Tower closures

Chino Tower

Many friends have asked me my thoughts on the tower closures caused by the sequestration and whether it will impact me. As in most things aviation related, much of what you read online, see in papers, or watch on TV is, at best, poorly informed and in many cases, flat wrong.

Closing towers != closing airports

First, let’s make sure that you understand that closing a tower is not the same as closing an airport. The majority of airports in the US are “non-towered” airports. At most “towered” airports, the tower is only open part-time; for example, El Monte’s tower is open 8:00am – 8:00pm. While not a perfect analogy, think of an intersection that has traffic lights that revert to flashing red at night (effectively becoming a stop sign). When we say an airport is “towered”, we’re really talking about whether there is a tower controller, a person who acts somewhat like traffic cop for takeoffs, landings, arrivals and departures in the immediate area around an airport. Pilots operate all the time, safely, at non-towered airports.

To tower or not to tower

The volume and type of traffic and the availability of funds all go into the decision on whether to have a tower or not. A high volume of commercial, jet, or military traffic seems to be the best indicator of whether a tower is established rather than total takeoffs and landings.

I’ve seen towers open and close in the years I’ve flown. Lake Tahoe (TVL) had a tower when I first flew in, but it closed soon after. San Bernardino “International” (SBD, the former Norton AFB) opened its tower a few years ago. Closing towers is usually triggered by some major change in funding or traffic patterns (like loss of air carrier service).

Efficiency vs Safety

While it’s true that tower and ground controllers can improve safety by providing guidance to separate aircraft, the impact is hard to actually see. Why? First, collisions between aircraft are exceedingly rare to begin with (12.4 midair collisions per year in the US). Second, the ways in which most pilots come to grief are not in any way influenced by controllers (weather, keeping the airplane under control, fuel starvation, maintenance, etc), so an improvement or worsening of collision statistics will most likely be hard to see in the overall safety statistics for airplanes. That being said, I like the comfort that comes from having an extra set of eyes and ears helping to lookout for me.

Much of what controllers help with is efficiency when things get busy by directing pilots in ways that might not happen at a non-towered airport. Think of traffic control by officers on foot at a busy sporting venue to help smooth the flow of traffic in or out in ways that a stop sign or even a stop light couldn’t do.

Tower vs center and approach controllers

Tower and ground controllers are associated with a particular airport and almost always are located at the airport in the tower. There are other kinds of air traffic controllers – approach controllers (e.g. SoCal Approach) and en route controllers (e.g., Los Angeles Center). These controllers usually sit in buildings far from the airplanes they are controlling and look at screens (radar) and talk over the radio to airplanes and to other controllers on the telephone. To the best of my knowledge, there’s been no changes in staffing for these controllers (yet) as a result of the sequester.

Alternate methods of collision avoidance

One common theme I’ve seen is concern about collisions between small aircraft leaving these newly non-towered airports and jets on approach or departure to/from larger airports. Several have pointed to one of the few collisions in the US between a small plane and an airliner. I speak of the Cerritos crash of 1986. While one can never say never, a crash of this sort was unusual in 1986 and even more unlikely with changes implemented since 1986. Those changes include mandatory transponders (something to report location and altitude) for airplanes operating in and near such busy airspace and implementation of TCAS (traffic collision avoidance systems) on all airliners and many other larger airplanes. In general, these changes along with approach controllers have much more impact on the those sorts of dangers than do tower controllers.

Contract vs FAA tower

The controllers in the national airspace system are a mixture of FAA employees, military personnel, and contractors. I’ve never been aware of whether a particular airport was a contract or FAA tower. However, it is obvious now, as the first round of announced closures is impacting contract towers, including local towers at Fullerton (FUL), Whiteman/Pacoima (WHP), and Fox Field/Lancaster (WJF), while leaving open Hawthorne (HHR) and Palmdale (PMD). These make it clear that the total operations (takeoffs and landings) is not the sole decider of what towers are left open, as both PMD and HHR have fewer annual operations than the 3 towers that are being closed. As reference, here’s the annual operations (in thousands) for several local airports (calculated by daily operations numbers shown on



For my part, I’ll have to see how the newly non-towered airports are working and how it has affected the patterns of other pilots. I’ll still go to some of those airports. If ultimately, the tower at EMT (my home base) is closed, it may significantly alter how we do our training. A considerable amount of the traffic at El Monte is small aircraft involved in training pilots. Overall though, I expect to continue to fly with rather small impacts to how and where I do it.


All of this being said, I find the manner in which these closures have been implemented to be unfortunate. It does seem to be a case of quick decisions and ones which may have the greatest visibility. I have no doubt that there are some towers that should be closed and that the process that should close towers is slow to respond. I hope in the future that we’ll find alternate methods of cost savings that can return some or all of our desirable  towers to operation.

NOTE: the picture above is actually Chino (CNO) tower, not one of the towers being closed

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