The modified Navions (the original ones only had two flap positions: full up and full down), suggest half flaps (about 17 degrees) for short fields.
How do you bring flaps up in a go around procedure?
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Caramon13
Pattern Altitude
I've heard of people using this technique on grass strips as well. The "pop" technique. I don't think I'd ever use it as to me it's inherently dangerous and distracting. Your hand should be on the throttle from the takeoff roll until you are at a safe altitude to clean up the plane. And after that clean up, right back on the throttle.
It's the same reason I disagree with adding anything in, flaps, trim, etc on short final because you should already be stabilized. More work = more distraction.
Use flaps or not on the takeoff, but don't decide to all of a sudden change the configuration on rotation, that's a bad time to do anything except fly the plane.
bnt83
Final Approach
None of those 172s have 40 degrees. There are a great many cases where 40 (or even 30) will just make things more difficult, high OAT/high elevation/@ gross/windshears/etc, or any combination of them come to mind.
My 150B had manual 40, I loved that setup. I flew a lot of rides with some big passengers on hot windy days, I would come in high enough to drag 40 and make shallow S-turns at idle. Easy way to make your non-flying friends turn green. Learned a lot doing that.
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midcap
Pattern Altitude
You mean that Cessna called it 40deg, but it really wasn't 40deg?
bnt83
Final Approach
Late serial numbers only have 30 and placarded 30. Early serial numbers have 40 and placarded for 40.
If the airplane is loaded and flown in conditions where the performance is marginal, full flaps can add enough drag to make overcoming a sudden sink or shear very... exciting...
Use the boat anchor wisely.
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BalooAirService
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Cloud Kicker
Just bring down the slats.
bnt83
Final Approach
Some folks like using full flaps and lot of power on final.
I lean more towards flying final closer to idle and using full flaps only when needed.
I lean more towards flying final closer to idle and using full flaps only when needed.
You can land trainer type aircraft with no flaps, 10, 20, 30 or 40 degrees of flaps. All either power off or partial power. And a good pilot should be able to do them all. Students should practice each of those combinations at some point in their training. Some aircraft can't climb very well with 40 degrees of flaps, especially if you have the carb heat on also, so watch that one. Cessna 172s have very large effective flaps. Pipers not so much. Mooneys hardly any at all. So it varies from plane to plane. Obviously stick within the limitations in the POH.
MAKG1
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That's a perfectly legit short field technique.
If you don't need such a technique, steepen the approach and do it at or close to idle. Full flaps are always called for, unless you don't like seeing the runway or like floating.
brcase
En-Route
I was taught to do TNG's with 20deg, then when you do the go part, simultaneously push in the throttle with your hand and push in the carb heat with your thumb, then climb out and once you have some altitude and cleared the obstacles, flaps all the way to 0.
I think it's nuts to do a touch in go with 40 deg of flaps, especially at the 2999' rwy I practice at.
As mentioned you will get a difference of opinions on this, Apparently I am not one of the "majority of instructors", I personally prefer 20 degrees or less of flaps for TNG's and normal landings. Especially with new students. One reason is that it makes Go arounds much easier just because you don't have to immediately reset the flaps.
It has been a while but I did some figures that once showed the stopping difference between 20 and 40 degrees of flaps was less than 100 feet difference IIRC. Just look at the difference in stall speeds it is only a few kts.
It would be interesting to do some testing to see if a TNG approach with 40degrees or 20degrees results in a shorter distance to clear a 50ft obstacle. Probably to many variables to really give a definitive answer, things like what speed do you slow down to and when do you change flap settings.
I also find that many 172's with 2 people are near the forward CG limit and landing full flaps power off it is difficult to touch down on the main gear 1st.
Many pilots compensate for this by landing with power on, which kind of defeats the purpose of landing with full flaps, especially when landing with 20 degrees power off will likely get you stopped sooner and it is much easier to touch down on the main gear.
Brian
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MAKG1
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Nonsense. It is substantially easier to land a 172 on the main gear first with full flaps than clean. If someone can't, they aren't flaring, and are probably combining that with a fast approach speed. In a 172 loaded to max, it's 61 knots. Not 65, and definitely not 70. That's not a problem with flaps, it's a problem with technique. Same thing with landing a 182 on the nosegear. They aren't "nose heavy," the pilots are lazy in the flare; there is plenty of elevator authority to do it, even at slow speeds with the power idle. And two big guys up front in a 172 puts you real close to the forward CG limit. I did almost all my instrument training that way.
You also misunderstand what landing with power means if you think it affects stopping distance. Once the gear is on the ground, the power goes to idle, every time. You can get quite short landing rolls that way, especially if you approach behind the power curve.
Power is not the commodity, energy is.
Checkout_my_Six
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yup....low energy is a bad thing.
midcap
Pattern Altitude
please clap...yup....low energy is a bad thing.
That's going to pretty much take care of itself when you apply full power.
Checkout_my_Six
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Yup....and folks we'll be here all week....and don't forget to tip the wait staff.
jesse
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Two of our 172s have 40 degrees...80725 & 73477 (M models). The N model, 734PG, does not. Regardless of if we're flying a M or N I teach to default to full flaps. I've landed them full flaps with the wind gusting over 50 knots more than once.
The "it makes it more difficult" is just perception. You're by far better off sorting out a difficult situation in an AIRplane while you're in the air and always touching down at the slowest speed. The additional drag then more quickly helps you decelerate and ditch lift. All of which are good things when you're transitioning from flight to driving down the runway in a vehicle that handles about as well as a shopping cart at high speeds.
Analyizing the NTSB reports makes it very clear that loss of control events on landing (like 90%+) are caused by excessive energy. Doesn't matter what the wind was -- their energy was excessive. The more flaps the less excessive energy problems. The less excessive energy problems the less loss-of-control events.
Pretty much the same policy the FAA espouses. Full flaps, all the time.
bnt83
Final Approach
It great how accident investigators can lump all accidents into one group and determine without a doubt that one thing would have prevented it lol, "if only they had less energy prior to crashing!"
https://www.faa.gov/news/safety_briefing/2010/media/MarApr2010-FlyingByTheNumbers.pdf
This says pretty much use whatever gets the job done, which seems reasonable to me in a small airplane. I don't want max drag in nasty conditions, I want to be able to initiate a go-around without max drag, hopefully escaping whatever sinking air / tail shear I might have flown into on final. It probably sounds like I've scared the crap out of myself once and you WOULD BE RIGHT! Max flaps with a heavy load on a hot day and flown into sinking air and full power doesn't arrest the decent, that's NOT COOL.
Arguing that touching down slower is gonna exponentially increase safety seems like a stretch when the stall speed with & without flaps a whopping 7 knots different. If you're way over on energy that causes an accident using full flaps probably wouldn't have changed it.
brcase
En-Route
There are quite a few different models of 172's newer ones land full flaps on the mains better than older ones. Many older ones at forward CG, power off, full flap, will only touch down about 3 point with yoke against the stop. I have put 50lbs in the baggage compartment of some when practicing short field approachs, for this reason.
My view on flaps comes from flying everything from cubs and champs with no flaps to gliders with 90 degree flaps. As a CFI and glider pilot I practice simulated power failure approaches and actual off field landings probably more than most pilots. I view flaps as a tool that can be used, to control the approach, not just an on/off selection for minimum touch down speed.
But I also teach to practice all kinds of approaches and decided for yourself what kind of approach and configuration you and the specific airplane you are flying works best for your normal landings. If full flap power on approaches work best for you then great. I just prefer partial flap power off approaches (kind of a requirement in my glider(no spoilers)). This is a middle of the envelope approach. But when I get in a new airplane I will practice different approaches to find out what I like for that airplane. I can't say I blanket teach any specific configuration because it changes from airplane to airplane.
I just looked and the C172N 2300GW 40 degree flaps, landing distance is shown as 520ft Ground Roll, 1250ft over 50ft obstacle
The C172P 2400GW 30 degree flaps, landing distance shown as 540ft Ground Roll, 1280ft over 50 ft obstacle.
So per the Cessna manuals, add a 100lbs and reducing the flaps from 40 to 30, increased the ground roll 20ft and the 50ft obstacle landing 30 feet.
Brian
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There is no use in arguing with him. He already knows everything.
dmspilot
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You have not flown many 182s. Some will still want to touch nose first with the elevator against the upstop.
If you stall an airplane in level flight with full flaps versus zero flaps, will the nose be higher, lower, or the same?
Is the nose higher or lower on a full-flap approach versus a zero-flap approach? Which one requires more pitch change during the flare?
MAKG1
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I've flown N, P, Q, R and T models. Is that enough?
Not one of them does what you say unless loaded outside the W&B envelope.
dmspilot
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How many letters are in the alphabet between A and N?
MAKG1
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Jeez, this is full of misdirection.
To land mains first, you need the nose above the horizon with the stall warning sounding. And that's it. You lift it higher, and you still land on the mains first, just with the tail a bit closer to the ground.
And add 1, because the first 172 was just a 172 (with no model letter). The 172A was the second mode.
jesse
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You're certainly free to have a different opinion - and free to teach it however you'd like once you get your CFI. I've said my perspective and what I teach when I have full control over a pilot's training from day one. It's based on four digit hours worth of sitting in the right seat and preventing new pilots and old pilots from crashing their airplanes when they land them. I have pairs of shoes that have more landings in Cessna's than most any private pilot will accomplish in their entire life, and I say that not because that means anything in itself. It's just a fact and evidence that I'm not just pulling this advice out of my ass. It works.
Overall, as an instructor, you pick and choose your battles. If I have control over a pilot from day one (zero hour to private) they're going to be using full flaps all the time by default. We certainly do landings with different flap settings.
None of these pilots I've ever created have ever bent an airplane NOR have they ever later felt that my advice on flap usage was incorrect or created an issue for them.
denverpilot
Tied Down
The drag effect of the flaps doesn't stop after the touchdown and the accident doesn't usually happen at touchdown, but later. 7 knots difference in stall speed but a large difference in drag AFTER touchdown. The real problem is arguing stall speed and not overall deceleration.
Stall speed is almost a meaningless number once the wheels are on the ground other than as a reference as to what speed one SHOULD have touched down at. It's too late at that point. Now the question is, will you get it stopped before it's in the ditch? You've already transitioned from a flying machine to a very poor efficiency go kart.
That is the FAA's line. You want to land with minimum energy in their estimation. That means as slow as possible. Actually, the operative number isn't really stall speed (though that helps. PLANES ARE NOT LANDED IN A STALL. The reason that you can land slower is that the lift is increased, allowing it to maintain the desired glidepath at a slower speed.
ircphoenix
En-Route
Wait... You all use flaps to land?
bnt83
Final Approach
The drag effect of the flaps doesn't stop after the touchdown and the accident doesn't usually happen at touchdown, but later. 7 knots difference in stall speed but a large difference in drag AFTER touchdown. The real problem is arguing stall speed and not overall deceleration.
Stall speed is almost a meaningless number once the wheels are on the ground other than as a reference as to what speed one SHOULD have touched down at. It's too late at that point. Now the question is, will you get it stopped before it's in the ditch? You've already transitioned from a flying machine to a very poor efficiency go kart.
Now we should discuss if braking works better with full flaps or no flaps and does braking decelerate the airplane faster than flaps
dmspilot
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It's not misdirection.
Point 1. Full flaps lead to a lower pitch attitude during approach (you acknowledged this in your "can't see the runway without flaps" comment). This means more pitch change is required to flare.
Point 2. You can raise the nose more without stalling without flaps.
I conclude it is easier to land nose-high (on the mains) without flaps. Explain how you have drawn the opposite conclusion.
mscard88
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Nonsense, and I've taught in those old 172s. Never had that problem.
mscard88
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I've had my CFI since '78 and have always taught this way and agree with your methods Jesse. Even 182s are not a problem landing on the mains as some of you are implying. Sure heavier nose but one compensates for that. Never had a student or checkout pilot experience a tail strike either in any Cessna, or any plane for that matter.
denverpilot
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MAKG1
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Quite easily.
You're assuming the total change in pitch is the only variable. It's not.
You're teaching student pilots. It's much easier if they can see the runway to a later time.
You DO NOT NEED to raise the nose more. Any positive pitch angle will do.
Why do you suppose these airplanes even had 40 deg flaps, if they were such a pain to use? They were NOT removed for any safety issue, but rather to raise the max gross weight without compromising climb rate at full flap.
bnt83
Final Approach
There sure are a lot of emergency procedures in the POH that recommend flaps (as required) and even a normal one that recommends 20 or less.
https://www.flyingd.net/documents/N739EF_172N_POH_000.pdf
https://www.flyingd.net/documents/N739EF_172N_POH_000.pdf
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Stewartb
Final Approach
To the original question.... it depends on the airplane. Your 172 will behave differently than a 185 when full power is applied with full flaps. Know the procedures for the airplane you're flying. Personally I always use full flaps to land and I leave full flaps out during go-arounds until I've cleared obstacles. If I wanted to demonstrate the shortest takeoff my plane can do it would be a full flap takeoff. A 172 wouldn't do the same.
Most of what's been said in this thread is specific to one or two airplanes. Beware.
Most of what's been said in this thread is specific to one or two airplanes. Beware.
Dan Thomas
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Those old 172s, like most older airplanes, are often way out of rig. Too much control surface travel, too little, rudder rigged off-center, ailerons out of sync, and so on. A lot of pilots get strong impressions from the airplanes they fly, and if the elevator's up-stop was set for three or four degrees too little up-travel, he'd think that these old 172s don't have enough elevator authority.
Checkout_my_Six
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those limits aren't checked every year?.....during the annual inspection?