why do aircraft have a tail number and a callsigh?

Question

why do some aircraft file a flight plan with the callsighs and not just their tail numbers.

Answer 1

the tail number is split into two parts, the first denotes where the aircraft is from ie G is UK registered, then the series of letters after this denotes its own identity, like a car numberplate it is unique.

the call signs denote the flight plan number of a given timed service from place to place for commercial airlines, private or smaller aircraft normally do use their tail numbers as callsigns.

Answer 2

In the case of a tail number, that is a single aircraft going from point A to point B. the purpose of the lfight plan is to locate the aircraft if it goes missing or does not show up at its intended destination.

In the IFR world, however, flight plans are not used for search and rescue, but for planning proposed routing and anticipating traffic conflicts. In the case of a call sign, one aircraft may fly many different flight in a day. For instance, my schedule today took me (all in aircraft N351SK) from KIND to MKKE, back to KIND, again to KMKE, to KMSN, and back to KMKE. If there were only one flight plan filed, it would have encompassed 6 hours of flying time and over 8 hours of total elapsed time. It would be difficult to have multiple flights all saved under the same tail number, as some of the legs were even the same route (KIND to KMKE)

So, instead of tail number, we file flight proposals by call sign. In our case today, they were SYX2050 and many others all starting with SYX. All the flight numbers are unique, so that ATC can differentiate between legs, and if we need to swap aircraft due to mechanical failures, we need not file a whole new proposal.

In some cases, it also helps differentiate between aircraft operating under part 91 rules and those operating under parts 135 or 121. Part 91 aircraft usually go by tail number while those operating under 135 or 121 (basically commercial operators) are granted a fleet call sign. It may be the name of the company (United, Delta, Northwest) or a derivative of it (Ace for ASA, JetLink for Express Jet, Skyway-Ex for Skyway) or something completely off the wall (Cactus for America West). this is helpful for the controllers as commercial operators have an additional set of rules they need to comply with. If someone is calling themselves by a fleet name, the controller knows automatically what additional information must be provided to the pilot(s) of that airplane.

Answer 3

To uniquely identify the aircraft. Just like number plates on a car. Most private aircraft use their tail number as their callsign. Commercial and military aircraft typically use callsigns. The flight plan cross references the callsign and the tail number.

Answer 4

Priavte aircraft noramlly only use there unique tail number as they are usually the only one in a fleet, where as commerical aircraft use callsigns such as TopJet (Thomas Cook), Speed Bird(British Airways), EZY (EasyJet) because there are usually many aircraft in the fleet and its easier to identify specific airlines for specific orders. I speak to aircraft on ground-to-air regularly as i work at an airport, and call signs are a very important part of RT.

Answer 5

The tail number, or the N number in the US is uniqure to the plane. Its the only ID for communication with the ground or other planes. A flight plan numver is nont referred to generally.

Answer 6

it is the identity of the aircraft! specially while taxiing and in flight. the tail number is for airline plane markings and serial number.

Answer 7

For the same reason you have a licence plate on your car...
There are lots of MD 80's and 737's arround. It's like being in a parking lot full of silver Honda Accords. The numbers and call signs keep traffic control working right.

Answer 8

Just an addendum to other answers:-

As well as airlines, you will occasionally find that some companies (usually with more than one aircraft) may use a call-sign.

Answer 9

they have it so that ATC (Air Traffic Control) can identify the aircraft on radar.

Answer 10

you fella's pretty muched summed it up.