(article) Flying Speed, Part 2

[Wilfred]

We've been reviewing the FAA's list of the Top 10 causes of pilot-error accidents. Second on their list is failure to attain or maintain flying speed, and yesterday we concentrated on speeds for takeoff and initial climb. Today we'll look at another component of airspeed control: landing speed.

 

Landing speed

 

Even more critical to safety than takeoff speed, it's vital to be on speed for landing. While on takeoff you can usually abort on the runway (if you catch the airspeed deficiency soon enough), on landing you have no choice but to fly, either up or down. Airspeed must be precise on landing because:

 

Too much speed may result in a runway overshoot, and

 

Too little airspeed can result in a stall short or the runway.

 

Here's the pitch

 

<STRONG title=http://www.aero-news.net/news/featurestories.cfm?ContentBlockID=59e6d7cb-4bb7-463e-a0b0-2cb8e06c69b9&Dynamic=1>As we said yesterday[/b], performance is a function of power and pitch attitude. With power at or near idle, there's a pitch attitude that results in the proper final approach airspeed. Note that the airplane needs to be in proper configuration (flaps, landing gear as appropriate); airspeed resulting from the expected pitch attitude, in fact, serves as a good crosscheck for aircraft configuration.

 

Use the "book" final approach speeds unless conditions warrant otherwise. It's commonly accepted that final approach speed should be increased in gusty winds, but one-half the "gust value". For example, if the wind is at 15 gusting to 25 knots there is a 10-knot gust value, so final approach speed should be increased about five knots to provide a cushion above stall should the headwind go away while you're close to the ground.

 

Stall on final approach

 

From the NTSB:

 

The airplane stalled on short final, impacted the runway's displaced threshold in a nose low pitch attitude and erupted in flames. The airplane was on final approach and the pilot was conducting a full-flap landing. He reported that everything was fine, but the airplane began descending too fast. He applied some power to go-around, but the airplane encountered a gust of wind and stalled on short final. Witnesses at the airport observed the airplane on short final. The nose pitched up to a level position about 50 feet above the ground and then nosed down until impact with the ground. The weather observation facility at the airport was reporting the wind at 7 knots down the runway

 

Aero-tip of the day: To avoid this common cause of aviation mishaps, failure to attain or maintain flying speed, know the airplane's landing speed and configuration and the proper pitch attitude for final approach. Be ready to go around if needed