Date: 201702
Local time of day: 1801-2400
Location: ZHU.ARTCC, TX
Aircraft: Light Transport; Low Wing; 2 Turbojet Eng
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZHU
ATC / advisory: Center ZHU
Second aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Reporter organization: Government
Reporter function: Enroute
Reporter qualification: Air Traffic Control Developmental
Human factors: Situational Awareness; Training / Qualification; Workload
Anomaly: ATC Issue All Types; Airspace Violation All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control
When detected: In-flight
Contributing factors: Airspace Structure; Procedure
Primary problem: Airspace Structure

Narrative: Aircraft X was doing a test flight. At the time of the airspace violation we currently had 18 aircraft on frequency stepping over each other and had about 25 data blocks up on our screen. I heard the Radar Controller issue instructions to Aircraft X to descend via the Touchdown 2 arrival and the aircraft complied. I typed in the route and went back to my scan. Just as the event occurred we had a NORDO aircraft; Aircraft Y at 25000 feet in the middle of our departure and arrival push; so I called different sectors to find this NORDO aircraft.We also had Aircraft Z a military flight at 26000 feet entering our airspace head on with all our arrival traffic. I called sector 78 to get approval for Aircraft Z direct El Paso to get him away from our arrival push. They approved it. I called 68 the controller who had control and communications to Aircraft Z to clear him direct ELP. He complied. Aircraft Z chose not to take the shortcut and told 68 he was not going to do that. Aircraft Z entered our airspace without a proper handoff made. Sector 68 put Aircraft Z on our frequency when he was supposed to be 10 miles north of his current position. We had arrival traffic in his way. I frantically coordinated with Sectors 68 and 78 to move Aircraft Z out of the way enough to where he would not impede arrival traffic. I also noticed just before the event occurred that Aircraft A was coming in too high for the arrival requirements at BELLR. I tried to call BELLR 62 three times to approve his slow descent. The first call I was ignored. The Radar Controller switched 4 planes including Aircraft X which they all read back correctly so I went along with my scan no longer looking at those 4 data blocks. I tried to call BELLR again for Aircraft A that was now at 16000 feet but supposed to be at 11000 feet at BELLR and never got a response. Watching Aircraft Z the entire time to make sure he was not a conflict with any other arrival traffic. The 3rd time I called BELLR they answered upset; said approved and hung up. Aircraft X was already 20 miles in their airspace descending out of 7700 feet and Aircraft A was also 3 miles in their airspace at 14500 feet. We could not turn either aircraft due to complexity and procedures. A violation happened in our airspace; a NORDO aircraft; high complexity; and traffic count; and data blocks overlapping. We were so focused about separation with multiple aircraft that we missed issuing a data block transfer. The communications were switched; but the handoff was never made. No weather effected this event.Arrivals into HOU and IAH need to change. GMANN and BELLR RNAV Arrivals are too close to provide real separation. When TRACON is on a west flow the arrivals must be between 16000-19000 feet which works because the HOU arrivals need to be at 11000-13000 feet. It's easy enough to get HOU arrivals under IAH arrivals. When TRACON is on an east flow it's DANGEROUS! IAH arrivals must be at 13000-16000 feet and the HOU must be at 11000-13000 feet. HOU arrivals coming from the WEST and IAH coming from the SOUTH. We have a window of 57 miles from the WEST to get HOU traffic from 24000-35000 feet all the way down to 13000-1100 feet; while avoiding the IAH arrivals that also need to descend to 16000-13000 feet. I feel it's unsafe and adds complexity to a very simple arrival. We also have departures to contend with going south so we have 2 arrival gates which are approximately 15 miles apart from each other and a departure corridor. In a span of 40 something miles. It's unsafe. I feel that there should be three arrival corridors. From the southwest GMANN is perfect where it is; BELLR needs to move down 5-10 miles; and I feel SKUBA our departure corridor should be for all the small satellite airports. Having departures fly into arrival corridors is scary and added complexity that doesn't need to be there. Also TRACON stated they had the communications of Aircraft X but not the data tag. That seems to happen at least once a week from Approach to Center; or Center to Approach.




Synopsis: A Trainee Center Controller reported allowing two aircraft to enter an adjacent sector without a handoff. The Trainee recommended new procedures for the arrival flow through the sector.