Chapter 9 — Solutions — Air Traffic Service Providers

Over 80 percent of reported bird strikes occur within the airport environment.


Control Tower
Photo courtesy NAV CANADA

If one were to liken the range of aviation professions to a hub-and-spoke airline system, Air Traffic Service (ATS) providers (departure and arrival controllers, tower and ground controllers and flight-service specialists) would form the hub. ATS providers are pivotal members of the aviation community, uniquely positioned to spearhead tactical riskmanagement activities associated with wildlife-hazard and strike reduction.

In constant communication with all staff operating in and around airports, these professionals:

  • detect bird activity electronically on Terminal Control Unit (TCU) radar monitors;
  • detect birds and mammals visually from tower cabs and FSS sites; and
  • convey critical wildlife information to airside operating staff, wildlife-managementpersonnel, pilots and other controllers operating in positive control environments.

Clearly, the vigilance of ATS providers is critical to the day-to-day prevention of bird and mammal strikes.

Roles and responsibilities


Controllers and flight-service specialists share a number of responsibilities in the prevention of wildlife strikes including:

  • providing pilots with current information concerning wildlife activity at ornear airports;
  • advising pilots of possible wildlife activity;
  • coordinating the use of ATIS and NOTAMs to communicate wildlife informationto pilots;
  • informing appropriate airport personnel about wildlife activity at airports;
  • advising shift replacements about current wildlife activity on airports;
  • providing options to pilots in the event of a potential wildlife-strike threat.Options include:
    • takeoff delay,
    • alternate flight profiles,
    • use of alternate runways for landing and takeoff,
    • approval of reduced aircraft operating speed, and
    • alternate routes and altitudes;
  • reporting all airport wildlife incidents through the Canadian Aviation Damage Occurrence Reporting System (CADORS) and any other applicable local airport reporting procedure;
  • encouraging pilots to file wildlife-strike reports after bird and mammal strikes ornear misses; and
  • ensuring that active wildlife-management activities pose no threat to aircraft operations.

The roles and responsibilities of ATS providers are clear in some jurisdictions, such as Canada. This country’s Manual of Operations for Air Traffic Controllers states:

Section 164.1 Provide all aircraft that will operate in the area concerned with information concerning bird activity, including:

  • size of species of birds if known;
  • location;
  • direction of flight; and
  • altitude if known.

Section 164.2 Base bird activity information on:

  • a visual observation;
  • a pilot report; or
  • a radar observation confirmed by:
  • a visual observation; or
  • a pilot report.

Section 164.3 You should warn an aircraft of the possibility of bird activity if you have an unconfirmed radar observation that you believe to be a flock of birds.

In the U.S., FAA Order 7110.65, 2-1-22—The Air Traffic Controller’s Handbook— requires controllers to inform pilots of:

  • the presence of bird activity,
  • the location of the activity,
  • the nature of the hazard (type of bird), and
  • the direction in which the hazard is moving.

Controllers are also instructed to continue transmitting warnings as long as the hazard is present.

Terminal controllers

Arrival and departure controllers are key members of the bird-strike risk-management team. In spring and fall, many North American TCU positions provide front-row seats for observation of migratory bird activity. Often the first to recognize the potential hazard, terminal controllers alert flight crews:

  • directly, by informing arriving and departing aircraft of the presence of high-riskwildlife activity;
  • indirectly, through tower controllers who advise flight crews still on the ground; and
  • through NOTAMs, informing crews of other aircraft who plan to operate at or nearan airport.

This vital communication increases pilots’ situational awareness and enables them to better manage flight profiles, reducing the probability and severity of wildlife strikes. As demonstrated in the following real-life scenario, quick actions of controllers in the TCU can make a vital difference in the event of a bird strike.

Scarcely airborne out of New Orleans with a full passenger load—operating at near-maximum gross weight—a Delta Airlines MD-80 suffered numerous gull strikes. The left engine never had a chance. The right engine, though severely damaged, kept passengers and crew airborne. The captain declared an emergency and requested an immediate landing on the nearest available runway. The tower controller provided an initial vector and handed them over to Approach Control. In a unique position to gauge the evolving weather conditions, the arrival controller informed the stricken aircraft’s crew that the weather had deteriorated; several aircraft had just conducted missed approaches over their intended runways. When asked about another runway—one with 100-foot lower minimums—the arrival controller responded, “We still have rain showers to the east, but visibility looks better that way than to the south.”

With windscreens obscured by bird debris and an engine incapable of powering them to an alternate airport, the aircraft broke out at minimums and made an uneventful landing—the flight lasted exactly 13 minutes. The actions of the arrival controller, the alert response of the well trained flight crew, the strength of the aircraft windscreens and the durability of the remaining damaged engine all helped avert disaster.

Tower and ground controllers

As noted in Chapter 2, tower and ground controllers are situated in the middle of the risk-management curve, strategically positioned in the system-safety network—and in the heights of tower cabs—to coordinate detection, deterrence and avoidance of wildlife strikes.

Activity inside a control tower.
Activity inside a control tower.

Tower controllers are often the first to detect wildlife activity and, using binoculars, can assess the type and size of flocking birds, their location and apparent direction of flight. Tower controllers also confirm sightings by airside staff and receive verbal pilot reports. In each case, these controllers adhere to established protocols to ensure that wildlife-management staff are advised, and that appropriate wildlife-management activity is coordinated and conducted safely. From control towers, their efforts are aimed at ensuring non-events—the avoidance of wildlife strikes.

The 1993 multiple-bird strike incident involving the B-737 at Calgary—described in Chapter 2—illustrates the important role of tower controllers.

The Calgary controllers and airport duty manager worked hard in the earlymorning hours to disperse a flock of gulls prior to the B737 occurrence. At 0537 hrs, the duty manager detected a 200- to 300-strong flock of gulls on Taxiway ‘F’—north of the threshold of Runway 28. After repeated attempts— using pyrotechnics and the horns on the wildlife-management truck—the duty manager eventually succeeded in dispersing the birds; air-traffic controllers were advised that the birds had moved north, east and southeast.

The 0600 hrs ATIS recording prepared by the controllers warned pilots of airport bird activity. At 0625, a large flock of gulls was seen heading north; 11 minutes later, the duty manager noted that gulls had returned to Taxiway ‘F’, gathering nearby. Throughout, the airport duty manager and tower controllers were in constant radio contact, coordinating bird-management tactics around landing and departing aircraft.

A number of unrelated events led controllers to assume the bird-strike risk was diminished. At 0626 hrs, a Federal Express B-727 landed, clearing the end of runway 28. At 0637, an American Airlines MD-80 also landed on runway 28; the aircraft stopped and completed a 180-degree turn to backtrack runway 34 to the apron. Neither crew reported bird activity to controllers, nor did the airport duty manager report any further bird activity. As a result, when faced with updating the ATIS recording at 0700—a recording the crew of the Canadian Airlines B737 received a few minutes later—the controller did not include a bird advisory.

The controller’s ability to prevent the bird strike was undermined by a lack of information. The only aircraft to operate from runway 28 that morning had been the Federal Express B-727 and American Airlines MD-80; it was never determined whether their crews detected birds. If they did, they may have assumed that the ATIS reference to bird activity meant the tower controllers and airport authorities were aware of the bird’s presence—too many assumptions by too many people.

There are important lessons to be learned from these near catastrophic events. Even though on-duty tower controllers were using binoculars to scan the area of both occurrences, none saw the birds until impact took place—when there was little more they could do.

Controllers play a key role in advance of strikes; they are central to the tactical prevention of these events, ensuring the best available information is conveyed, and that suitable responses are coordinated and implemented.

Flight service specialists (FSS)

Flight service specialists (FSS) work at uncontrolled airports and provide pilots with information vital to timely and well informed decision-making.

Only a few years ago, the largest aircraft to operate from uncontrolled airports were DC-3s. Today, it’s not unusual for these facilities to host B-747s, heightening the role and responsibility of FSS.

Like their counterparts in control towers, FSS:

  • detect and identify birds, and estimate their numbers, location and direction of movement;
  • advise airport managers of the need for wildlife management; and
  • relay information among pilots, airside workers and wildlife-management personnel.

Unlike tower controllers, many flight service specialists live and work in smaller communities, and are familiar with local flying conditions and regular airport users. While valuable, this knowledge can lead to assumptions, and assumptions lead to danger. Perhaps an FSS knows a certain pilot is aware of seasonal bird activity, or that

another is familiar with the location of breeding grounds in the vicinity of an airport. Regardless, taking stakeholder awareness for granted immediately compromises wildlife-management system safety. Assume nothing! If employed wisely, familiarity with airport operating conditions is a boon to safety; assumed, it is a recipe for disaster. The FSS may need only to highlight the specific circumstances of bird activities on a given day.

Transient airport users in particular benefit from FSS knowledge. They can rely on these professionals for information on:

  • local-wildlife movements; and
  • land-use activities that attract wildlife to an airport and surrounding area, such as:
    • bird and wildlife sanctuaries,
    • landfill sites, and
    • fish-packing facilities.

Flight Service Specialists may also be able to advise pilots of dusk and dawn bird-flight paths, as well as locations of local nesting colonies.

When a bird strike does occur, FSS are often the first advised. In these cases, FSS should report all airport wildlife incidents via the Canadian Aviation Damage Occurrence Reporting System (CADORS) while adhering to any other applicable local airport procedures. FSS should also encourage pilots to report occurrences using procedures found in the Rules of the Air and Air Traffic Services Section (RAC) of Canada’s Aeronautical Information Publication (A.I.P.).


There is little question that ATS providers are an important part of the system safety formula. Tactically, they are on the front lines in the day-to-day battle to prevent wildlife strikes, the link between people on the ground and pilots in the air. By reporting wildlife activity and strikes—and encouraging others to do the same—ATS providers ensure the scope and nature of airport wildlife hazards are better identified and understood.

Strategically, ATS managers and staff have the opportunity to participate in local and regional safety committees, and on Transport Canada’s National Bird Strike Committee. At this strategic level, the exchange of knowledge among all aviation industry stakeholders is a fundamental aspect in the effort to reduce wildlife-strike risks.

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