Figure 1. Separation marking between the movement and non-movement areas.
Figure 2. Surface incidents/runway incursions involving mechanics taxiing or towing aircraft and driving tugs into the movement area by fiscal year (FY).
Figure 3. Surface incidents/runway incursions involving mechanics taxiing or towing aircarft and driving tugs into the movement area by fiscal year (FY).
Preventing runway incursions is one of the Federal Aviation Administration's (FAA's) highest priorities. Though relatively small in number when compared to the high level of traffic that moves safely through the nation's airports every day, runway incursions present a special challenge. Not only do they have the potential to put lives at risk due to the number and proximity of aircraft operating on the airport surface, but they also take place in a complex and dynamic environment.
Pilots are trained to carefully plan the en route portion of their flight, and the Office of Runway Safety & Operational Services is stressing the importance of using the same type of careful planning for ground operations. In fact, recently published standard operating procedures (SOPs) emphasize safe surface operations. For example, one SOP recommends that pilots review airport diagrams before taxiing or landing, particularly at unfamiliar airports.
What makes up an airport?
Besides the hangars (buildings for housing and servicing aircraft), airports are usually equipped with office and terminal buildings which house administrative, traffic control, communication, and weather observation personnel. An airport (airfield) is a place for landing and departure of aircraft, and for receiving and discharging passengers and cargo. In addition to the wide paved strips known as runways, there are narrower paved strips called taxiways connecting the runways to other parts of the airport. A taxiway and a runway are usually connected at each end and at several intermediate points.
From a safety perspective, an airport is divided into two distinct areas. One area is known as the movement area, which is under the control of air traffic, and usually includes the runways, taxiways, and other areas of an airport that aircraft use for taxiing, takeoff, and landing. The other area, known as the non-movement area, usually includes taxi lanes, aprons, ramps, and other areas not under the control of air traffic. The movement of aircraft or vehicles (i.e., tugs) within the non-movement area is the responsibility of the pilot, mechanics, the aircraft operator, or airport management.
At most airports, the movement and non-movement areas are separated by a solid yellow line and a dashed yellow line (See Figure 1).
It is permissible to cross from the dashed side to the solid side; however, ATC permission is always required to cross from the solid side to the dashed side at an airport with an operating control tower.
What should mechanics know?
A surface incident is a broad term encompassing all movement areas (including runways and taxiways) and is “any event where unauthorized or unapproved movement occurs within the movement area, or an occurrence in the movement area associated with the operation of an aircraft that affects or could affect the safety of flight.” Surface incidents may be caused by pilots and reported as pilot deviations (PD), by vehicle drivers or pedestrians and reported as vehicle/pedestrian deviations (V/PD), or by air traffic control and reported as operational errors/deviations (OE/OD). A V/PD report includes incidents caused by mechanics taxiing and/or towing aircraft. The FAA further classifies a surface incident as either a runway incursion or a non-runway incursion.
The current definition of a runway incursion is “any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle or person on the protected area of a surface designated for the landing and take-off of aircraft.”
The FAA knows who, what, where, and when aspects of a surface incident or runway incursion, but not always the why. Under the voluntary runway incursion information evaluation program (RIIEP), questions have been designed to help answer the why. For example, when a mechanic taxiing an aircraft is involved in an incident and decides to participate in RIIEP, some basic questions will be posed, such as: (1) Was the mechanic familiar with the airport layout? (2) Were airport signs, lights or markings contributing factors? (3) Did language or clearance interpretation problems contribute to the event? (4) Did radio communications play a role? and (5) What does the mechanic believe caused the incident? The RIIEP program has been discontinued.
Where can the mechanics be found?
The vast majority of mechanics can be found performing maintenance and other related tasks in the hangars. There are a few mechanics selected to work next to the terminal buildings on the ramp or apron servicing aircraft. Regardless of where the mechanics work, they rarely venture into the movement area. However, it is that rare entry into the movement area that poses a challenge for the mechanics as well as air traffic controllers and pilots. During the course of their shift, mechanics may be required to reposition an aircraft before or after maintenance. The repositioning of aircraft is usually accomplished by either taxiing or towing and may require the mechanics to enter the movement area. Between FY2001 and 2004, mechanics have been involved in approximately 163 surface incidents/runway incursions (See Figure 2). Between FY2005 and 2009, there have been 162 surface incidents/runway incursions involving mechanics (See Figure 3). After analyzing the incident reports, it was found that the mechanics did not have any problem with communications, or communicating with air traffic. As a matter of fact, air traffic reported mechanics had acknowledged the taxi/tow instructions and read the instructions back correctly; however, they still proceeded into the movement area, crossed active runways, and entered active taxiways without proper authorization or clearance.
Navigating around the airport
Most towered airports have markings, signs, and lights designed to assist you in navigating around the airfield. Runways are identified by the wide, white-painted edge lines and white-painted dashed centerline. Taxiways are marked with double yellow-painted edge lines and a yellow-painted solid centerline. Remember, the yellow taxiway centerlines may lead on, lead off a runway.
During low visibility or night operations, the runways, in addition to the white-painted markings, have white lights along the edge, centerline, and touchdown zone. However, it should be noted that on instrument runways the last 2,000 feet will have yellow edge lights. The taxiways are illuminated with blue edge lights (or reflectors) and green centerline lights (or reflectors). Mechanics need to know that when these markings, signs, and lights are missed or ignored, the opportunity for errors increases. Guidance on how to operate safely in the airport environment is critical.
What can be done?
The Office of Runway Safety & Operational Services offers the following recommendations:
The FAA Aviation Maintenance Technician Schools, in addition to teaching their students how to taxi aircraft, should teach airfield markings, signs, and lights and basic airport layout. The aviation maintenance technician school is responsible for teaching mechanics to inspect, repair, and maintain today's technologically advanced aircraft. According to the curriculum, maintenance technicians are provided instructions in ground operations including taxiing and towing aircraft. It is during these instructions that safe surface operations should be introduced.
The employing aviation company, in addition to reinforcing basic airfield markings, signs, and lights, should invest some time in conducting advance airport layout training or ensure that their mechanics attend equivalent training that may be conducted by airport operations. This course would be specific to the airport where they operate.
Dr. Paul M. Foster is the FAA Safety Team Inspection Authorization Refresher Course Coordinator (IA RCC). He is also an adjunct professor with Embry-Riddle Aeronautical University teaching graduate and undergraduate courses in aviation safety, management, and aircraft maintenance. He holds an EdD in Organizational Leadership, EdS in General Education Administration, Masters of Art in Management, and Bachelor of Professional Aeronautics from Pepperdine University, Troy State University in Montgomery, Webster University, and Embry-Riddle Aeronautical University, respectively.