Collision Avoidance at Non-Towered Airports

by tom turner

NOTE: This article is re-posted with permission of the author. Click here to read the original.

As reported by AvWeb:

Two people died when a Cessna 150 collided with a Cessna 525 Citation jet on the runway at Marion Municipal Airport in Indiana on Monday afternoon, the FAA has reported. The C150 was attempting to take off to the southeast, at about 5:09 p.m., when it struck the tail of the Citation, which had just landed from the north. The tail of the jet was shorn off, and the C150 crashed and caught fire. The pilot and passenger in the 150, both from Indiana, were killed. Five people, including the crew, were on board [the jet], and none were hurt. The airport, about 50 miles north of Indianapolis, has no control tower, and pilots coordinate via CTAF [Common Traffic Advisory Frequency]. The NTSB will investigate.

Information about this crash is still coming in, and likely will be for some time. From reports to date it appears that the scenario is similar to that in my obviously exaggerated illustration of the Marion, Indiana airport at left: the Cessna 150 was taking off from Runway 15 (“to the southeast”) in the shorter runway, while the Cessna 525 Citation was landing from a right base or straight in to the more jet-friendly Runway 22.

What are the odds the two airplanes arrived at the intersection of the two runways at the precise, simultaneous time? I can’t image them doing it on purpose without significant planning and practice, and active communication between airplanes during the attempt. Yet, they did collide. The timing was exactly wrong.

This makes me wonder: Since actually arriving at the same point at the same time is challenging at best when attempted intentionally, and completely random at any other time, how many times is more than one airplane using conflicting runway and traffic pattern space, but a collision does not occur solely because the timing was not wrong?

In other words, how often does the unsafe condition of traffic pattern and runway conflict at nontowered airports occur, but we never hear about it because the aircraft do not collide? It’s not all or nothing, a collision or five miles separation. Scary thought, huh?

At the same time, every time a pilot holds short or goes around because he or she detects a possible conflict, the system worked. It’s obvious, however, that we need to remain vigilant.

ADS-B, even after the January 1, 2020 installation deadline (in the United States), probably would not have made a difference. The Cessna 150 almost certainly operates in airspace where ADS-B will not be required. If the C150’s operation does require ADS-B, its owner may well elect to equip with ADS-B Out only…the Citation pilot might have “seen” the C150 on ADS-B, but the C150’s occupants would not have seen an ADS-B plot on the jet. Even if both aircraft had in-cockpit traffic display, and both crews could see the other aircraft on their screens, one or both pilots would have to act to avoid the collision before it was too late.

Two recent publications address collision avoidance at non-towered airports:

The National Business Aviation Association (NBAA) has published “Operating Into a Non-Towered Airport?” The NBAA document is aimed primarily on the issue of closing contract control towers, turning Class D airspace into Class E and often Class G close to the surface. The guide states:

When approaching the airport, crews should also make a point to keep their eyes outside the cockpit in order to see and avoid other traffic and monitor the radio to help ascertain the positions of other aircraft in the vicinity. Pilots should also communicate their position and cooperate with other pilots in the area to establish the safest approach to the field, with the least potential for conflict with other traffic.

This is fairly basic guidance, and is prefaced by this statement:

…pilots operating under an IFR flight plan to a newly non-towered field will need to be prepared for the transition from the positive control environment of instrument flight when approaching their destination. “These are skills that all business aircraft pilots should be familiar with, but now will have to be applied at locations with newly closed control towers….”

Well, yes, business pilots not only should, but must follow the rules of visual flight in nontowered and uncontrolled airspace. See and avoid is the first and last defense, regardess of the aircraft type or performance.

The NBAA guide does not address the issue of nontowered operations at airports with intersecting runways.

Just last month the FAA issued Advisory Circular 90-66B, “Non-towered Airport Flight Operations.” Also basic in its guidance, it states:

The pilot in command’s (PIC) primary responsibility is to see and avoid other aircraft and to help them see and avoid his or her aircraft. Keep lights and strobes on. The use of any traffic pattern procedure does not alter the responsibility of each pilot to see and avoid other aircraft. Pilots are encouraged to participate in “Operation Lights On,” a voluntary pilot safety program described in the AIM, paragraph 4 - 3 - 23, that is designed to improve the “see - and - avoid” capabilities.


Pilots should clearly communicate on the CTAF and coordinate maneuvering for and execution of the landing with other traffic so as not to disrupt the flow of other aircraft. Therefore, pilots operating in the traffic pattern should be alert at all times to aircraft executing straight-in landings…. Instrument approaches should be particularly alert for other aircraft in the pattern so as to avoid interrupting the flow of traffic, and should bear in mind they do not have priority over other VFR traffic. Pilots are reminded that circling approaches require left-hand turns unless the approach procedure explicitly states otherwise. This has been upheld by prior FAA legal interpretations of § 91.126(b).

The AC goes on to describe radio communications and traffic pattern entries in detail. But it doesn’t provide any specific guidance for nontowered operations with intersecting runways. In fact, even the Aeronautical Information Manual fails to mention this directly.

But maybe I’m overthinking this. Regardless of the number of runways, and whether or not you hear any reports on the radio, report your position and intentions on the CTAF, and look all around the airport before you begin your takeoff roll, and also as you’re coming in to land.

Thomas P. Turner is an M.S. Aviation Safety Flight Instructor Hall of Fame 2015 Inductee, the 2010 National FAA Safety Team Representative of the Year, the 2008 FAA Central Region Flight Instructor of the Year and a three-time Master CFI. For questions and comments on this post contact him via email at [at] For more information visit