The Mark XLII Armor is Tony Stark's forty-second Iron Man suit and was built to serve as his main Iron Man armor following the Battle of New York and the construction of the Iron Legion. Designed for automatic deployment and assembly, the suit is composed of several separate sections that can collapse into small pods. Using an independent propulsion system, each section can fly to the user and automatically assemble on their person. The suit can be summoned at any time, responding to impulses relayed by microchips implanted in Tony Stark's left arm.
The Mark XLII never became finalized, as it was still in its testing phase when Stark was forced to start using it, thus it retained some design flaws in the weapons system and other functions.
Tony Stark built the Mark XLII a few months after the Battle of New York. It was first used in action when the Mandarin attacked his house. Stark used the suit to mentally suit Pepper Potts up in it to protect her from mortal danger during the attack. Pepper then made her way out of the mansion with Maya Hansen. When Pepper was clear of the explosions, Stark had the armor detach itself from her and donned it himself.
Since it was at 22% power, Stark had a difficult time defending himself. Nonetheless, he still managed to take down two of the three assault helicopters that were attacking. However, when he destroyed the second chopper, it came flying at him, sending Stark into the water.
Back to Basics
Stark fell unconscious, but J.A.R.V.I.S. helped him escape and flew them to Rose Hill, Tennessee, following a flight plan from his investigation on the Mandarin. His armor lacked enough power to fly back to California and the world believed him to be dead.
Saving the Air Force One Crew
It was later repaired and recharged and used to save Stark from the Mandarin's compound and to save most of the passengers and flight crew of Air Force One from the rogue Eric Savin's attack, before falling out of commission again after colliding with a truck. 
- "I'll be damned. The prodigal son returns."
- ―Tony Stark
Later, in the battle against the Mandarin, it responded to Stark's anxiety and flew to him shortly after the Mark XL's destruction. It was used by Stark to trap Killian against a wall. In an attempt to kill Aldrich Killian, Stark had J.A.R.V.I.S. activate the Mark XLII's self-destruct. The resulting explosion was so powerful that it destroyed most of the oil platform and ripped through the Mark XLII.
Transported to the New Avengers Facility
Considering it the "prodigal son", Stark reassembled the Mark XLII sometime later and kept it in Avengers Tower. As Stark was moving the Avengers stuff from the Avengers Tower to the New Avengers Facility, the Mark XLII was one of the precious items on the Stark cargo plane.
- "Mark 42 autonomous prehensile propulsion suit test. Initialize sequence."
- ―Tony Stark
The Mark XLII Armor is undoubtedly one of the most unique and most powerful suits Stark has developed. Due to a series of computer chips he has implanted in his arms, Stark can summon the armor, as well as place the armor on others, with a simple gesture. He can mentally command the suit remotely with the aid of a Telepresence Headset. Unfortunately, it is very unstable and crashes several times due to still being a prototype armor. The also possessed a seemingly unique ability to electrify surfaces through physical contact, as Stark did to Heather and the rest of the crew members of Air Force One to keep their hands from opening when they grabbed each other to make a human chain. This suit also has qualities based on the Mark V and Mark VII that helped with the armor's portability, allowed the various parts of the suit to collapse for the user to step in and out of it seamlessly. 
| Mark I • Mark II • Mark III • Mark IV • Mark V • Mark VI • Mark VII|
Mark VIII • Mark IX • Mark X • Mark XI • Mark XII • Mark XIII • Mark XIV • Mark XV • Mark XVI • Mark XVII •
Mark XVIII • Mark XIX • Mark XX • Mark XXI • Mark XXII • Mark XXIII • Mark XXIV • Mark XXV • Mark XXVI •
Mark XXVII • Mark XXVIII • Mark XXIX • Mark XXX • Mark XXXI • Mark XXXII • Mark XXXIII • Mark XXXIV •
Mark XXXV • Mark XXXVI • Mark XXXVII • Mark XXXVIII • Mark XXXIX • Mark XL • Mark XLI
Mark XLII • Mark XLIII • Mark XLIV/Veronica • Mark XLV • Mark XLVI • Mark XLVII • Mark XLIX • Mark L
|Mark I • Mark II/Iron Patriot • Mark III • Mark IV|
|Mark I • Mark II|
|Tech Suit • Iron Spider Armor|