Designing an airport runway

December 09th, 2008 | Category: Airports, Regulations

One of the key elements of an airport is the runway. In fact, if there is no runway, there is no airport anyway. The runway is the place where airplanes take off or touch down. Then, the runway features will be an important issue to bear in mind.

First of all we have the runway orientation. The runway direction will be a major fact in terms of airport operations. A wind intensity and direction research must be done in order to obtain and gather wind data, and then determine the most likely wind direction in that area. Now let’s talk about physical characteristics.

The two more important sizes are the runway length and the width. Depending on the aircraft expected to operate on that airport, you might use larger or shorter distances. There is no specific runway length established by FAA or ICAO, but could change from 200 meters to infinite (if we could have that region). About the runway width it is mandatory to be greater than 18 meters up to 60 meters (able to land an A380). There are other physical matters, like strips up to 150 meters (around the runway) and shoulders up to 15 meters (paved margins at both sides of the runway).

 

Strip and Shoulders

In addition, to promote the most rapid drainage of the water, there should be a transverse slope not greater than 2%. Longitudinal slopes cannot be greater than 2% (just imagine a 3000 meters runway, 2% would mean 60 meters of vertical variation).
 
vuelos baratos

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North Atlantic Routes: I eat beef, you eat fish

November 07th, 2008 | Category: Airlines, Regulations

Every single day, hundreds of commercial airplanes cross the north atlantic, flying transcontinental routes linking North America and Europe basically, the NAT (North Atlantic Tracks). The performances of these flights are much different and complex due to its distant routes from any kind of airport.

The twin-engine aircrafts operating these flights (usually big ones) must have the ETOPS rating, explained in other post. That is because the nearest alternative airport when flying above the atlantic is 180 minutes far. If an engine failure happens (or any other system), this aircraft should divert to the closest airport immediately.

Another huge problem is the radar coverage. As a matter of fact, this radar coverage does not exist. Radars must be set up on ground or close (not floating over the sea). The main Air Traffic Control facilities (Shanwick Oceanic for European side and Gander Oceanic for US side) are equipped with air traffic management systems that by means of pilot manual position reports, they have some sort of “radar-like” screen with all the airplanes’ positions.

The third and big problem as well (but solved anyway) is about communications. The communicacions between pilots and controllers use VHF (Very High Frequency from 30 MHz to 300MHz) frequency range. VHF waves only reach “line-of-sight” spaces. So, in that case they must use HF (High Frequency from 3 MHz to 30MHz) that bounces off the ionosphere and give coverage to greater distances. Nevertheless, even this advantage, sound quality is much poor.

The NAT routes are designed and published daily. They are defined with an entry waypoint, an exit waypoint and between, waypoints are defined with coordinates (there are no navaids to define them). Early in the morning, westbound routes are published. Then late at night, eastbound routes are published. Europe incoming routes are usually defined at higher latitude, to take advantage of the Jet Stream (high speed wind, will post about this).
By the way, pilots flying these routes cannot eat the same meal. ;-)

Here we can appreciate North Atlantic Routes all the day long
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