A hilarious but actually really important concept featured above in this meme. I can't say how many times a student has done this with me in the plane on a go around, once about 8 feet above the runway where I had to immediately take controls to avoid slamming back in the pavement.
If I could create a national movement about bringing flaps up in increments always, I would. I'd be extra dramatic and have t-shirts made, posters, a Facebook group...the whole 9 yards.
But, let's talk about some concepts here. WHY is it dangerous for flaps to be brought up or down all at once???
Flaps serve several purposes for flying and can affect the plane in multiple ways:
- they change the camber of the wing, so when you bring them down they increase lift
- because they're changing the camber they also decrease stall speed (therefore it becomes harder to stall the plane)
- although they increase lift, drag is also increased
- when coming in to land, descent angle is increased without increasing airspeed
- as flaps are brought up, lift and drag are decreased back to normal
Pictured below is the concept of descent angle using flaps:
In all 3 scenarios constant airspeed and constant power is kept (so the nose isn't pushed down more to compensate, and power is also not taken out) and as more flaps are added the plane is able to reach the runway at an earlier touchdown point.
All of this is taken into account in the factor of why we teach to never just put in or take out all of your flaps at once.
To simplify these terms, let's say that we're coming in to land on final. You realize on short final you forgot to put in any flaps so you hit the switch to put them all down. If flaps increase lift, this means your nose is going to pop up and you're going to have to counteract it by pushing back down. BUT because it increased that lift in that time span, now you're going to land farther down the runway because it increased your altitude! This is an important concept to avoid, however a trick where you can use this to your advantage is if you lost your engine and need an extra 40-50 feet to make your landing point. Dump all the flaps in at once! Practice a power off 180 in the pattern one day and don't put in any flaps until short final, them dump them all in and you'll see what this does. It's actually very cool.
Now let's say we're coming in to land and about 10 feet above the runway (so pretty low) another plane crosses the runway in front of us. If we continue the landing, bad things happen so therefore we execute a go around.
On the go around our steps are:
-carb heat off (if carb heat was on)
-ONE knotch of flaps comes up
-wait for positive rate of climb (+VSI), then 2nd and 3rd knotches of flaps come out in increments.
The reason this happens is because let's say we're on our very initial climb out above the runway and I hit all the flaps to come up at once. All that lift is immediately lost, therefore the nose sinks down. You can counteract this by pulling the yoke back of course but it has to be at such a fast right that you'll stall. So, if you execute a go around the WRONG WAY like this then basically you'll come back down to a not-so-soft touchdown on the runway.
For all the readers out there who have seen Surf's Up (the world's best Disney movie) and remember Chicken Joe, think to yourself to be like Chicken Joe when you fly. For those who have not seen it....I'm sorry for what you're missing. Chicken Joe is always very relaxed, never panics, and does everything smooth when he surfs. On a go around when you're reaching for that flap switch to bring it straight up, think about Chicken Joe. What would Chicken Joe do? He'd be smooth and take them out in increments. Be like Chicken Joe.
To conclude everything, flaps have multiple functions and affects on the aerodynamics of the airplane. Understand these concepts before you use them, because if you don't understand what's happening then you could be putting yourself in danger.
Always fly smooth, never panic when you fly, and no matter what maintain positive control of the airplane. This is what makes safe pilots.
For those sitting at home waiting out this pandemic, itching to fly again, check out the other posts and features on our home page for some interesting reads. Stay safe out there and to our fellow pilots, the industry is only going to get better after the pandemic is over. Keep your heads up!
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