Air Traffic Bulletin

Issue 00-3 SPRING 2000

Table of Contents: [Back]
National Route Program (NRP)
Speed Control and B737 Speed Limitations
Spring 2000 - Where Are We?

National Route Program (NRP)

/*TE/ The NRP has developed into an international program aimed at giving National Airspace System users flexibility in their flight plan filing at and above flight level 290 throughout Canada and the conterminous United States within published guidelines. The user savings generated are directly related to the efforts of air traffic controllers and traffic management units. However, questions have recently arisen by pilots concerning the initiation/acceptance and cancellation of direct routes clearances. These questions, and their answers, are as follows.

Question 1: An aircraft has been given a direct routing which was not requested by the pilot. The route reconnects to the aircraft's original NRP routing. Is the aircraft still receiving priority under NRP?

Response: Yes. It is assumed that the aircraft was moved for weather, traffic, or other tactical reasons and then returned to the original routing. Reference FAAO 7110.65, Air Traffic Control, Paragraph 2-2-15a, National Route Program (NRP) Information, which states:

"a. 'NRP' shall be retained in the remarks section of the flight plan if the aircraft is moved due to weather, traffic, or other tactical reasons.

Every effort should be made to ensure the aircraft is returned to the original filed flight plan/altitude as soon as conditions warrant."

Question 2: A controller asks an aircraft on NRP if it wants a direct routing where the new routing reconnects to the original NRP routing. The pilot says, "Yes." Is this NRP?

Question 3: A pilot asks for a direct routing which would reconnect the aircraft with the NRP route currently being flown. The controller clears the aircraft via the requested route. Is this NRP?

Responses: The answer to questions 2 and 3 is "No." When a controller asks a pilot if they would like a direct routing, and it is not for weather, traffic, or other tactical reasons, or when the pilot asks for a routing change, it cancels NRP. Pilots may query air traffic control if they will remain on NRP if they accept the direct routing offered. Reference: FAAO 7110.65, Paragraphs 2-2-15a and b, which state:

"a. 'NRP' shall be retained in the remarks section of the flight plan if the aircraft is moved due to weather, traffic, or other tactical reasons.

Every effort should be made to ensure the aircraft is returned to the original filed flight plan/altitude as soon as conditions warrant.

b. If the route of flight is altered due to a pilot request, 'NRP' shall be removed from the remarks section of the flight plan." (ATP-100)


Speed Control and B737 Speed Limitations

/*TE/ Speed adjustments should be kept to the minimum necessary to achieve or maintain required or desired spacing. Speeds as low as 170 knots can be assigned to turbine-powered aircraft operating below 10,000 feet within 20 flying miles of the airport of intended landing.

However, as a result of rudder incidents, certain Boeing 737 (B737) aircraft maneuvering speeds have been increased by as much as 20 knots. A heavily loaded B737-400, for example, may have a minimum maneuvering speed of 180 knots at flaps of 10 degrees. Any slower airspeed requires that the landing gear be extended; otherwise, the gear warning sounds continuously and cannot be silenced. For these reasons, some B737 pilots may request higher speeds when assigned minimum speeds by air route traffic control centers and terminal radar approach control facilities.

It remains the pilot's responsibility and prerogative to refuse a speed adjustment that he/she considers excessive or contrary to the aircraft's operating specifications. (ATP-100)


Spring 2000 – Where Are We?

/*TEF/ The efforts to mitigate delays and flight cancellations are well underway. On March 12, 2000, the Strategic Planning Team (SPT) became fully functional at the David J. Hurley Air Traffic Control System Command Center (ATCSCC). The SPT members are a highly trained cadre of traffic management coordinators that, along with the users, plan (via telcons every other hour) what traffic management initiatives will occur in the next 2- to 4-hour period. They start at 0500 EDT and continue to 2200 EDT daily. Supporting their effort is the Collaborative Convective Forecast Product, which allows the users and the SPT to look at the same weather presentation and prepare Severe Weather Avoidance Plan (SWAP) routings in advance.

A big step forward from last year's "reactive" mode of operation! Also assisting with the pre-planning operation are the National "Playbook" and Coded Departure Routes (CDR). By sharing the expected SWAP routes in advance, these two tools allow the users to organize and implement reroutes in a timely manner which also reduces the amount of flight plans in the HOST computer system. Additional automation advances are the Departure Spacing Program (DSP) currently in use in the New York metropolitan area and the Collaborative Routing Coordination Tool (CRCT) which began testing in Kansas City ARTCC on April 17. DSP evaluates proposed departure times along with initial departure fixes, then assigns a numerical departure sequence for all New York area departures passing over the same fix. This provides more accurate departure scheduling data for both users and controllers; it also increases productivity by reducing miles-in-trail restrictions on departures.

Our initiatives are already being tested by the most severe weather of any April in history. Thus far, customer comments and internal evaluations are indicating that our traffic management programs are heading in the right direction. Remember, no one can influence the weather but we can all influence the national airspace system. (ATT-10)


Are you looking for trouble, or is trouble looking for you?

We have seen a number of serious separation losses in the past few months involving airborne as well as taxiing aircraft. In all cases, the controller failed to scan the airport environment or the radar display effectively. How is it that head-on or converging traffic is missed on the radar display? How is it that aircraft or vehicles are not observed moving on or across runways? The answer is usually ascribed to poor scanning technique. However, in almost all cases, the controller involved did scan the troublesome area, but failed to detect or see the conflict.

It may be that the term "scanning" is inappropriate as it pertains to air traffic control. In the cases where separation is compromised or a near collision occurs due to poor scanning, the controller often has executed the scan in a rapid and casual fashion. In such cases, the controller is not looking for anything in particular other than something described vaguely as "traffic." According to Webster's II Riverside University Dictionary, the word "scanning" has two different definitions; 1) "to look over rapidly but thoroughly, to examine closely" and 2) "to look over or leaf through hastily or casually." Unfortunately, many controllers subscribe to the latter description, which can be disastrous when applied in ATC matters. What controllers should be doing is searching or looking for trouble.

The terminal controller should be looking for aircraft movement where there should not be movement. Train yourself to look for threats to the safety of the aircraft operations. Excellent instructors train their students to look for aircraft, vehicles, people and objects that do NOT belong. They look for aircraft and vehicles on the runway before, during, and after a takeoff or landing clearance has been issued. They train to systematically check for aircraft, vehicles and people approaching the intersections to the runway. They check the departure flight path. They check the final and both base leg paths. They check and re-check to assure that the traffic is moving the way they want and expect it to. They are wary and they are careful. They are thorough. Because they are looking specifically for trouble, they prevent trouble.

The same principles apply to the terminal radar approach and en route controller. Here, excellent instructors train their students to systematically look at the scope, searching for anomalies and checking the progress of their aircraft. Before a climb, descent, or turn is issued, the area around and ahead of the aircraft is re-checked for threats or conflicts. Route information that is available on the CRD display and flight progress strips must be incorporated into the scan of information in order to be able to look for trouble before trouble finds you. The shift from "scanning" to "searching" for specific information is a subtle but very powerful mindset. Please give it some thought.

To combine or not to combine…

These days the traffic "pushes" can be intense and press the controller to the maximum to keep traffic moving smoothly. However, the most common mistake that a controller can make that can profoundly affect controller workload is to inappropriately combine radio transmissions. Combined messages that incorporate more than five or six numbers, such as transponder codes, frequencies and headings, are particularly prone to misunderstanding. For example, "UAL243 turn left heading 2-5-0, contact Bravo departure on one one eight point three five," should be broken into two separate transmissions. This makes it easier for the pilot to remember because the information arrived in small, easy to mentally file chunks. When the information is given in large groupings, it is difficult, and in some cases impossible, to remember accurately. For example, the transmission, "AAL314 contact Tango center on one three three point six five squawk five one two seven," may be difficult for the pilot to recall by virtue of the total number of digits making up the frequency and the transponder code. Remember, any time you have to repeat a transmission, your workload is increased. Avoid setting yourself up to have to repeat transmissions. (AAT-200)


Air Traffic Publications