 2022 at 1:27
5
$\begingroup$

In my experience the best altitude for a fully stalled landing is about 1 inch. Seriously though, the method I use is to fly as close as I can to the ground without touching down with practically no throttle and finally reducing the remaining throttle whilst maintaining the height above the ground by increasing the angle of attack until it finally stalls and drops that last few inches onto the ground. It's difficult to get right but if you land prematurely it's not the end of the world, but if you use too much elevator too soon you will balloon (increase height) and you don't want to stall from there, apply a bit a power and try again. I would suggest paracticing by flying as close to the runway as you can without touching it, using throttle and attitude to remain just above the stall, using the end of the runway as your reference (v. important), climb out, do a circuit and trying again until it 'click's. It all depends on the aircraft and wind conditions, but if you're flying a light aircraft without a significant cross wind, this is pretty much the best way and eventually you'll be able to maintain a few inches just above the stall and then close the throttle to settle fully stalled onto the ground. If it's done right your stick/control column should be fully back. As I say this is my experience and I know there are people who would vehemently disagee, but it works for me.

$\endgroup$
5
  • 2
    $\begingroup$ Just to be sure, you do this in the real world or in the sim? $\endgroup$
    – PapaMike99
    Commented Sep 27, 2019 at 9:36
  • $\begingroup$ That's a bit unnecessary PapaMike99. I fly real aircraft in the uk and have had a pilot's licence for about 20 years. I don't fly that regularly admittedly but I'm giving my opinion in good faith, take it or leave it. I have never used a sim - I don't play computer games at all and I'm close to retirement age. $\endgroup$
    – Phil
    Commented Sep 27, 2019 at 10:05
  • 4
    $\begingroup$ Phil, I am extremely sorry if my comment sounded disrespectful. I am simply looking forward to gaining knowledge and just wanted to know how much real world influence your knowledge had. I absolutely appreciate you taking the time to answer my amateur question; it's just that I am quite confused right now after reading various opinions from different people, so am a little obsessed with verifying the authenticity of statements at the moment. I once again apologize and sincerely thank you for your answer. :-) $\endgroup$
    – PapaMike99
    Commented Sep 27, 2019 at 10:11
  • $\begingroup$ I had considered being "vehement", but easing out the last bit of throttle before settling is a good idea. Throttle control can really "fine tune" things, as it's control is more precise. Good answer! $\endgroup$ Commented Sep 27, 2019 at 14:08
  • $\begingroup$ I have had several such "drop an inch" landings as a passenger on LOT Polish Airlines in the 80s and early 90s. They were especially memorable on AN-24 where you could see the wheels floating so close to the runway that their shadow was mostly obscured by the wheel, and then you could see the struts compressing relatively slowly. IIRC it was mostly done in good weather and runway conditions, and not all pilots did it. $\endgroup$ Commented Dec 22, 2023 at 16:04
2
$\begingroup$

I'm training in a Cirrus SR-20 which is a small single engine a/c. The way I was taught was to start rounding out and pulling power simultaneously, roughly 10-20 ft. above the ground. You want to flare to about 5 degrees pitch up and ideally hear the stall horn as the mains touch the ground. I should add also that when you hear the stall horn, at least in the SR-20, it is not indicating a full stall, in fact it is just indicating an incipient stall, i.e., you are about to stall. Again, this is just how I was trained, and this is something my flight school really stresses on.

Personally, I believe the aim is to be pitched up enough so that you aren't landing flat on all 3 wheels, and so that you've lost enough energy to prevent the a/c from bouncing once you do touch down. You want to be slow enough and losing enough lift that the aircraft wants to land. But the key is that you're not doing this when you're still 20 ft. above the ground. You should only be a few inches off the ground when you reach your flare attitude and hear the stall horn. And you want to hold that attitude until the mains are both down and you can't hold the nose up anymore.

Good rule of thumb is to fly the airplane down to the ground. Do not stop "flying" your aircraft until you have fully landed. Hope this was helpful!

$\endgroup$
1
$\begingroup$

Depends on the airplane and type of landing gear it’s equipped with, and the toe of landing you are performing, but in general, stalling the airplane during the roundout is NOT recommended.

It is true that, while performing a three point landing in a tail wheel airplane, you will touchdown on all three wheels in a stalling attitude. And the aircraft essentially does stall about 1 to 2 feet above the ground, thence plop down on all three wheels. But this applies only to a tail wheel airplane and only a specific kind of landing. You don’t stall a tailwheel airplane on a wheel landing, and he will not do so on a tricycle gear airplane, either.

Remember that a roundout (flare) is performed to accomplish two things: 1) arrest your rate of descent on approach as you near the ground and 2) place the airplane in the correct attitude so that it gently makes contact with the ground on its landing gear. This requires the pilot to fly a final approach to the runway at an airspeed Vref either recommended by the manufacturer, but not less than 1.3*Vso. Flying this airspeed on final approach allows the airplane just enough kinetic energy to accomplish the two required tasks of the roundout before being exhausted and settling onto the runway without excessive floating and using up too much runway in the roundout.

Exact techniques vary a little between airplane to airplane, but typically for light airplanes with tricycle landing gear, you will fly your short final stabilized at Vref towards your aimpoint for starting the roundout (not the touchdown point). If you have not achieved a stabilized, and trimmed up approach at Vref by short final, you should execute an immediate go-around, re-enter the pattern and try again. At approximately 10 to 20 feet above the runway, power should be smoothly reduced to idle, and aft stick pressure should be applied to arrest you descent so you end up in level slow flight approx 1-2 feet above the runway. Height above the ground should be judged by perspective alone, not the appearance of the runway to avoid narrow runway illusions. Thereafter you will use aft stick pressure to bring the aircraft into the correct touchdown attitude, and hold it in that attitude until the airplane settles onto the runway. If you were on the Vref on short final, the aircraft should use up ~400 ft of runway in the roundout, so pick you aimpoint some 400 or so feet before your desired touchdown point. The instant touchdown occurs, you transition from slow flight into a high-speed taxi. Gently release aft stick pressure following touchdown to gently lower the nosewheel onto the runway, then apply brake pressure to slow the airplane down to safe taxi speed prior to exiting the runway.

Due to the more rigorous demands on the landing gear during a soft field landing, you will touchdown as smoothly and as gently as possible on these types of landings. In a soft feel landing, you may will hear the stall warning horn, but only a fraction of a second before the airplane makes contact with the runway, not sooner. Short field landings are a totally different animal. The same basic principles apply in a short field landing as a normal landing, but touchdown at a desired point on the runway, while consuming minimal distance in the flare is required. These types of landings will not be greasers, although a hard or excessively rough landing shows bad flare technique. You want to plop it on the ground and keep it down as quickly as you can, but do so following the correct landing technique and not so hard it could damage the airplane.

Jet airplanes are typically flown onto the runway, as opposed to doing some sort of hold off until just short of stall. The reason for this is to prevent the airplane from consuming an excessive amount of runway during the round out and jets are aerodynamically pretty slippery without a windmilling propeller attached to them slowing them down.

$\endgroup$
1
  • $\begingroup$ thanks for including energy management in your answer! $\endgroup$ Commented Apr 5 at 3:56
1
$\begingroup$

I practised flapless landings with a Saab Supporter, flying the aircraft unto the runway and controlling speed only by the throttle till touchdown. I kept the aircraft low and slow and must hear the horn to flare which stalls it unto my aimpoint. Errors in height judgements caused hard landings. But the aircraft was strong and I had leeway in flying as it was a military airfield.

$\endgroup$
1
$\begingroup$

Hearing the stall warning during landing is how you know you’ve squeezed the very last ounce of lift out of the wing and are landing at the absolute slowest ground speed possible in the current conditions. Except in instances of strong crosswind or soft field conditions, you want to hear the stall warning horn on every landing. 20+ years of flying, I can only manage it 1 out of every 5 landings.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .