Glitch

This article lists them many glitches present throughout the Ace Combat series. In its broadest sense, a glitch is defined as "an unintended effect or fault in software". Glitches often range from simple collision detection failures to physics defying.

Wingmen collision detection
Wingmen in Ace Combat 5 feature often unusual collision detection. For example, if flying too close to the ground, they will not crash, but instead phase through the scenery. Unlike enemy fighters, however, wingmen are solid to physical contact, and the player will be instantly killed if they ever ram a wingman in mid-air.

Arkbird glitch
A particularly famous glitch can be witnessed in mission #24, "White Bird (Part II)". When playing in Ace difficulty, once the player has to destroy the Arkbird's final & main engine, there is a very rare chance that the Arkbird will glitch and begin flying in a way that defies the laws of gravity; that is, moving around like a normal fighter despite its size. This glitch is harmless and will not have any serious consequences after the mission, although the Arkbird's increased movement speed can make the task of destroying the main engine very difficult.

Aces tunnel flight
In mission #27, "Aces", it is possible for the player to fly into the Sudentor tunnel network by entering through the other side, which is normally where the player escapes at the end of the mission. To do this glitch, play normally until the allied forces raise the tunnel's steel gate. Once AWACS Oka Nieba asks you if you are ready to fly into the tunnel, do not fly inside; instead, fly towards the north of the map. The SOLG will continue opening fire from the atmosphere as usual, but will not harm you. Upon the way, you will be able to hear dialogue that normally you would not hear at this point (ie. Yukes and Oseans talking with each other, President Vincent Harling and Prime Minister Nikanor's full speech, etc.) Once you reach the northern desert and the tunnel entrance, you will hear Jack Bartlett's "coming at you, Booby" transmission as though you destroyed the first SOLG core within the tunnel, followed by Hamilton's scripted dialogue. After this part is done, return to Sudentor and fly into the tunnel as usual. Once the SOLG's control core is destroyed, the mission will be automatically over, and the game will instantly jump into the scene where the Ghosts of Razgriz escape. The reason behind this glitch is that the player's actions led the game into believing that they had played the mission normally when flying north.

Flight ceiling glitch
Under certain circumstances, it is possible to "pierce" the standard 40,000ft. flight ceiling. To do this, use a plane with a high speed stat (the MiG-31 Foxhound is highly recommended for this task), then select any mission. Once the game loads, raise your nose in a °90 degree angle so that your plane perfectly points upwards, then hit the throttle. If done right, you will bypass the flight ceiling. After crossing this "boundary", keep R1 held down. Once enough altitude has been gained, the sky will turn pitch black, and the screen will shake wildly. It is possible to attain altitudes of over 100,000 feet. If this glitch is seen in replay mode, minor glitches can be seen, such as the player's plane appearing to spin wildly and black "holes" appearing through the sky.

A related glitch is the "flight ceiling bounce" glitch. To do this, select a fast aircraft like a Foxhound, then select any mission. Fly into the flight ceiling at full speed so that you are bounced back into lower altitude. Keep R1 held down, then keep flying towards the flight ceiling. As time passes, you will be bounced into Earth at increasingly higher speed, up until the point where you are bounced off the boundary at an extreme speed back into Earth.