Draft AC's On Tap
By Donna Speidel

The FAA's two principal airfield marking advisory circulars (AC) are being revised. AC 150/5340-1 - Standards for Airport Markings, and 150/5370-10 - Standards for Specifying Construction of Airports, are in "draft". There are significant proposed changes related to airport markings, so let's unpack it to see what's on tap.

150/5340-1M - Standards for Airport Markings

This draft guidance has been out since early 2017, and industry comments were due back in May 2017. Standards related to what individual airfield markings are, when and where they're used, and how they're configured is all in the 5340. From what I can tell, this guidance is in the final stages of publishing and should be made official any day. The following are a few of the primary changes:

• Preformed Thermoplastic - Still approved for use on airfields. A life cycle cost analysis of the material should be conducted and submitted if the material is specified. Further clarifies this material is "not to be used on runways because of the significantly lower friction readings recorded as compared to dry pavement."
• Pattern B Holding Position Markings in Runway Approach-Departure Areas - On taxiways where aircraft may taxi under landing/departing aircraft, the standard marking to use to delineate the runway protection zone will be a Pattern B, formerly known as an ILS, holding position marking. In my experience, I have commonly seen Pattern A holding position markings used in this situation, and occasionally accompanied by enhanced taxiway centerlines despite no actual intersection with a runway. The use of the Pattern B holding position marking is intended to reduce air traffic control and pilot workloads in the long run.
• No-Taxi Islands - Designed to enhance safety on taxiway routes. There are many possible applications; however, the AC does discuss common taxiing situations and existing airfield layouts in which these enhancements may be of benefit including exiting aprons, taxiing between aprons and entrance taxiways, and entering runways.

This draft guidance was released in November 2017 and was available for industry comment right up until about a month ago, January 2018. There are many construction elements defined within this particular AC. Comments are likely under review and being considered by those in the FAA who are responsible for the document.

Specifically, Item P-620 addresses standards for the installation of Runway and Taxiway Markings during "new" construction projects. It is the only part of an FAA advisory circular that regulates how markings on airfields should be applied, specifying materials, equipment, application rates, surface preparation, etc. Here are a few noteworthy revisions:

620-3.2 - Equipment. "[Painting equipment] shall produce an even and uniform film thickness and appearance of both paint and glass beads at the required coverage and shall apply markings of uniform cross-sections and clear-cut edges without running or spattering and without over spray. The marking equipment for both paint and beads shall be calibrated daily."

620-3.3 - Surface Preparation. "Preparation of pavement to remove existing markings. Existing pavement markings shall be removed by rotary grinding or by other methods approved by the Engineer minimizing damage to the pavement surface. The removal area may need to be larger than the area of the markings to eliminate ghost markings. After removal of markings on asphalt pavements, apply a fog seal or seal coat to 'block out' the removal area to eliminate 'ghost' markings.

620-3.5 - Application. CAUTION: Prior to reopening pavements at Part 139 airports verify that all markings comply with Part 139 requirements. Temporary markings not in compliance with AC 150/5340-1 will require a NOTAM regarding any non-standard marking be issued. For example, temporary markings without beads.

620-3.7 - Control Strip. "Prior to the full application of airfield markings, the Contractor shall prepare a control strip in the presence of the Engineer. The Contractor shall demonstrate the surface preparation method and all striping equipment to be used on the project. The marking equipment must achieve the prescribed wet film thickness of paint and population of glass beads (per Table 1) that are properly embedded and evenly distributed across the full width of the marking. Prior to acceptance of the control strip, markings must be evaluated during darkness to ensure a uniform appearance.

To summarize, the FAA's Airport Engineering Division is focused on the installation of quality markings: those that are longer lasting, more effective, and promote safer navigation. There is no guarantee that the recommended changes will become standards, but it is encouraging to see the deliberate attempt to continue to improve the process. Once the draft is made official, we will revisit and report on it.

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