Pilot Speak: Breaking Away from Runway Overruns – The FAA’s New Rules for Runway Condition and Braking Action

There is a premise among professional pilots that some FAA rules are intentionally vague and often open to interpretation in order to provide operational flexibility (within reason). For years, such has been the case with runway condition assessments and braking action reports. For example, most pilots who have operated under Federal Aviation Regulations (FAR) Part 91K, 135, or 121 have had hard limits for what runway conditions and braking action reports would permit or prohibit a runway’s use. Yet, pilots and controllers alike understand the “game” and what is sometimes necessary to complete the mission, while also remaining firmly within the rules.

Playing the Game

Consider this theoretical situation between a King Air charter operation (Part 135) and Air Traffic Control (ATC). Assume the charter operator’s Operating Specifications (OpSpecs) state that landing is prohibited with braking actions, or Mu-reading equivalents, of less than Fair, with the most recent report being controlling. An airliner is cleared to land on runway 18 and is given the most recent Mu readings for that runway of .30/.30/.30 [touchdown, mid and roll-out zones, respectively]. A Mu (or co-efficient of friction) measurement of .30 is generally considered to be the bottom of the Fair braking action range, before entering the Fair-to-Poor range of .29 to .26 [see Figure 1]. After landing, the airliner reports braking action as “Poor.” The King Air on approach is told of this latest report. The pilot responds that he cannot land with braking action reported as less than Fair and is, thus, issued a holding clearance and told that airport operations will not be taking the next Mu-readings for 40 minutes. Meanwhile, a corporate jet (operating under Part 91), overhears this exchange, completes an approach and landing, subsequently reporting braking action as “Fair” (knowing full well that his report will supersede the previous airliner’s report, thereby allowing the King Air to accept an approach and landing clearance). This newer report is relayed to the holding King Air charter flight, who then accepts a new approach clearance and lands uneventfully. This is in no way an unrealistic or uncommon scenario. Similar situations play out at airports around the world regularly, often with ATC being proactive in soliciting braking action reports while indirectly letting landing aircraft know what approaching aircraft might require to “get in.” It’s a game that pilots, controllers and regulators know happens and those who believe otherwise are either in denial or do not operate in the system often enough to have seen or heard it unfold firsthand. Each aircraft is likely reporting in a perfectly honest way, but runway conditions and braking actions do not affect all aircraft types the same. So, as one might imagine, such situations can also lead to overrun incidents or accidents as aircraft of varying capabilities utilize the reports of aircraft with very different performance parameters. The FAA has recently made several significant changes to bring more clarity, and more rigid requirements to Takeoff and Landing Performance Assessments (TALPA) and runway condition and braking action reporting. These changes address such issues as the example given, as well as rejected takeoff situations.

Figure 1: Comparison of New and Previous Braking Action Information*

*The two left columns reflect the new system and terminology, effective Oct. 1, 2016. The two right columns reflect the previous system and terminology, now superseeded, presented strictly for comparative purposes.

** No official correlation between pilot-reported braking action terminlogy and Mu measurements exists under the previous or the new rules and systems, and sources vary slightly on these values. Under the new rules, a RwyCC of 0 is considered “Nil” braking action, rendering that runway closed to all flight operations.

*** Mu readings of less than .25 are considered unreliable and, thus, should be considered to indicate the potential of Nil braking action.

The TALPA Initiative

Beginning on Oct. 1, 2016, a new format of Field Condition (FICON) Notices to Airmen (NOTAM) will be utilized to report runway conditions determined via the new TALPA procedures at federally obligated airports. These changes are a result of findings from the TALPA Aviation Rulemaking Committee. Originated in 2006, the project was designed to provide airport operators with a common method for accurately determining contaminated (non-dry) runway conditions, in order to reduce the risk of runway overruns. Such information can then be utilized by pilots, dispatchers, operators and other flight planners to calculate minimum runway lengths for landings or rejected (aborted) takeoffs, when combined with the manufacturer’s aircraft specific data. In overly simplistic terms, the former subjective assessments of runway conditions have been replaced with more objective means. Now, runway conditions are based on both the type and depth of the contaminate and are expressed using a corresponding runway condition code [see Figure 2]. Such specific information can be better applied to aircraft-specific performance charts for calculating the most accurate runway requirement data.

Braking Action Changes

Also effective Oct. 1, 2016, Mu reports will be replaced by Runway Condition Codes (RwyCC), which may take Mu measurements into account, but will also incorporate specific contamination types and depths. While braking action reports from pilots will continue to be solicited and used, the acceptable terminology has changed. The most significant change is that the term, “Fair” has been replaced with “Medium” to better conform to International Civil Aviation Organization (ICAO) standards [see Figure 1]. Along with this, a report of “Nil” will no longer be acceptable for an active runway. Instead, a braking action of “Nil” (as ascertained by pilot reports or RwyCC) will render that runway unusable and necessitate its immediate closure. This eliminates the option of using such a runway by operators who could otherwise do so legally; a decision which has led to many runway overrun incidents and accidents in the past. This has been especially true with turboprop operators who often rationalized the use of a runway with Nil braking action by considering their slower landing speed, reverse thrust prop capabilities (beta plus power), and a greater headwind or less crosswind on that runway. Accident history has proven those perceived “positives” do not outweigh the negative of little or no runway braking action. Thus, any such runway is now considered closed, by definition, and cannot be considered re-opened until braking action can be measured and reported as something greater than “Nil.”

Information Assessment: Good!

Many regulatory and operational changes made by the FAA in the past have been accompanied by corresponding educational information that is difficult to find or challenging to translate from regulatory language. Not so with TALPA and the changes highlighted here. Below are just a few of the many resources available for a deeper understanding of these changes and what they mean for your operations and missions:

• The FAA website has a page dedicated to TALPA with a multitude of links corresponding to specific operators and the various regulatory sections effected. See URL: http://www.faa.gov/about/initiatives/talpa/
• Advisory Circular 25-31 “Takeoff Performance Data for Operations on Contaminated Runways,” dated 12-22-2015
• Advisory Circular 25-32 “Landing Performance Data for Time-of-Arrival Landing Performance Assessments,” dated 12-22-2015
• Advisory Circular 91-79A, dated 04-28-2016
• Current edition of the Aeronautical Information Manual (AIM)

Copyright 2016, Matthew McDaniel. First publication rights granted King Air magazine via the Village Press. All other rights reserved by copyright holder.