Visible crew/equipment: After Johnny and Roy save the man at Vic's party, when they are leaving, the reflections of crew members and production equipment are visible on the orange surface of the ambulance as it drives away.
The Promise - S3-E11
Visible crew/equipment: Once the ledge rescue is over, after Johnny tells Brackett that he could put in a good word for him to join the paramedic program, when Roy opens the squad door to get in, the wing mirror offers up nice reflections of a few crew members.
Visible crew/equipment: When Roy has trouble sleeping in the middle of the night, he gets up, and when he goes to the bathroom sink, there is a fully dressed crew member whose reflection is visible in the mirror, as he moves around and looks through the door window towards the actor. Then 51's tones drop, and in the next shot we see that all the other guys of Station 51 have been lying in their beds, before getting up and putting on their turnouts.
Visible crew/equipment: During the emergency surgery on the boy who was shot with a pellet gun, the wired microphone that is taped to Brackett's shirt with black tape and hidden under his white coat becomes visible when he puts the gloves on, and during the surgery.
Visible crew/equipment: During the structure fire, Johnny and Roy rescue the security guard, and when Roy breaks the window with the chair, we can see a couple of crew members, equipment, and lighting on a c-stand outside down below.
The Wedsworth-Townsend Act - S1-E1
Visible crew/equipment: When Station 10 is dispatched to the factory fire, a few shots after the closeup of 105's door that reads "fire dept deluge", there's an overhead long shot of the men using the hoses against the fires in the doorways, and a cameraman wearing blue, holding a handheld camera, is visible sitting at the back of a squad.
Visible crew/equipment: Just after Herbert leaves the station in the morning, dispatch sounds the alarms, and when Roy and John are in the squad while the dispatcher begins talking, there are nice reflections of the camera, reflector screen (in the background), and crew members/cameraman who move around, that are visible on the surface of the spotlight. Additionally, the shadow of the boom/mic is perfectly visible on the windshield as it moves down.
Visible crew/equipment: When Station 51 arrives at the salvage yard's fire, Johnny gets out of the squad, and when he puts on his turnout coat as the camera zooms out, a dark haired crew member wearing a short sleeve white shirt is visible at the lower right corner of the screen.
Visible crew/equipment: During the rescue of the two guys up on the scaffold, when Gage is putting on his pack and harness, an actor's T-mark is visible on the ground, which Captain Stanley promptly stands upon when he asks Gage if he has his handy-talkie.
The Wedsworth-Townsend Act - S1-E1
Visible crew/equipment: As the camera pans to the left at the start of this episode, while everyone is asleep in the dorm upstairs, a crew member standing near the production's lighting equipment is visible between Squad 10 and the wall. Also note that the lighting equipment is gone when the guys are dispatched.
The Lighter-Than-Air Man - S5-E8
Visible crew/equipment: When all the guys are on site of an overturned tractor trailer, Captain Stanley says "Let's cool off that cab." In the next closeup of Stoker spinning a gear, the reflection of the cameraman (with mustache and hat) holding a handheld camera is visible on the engine's red surface.
Inventions - S3-E22
Visible crew/equipment: At the site of the major chemical leak, after Johnny falls from the pipes and Roy lifts him up, a couple of shots later there is a medium shot of one of 105's guys on Deluge 105 pumping out water, and we can see a cameraman (filming Deluge 105's closeups that we see during this scene) holding a handheld on the right of the screen, behind the pillar.
Visible crew/equipment: When Roy and Johnny are driving in the squad, while discussing Roy's last phone call from Susan, Johnny's lack of tact, etc., and particularly as they're being dispatched to the "possible maternity case," in every shot facing Johnny pay attention to the window behind the guys, because we can see a crew member's right hand, wearing a ring, who's holding a rope while he's riding on the back of the squad.
The Wedsworth-Townsend Act - S1-E1
Visible crew/equipment: During the factory fire, the Battalion Chief tells dispatch over the HT, "Fire through the roof, send me a third alarm," then in the next shot we see Engine 36 arrive, and when the engine comes to a full stop we can see two tripod lighting rigs and stacked film canisters, at the right of the screen.
Visible crew/equipment: On scene at the traffic accident with Paula, after Johnny brings the IV bottle to Roy, it cuts to the overhead shot of the ambulance arriving, and a large reflector screen is visible at the left of the screen.
Visible crew/equipment: When Chet, Roy, and Johnny are with the mother and child at the scene of the vehicle accident, the reflections of location set array lights, four side-by-side reflector screens with some crew members holding them and the camera/cameraman are all visible in the window and surface of the funeral home hearse, as it arrives and then pulls to the side of the road.
Inventions - S3-E22
Visible crew/equipment: After Roy and Johnny rescue the worker in the midst of the chemical leak, when Captain Stanley asks the Chief over the HT to send the ambulance, two crew members are seen behind him. When the victim is pulled across the lifeline, as he reaches the engine a crew member, with black hair wearing a white shirt, is seen standing behind the engine. Then, when Johnny hauls himself across the lifeline, just as he reaches the engine we see a crew member, with black hair wearing a white shirt (likely same one as earlier), who arches up then ducks back down behind the engine.
Visible crew/equipment: When Engine and Squad 51 are at the cliff with the young unconscious boy, Captain Stanley calls in to dispatch, with Stoker standing beside him. The reflection of the camera crane and location set lights are visible in the side door mirror.
Visible crew/equipment: During the fire late at night, after Johnny and Roy run to the burning house, when Captain Stanley tells Chet to get the exposure and later warns to watch for spot fires, the moving shadow of the cameraman/camera is visible on the ground, right beside Captain Stanley's shadow.
Propinquity - S3-E20
Visible crew/equipment: At the abandoned refinery, just after Roy attempts to pull out the man pinned under a tank, but is unsuccessful the first time, when it cuts to Captain Stanley and Chet, who are on the third level hosing the fire through the doorway, at the left of the screen a crew member is visible, watching them.
Answer: I believe you are speaking of the old man, Mr. Wilson. He's played by J. Pat O'Malley.
Bishop73
Correct, it was J. Pat O'Malley...he also played the grandfather with his grandson when their rocket exploded, and also played "Old Bill" in the episode with Ann Prentiss, where Gage saves the little girl from the burning tree house, and her mother falls in love with him.