B737 Undifferentiated or Other Model
Air Traffic Control Fully Certified
ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
General None Reported / Taken
Human Factors; Procedure
A fire truck; wanted to drive from the north side of the ramp to Fire Station E via C; V; E. I approved his request. Noticed that Air Carrier X was pushed back from his gate and I was preparing for him to call me for his taxi instructions. Most aircraft are told by Ramp Control to taxi up to and hold short of C at C2. This aircraft never held short. He exited the ramp at C2 and taxied to the C deice pad without ever calling me at Ground Control. When he exited C2; the rescue vehicle had to stop to avoid an incident/accident. I tried multiple times to contact Air Carrier X on my ground frequency but he never responded. I then had the FLM call the C Deice pad to see if he was on their frequency; he was. Air Carrier X then called me on my frequency and said he was sorry and that he got confused. I told him he needed to call the facility.
After push back; we requested taxi from ramp. I read back; 'Clear to taxi via C2 to C Runway 28R;' and I also stated we need to deice. He stated we were clear to use the available deice ramp. I then switched to Iceman 'IDT' to see if they can acknowledge if Pad C was available. While I was off; the Captain contacted Ramp again to confirm taxiway instructions; 'C2 C' and Ramp Control responded 'affirmative.' These taxi instructions were sufficient to get us all the way to Pad C deice pad. After into Deice Pad C; Iceman informed us that Ground Control wanted us to contact Ground Control. Ground informed us that we did not get clearance from Ground to proceed and we taxied on active taxiways with emergency traffic. At no time did we hear or read back a taxi clearance limit such as hold short or proceed to spot to contact Ground. We do have airport in the system where Ramp gives instructions to taxi across active taxiways to the deice pad. The first time after you contact ground is after being deiced.
PIT Controller described an unsafe condition when an air carrier taxied from the ramp to a de-icing area without contacting Ground resulting in a developing conflict with a fire truck.