The Defender class Multirole Fighter is a Generation 1 Imperial Fighter designed by the long since bankrupt Crown Manufactures.
It was built right on the dawn of the Great Rebellion, which means it served through the entirety of it, and served as the symbol for the Imperial Air force.
It was shortly called Obsolete once Imperial Industries introduced the Generation 2 fighter, the IF-50 Firefox.
Nevertheless, whenever someone sees the Defender, they are reminded of the valor its pilots have shown in defense of the great Empire.

As mentioned previously, it was designed by the long since bankrupt Crown Manufactures. At the time, everyone knew that there was going to be a Rebellion. The tension in the air was all about when it would happen.
Spring, 2013, Age of technology, the fires of Rebellion were lit when the Amethyst tower collapsed.
The philosophy behind the Defender's design was rather simple. "Guns, missiles, and be very loud"
It was greatly successful, however there was always issues with it.
It was unstable, and at the time, the Fly-By-Wire system has not been invented yet so Crown Manufactures had to settle with sticking "Balance Bombs" as they called it on the wings.
While they can be used as conventional bombs, its better to leave them there.

Crown Manufactures went bankrupt while designing the successor of the Defender, called the "Protector" which also had problems with the design.
The stubbornness of the Company's CEO, John Johnson III, who insisted that this design must be how it looks to "Strike fear into the enemy" is most of the reason why the company went bankrupt. Throwing money at a thing that doesn't work is bound to not work. Who'd a thunk it.

The Defender, losing its main manufacturer, was being kept alive by House Magnus' many factories in the central deserts of Calderina, stating that it is the only modern combat plane that the Empire truly had. They had no intention on keeping it up, however, as they also said that they'll stop production by 2015, if the Rebellion stretches out to that point. Which it did.
By then, however, Imperial Industries, a new company at the time, came in with their new General Purpose aircrafts.

The war was shortly won by Winter, 2016.
The Defender, these days is used merely as a symbol of hope, and a beautiful scene whenever there's a Military Air-show, along with other historical warbirds that graced the skies, once upon an age.