Warning! Spoilers for The Immortal Hulk #47 by Marvel Comics Below.
Iron Man isn't too worried about one of his Avengers' teammates getting thrown halfway across New Jersey, even if Captain America is. The Immortal Hulk has been confronted by the Avengers, who have been called into action under the threat of a potential attack by their former ally. In previews for the ensuing battle, the Hulk throws Blade across the city, which doesn't worry Tony Stark all that much.
The Avengers were called to New Jersey by Gamma Flight after the Hulk completely obliterated the U-Foes after returning from the dead stronger than ever. Evil government agent Henry Gyrich panicked after seeing his gamma team get so easily defeated and decided to bring in the big guns. In Immortal Hulk #46, Hulk fought against Thor and the rest of the Avengers, while his mutated wife, the Red Harpy touched down to help her husband against his former friends. The two gamma mutates are teaming up to take on seven Avengers and previews of their upcoming battle start off with a bang.
In previews for The Immortal Hulk #47 by Al Ewing, Joe Bennett, Ruy Jose, Paul Mounts, Belardino Brabo, and Cory Petit, an emergency alert is created for the Hulk's attack, as those in the surrounding area are evacuated due to the "monster" and his rage. Blade seems particularly angry in the Avenger's battle against the Jade Giant as he accuses him of being a vampire due to his ability to rise from the dead. Hulk responds by asking him if he can turn into a bat, when Blade says no, he throws him halfway across the city.
Given Blade's healing factor, Iron Man isn't too concerned when Captain America calls for his assistance to gather the vampire hunter. He tells Steve Rogers, "Blade's tough enough to survive the fall, Cap--," before he's told to make certain he survives. Iron Man tells his team Blade won't like being saved and that getting split up is exactly what the Hulk wants.
Iron Man is correct in assuming Blade would have likely survived being thrown a great distance - after all, he's got a healing factor that makes him very hard to kill. But, Captain America doesn't want to test out his limits and called for Iron Man to save him, despite Tony Stark's trust his fellow Avenger could take the fall. It's probably best Captain America is leading the fight against the Hulk because Iron Man's trust, while well-intentioned, could have gotten his teammate killed. The Immortal Hulk #47 is in comic stores this Wednesday.