I had an interesting real-world learning experience about airspeed during short-field landings

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x4457@reddit

Great news, you had at least another 10 knots before you stalled. Less great news, you're not as good as you thought you were. More great news, that's why you have an instructor sitting next to you because you're still learning.

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Saltyspaceballs@reddit

Can’t have a better lesson in flying than one where you walk away and think fuuuuccckkkk. You’ll never make the mistake twice

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Mh401k@reddit

Yea, like when I departed LGB last week in a 182 with 400ft ceiling and got a pitch trim error and “don’t sink” message at about 1000ft in the clouds? My minimums have been adjusted lol.

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Saltyspaceballs@reddit

Those sorts of words being yelled at you scare you at any altitude I assure you. I've had a full "woop woop pull up" at 24,000ft and it still scared the hell out of me despite the lack of terrain. It's a good thing though, that fear is what keeps you alive

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Drunkenaviator@reddit

> Less great news, you're not as good as you thought you were. But, still great news. Any time you can learn that and still be able to talk about it later is very valuable.

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BrtFrkwr@reddit

An old bush flying technique is, since your stalling speed will be different for each weight, is to slow at a safe altitude and note when the stall warning horn just begins to sound. Add a comfortable margin to that for your final approach speed. Airlines pad half the steady state wind plus all the gust factor, but that's assuming you have wind reports from a tower, which you don't often have with real short fields.

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Vast_Anxiety_3269@reddit

Bold of you to assume the airplane has a stall horn 😂

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BrtFrkwr@reddit

It's a 172. It has a stall horn.

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Mithster18@reddit

If it's working

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satans_little_axeman@reddit

It is on all airworthy examples.

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Headoutdaplane@reddit

CAR 3 aircraft were not required to have them, and the majority still do not. Neither of my planes, a 1964 Dehavilland Beaver and 1948 Aeronca Sedan, have them.

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satans_little_axeman@reddit

1956 was the first year the 172 was built. The 1956 172 Owner's Manual I found makes no reference to the stall warning system being optional. My statement stands.

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Headoutdaplane@reddit

I have no idea about the 172, as I have never owned one, or even flown one that old. I also am ignorant of when the certification standards changed, the Beaver was designed and type certificated in 1947, and although they were built into 1967 the design was still CAR 3. However, under CAR 3 stall warning systems were not mandatory for aircraft to be certificated. You can just Google CAR 3 certification, and you will see it stall warning wasn't in there. The basic premise of my post stands that there are a lot of airworthy aircraft that don't have stall warning systems.

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satans_little_axeman@reddit

Ah, basic misunderstanding. I was never talking about "all aircraft", just all 172s.

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makgross@reddit

While technically true, it’s not particularly useful. No one checks them, so there are a lot flying around with inop stall warnings.

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satans_little_axeman@reddit

Yes, they're checked. It's part of the pre-flight checklist. Don't normalize deviance.

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makgross@reddit

Uhh, just because it’s on the checklist doesn’t mean people do it. Not sure how I’m normalizing deviance. I’m the guy who finds all the broken stall warnings and pisses off MX by grounding multiple aircraft at once.

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satans_little_axeman@reddit

>Uhh, just because it’s on the checklist doesn’t mean people do it. Okay, so why does your flight school not encourage checklist usage?

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makgross@reddit

You got a bit to learn about safety culture, or lack thereof. No flight school is good at that. Some are passable. Most aren’t.

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satans_little_axeman@reddit

I've seen plenty. Shitty safety culture exists because people tolerate it.

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makgross@reddit

You haven’t seen much if you think you’re going to change that by attacking your allies…. You can fight that windmill all you want, but you aren’t anywhere near powerful enough to fix it on your own. Yes, there is a problem with poor safety culture. There are also a lot of unairworthy airplanes flying, like it or not. Which is the thing you went off about.

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satans_little_axeman@reddit

The FAA defines Resignation as a hazardous attitude. Just something to think about.

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BrtFrkwr@reddit

So easy to find out.

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BigBadPanda@reddit

Towers aren’t required to report gusts, but a lot of them seem to. Gust is typically derived from ATIS, but that can be pretty stale info. When we check in with tower and they give us the steady wind, people immediately jump to take out the gust factor. It’s fun to watch people hem and haw over headwind components (15 knots, gee whiz, should we add 7 or 8?!). People like to bust out the micrometer when we’re swinging an axe.

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Drunkenaviator@reddit

I love the guys who are like "Yeah, you want to set target at 138 or 139?!?". How about you just bug something in there and I'll try to keep it in the general vicinity. My ass ain't holding a knot or two difference when it's gusting to 35.

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Headoutdaplane@reddit

And on top of that the instrumentation is not accurate to a knot. Our PFDs can have up to 4 kt difference before we get a miscompare CAS

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Hour_Tour@reddit

No idea if this is true for FAA, but in UK we report a 2min average wind value which is computed by the system continuously, showing both gusts and lulls if deemed significantly by it. We sometimes give instant winds too if warranted. METAR/ATIS wind is 10min average leading up to report.

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BigBadPanda@reddit

Take anything reasonable and smart and assume the FAA doesn’t do it.

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BrtFrkwr@reddit

People try to quantify what is essentially a qualitative judgment. Think about it, try it and see how it works. And what works well in one airplane may not in another.

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Mithster18@reddit

Is this the power/attitude for profile and Airspeed argument again?

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ByTheBookerInvests@reddit

I’m surprised you didn’t get a horn before 45kts. I am a student flying a PA-161 and I feel like I get a horn around 55-60kts usually. To be fair 3-4 seconds of raising the nose on short final is quite along time assuming you had very little or no power in. Thanks for sharing!

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WhiteoutDota@reddit

I instruct in PA28-161 planes and only get the stall horn at like 42kts in a landing configuration, around 50 in takeoff

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ByTheBookerInvests@reddit

My POH has 50 as the actual stall speed in clean configuration and 44 with flaps. Wouldn’t you expect the horn 5-10kts before? Not much of warning if they are the same.

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__joel_t@reddit

Remember, stall is a function of angle of attack, not airspeed. POH "stall speed" is the airspeed at which, in a particular configuration and weight, you need to be at the critical angle of attack to maintain straight and level flight. So you can absolutely be below the "stall speed" and not stall, for example, if the aircraft is less heavily loaded.

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Headoutdaplane@reddit

Great explanation.

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WhiteoutDota@reddit

Take a look at the stall speed chart in the performance chart section. Stall speed changes with weight.

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the_silent_one1984@reddit

Cessnas have a little whistle apparatus to detect excessive angle of attack, unlike the Piper's switch thingie. So what I've observed in the 172 is as the stall approaches you kind of hear a light howl of sorts first, which slowly grows into a louder whistle. It's hard to explain. 45 knots won't make you stall immediately, either if you aren't abruptly yanking on the yoke. You just need to pitch up more and more to maintain that speed, resulting in a stall very soon afterwards.

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makgross@reddit

What I find is that no one checks the Cessna stall warning during preflight ‘cause it’s icky, and half of them are broken.

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Professional_Read413@reddit

Damn really 60 knots? I'm in a 151 but I typically don't get it until like 55-60 MPH (47-52 knots) And yeah agreed 3-4 secs is a long time. My airspeed changes every second or so if I'm not on it while coming in on final

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Skydance98@reddit

Typically a 172 will trim around 60kts with full nose up trim. It should help you feel deviations from approach airspeed given you must add back pressure to slow down.

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bryan2384@reddit

Learned this trick if you get in the soup and aren't rated. One of the ways to survive... won't go into it here, but useful.

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MontgomeryEagle@reddit

172s are entirely too forgiving of speed indiscipline. Even a Cherokee wouldn't have let you mess up that bad, and their are incredibly forgiving.

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will-9000@reddit

"watch your airspeed, get the nose down." Probably my second most repeated mantra after " pitch, power, trim." Gotta keep that airspeed crosscheck going always.

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JasperinWaynesville@reddit

Agreed but I always include bank in that mantra. As in Pitch Bank Power and Trim. The FAA discusses l this at length in its Airplane Flying handbook (Chapter 3, Basic Flight Maneuvers.) As you know an aircraft's stall speed increases in proportion to the square root of its load factor. Load factor is a measure of the gravitational acceleration an aircraft is experiencing relative to normal flight, which is 1g. For example, if an aircraft has a stall speed of 50 knots in level flight, its stall speed will increase to 70 knots in a 60° banked turn. This is because the load factor at a 60° bank is approximately 2, so the stall speed increases by the square root of 2, or 1.4. [https://www.faa.gov/sites/faa.gov/files/regulations\_policies/handbooks\_manuals/aviation/airplane\_handbook/04\_afh\_ch3.pdf](https://www.faa.gov/sites/faa.gov/files/regulations_policies/handbooks_manuals/aviation/airplane_handbook/04_afh_ch3.pdf)

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satans_little_axeman@reddit

Stall speed and load factor increase in a *level* banked turn. Important distinction.

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rustydominoV2@reddit

And in any constant vertical speed descent or climb. It's a myth that stall speed only increases in a level turn. It increases with load factor, which increases with bank angle, no matter if you are climbing, descending, or level. When you bank an aircraft, it has to reach an equilibrium and it will do so by load factor. This is why I said constant vertical speed.

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Bot_Marvin@reddit

So you're saying if I bank with zero increase in back pressure my load factor will increase?

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satans_little_axeman@reddit

That's not constant vertical speed though.

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rustydominoV2@reddit

Yes but the aircraft will eventually reach equilibrium by accelerating and speeding up unless you are at like 90 degrees of bank lol you'll definitely be accelerating then

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rustydominoV2@reddit

Bot\_Marvin yes, if you do not pull back aka increase the angle of attack your lift will no longer equal the load factor required for the banked turn in an equilibrium state and the aircraft will speed up to the airspeed and aoa combination required to sustain that bank angle which will give you some load factor.

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satans_little_axeman@reddit

Constant vertical speed is the most technically correct, the best kind of correct. Saying load factor always increases in a bank, though, is wrong and promotes a superficial (and insufficient) understanding of the forces at work.

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rustydominoV2@reddit

true I like this answer better, some situations where you wouldn't have load factor in a bank could be something like aerobatics where you constantly push the nose forward to keep 1g But for normal operations we are usually in equilibrium aka constant vertical speed so that's why I said that

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JasperinWaynesville@reddit

"Stall speed and load factor increase in a *level* banked turn" Yes, and in climbing and descending turns too. For reference I recommend that you read: FAA's Airplane Flying Handbook (Chap 3 and 10) Aerodynamics for Naval Aviators (Chap. 5) Flight Theory and Aerodynamics: A Practical Guide for Operational Safety (4th Ed.) (2023) (Chap 11)

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the_danimal@reddit

does it win over "more right rudder"?

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will-9000@reddit

Fair point, #3 then.

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Equivalent-Web-1084@reddit

depends on the horse power

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dyljcks@reddit

You're gonna hear him say that all the way through training

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MostNinja2951@reddit

Remember that AoA causes a stall, not speed. It's good to watch your speed and react appropriately if it starts to drop but the absolute most important thing is **don't pull**. If you have light pressure on the yoke and don't pull through the stall warnings then outside of dramatic wind shear you will not stall, you'll just drop the nose a bit as you lose speed and lift. Go do some more stalls and slow flight and pay attention to the warning signs and how much pressure on the yoke it takes to stall if you're trimmed for approach speed. Also, go to an actual short field with real obstacles for your practice. You'll learn a lot more that way and be much more prepared to do it for real.

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Sharp_Reaction_8933@reddit

You can feel that 45 IAS in the seat of your pants with experience. Seriously. Figure out how to connect that to your eyes and relate it to what is going on. It’s a weird connection

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Kotukunui@reddit

Yep. I also find I can tell something is going on by the noise of the airflow past the aircraft, even with headphones on. I was sitting in the back once when we’re on approach and just felt, “it’s awfully quiet”. Looked over the pilot’s shoulder and the ASI read about 65. I said, “It feels like we are really slow…”. The guy in the right seat reached over and tapped the glass of the ASI, the needle jumped down to just under 50. If you fly enough, you start getting little clues from all sorts of senses which we group together and call “_seat-of-the-pants_”

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dkmy1@reddit

Student pilot here, and we literally just covered this last week during instruction so it’s pretty cool to see your post- glad you’re OK! You probably already know this but for anyone reading that doesn’t, I believe the gust factor calculation you should do before landing is wind speed - gust speed to get your gust factor, then take that and determine your final approach speed which should compensate for the gusting conditions. Landing speed = landing reference speed + (gust factor / 2). So, if winds are 180 @ 7G18, the gust factor would be 18-7 which is 11. That divided by 2 is 5.5, rounded up to 6, (let’s say landing speed is 70) plus 70 knots, you’d want to be coming in to land at 76 KIAS. There’s a lot of guys here with loads of experience so please tell me if I’m saying this wrong. :)

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Thats_my_cornbread@reddit

If you trim for speed, you’ll feel it with out ever looking at the airspeed indicator. 90% of students and probably 50% of licensed pilots never learned the relationship between trim and speed

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dmspilot00@reddit

Sounds like you had the right idea but raised the nose excessively. It doesn't take much when you're in a high drag configuration. Also you can use other cues for airspeed like wind noise and control feel. Finally make sure you are using trim to maintain speed, not elevator pressure.

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xtalgeek@reddit

I would strongly suggest using trim for speed adjustments on final. When you are horsing the yoke against the trim to adjust airspeed/AOA, it is hard to maintain a consistent attitude/AOA/airspeed, and it can get away from you if you are also trying to do other things at the same time. I like to get lined up on final, and if airspeed needs adjustment, roll in some trim in the appropriate direction then let things settle down. Once you know the plane well, you will know just how many turns to roll the trim to adjust the attitude to change the airspeed 5 or 10 knots.

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cafe_brutale@reddit

Mind you that 3-4 seconds is an awfully long time to not be looking at the IAS, especially in short final. Always remember to scan. You'll get better and faster with time.

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PutOptions@reddit

I’ve had the wind quit on me many times. Fortunately my stall horn initiates at >10knots above anything scary so it is easy to catch. 70 down to 45 is a little freaky. Either that pull was a little aggressive or you hit some shear. Or a little of both.

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wt1j@reddit

That’s a great learning experience and it’s the kind of thing that you have to experience to develop that short final scan where you’re glancing at airspeed frequently, especially after you’ve made a control input and should be looking for the result. Thanks for sharing!!!

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Vans-RV9A@reddit

This happened to me recently, I was landing at an airport without an ASOS station and didn’t expect to lose so much airspeed on short final leading to a stall and the plane dropping onto its wingtip before setting onto all 3 wheels. I did also flare too high which was part of it too. Lessons learned and the plane should be fine after some repairs!

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rFlyingTower@reddit

This is a copy of the original post body for posterity: --- Last week the wind was coming straight down the runway at 11 gusting to 15kts. I am practicing short-field landings with an imaginary obstacle at the end of the runway that I need to clear. I am on final in a c172 at 70 kts IAS with full flaps, so I decide to bring the nose up just a touch to bleed off some airspeed to get us down to 55-60kts. While I am doing this, I adjust the controls slightly to keep us on center line...all of a sudden, my instructor calmly says "watch your airspeed, get the nose down." I look at the airspeed indicator and it was reading 45 kts. So I put the nose down, add some power, and land without incident. The sobering thing was that from the time I saw 70 kts IAS, to the time I saw 45 kts IAS was probably only 3-4 seconds. I know, because I try to watch the airspeed indicator like a hawk when close to the ground. Before this, I had trouble understanding how people get below stalling speed in the pattern. Now I am starting to get it. --- Please downvote this comment until it collapses. --- I am a bot, and this action was performed automatically. If you have any questions, please [contact the mods of this subreddit](https://www.reddit.com/message/compose?to=/r/flying).

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