Ask the Captain: Hard landings not bad ones

Question: Why are some landings so rough and others so smooth, sometimes even on the same plane in similar conditions?                     

— Submitted by reader Betsy Tutchton, Montrose, Colo.

Answer: There are many variables in a landing. The target is a constant descent to just above the runway, then to “flare” the airplane, allowing for a gentle touchdown. If a wind gust catches the airplane at the wrong time or if the pilot slightly mistimes the flare or there is turbulence just above the runway, a firm touchdown happens.

Under some conditions, a firm touchdown is necessary. When the runway is contaminated, touching down firmly allows the wheels to spin up and be much better at decelerating the airplane. When the runway is short, a firm touchdown is used to maximize the braking capability.

Q: I do not like flying out of DCA, and the two most recent times, the landing was so rough it felt like the plane was going to disintegrate. Are there any stats showing damage or injuries there?

— Daphne Poblete, Martinsburg, W.Va.

A: I have flown in and out of DCA for many years. The runways are relatively short, so it is a place where a pilot wants to precisely place the airplane on the runway to have the necessary stopping distance.  I do not remember cases where a hard landing at DCA caused damage. Airplanes are designed to take hard landings without damage.

Q: My 757 hit very hard as we landed in FLL. Are the stresses of flight greater than that of a very hard landing?       

— J.R. Northrup, Oklahoma City

A: They can be. A hard landing causes stress on the landing gear and the attachment points. In flight, stresses are in the wing and tail. In each case, the designers have calculated the maximum force and added a substantial safety factor.

Q: What happens after a hard landing?

— Vivek, USA

A: Depending on the severity of the landing, an inspection by maintenance may be required before the next flight. It is rare to have a landing of this type.

John Cox is a retired airline captain with US Airways and runs his own aviation safety consulting company, Safety Operating Systems.