Ask the Captain: Finding the runway through the clouds

Question: I am always amazed when my flight descends through all the clouds after a 2-hour flight and the runway is right in front of us. How do you do that?

-- submitted by reader Bill, Warrenton, Va.

Answer:

Pilots traditionally used radios to navigate. The FAA ground stations known as Very High Frequency Omni Directional Range (VOR) provided the enroute guidance. Lining up with the runway used the Instrument Landing System (ILS) which provided lateral (left – right) and vertical (up – down) guidance.

Since the widespread use of the Global Positioning System (GPS) modern airplanes have used this technology extensively. Precise navigation is the short answer to your question.

Q: How do pilots find the distance to an airport?

--Eric, Norway

A: At many airports there are special radio transmitters that send information to special receivers onboard the airplane. This system is known as Distance Measuring Equipment (DME). In the more modern airplanes with more advanced navigation equipment, the distance to the airport is displayed to the pilot. Newer airplanes know by GPS, inertial, or radio navigation where they are, where the destination airport is and the distance to it.

Q: Captain Cox, as a plane approaches landing and we have to stow electronic devices etc., how do pilots keep the perfect speed as they approach the runway? Are they on autopilot or gauging it by themselves?

-- Joe, Sacramento, Calif.

A: Airspeed control is one skill pilots learn from primary flight school. In today's modern airlines, the autopilot/autothrottle systems maintain the selected speed, similar to cruise control in an automobile. Often the pilots will disengage the autopilot and autothrottle to manually fly the airplane. In manual flight, the pilot maintains the proper speed, frequently scanning the instruments for verification. Pilots learn effective scanning techniques early in training and maintain them throughout their career.

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