Museum of Air Traffic Control Trip Report
Air Traffic Control Tower and TRACON
Boise Air Terminal/Gowen Field (BOI/KBOI)
3105 Airport Way
Boise, Idaho 83705

Boise Airport Traffic Control Tower, February 2007

Google Earth view of BOI. The raw dirt area in the center to lower right of the image is the "Assault Strip." The BOI VORTAC is between the Assault Strip and the east end of the parallel runways.

We visited the Boise Air Traffic Control Tower and Approach Control late in the afternoon of 5 February 2007. In addition, we listened to more than six hours of BOI tower, ground, clearance delivery, and TRACON radio traffic live over a period of two days.

BOI is an upstairs/downstairs facility, meaning that the controllers work both the tower and the TRACON. Full Performance Level certification at this facility requires that a controller be completely checked-out on both the tower and TRACON positions.

BOI is a 24 hour-per-day Level 8 (Level 3 in the old system) facility located in the FAA’s Northwest Mountain Region (ANM). BOI’s Class C airspace lies within the Salt Lake Center (ZLC) area and is depicted on the northern half of the Salt Lake City Sectional. BOI is located at 43-33-51.7000N / 116-13-22.3000W ( 43.5643611 / -116.2228611) and lies at an elevation of 2871 feet (875.1 meters) above sea level. BOI has a magnetic variation of 17E and is UTC -7 (UTC-6 during Daylight Savings TIme). The facility manager is Gordon Stewart. BOI won ANM facility of the year in 2003. See link at right to view recent BOI traffic counts.

Boise tower local controller, ground controller, clearance delivery position, and supervisor (wearing a tie, as prescribed).

The TRACON consists of two positions: a north controller and a south controller. The positions are split by an imaginary line projected east and west from between the north and south runways, with the south controller owning the centerline and calling the sequence. The majority of the traffic arrives from the south, and the south controller also has to deal with a large restricted area, R3203 (A and B), in its airspace. R3203 A and B extend from the surface to FL220, but most of the activity in this area consists of artillery rather than aircraft.

Boise (BOI/KBOI) is on the northern half of the Salt Lake City Sectional. Note that Mountain Home AFB (MUO/KMUO) 33 miles southeast of BOI has a tower as well as its own ASR-equipped approach control. MUO and BOI ASR coverage overlaps at altitude.

Primary and secondary radar at BOI are provided by an ASR-11 system. BOI was the first fully-operational ASR-11 facility and personnel from Boise ATCT made up part of the certification team.

The Boise local controller sits in front of a BRITE and ARTS II keyboard. Note the tube between the keyboard and the BRITE. It allows the local controller to drop flight progress strips to the TRACON directly below.

This toy aircraft sits atop the Boise Tower BRITE

The TRACON is generally open until around 2100 local, then the radar positions are combined in the tower cab (TRACAB). Depending on traffic they may combine the two TRACON positions within the TRACON before 2100, or combine Ground Control with the Clearance Delivery position to cover breaks. Given that the normal configuration is 6-1-6 with a supervisor working 1000-1800, if two control positions are not eventually combined, someone will end up being on position more than two hours. Even so, given BOI ATCT’s less-than-optimal staffing level and traffic, the controllers’ claim to fame here is that they work more aircraft per controller than anywhere else in the country.

The Boise Tower Local Control Position

Controllers at BOI use a perforated paper flight progress strip. The left side of the strip is used for IFR aircraft. The right side of the strip is detached from the portion used for IFR and saved. This saved portion is flipped-over and used for VFR traffic. This provides an additional method by which IFR traffic may be distinguished from VFR traffic.

BOI enjoys parallel runways, but because the centerlines are only 700 feet apart, for wake turbulence purposes they considered a single runway. Currently the approach with the lowest minimums is a CATII ILS, but a CATIII is expected to be commissioned by Spring 2008. Note that surveillance approaches (ASR) are not provided and controllers are not required to maintain currency in ASRs.

Boise Airport Diagram

The current BOI ATCT is near the terminal building on the north side of the airport, around 75 feet tall, and something of a historical structure, with the TRACON on the level directly below the tower cab and administrative facilities in a 10 year old building at the tower base. A new tower is planned for commissioning in 2011 and will be located across the airport on the south side of the runways. The new tower is planned for a height of 275 feet which will provide far better visibility.

Boise CATII ILS plate. CATIII is on the way.

Also on the south side of the airport, some 2,000 meters south of the approach end of runway 28R, is an additional runway known as the “Assault Strip.” The Assault Strip is a dirt runway not authorized for use beyond limited use arranged-for through a Letter of Agreement. In any case, BOI ATCT will not provide takeoff or landing clearance to aircraft using this runway as it is not reasonably viewable from the current tower location. Pilots are cautioned to avoid confusing the Assault Strip with runways 10R/28L. Boise Tower Letter to Airmen No. 04-02 covers use of the Assault Strip.

Boise VORTAC (113.30 MHz) 1.5 miles east of airport reference point

Armed with AH64 Apache attack helicopters and UH60 Blackhawk utility aircraft and stationed at BOI, the 1st Battalion, 183rd Aviation serves as the air component of the Idaho Army National Guard. Also headquartered at BOI, the 124th Wing, Idaho Air National Guard includes two squadrons of A10s and 12 support units.

This report would be incomplete if we failed to make mention of the issue of the location of BOI’s TRACON. The FAA has proposed moving the BOI TRACON out of Idaho and co-locating it with other approach control facilities in Salt Lake City as a cost-saving measure. This proposal has met with a great deal of opposition across Idaho. Having toured the BOI facility and met with the controllers, we find ourselves joining those who oppose this move, but for reasons which differ from the reasons espoused by some of the most vocal opponents.

Some member of Idaho’s Congressional delegation have complained that the departure of the BOI TRACON for Salt Lake City would make Idaho the only State in the US to lack a TRACON. Although true, this fact does not strike us as sufficient reason to block the proposed move. However, we do believe that the BOI TRACON should not be moved away from Boise. Our reasons for this belief are exclusively operational and implicate safety, and will be explored at length in an upcoming paper concerning consolidated TRACONs.

We found the management and staff at BOI ATCT and TRACON to be a talented, close-knit group, who provide a level of service second-to-none in a highly professional environment.

Quick Links

• BOI Traffic Count
  2000-2006