Can I use the doors on my C172 as spoilers/speed brakes?

Question

I'm not asking if I should, I know I shouldn't. That would be stupid. I want to know if I could. On touchdown, if me and my passenger push our doors open as hard as we can, would they slow us down really fast or would they break at the hinges?

GO!

Answer 1

well now you're just being stupid.

Answer 2

Well, naturally that would help to slow the plane. At 45 knots, I doubt that would be enough to tear them off the hinges. They would just be really hard to open.

Answer 3

Just because a chief pilot says he did something, does not mean he did it. I know a few higher ups at a flight school I used to go to that talked about flying inverted in a 152 until the engine quit then did a loop to recover and fired it back up. It makes for a good "I'm such a good pilot" story but it probably didn't happen.

The last thing you should do when landing is take your hands off the control and open and hold the door open. If you want to have your passenger do it, then I think its a reasonably safe thing to try.

Also, as for pulling the flaps up as part of a short field landing, don't do it. On a low wing then yes, its a good idea. you want to get those flaps up because they are so close to the ground and very much so affected by ground effect. On a Cessna, as you pull the flaps up you aren't going to be able to increase the weight on the wheels all that much. You will end up decreasing the drag, and as you pass through 10 deg. of flaps you will INCREASE your lift. Its just not very effective.

Answer 4

Basic answer is don't put yourself in a situation where you have to consider options that don't fit into the safe parameters.  

And for sake of sanity don't listen to net mavericks like JB.  Cross control configuration can degenerate lift while maintaining desired heading but it has more chance of increasing airspeed than reducing it.  That's why you use it.  

The last time I heard of Slip Slide was at Six Flags.

Answer 5

Sure, the doors would cause drag and slow the plane down....which is what speed brakes do.

In the end, your passengers might have a broken arm or two, and you might not have a door on your Cessna.

Answer 6

With a stall speed that low, why bother?

Why would a Chief Instructor "brag" about opening the door(s) on a 172? I mean, that's not much to brag about.

Good luck with your doors. And be alert for asymmetrical door deployment, pilot distraction, etc.

Answer 7

Spoilers?  No.  

Speed brakes?  Yes.

If you're flying at a slow speed in order to open the door and throw something out, and after the stuff is thrown out  the passenger pushes the door out in order to stick his head out and look aft at where it is landing.........that causes plenty of drag, and can make it very difficult to get the plane climbing even with full power.  If you're already as low as the trees ahead it can be a problem.

Answer 8

Without all the added "that's stupid" or "it will break something" or even "it isn't practical" comments I will tell you yes, it is possible. Not advisable, but yes, possible.

Long ago in my younger piloting years I flew traffic watch in 172's and we'd chock the doors open on each side with chunks of thick scrap leather wedged in the hinges to hold the doors open while we flew. The window/door assembly was a one piece construction on some of the planes not allowing the window to be opened. Furthermore, it was too cool in the early morning hours to justify removing the doors completely. So we'd cover the early morning comute, fuel up, crack both doors and do the mid-day and evening coverage with the doors 1/4 the way open.

So in short - It is possible.

Answer 9

Are you He-Man ? It may work, but the arm is not very strong. i bet it woudnt do much, i doubt you could open the door very far until you were below 40 knots or so. Unless you can rip the door off with one hand i doubt it would break at the hinges. Save your strength for aerodynamic breaking by pulling back on the yoke. This will add a small amount of parasite drag and put more weight on the main wheels making the tires grip more and making the brakes work better.

Answer 10

uh. yeah you could. but why would you? did nobody ever teach you to use a ton of rudder in one direction and oposite alieron? what the h**l is that called now,,,,,let me think. ah got it. a side slip? jeez man, full cross control in my pitts s2b used to bring me straight down. no speed brakes will do that.

ah h**l just realized you are talking about as a stoping device after landing. why not just open a window and toss out an anchor?

Answer 11

It would certainly be frowned on by the FAA.  First response is valid.  C-172's have large effective flaps, so you really don't need much spoilage.  Your real problem would be this: you might get yourself down on a short strip from which you could not take off again.

Answer 12

How about cutting a hole in the bottom of the 172 and use your feet as the brake, Flinstones style.  Tell your instructor you have a new short field braking technique

Answer 13

Why not set it up to deploy a drag chute like the F4 used to use? That would be more effective.

Answer 14

Haha, yes they would slow you down. I landed in a small aerodrome with a door open (it was jammed) and it slowed us down faster than it normally would take

Answer 15

Is this the same alleged 172 you want to put the jet engine in?

At a ground speed of only 35 knots, why not use the brakes?  If you are touching down at 45 knots every time, you ARE the Cessna King since you can stall it onto the runway every time.  Most of us carry a little extra speed just to be sure.  Wow!

Opening the doors would in theory slow you down, but at that low ground speed, they wouldn't really be that effective.  It's also kind of hard on the doors and possibly the people in the plane.

You can also use the doors to turn while in flight, but that doesn't mean it's a good idea.

Doesn't work so well in most Pipers, unless you want to turn to starboard.

Answer 16

the hinges should hold.. the majority of the force is probably going into your legs/arms (whatever you're pushing the doors with)  but um.. why would you need to?  pull the flaps up when you touch the mains down, and pull back all the way... it's not hard to stop a 172...  you can do it in... probably 110 ft...

Answer 17

As a pilot and former student, I can honestly say that if I was attending a flight school where our "chief pilot/instructor" bragged about doing something so stupid...

... I'd find me another flight school and never, ever let myself or anyone I cared about fly with this idiot.

"There are Old Pilots and there are Stupid Pilots... There are never Old, Stupid Pilots"

Answer 18

First off, stall speed on a C172 is between 41 and 47 kias.  Check the POH...

If you are touching down at 45 knots, you are right where you should be.  You should hear the stall warning buzzer come on at touchdown.  If you are doing that, then you are at the lowest safe speed.

What you are asking falls into the category of possible, but not safe.  And if you question if the CFI did something, then have the guts to ask him/her.  If not, then don't believe everything you hear..