B737900 From United States of America, joined Aug 2010, 186 posts, RR: 0 Posted (3 years 9 months 3 days 15 hours ago) and read 2945 times:
Hello all. I recently flew from Miami (KMIA) to Granada, BWI (TGPY, GND) and back on American Airlines flights 2171 and 2011. Wonderful vacation! I was interested to know if our route took us over Cuba. I went to Flight Aware and saw that it did not. I noticed that Flight Aware listed the rout as a series of letters/numbers such as: SKIPS 1, SKIPS, BR53V, RAJAY, etc, etc. My question: what do these letters/numbers mean and how are they used? Thanks.
[Edited 2011-03-24 09:52:56]
Sounds like a Beaver on floats..........we're saved!!
Well, it's complicated. There's many ways to write a flightplan route. Also bear in mind flightaware isn't known for being accurate and the filed route it usually displays is normally missing information.
I'll try to simplify it as much as I can...
In a nutshell, and *most* of the time, a flightplan displays the departure procedure, the airways to be followed and their respective changeover points, and an arrival procedure.
Here's a full rote I found for MIA to GND:
SKIPS1.SKIPSBR53V RAJAY A555 GTK L452 ANADA UG449 PERRY
The blackened numbers/letters are airways. The 5 letter figures that are normally meant to be pronounceable are fixes along those airways, and are displayed in the route since a fix may apply to more than just one airway and in this case indicates the point when you leave on airway and go to the next one. 3 Letter waypoints are for ground based navaids, in this case GTK is the Grand Turk VORTAC.
That's and extremely rough explanation but I'm sure someone else will chime in with more detail.
bio15 From Colombia, joined Mar 2001, 1089 posts, RR: 7
Reply 3, posted (3 years 9 months 3 days 12 hours ago) and read 2890 times:
The Instrument flight plan typically consists of three parts:
1 - Departure
2 - En route
3 - Arrival
1 - The first part consists of a Standard Instrument Departure (SID), or Departure Procedure (DP). This procedure is designed to guide the airplane from takeoff until it reaches a point that connects with the airway network. Depending on the runway you use for takeoff, the SID/DP indicates a series of turns and climbs that will put you on the desired airway point and on the desired heading. The SIDs/DPs are designed by the state authority on most cases, and they organize and expedite terminal traffic flow. On your example, SKIPS 1 is a SID that ends on SKIPS, which is a point that belongs to an airway called BR53V. Once you reach SKIPS, you are inside the airway, and from there on you just follow the airway. You have the SID/DP charts available in the flight deck.
Another departure option is to takeoff and just follow Air Traffic Controller instructions (called radar vectors) until the airplane reaches a point on the airway network. The SID/DP sometimes specifies a part of the SID/DP upon which you will be given radar vectors.
2 - The second part consists of a list of airways, or Air Traffic Services routes (ATS Routes), that are connected to lead you to your destination. On some flights there is a unique airway/route that leads you all the way to your destination, but in most other cases you have to use several different airways/routes connected with each other. Each airway/route is defined by many points which may be either Navigation Aids (radio based stations on the ground) or imaginary points which are called fixes or waypoints. The airway is simply created by "connecting dots".
Airways are designed to create the straightest possible routes to connect various airports and airspaces. On your example, BR53V is an airway that starts at the Virginia Key navaid just east of Miami, and goes to the west towards the Nassau navaid. SKIPS is an imaginary point located 43 Nautical Miles out of the Virginia Key navaid on the BR53V airway. The SID SKIPS 1 guides the airplane from the Miami airport so it can join the BR53V on the SKIPS point, so it can fly on the BR53V airway from there on. If the BR53V has many many points, you don't necessarily have to name them all on the flight plan. You just put the point on which you enter the airway, and the point in which you leave the airway. For example, if after RAJAY you will fly another airway called X444, the flight plan would read: "...SKIPS BR53V RAJAY X444...". If there were several points between SKIPS and RAJAY you don't usually have to name them because BR53V contains them all.
Another simpler way to fly en-route is to fly direct between navaids or points, which implies flying away from a specific airway but usually in an even straighter line. For this you must usually obtain a specific ATC clearance.
The en-route charts are large format charts also available in the flight deck.
3 - The last part is just the opposite of the first, and consists of Standard Terminal Arrivals (STARs). These are procedures designed to connect one point of the airway system with the approach terminal area of an airport. If you were arriving at Miami, you could use the FLIPR arrival which connects the easterly arriving airplanes with the Miami terminal airspace starting from several points along the airways. It is also usual to be given ATC instructions of heading, altitude and speed, (radar vectors) until you arrive at the airport, and this may be included in the STAR as "Expect Radar Vectors". The STAR navigation charts are usually in the same format as the SIDs and are available in the flight deck.
The last portion of the STAR should connect with an instrument approach procedure, which leads the airplane from a specific terminal point to the runway in use. This is not listed in the flight plan.
On big airlines the company just hands you the flight plan and you're usually familiar with it. You normally enter the flight plan into the navigation computer, and the autopilot may be coupled with the navigation computer to fly the flight plan accordingly. Pilot double-check is always required to monitor that the flight plan is being correctly followed by the computers.
Have in mind that the flight plan is just the initial flight clearance. You may deviate from the route, or ask for new clearances in the air to fly via different routes. Bad weather is a very common factor affecting the flight plan because pilots are constantly asking for deviations to avoid this bad weather. You may fly the same flight a million times and it will never be the same.