Supersonic Passenger Plane

Supersonic Passenger Plane (超音速旅客機) is used in Toaru Majutsu no Index a few times during the course of the series. As the name indicates, it is a supersonic plane designed to carry passengers used by Academy City. Is most often used to carry Kamijou Touma.

Principles
The plane's size was bigger than the usual passenger plane and is almost 80 meters long. Despite this, the plane can go up to 7000 kilometers per hour (1944.44 meters per second) and can easily exceed Mach 3. It can go from Japan to Western Europe in about 2 hours. It's existence is enough for Touma to assume that the plane is the North American X-15.

The plane also has autopilot, requiring only for it to be lifted and landed on the ground to reach its destination properly. The plane can also be fired from an electromagnetic catapult for a quick take off. Moreover, to prevent technology from leaking out. Academy City designed the plane to thoroughly destroy itself using a special jet fuel and powerful acid when the plane could no longer fly. By the time it reaches the ground is a black dust of which the components cannot be analyzed even with a microscope.

Criticisms
Riding in one, Heaven Canceller describes it as having the feeling like there's no gravity, and even allows Touma to ride despite having injuries. Tsuchimikado Motoharu also expresses confidence in the vessel.

However, Touma on the other hand, states that the vessel is too fast and describes it as feeling "like a a thick metal sheet was slowly crushing my body [his] body," referencing to the powerful G forces that were acting on his internal organs.

La Regina del Mare Adriatico Arc
Heaven Canceller calls Touma to inform him that he doesn't want outsiders tampering with his body as he is part of Academy City, telling him that a supersonic passenger plane is waiting for him and Index to pick them up in Marco Polo Airport.

Their experiences with the plane did not leave any good impressions, and Touma refers to this incident that "closed Index heart to science."

Document of Constantine Arc
Tsuchimikado Motoharu and Touma go to School District 23 to find a plane there to get to Avignon, France. Despite Touma's remonstrations, he is forced to use the plane despite his terrible experience with it, and much to his horror, is later forced by Motoharu to jump out if it mid-flight in order to parachute into the city.

British Royal Family Arc
Both Touma and Index discover that the plane they were to take to England after being summoned was the supersonic passenger plane. Here, they both decide to abandon the plane and take an ordinary flight, and abandons Sphynx to the plane, who later arrives in London first, safe and sound in contrast to its masters.

DRAGON Arc
In order to escape from Mugino Shizuri, Hamazura Shiage and Takitsubo Rikou take a supersonic passenger plane and launch through the use of an electromagnetic catapult, just in time as Shizuri arrives for her revenge. On autopilot, Shiage and Rikou are taken into Elizalina Alliance of Independent Nations.

Shiage and Rikou later set up explosives on the plane in order for outside forces not to discover the planes secrets. They then parachute out of the plane mid-flight.

Magic God Othinus Arc
Academy City lets Leivinia Birdway and Lessar's group borrow the plane in order to conduct missions against GREMLIN in conjunction with the Anti-GREMLIN Alliance.

Leivinia, Lessar, Touma, Index, Mikoto, and Kumokawa Maria all ride the plane as the GREMLIN invasion of Tokyo begins. It is later attacked by Freyja's Nidhoggr, making it crash and forcing its passengers to escape using parachutes. Maria later mentions that the plane has been thoroughly destroyed as it has been designed to, and mentions that the pilot should be a professional and can only hope he did not mess up his escape.