What do the following air traffic radio transmissions have in common?[audio:http://atccommunication.com/wp-content/uploads/2010/10/SA.mp3]
While each of these air traffic radio transmissions are intended to accomplish a specific purpose: a safety advisory, a position report, and a landing clearance, each transmission also helps a pilot build situational awareness.
Situational Awareness-What is It, and Why Do I Need It?
Situational Awareness, or SA, is exactly what it sounds like. If you have good SA, you have a good awareness of the situation, specifically:
- Your own location and status.
- The location and status of everything else that has a bearing on your flight.
- Where items 1 and 2 are going to be in the next few seconds and the next few minutes.
Let’s say, for example, you are flying into Boulder Municipal Airport at Boulder Colorado. Let’s build some SA:
- You are located 15 miles north of the airport at 8,500 ft MSL, heading 175, airspeed 110 knots indicated, level flight. Your left and right fuel tanks are at half with the fuel selector on the left tank. Your GPS indicates your groundspeed is 120 knots so there is a tailwind component of 10 knots. This comprises your location and status.
- The mountains are 20 miles to your right with the peaks ranging from 8100 to 9300 feet MSL in your immediate area. AWOS for the airport reports clear skies, unrestricted visibility, with winds blowing from 100 at 8 knots. Boulder traffic information reports the airfield is using Runway 8 with a left traffic pattern, and there is one aircraft in the pattern.
- Since traffic pattern altitude is 6300 feet MSL, you will need to descend 2,200 feet by the time you reach the traffic pattern. A 500 foot-per-minute rate of descent means it will take a little over 4 minutes to lose that altitude. You are moving over the ground at 2 miles per minute, so you should begin your descent no later than 8 miles from the traffic pattern entry point.
You’ve Got it Covered–Almost
Seems like you have all the SA bases covered . . . except one. How is your arrival into the Boulder traffic pattern, 6 minutes from now, going to mesh with the aircraft that is already in the traffic pattern? Any ideas on how to figure that out? I’ll have the answers in the next article. Stay tuned.