Deliberate mistake: When the show premiered on March 18th, 1981 Ralph's last name started out as Hinkley, but after a couple of episodes had aired on TV, on March 30th a man named Hinckley shot then U.S. President Reagan and three other people, so in the remaining episodes of season 1 Ralph's last name was changed to Hanley. His last name was changed back to Hinkley in season 2.
The Greatest American Hero (1) - S1-E1
Continuity mistake: When Ralph picks up the chair that was tossed out of his classroom, in the exterior shot he walks into the room holding the backrest's left metal post, but in the interior shot as he walks in Ralph is now holding the backrest's right metal post. (00:05:35)
The Greatest American Hero (1) - S1-E1
Visible crew/equipment: When Ralph walks into his classroom carrying the chair, in wide shots facing his students we can see several T-marks taped to the floor. (00:05:40)
The Greatest American Hero (1) - S1-E1
Visible crew/equipment: When Ralph joins hungover Bill in the boys bathroom, in some shots the boom mic casts two moving shadows on the door and wall, at the top of the screen.
The Greatest American Hero (1) - S1-E1
Continuity mistake: When Ralph is driving his station wagon, the rearview mirror disappears and reappears between the interior and exterior shots.
The Greatest American Hero (1) - S1-E1
Continuity mistake: While Bill and Ralph are in the car, John Mackie appears under the ship carrying the case with the suit. After John places the case in the car's trunk he walks back towards the ship empty handed, but in the last shot of John standing under the ship he's still holding the case.
The Greatest American Hero (1) - S1-E1
Continuity mistake: In one scene, Ralph is in a phone booth desperately trying to make a phone call. Ralph is nervous and panicky. But when you look at his reflection on the phone, you can see a big relaxed smile on him. When it cuts back to him, he is still acting nervous and panicky.
The Greatest American Hero (2) - S1-E2
Continuity mistake: At the hospital, when Ralph is sitting in the wheelchair the nurse calls for the orderly to help subdue Ralph. Two orderlies appear, and the black orderly's tunic has short sleeves well above his elbows, but as they all enter room six that orderly's tunic now has sleeves considerably longer and baggier than the previous shot. (00:02:45)
The Greatest American Hero (2) - S1-E2
Continuity mistake: When the police take Ralph to the hospital he's wearing his red suit that has slim fitted sleeves without cuffs, but as Ralph's right wrist is being forcibly restrained to the gurney, in the closeup Ralph's right sleeve appears to be the long sleeve of a red fleece shirt instead of his red suit. Additionally, in this closeup the white orderly's arms are much hairier and his watch vanished as well. (00:02:50)
The Greatest American Hero (2) - S1-E2
Continuity mistake: When Ralph is taken to the hospital and forcibly restrained to the gurney in room six, the black orderly is wearing a watch on his left wrist, but as he closes the restraint strap around Ralph's left wrist in the closeup that orderly's watch has vanished. (00:03:10)
The Greatest American Hero (2) - S1-E2
Continuity mistake: When Ralph escapes from the hospital and jumps into Pam's car, we see the entire front windshield without any sun visors or rearview mirror, but two sun visors and a rearview mirror suddenly appear in the closeup, which then disappear only to reappear and disappear again. (00:07:30)
The Greatest American Hero (2) - S1-E2
Continuity mistake: While Ralph's students are babysitting Kevin, when Shackleford takes Ralph, Bill, and Pam prisoner and brings them to the headquarters Pam is wearing white sneakers, but when they are led downstairs Pam is wearing black pumps thereafter. (00:28:00)
The Greatest American Hero (2) - S1-E2
Continuity mistake: After the trio escape from the locked room, Bill tells Captain Crash to stop the President's helicopter, and when it cuts to the long shot of the approaching chopper, a different type of helicopter is in following shots. (00:32:45)
The Greatest American Hero (2) - S1-E2
Visible crew/equipment: When Ralph tries to warn the President's chopper pilot about the danger in landing, while Ralph is in mid-air the stunt cables and carabiner hooks are visible at Ralph's waist in a few shots. Additionally, one shot of Ralph in mid-air is flipped, with his watch on his right wrist. (00:33:00)
The Greatest American Hero (2) - S1-E2
Visible crew/equipment: When Ralph flies up to the President's helicopter to warn the pilot, Ralph circles the aircraft and shouts "Get out of here, dummy," and as the pilot turns his head during this stunt while he's in mid-air, we can see the appearance of filming equipment right outside the cockpit's other open window. (00:33:35)
The Greatest American Hero (2) - S1-E2
Continuity mistake: At the end, when the aliens appear in the desert again, Ralph is in the front seat of Pam's car as the aliens suggest Ralph try invisibility, but after Ralph shouts that he lost the instruction book, when it cuts to a long shot Ralph is standing in front of Pam's car, then he's back in the front seat. (00:44:00)
The Hit Car - S1-E3
Deliberate mistake: When Starlet asks Ralph if he believes that stars can predict his future, Bill tells them to put a dimmer on the googoo eyes because of the killers on their tails, and the two shots facing Bill are flipped. (00:14:40)
The Hit Car - S1-E3
Deliberate mistake: While Bill and Ralph are with Starlet in the motel room and the shooting starts Bill tells Ralph to go get the guys, and when Ralph changes into his suit and flies out of the window, the shot inside the bathroom is a flipped shot. Not only is Ralph's watch on the wrong wrist in this shot, but later the bathroom is shown the correct way. (00:15:15)
The Hit Car - S1-E3
Continuity mistake: After Bill is shot in the hand at the beachhouse one of the hitmen takes off in a van with no side windows, but as Ralph begins to run after it the speeding van is different and has windows on the side, then it's back to the original van. (00:27:35)
The Hit Car - S1-E3
Continuity mistake: When Ralph catches the guy in the van Bill pulls his car up alongside, and when Bill gets out of the car he has a blood stained gauze bandage around his left hand, but as Bill cuffs the guy in the closeup the gauze bandage has vanished. (00:28:20)
