The Wrong Flaps

We are all trained to prepare a plane for landing. Generically, this includes the reduction of power to provoke descent, extension of flaps as called for in the Pilots Operations Handbook or POH, and extending the landing gear on those planes with retractable gear, before we make a safe landing. However, there are times when the use of full flaps isn’t necessary, and by knowing when these cases arise, you will be better able to handle them.

As we explained last time, flaps can help your plane to slow down and also allow the aircraft to make a steeper descent without an increase in airspeed. A slower approach means you have less energy to absorb in the landing and by your brakes as you transition from flight to ground operations.

THERE ARE TIMES THAT LARGER ISN’T NECESSARILY BETTER WHEN IT COMES TO FLAPS. Specifically, if there are heavy headwinds, or gusty crosswinds, having all your flaps hanging out there can actually give you more trouble than they save you on landing. For the Beech Bonanza for example, the first 10 degrees of flap operation make the wing bigger. The next 20 degrees (for the earlier models) really increases drag more than anything else. For the purists out there, yes, they also make the wing a little larger. This means for the Bonanza line, in gusty winds and wild headwinds, you need only extend 10 degrees of flaps and get most of the low speed performance and “bang for your buck” that you need to land safely. Besides, with any luck, the winds will be down the runway and your speed over the ground will be slow enough without flaps.

DON’T FORGET THAT THERE ARE RIGHT AND WRONG FLAP SETTINGS FOR PARTICULAR ENVIRONMENTS. Many planes have provisions to extend 10 degrees of flaps or more to improve takeoff performance. Remember – more flaps = more lift and more drag – so on takeoff, more flaps isn’t always better – it can actually be WORSE! Keep your head in the game and know your POH flap limits. Better yet, develop an understanding of why the handbook calls for those limits. Ask an instructor or contact a type club for the aircraft models you fly.

WHY FIND OUT THE DETAILS ON YOUR FLAPS? Because there are times when you will really need them. What if…

  1. Your flaps fail to extend fully, and you aren’t sure what the effect is.
  2. You have to land in a headwind of 50 knots, and by dropping your flaps (and speed) you drop your approach speed to 15 knots!
  3. The turbulence has already turned your passengers green, and lunch is on the way for an encore performance!
  4. The turbulence is so bad, that it has turned YOU green, and putting the flaps down is only going to make the rock-and-roll worse.

THERE MAY BE TIMES WHEN FULL FLAPS ARE TOO MUCH. Knowing how much of your flaps you need to extend on a routine basis is an important part of being a pilot. You can find much of this information in your POH, but if it isn’t available there, spending some time with an instructor and reviewing the right procedures for flap use can make a big difference in your ability to fly with the flaps in varying degrees of extension.

THERE MAY BE TIMES WHEN YOUR FLAPS DON’T EXTEND FULLY. By working now to understand the effects, techniques and requirements for your flaps, you will be better prepared to deal with them when Murphy takes the right seat and plays hob with the normal routine. While this may put you slightly outside of the POH, knowing what to do when stuff happens will assure that you can get to the ground when you need to, instead of waiting for a revision!