Air Traffic Bulletin

Issue 00-5 SUMMER 2000

Table of Contents:
Land and Hold Short Operations (LAHSO)
Monitor Alert Parameter (MAP)Shortcomings
INCIDENT'LY:

 

Land and Hold Short Operations (LAHSO)

/*T/ The revised standards for conducting LAHSO, as specified in FAAO 7110.118, effective August 14, 2000, include the requirement that the LAHSO runway available landing distance (ALD) must be dry.

There have been questions as to the responsibility of air traffic control tower supervisors/controllers in charge (CIC) in determining whether the LAHSO runway ALD is dry (or not). As specified in FAAO 7110.65, paragraph 3-3-1, it is the responsibility of the airport management/military operations office for observing and reporting the condition of the landing area and to provide the tower with current information regarding airport conditions. Accordingly, the airport management/military operations office determines and reports the condition of the landing area, including a determination as to whether the runway is dry.

It is important to distinguish between a determination of the condition of the landing area and an operational determination regarding the safe use of that landing area for LAHSO. FAAO 7110.118, paragraph 11(l) states that "LAHSO shall be terminated for any situation or weather condition which, in the judgment of the airport traffic control tower supervisor/controller in charge, would adversely affect LAHSO." Therefore, in situations such as observed precipitation from the tower, visible moisture on the runway, pilot reports of water on the runway, or any other information that could adversely affect the safe conduct of LAHSO, air traffic supervisors/CIC are expected to take appropriate action to suspend LAHSO and to relay the information to the airport manager/military operations office concerned. The airport manager/military operations office should provide the tower with information regarding the current status of the runway. LAHSO may be resumed after the authorized airport management/military operations office has advised air traffic control that the LAHSO runway ALD is dry. (ATP-120)

Monitor Alert Parameter (MAP) Shortcomings

/*E/ The MAP is a useful tool, enabling traffic management unit personnel to monitor sector workloads, thus helping to ensure safety. However, just like the Roto-Tool it does have some limitations. The first and probably most significant limitation is that an aircraft with a "T" (temporary) altitude in its data-block is not moved into the receiving controller's MAP. This could result in the receiving sector not reflecting a yellow or red alert.

Another significant limitation is that MAP uses the flight plans in the host computer to track traffic. The drawback is that when a re-route is issued that takes an aircraft out of one sector's airspace and through another sector's airspace without a flight plan change in the host computer, it will not modify either sector's MAP status. This limitation is especially relevant during the summer due to aircraft deviating around weather and transitioning through adjacent sectors.

The MAP cannot combine sectors, therefore, during periods of light traffic when sectors are combined the MAP still reads the sectors individually and will not provide an alert for the airspace being worked. This limitation means that dynamic sectorization is not supported by MAP. Also, some MAP alerts are based on proposed departure times, which may result in inaccurate indications when traffic management initiatives are in place.

There are two more significant limitations: first, MAP updates every 5 minutes sometimes resulting in untimely alerts, and second, MAP does not support TRACON sectors, which could result in no-notice holding or 360's at airspace boundaries. (ATT-3)

 

INCIDENT'LY

Can You? Will You? and Positive Control?

The following four scenarios are examples of situations that resulted in an operational error because the controller left out one detail and assumed that the pilot would fill in the blanks.

1) Air Shuttle 257 traffic 12 o'clock, 2 miles at 8,000.

Traffic in sight, Air Shuttle 257.

Air Shuttle 257 climb and maintain one zero thousand.

Roger, out of 7,000 for one zero thousand.

Result: Separation lost.

Reason: Aircraft was not instructed to maintain visual separation with the other aircraft.

2) American 416, can you be level at FL330 in 2 minutes or less?

We can do that, American 416.

American 416, climb and maintain FL330, no delay in the climb; traffic a B757 north-east bound at FL310.

Roger, out of FL270 for FL330, AAL416.

Result: Separation lost.

Reason: Pilot was not issued 4-digit time climb restriction and was not able to reach the assigned altitude in the time frame the controller needed.

3) Malibu 25598 can you maintain visual separation with the B737?

Affirmative.

Malibu 598, descend and maintain 5,000.

Result: Separation lost.

Reason: Aircraft was not instructed to maintain visual separation with the other aircraft.

4) DAL553 climb to FL330 I need you level in 3 minutes.

Roger, out of FL280 for FL330, DAL553.

Result: Separation lost.

Reason: Aircraft was not issued climb restriction expressed in four digit time.

The remedy for Scenarios 2 and 4 is to use the phraseology described in FAAO 7110.65M paragraph 4-5-7 b. All inappropriate assumptions are eliminated when the paragraph's requirements are followed. The remedy for Scenarios 1 and 3 was for the controller to issue the control instruction which clarified who was providing separation. In other words, the controller needed to seal the deal! Instead, the controller created a "deal" (operational error).

Although the controllers asked the appropriate questions, all four failed to issue the appropriate control instructions. The controllers got caught in the trap of assuming that the pilot had agreed to be responsible for a certain action when in fact, the pilot had agreed to nothing. In all four of the incidents, one could argue semantics; that the pilots should have caught on to what the controller needed them to do by virtue of the type of questions that were asked. Perhaps, but the air traffic system leaves little room for assuming anything.

Outside of the air traffic environment it may not be entirely unreasonable to make such assumptions during a conversation because it is common for people to communicate in this way to some extent. People who converse in this manner will not succinctly state their desires. They will make hints, or they will talk around the subject, but they will not clearly or directly state what they want or expect.

If you practice this type of behavior, your listener will never be entirely certain whether you are just making an observation, gathering information, or hinting that you want something. What you can be sure of is that you will be relying on the listener to read your mind, or catch on to what you really want. Such behavior can strain relationships outside of work, but in the air traffic arena the results can be much worse. In our professional lives, we cannot make such assumptions. Bottom line; if a control instruction is not issued, then no clearance has been issued. Control instructions that are defined and leave no question as to what is expected are an example of positive control.

 

 

He Came, I Saw, He Missed........

Visual separation is not:

The above are examples of visual observation. Visual observation is the case where no particular method of approved separation is being utilized or where the intended separation failed and you are left with watching the aircraft pry themselves apart or whiz past each other. Visual observation is where no controlled plan is in place to assure safe proximity between the aircraft. Typically, visual observation takes place after things have gotten out of control and the CPC is resigned to spectator status. Afterwards, he/she may say, "Oh, I had visual separation!" Right!

Visual separation is:

Where you place aircraft on a certain path where you can monitor their progress and assure that they are in no danger of colliding, and maintaining this vigilance until lateral, vertical, or pilot visual separation is in place. In other words, it is planned ahead of time, and executed correctly, and will not result in a loss of separation or a near mid-air collision report. (AAT-200)