SATURDAY’S helicopter-plane collision over the Hudson stems in part from the politicization of decisions about air safety and air traffic control, both of them the province of the Federal Aviation Administration.

When a crash occurs, members of Congress from the area are quick to point fingers and call for tougher regulations. But few people realize how much Congress and aviation interest groups can be obstacles to improved air safety.

Private planes like those involved here are referred to as “general” aviation (as opposed to commercial aviation — mostly airlines). The general aviation trade associations have large memberships in every congressional district, and are very active in both lobbying and campaign donations. So when these groups take a position on aviation issues, members of Congress on aviation subcommittees feel considerable grassroots pressure to make decisions that are GA-friendly.

One example is defining the airspace under which planes needn’t file flight plans or be directed by air traffic control. That’s the category of airspace over the Hudson River below 1,100 feet, where the collision occurred.

Everyone recognizes that airspace above and around major airports must be controlled, but GA groups resist any expansion of controlled airspace, which restricts their members’ freedom to fly. In turn, because the GA crowd has a lot of clout with Congress, the FAA (which gets its budget from Congress) must take that into account in any redesign of airspace.

Another example is the use of next-generation technology to keep track of where planes are, even outside of controlled airspace. Today, all planes must carry transponders which, when interrogated by FAA radars, transmit the plane’s ID number and altitude, which appears on the air traffic controller’s display.

But radar only scans once every 5 to 12 seconds, and isn’t very effective where there is lots of ground clutter.

The FAA is beginning to implement new technology called ADS-B, which dispenses with radar for this purpose. Instead, each plane equipped with ADS-B reports its position (based on GPS) every one to two seconds, giving the controller much faster and more accurate information. And the more advanced version will put a display in every cockpit, showing the pilot where other air traffic is, in real time.

But here’s where the politics of GA comes in. Even in large-scale mass production, the ADS-B box that includes the traffic display will likely cost several tens of thousands of dollars. GA groups, out to protect their members from increased costs, have fought hard to put off the deadline date for installing even the basic (no-display) version of ADS-B until 2020. And the FAA knows that imposing a more aggressive schedule would lead to intense GA lobbying of Congress, so it has so far gone along.

Besides the political problem, the FAA has a built-in conflict, because it has two distinctly different missions. One is to be the aviation-safety regulator — deciding the rules of the airways, licensing pilots and mechanics, certifying new planes as safe to be manufactured, overseeing airline maintenance, etc. In carrying out that role, it is quite properly at arm’s length from the parties that it regulates.

But its second mission is running the air-traffic-control system, which includes decisions about implementing new technologies like ADS-B.

The ATC system is a 24-hour- a-day, high-tech service business, trapped inside a government bureaucracy. When it tries to make modernization decisions (like replacing radar surveillance with ADS-B), it can’t simply consult with its customers and work out an implementation plan. Instead, it must make every decision with one eye on Congress, knowing that some interest group will complain to the politicians that the decision hurts its members. And when regulating the safety of air traffic control, the FAA is “regulating” itself.

Nearly all Western nations (including Australia, Canada, the UK and almost all EU members) have separated air-safety regulation from the ATC business, usually divesting ATC as a stand-alone, customer-supported enterprise. That puts safety regulation at arm’s length from ATC operations, while depoliticizing business decisions such as ATC modernization.

The Clinton administration tried to make the same reform here, but got shot down by GA and other interest groups.

Depoliticizing air-traffic control would be very positive for air safety. It would speed the introduction and use of better technology like ADS-B, while freeing the FAA to focus on tougher safety regulation.

It’s too late for the victims of Saturday’s crash, but such changes could prevent many future collisions.

Robert W. Poole Jr. is the direc tor of transportation studies at Reason Foundation.