ZHU Capping & Tunneling Plan

Houston Center (ZHU) will utilize capping/tunneling procedures during significant WX events or when high or ultra-high altitude sector volume is such that an operational advantage can be gained by utilizing the lower altitude stratums based on the direction of departures/arrivals to and from underlying ZHU facilities. This plan covers George Bush Intercontinental Airport(IAH), William P Hobby(HOU), Austin-Bergstrom(AUS), and SanAntonio International(SAT) airports. These airports within ZHU are commonly used for Capping and Tunneling.

For this plan, "Capping" refers to stopping departure aircraft at or below FL230 until a point-in-space beyond the constrained high altitude sector(s). Beyond that point, these capped flights can be safely climbed to their requested altitude.

For this plan, "Tunneling" refers to the practice of descending arrivals, earlier than normal, at or below FL230 due to conflicts occurring with the volume and complexity issues in the high altitude sectors.

Capping Plan Descriptions:

Climb points describe a flying distance specific to a certain Standard Instrument Departure (SID) from IAH/HOU, AUS, and SAT from which aircraft may be climbed to the next altitude stratum based on current overhead volume. An enroute fix along the SID is listed after each SID in the remarks section. The normal cap altitude will be either FL220/FL230, direction dependent. Any distance not covered will be determined dynamically for each weather/volume scenario.

NOTE: An advisory will be issued by the ATCSCC informing customers which Escape route is being used.

DEPARTURE SID	REMARKS
PITZZ/BNDTO	Expect AOB FL220 until JCT
PITZZ/BNDTO	Expect AOB FL220 until FST
RETYR/BORRN	Expect AOB FL220 until JCT
RETYR/BORRN	Expect AOB FL220 until FOWLR

HOUSTON EAST ESCAPE:

DEPARTURE SID	REMARKS
MMUGS/GUMBY	Expect AOB FL230 until LSU
ELOCO/MMALT	Expect AOB FL230 until LLA

HOUSTON SOUTHWEST ESCAPE TO MEXICO:

DEPARTURE SID	REMARKS
RITAA/PTRON	Expect AOB FL220 until CRP
KARRR/PSX	Expect AOB FL220 until PSX

HOUSTON SOUTHWEST ESCAPE:

DEPARTURE SID	REMARKS
RITAA/PTRON	Expect AOB FL220 until CRP

AUS NORTH ESCAPE:

DEPARTURE SID	REMARKS
ELOEL	ELOEL Expect AOB FL220 until FUZ (destinations north of ZFW)
MUCKY	Expect AOB FL220 until JCT

AUS WEST ESCAPE:

DEPARTURE SID	REMARKS
MUCKY	Expect AOB FL220 until JCT
ELOEL	Expect AOB FL220 until ABI (Destinations to the PAC NW)
BNDIA(southwest swaps)	Expect AOB FL220 until DLF
AEROZ	Expect AOB FL220 until SJT

AUS EAST ESCAPE:

DEPARTURE SID	REMARKS
ILEXY	AOB FL230 until ZENZI

SAT NORTH ESCAPE:

DEPARTURE SID	REMARKS
ALAMO	AOB FL230 until FUZ

SAT WEST ESCAPE:

DEPARTURE SID	REMARKS
ALISS	AOB FL230 until JCT
MILET(SW swap only)	AOB FL230 until DLF

NOTE: All flying distances(NM) are approximate and dependent upon current conditions.

TUNNELING (Arriving SAT/AUS)

Tunneling aircraft below constrained airspace may occur during periods of heavy enroute volume and/or complexity. Tunneling will enter ZHU at below FL270. Tunneling aircraft inbound to IAH/HOU airports is less common due to ZHU sector configurations, but when used is typically on a more tactical basis than capping procedures. Tunneling is commonly used for flights arriving the Austin-Bergstrom (AUS) and San Antonio (SAT) airports due to sector configuration and arrival flows with adjacent centers being within descent points on arrival STARs.

AUS AND SAT TUNNELING:

ARRIVAL STAR	REMARKS
LAIKS to AUS	Enter ZHU AOB FL270 from ZFW/ZHU Boundary until STAR descent point
CSI to SAT	Enter ZHU AOB FL270 from ZFW/ZHU and ZAB/ZHU Boundaries until STAR descent point

Additionally: Tunneling and capping procedures may add significant volume and complexity to low altitude sectors that provide airport sequencing/control at many airports. Therefore, additional TMIs (e.g. miles-in-trail) may be needed to manage the volume in those sectors. All plans to cap or tunnel will be briefed on ATCSCC planning telcons and via advisories, so extra fuel can be planned accordingly. Dispatchers should remind pilots not to ask for higher during capping initiatives. Thorough coordination will be accomplished between Towers/TRACONs and each affected ZHU sector. TMU will also coordinate with adjacent facilities if flights will remain capped until a point inside their airspace.