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Ep 27 – Runway Surface Conditions Using GRF and TALPA

Regs, Podcast | June 29, 2021

Introduction

Hello everyone. Today I’ll be talking about ICAO’s new Global Reporting Format (GRF) for runway surface conditions.

GRF Applicability

The 4th of November 2021 applicability date is the start for ICAO’s Global Reporting Format.

Purpose

GRF, referred to as Takeoff and Landing Performance Assessment (TALPA) in the U.S., is used for assessing and reporting runway surface conditions. The aim of GRF is to reduce the risk of runway excursions by bringing all the stakeholders, such as airports, aircraft operators, and aircraft manufacturers, under one roof and making the information shared between these groups easier to collect and understand. For example, ICAO says that a trained runway observer will create a Runway Condition Code for each third of the runway using globally recognized descriptors, thereby creating a Runway Condition Report (RCR). This information will be passed to ATC for the creation of a SNOWTAM or other method of distribution. The flight crew will receive the RCR information and correlate it to their aircraft performance data, enabling them to calculate accurate takeoff and landing performance information.

Available GRF Information

In ICAO’s world, you find information about GRF in:

Effect

ICAO’s Global Reporting Format is called TALPA in the U.S. TALPA has been in use since 2016, whereas other countries, including Canada’s, GRF becomes effective later this year. ICAO’s date is this November 2021 and Canada’s is August 12th, 2021.

Training

Training will be available at TrainingPort.net, so speak with one of our sales representatives.

The majority of the information I’m talking about today comes from the draft Advisory Circular 700-057, which will probably become effective in Canada on August 12th, 2021. But its contents apply to everyone.

Runway Surface Condition Reporting

While there are some differences between TALPA and GRF, the basic premise remains the same. The key to both is the Runway Condition Assessment Matrix (RCAM).

TALPA Aviation Rulemaking Committee (ARC) Recommendations

After the 737 overrun in Chicago Midway in 2005, the FAA convened a TALPA committee to investigate runway condition reporting. The committee came up with recommendations that developed consistent terminology and runway assessment criteria, presented in a standardized format.

This new runway condition method is used by:

  • Airport operators for the reporting of runway surface conditions;
  • Aircraft manufacturers for the development of performance charts; and
  • Flight crews who utilize the reported runway surface conditions and TALPA-based performance information to determine takeoff and landing performance numbers.

The issue before GRF or TALPA was that the language used by the different groups did not cross over well. Pilots who were trying to determine a takeoff or landing distance were given information that did not speak well to the aircraft manual. So, the biggest part of GRF is the Runway Condition Assessment Matrix (RCAM).

Runway Condition Assessment Matrix (RCAM)

The RCAM takes standard runway conditions, airport reporting codes, braking action reports, and aircraft performance found in the manual, and brings it together.

The major manufacturers of Transport Category airplanes have produced performance information that is based on the TALPA methods. This TALPA-based performance information addresses operations on wet and contaminated runways, and provides a significant advancement over the previous performance methods and practices.

ICAO has mandated a GRF which incorporates many of the significant safety enhancements that resulted from the TALPA committee. Runway condition reporting must be clear to everyone so ICAO says that the runway condition reporting process must include:

  • An agreed set of criteria used in a consistent manner for runway surface condition assessment, airplane performance certification and operational performance calculation.
  • A unique Runway Condition Code (RWYCC) linking the agreed set of criteria, and related to the braking action experienced and eventually reported by flight crews.
  • Reporting of contaminant type and depth that is relevant to takeoff performance.
  • A standardized common terminology and phraseology for the description of runway surface conditions that can be used by aerodrome operator inspection personnel, air traffic controllers, aircraft operators and flight crew.
  • Globally-harmonized procedures for the establishment of the runway condition code with a built-in flexibility to allow for local variations to match the specific weather, infrastructure, and other particular conditions.

Canadian implementation will meet the intent and safety elements of the GRF and will also provide some enhancements. One of the main differences from the ICAO format is the ability to report two contaminants per runway third; or for the entire runway, when the runway condition report is for the full runway length.  The U.S. Field Condition NOTAM (FICON) also lists two contaminants.

Runway Condition Code (RWYCC)

The Runway Condition Code (RWYCC) is a number, from 0 to 6, which represents the slipperiness of a specific third of a runway. A RWYCC of 0 corresponds to an extremely slippery runway, and 6 corresponds to a dry runway. RWYCCs can be used by pilots to make a time of arrival landing performance assessment for those aeroplanes with suitable performance information. Check your aircraft manual.

RWYCCs are only reported if:

  • The runway condition information is reported by runway thirds; and
  • The runway surface is paved.

An RWYCC is reported for each runway third, with each third separated by a forward slash, for example 5 slash 5 slash 5.

In the event the full width of the runway is not cleared, the RWYCC will be determined based on the contaminants present in the cleared portion of the runway, typically the centre 100 feet.

The Runway Condition Assessment Matrix (RCAM) is used to determine a RWYCC from a set of observed runway surface condition(s) and associated procedures.

Runway Surface Condition (RSC) Validity Periods

One of the issues that has come up in runway overruns is up-to-date information. The flight crew may have calculated a correct landing distance, but, when they get to the runway, the conditions have changed enough that the braking is not what they expected. An example would be a rain shower that has passed by depositing water on the runway or snow has started to fall.

Although not a runway condition itself, increased WIND or the wind direction and speed could change significantly enough to alter landing distance.

So, with that is mind, it’s important to understand validity periods.

The RSC NOTAM contains the information from multiple sources.

The validity period stated in the RSC NOTAM:

  • Reflects the validity period for each runway condition; and
  • Should not exceed the published operating hours for an airport or aerodrome, unless the surface conditions are being monitored.

For airports, the maximum validity period is 8 hours.
For aerodromes reporting RWYCCs, the maximum validity period is 8 hours.
For aerodromes not reporting RWYCCs, the maximum validity period is 24 hours.

Even if you have a valid RSC, conditions may have changed, as I said earlier. In other words, conditions could be active. What if precipitation of any kind has occurred since the runway condition report was issued? Does a new ATIS say it’s snowing? What if a similar type aircraft gave a Braking Action Report for the runway you plan to use? This information must be considered. As you can see, there can be multiple steps to determine an accurate takeoff and landing distance. I have only scratched the surface here, so have a look at the documentation and your aircraft manual. TrainingPort.net will have a topic on this soon.  Go through a scenario of poor runway conditions at your home airport or maybe a shorter runway you go to and determine if you can land or take off with a contaminated runway. There are many steps involved, and then you might get a wind report or a new ATIS late in the approach that requires modification to your calculations.

Important Considerations

The new GRF will not prevent all runway excursions. Pilot approach and landing techniques are crucial. Some things to consider:

  • Are you always on speed crossing the numbers? What is the maximum crosswind for your airplane with medium braking reported?
  • Do you always touchdown in the touchdown zone? Even if you are asked or allowed to exit the runway at the end. Do you use the VASI or PAPI all the time? Is there a tendency to duck under or fly high on these indicators?
  • Do you always deploy reverse thrust, even idle reverse? When do you stow the reversers? Occurrences have happened after reverse thrust was stowed trying to clear the runway at the end but then control was lost due to excessive speed. Also, the thrust reverser logic of your airplane might mean deploying reverse thrust only after deciding that you need it will make it ineffective because of the time it takes to deploy the thrust reversers and spool up the engines. Also, we know that thrust reversers are most effective at high speeds and are usually limited at lower speeds.
  • What does your manual say to do when the aircraft starts to slide and reverse thrust is being used? My manual says to select idle reverse which allows the tires to regain grip, then increase reverse thrust again to slow the airplane. Revisit your aircraft manual and recommended procedures for wet and contaminated runway conditions.

In The News

Let’s switch gears for a moment. In The News is a section of the podcast where I talk about other happenings in aviation.

Preflight Briefings

Many times when there is an occurrence, there seems to be something that the crew did not perform once or perhaps they rarely perform it all. I’m not a trained accident investigator; however, many times in my readings of accident reports, checklists or briefings are often omitted. The FAA has released Advisory Circular AC 91-92 – Pilot’s Guide to a Preflight Briefing, which highlights the need for proper and structured preflight briefings. This is a great way to set the tone for the flight and the trip. The AC itself is aimed at Part 91 operators and mentions “self-briefing,” but it is a good preparatory tool with many links to weather related websites and videos. Have a look using the link in the notes on our website, TrainingPort.net.

Also, don’t underestimate the value of a postflight briefing—what went well, what didn’t go as well, and what can we do to improve.

NAT Operations: Two Long Range Communications Capabilities

Also, just a quick note for the North Atlantic:

NAT Operations now requires two long range communications capabilities, one of which must be High Frequency (HF). You may not enter North Atlantic High Level Airspace without a functioning HF. This is a new rule which can be found in the updated North Atlantic Operations and Airspace Procedures Manual, dated February 2021.

Thanks for listening, and have a great day!


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