Runway and Field Condition Reporting

Field Condition Reporting, FICON

For many years airfield condition reports have been scattered between separate NOTAMs and ATC reports for braking action, friction meter readings and runway surface contamination descriptions. The local airport “Owner” was responsible in generating condition reports and publishing these to the FAA and ATC. There is no one standard on describing the "slipperiness" of a runway, taxiway and ramp surface. Operational pilots have no one reliable source for timely and accurate information on what to expect at departure or at the time of landing.

1OCT16 will signal a shift in reporting airport field contamination, braking action reports and required actions for operational pilots inside the USA. This new reporting system inside the USA has been harmonized with ICAO Standards and Recommended Practices, SARPS found in Annex’s 3, 14 and 15. It is easy to see the implication for domestic winter operations in the USA and internationally.

A New System of Field Condition Reporting

NOTAMS for Field Condition, “FICONs” are not new. Previously you might have seen separate NOTAMs for braking action, Mu readings and runway surface contamination descriptions. The old system took all three elements into account when creating a Runway Condition Code, RCC. The old system used one code for the condition of the entire runway. This was a poor system because of the varying conditions over the length of the runway.

Beginning 1OCT16, airport management will issue FICONs for only the active runways and only for the landing direction. The RCC code reflects the summary of Mu Values, contaminant observations, and braking action reports. RCC numbers are only generated when at least 25-percent of the runway has some kind of contaminant. If there are only a few spots of snow, water or ice along the surface, the contaminants will be reported, but a code will not be generated. Every FICON NOTAM will have the time that the conditions were observed. If unable to obtain an observation time, ATC will use the time when the NOTAM information is received.

The RCC code will now consist of three numbers separated by a slash. Each number relates to the slipperiness level of the touchdown, midpoint, and rollout thirds of that runway. The RCC code levels vary between a low of zero to a high of six. After the RCC numbers, and separated by commas there is a description of the contaminants and a percentage of coverage as described by the airport managers. If an RCC code of zero is issued, or If the computer determines the conditions warrant a “RCC Zero”, a FICON NOTAM is locked out and Part 139 airports become closed to commercial traffic on that runway, ramp or taxiway.

Here is an Example:

RWY 36 FICON 4/3/3 60 PRCT WET SN, 75 PRCT IN WET SN OVER COMPACTED SN, 80 PRCT 1IN WET SN OVER COMPACTED SN

Described in plain language:

The RCC for the touchdown third which is “4” and is described as having a 60-percent coverage of wet snow. The second "3" is the RCC for the middle third of the runway and described as 75-percent covered with wet snow over the top of compacted snow. The last  "3" is the rollout portion of the runway and it has 80-percent coverage of one inch of wet snow over compacted snow.

Keep in mind a couple of notes here: If the words “PILOT REPORTED” precede “FICON” this is a PIREP from an operating pilot and can be as old as 12 hours. “CONDITIONS NOT MONITORED” is used when field conditions will not be monitored and follow the most recent observation.

Braking Action Reporting Changes

Pilot-reported braking action is a subjective assessment of runway slipperiness. Braking action will now be described as “Medium” replacing the older term “Fair.”  You may still see a “Nil” report at general aviation airports. GA airport managers may decide to keep a surface open because they have no other options for helicopters or other activities. Only the runways will be different. ATC is required to solicit PIREPs of runway braking action. When runway braking action reports are received from pilots or the airport management determines that weather conditions are conducive to deteriorating or rapidly changing runway conditions, “Braking Action Advisories are in effect.” Will be included on the ATIS broadcast.

During the time Braking Action Advisories are in effect, US ATC will take action to issue the latest braking action report for the runway in use to each arriving and departing aircraft early enough to be of benefit to the pilot. If no report has been received for the runway of intended use, ATC issue an advisory to that effect.

Here is the new list of Braking Action Reports pilots are to use:

Good

Braking deceleration is normal for the wheel braking effort applied, and directional control is normal.

Good-to-Medium

Braking deceleration or directional control is between good and medium braking action.

Medium

Braking deceleration is noticeably reduced for the wheel braking effort applied, or directional control is noticeably reduced.

Medium-to-Poor

Braking deceleration or directional control is between medium and poor.

Poor

Braking deceleration is significantly reduced for the wheel braking effort applied, or directional control is significantly reduced.

Nil

Braking deceleration is minimal to non-existent for the wheel braking effort applied, or directional control is uncertain.

Runway Surface Conditions Defined

Dry Runway, FAA, A runway is dry when it is neither wet nor contaminated.

Dry Runway, ICAO, The surface is not affected by water, slush, snow, or ice.

Damp Runway, ICAO, The surface shows a change of color due to moisture. If there is sufficient moisture to produce a surface film or the surface appears reflective, the runway will be reported as wet.

Wet Runway, ICAO Reporting Purposes, The surface is soaked but there is no standing water

Wet Runway, FAA Reporting Purposes, A runway is wet when it is neither dry nor contaminated. A runway can be considered wet when more than 25 percent of the runway surface area is covered by any visible dampness or water that is ⅛ inch (3.17mm) or less in depth.

Wet Runway, ICAO For airplane performance purposes, A runway where more than 25 percent of the runway surface area whether in isolated areas or not within the required length and width being used is covered by water more than 3 mm (about 1/8in) deep.

Water Patches, ICAO Reporting Purposes, Patches of standing water are visible. Water Patches means standing water covering more than 25 per cent but not exceeding 50 per cent of the runway surface area whether in isolated areas or not within the required length and width being used is covered by water more than 3 mm deep

Flooded, ICAO Reporting Purposes, Extensive standing water is visible. Flooded means standing water covering more than 50 per cent of the runway surface area within the required length and width being used and is covered by water more than 3 mm deep.

Contaminated Runway, FAA Reporting/Certification Purposes, A runway is considered contaminated when more than 25 percent of the runway surface area (within the reported length and the width being used) is covered by frost, ice, and any depth of snow, slush, or water. The definition of water in the context of condition reporting and airplane performance is defined as a depth of greater than ⅛ inch (3 mm).

Contaminated Runway, ICAO Reporting Purposes, A runway is considered contaminated when more than 25 percent of the runway surface area (within the reported length and the width being used) is covered by any depth of compacted snow, ice or wet ice. Any loose snow at the depth of greater than 20mm/ 3/4in and any slush or water at a depth of greater than ⅛ inch (3 mm).

Runway Friction Information

There is no globally accepted procedure for the use of friction measuring devices. Some countries have developed procedures for use and reporting of specific friction measuring devices. The coefficient of friction is dynamic property inside several different factors consisting of the: pavement surface; tire pressure/tread depth; Contaminant, contaminated depth and atmospheric conditions

There is no universally accepted relationship between the measured coefficient of friction and the braking response from the aircraft. Historically, the goal has been to measure surface friction in a manner that was relevant to the friction experienced by an aircraft. To avoid misunderstanding and confusion, measured surface friction should be referred to as measured friction coefficient, which is used in the current SNOWTAM format. The ICAO SNOWTAM format uses the term “estimated surface friction” and should be understood as the total assessment of the slipperiness of the surface as judged by airport ground staff based upon all information available.

Countries differ with respect to what information is provided. Some countries provide the measured friction values to pilots while others only provide them with a general indication of braking action according to the ICAO scale given in Annex 14, Volume 1. Many of these countries include statements in their AIP regarding the limitations of this scale and some include a code in the format to signify that the runway conditions are unsuitable for measurement with a friction device. For example in the USA publication of the friction value is “Permissible” to be reported but not recommended. In Finland, Germany and Canada the friction values are always reported and an ICAO scale is used for braking action reports.

But What About the Mu’s ?

FAA reporting of friction measuring reports are to be expressed using the name of the FAA-approved device (15 separate devices are approved) followed by the word “Mu”(pronounced “mew”), followed by the reported values, then followed by the actual time of the measurement. FICON NOTAMs are used by airport management to report braking action and MU values. A Mu value for the thirds of a runway should be reported when contaminant(s) are present or there is precipitation occurring. Mu readings of greater than “40” are not routinely reported.

What Does Canada Do?

The Canadian Runway Friction Index, CRFI and associated recommended landing distance tables are commonly used in Canada as a pilot aid in determining whether a landing can be safely accomplished on a winter-contaminated runway. Airport management will use a decelerometer mounted to a ground vehicle to determine the effect that a contaminant has on reducing the surface friction. The readings taken by this instrument are averaged and reported as a CFRI.

The CFRI used only during winter operations and only on surfaces contaminated by ice or frost, wet ice, sand, aggregate material, compacted snow, loose snow up to 2.5 cm (1 inch) deep, and ice covered by slush. They are also used when anti-icing or de-icing chemicals have been applied to the runway. Decelerometer readings may be inaccurate under certain conditions so a CRFI is not provided to pilots for wet surfaces with no other contaminant, for slush with no other contaminant or when loose snow on the runway is deeper than 2.5 cm (1 inch).

The Runway Condition Assessment Matrix, RCAM

Following the overrun of a B-737 at KMDY in December 2005, the FAA issued SAFO 06012. Inside this SAFO FAA recommended that operators of turbojet airplanes develop procedures for flight crews to assess landing performance based on conditions existing at the time of arrival at the destination airport. Part 135 pilots can expect this calculation to be required as a required action. The FAA worked with two airlines and 29 airports to validate the Runway Condition Codes on the Runway Condition Assessment Matrix, RCAM. The correlation of the Mu values with runway conditions and condition codes in the Matrix are only approximate ranges for a generic friction measuring device and are intended to be used only to downgrade a runway condition code. Airport operators use their best judgment when using friction-measuring devices for downgrade assessments, including their experience with the specific measuring devices used. This ability to raise the reported runway condition code to a code 1, 2, or 3 can only be applied to those runway conditions listed under codes 0 and 1 in the Matrix. Temperatures near and above freezing (at -3°C and warmer) may cause contaminants to behave more slippery than indicated by the runway condition code given in the Matrix.

Where to Find Runway Surface Conditions Reporting

 
Aeronautical Information Publication, AIP

Inside the Aerodrome section of a State’s AIP, operators will find a description of a runway’s physical characteristics and a detailed description of a runway physical characteristics. The “Snow Plan” is a brief description of related friction issues including measuring methods and measurements taken; system and means of reporting cases of runway closure; and distribution of information about snow, slush or ice conditions.

Aeronautical Information Circular, AIC

An AIC is published by the State whenever it is necessary to promulgate aeronautical information that does not qualify for inclusion in an AIP or a NOTAM. For example: advance seasonal information on the Snow Plan.

Notice To Airmen, NOTAM

A NOTAM is originated and issued promptly whenever information to be distributed is of a temporary nature and of short duration or when operationally significant permanent changes or temporary changes of long duration are made at short notice.

SNOWTAM

SNOWTAM is a special series NOTAM notifying the presence or removal of hazardous conditions due to snow, ice, slush or standing by means of a special format. Information collected and assessed on the pavement surface is disseminated using forms prepared by the State for SNOWTAM and NOTAM or in Europe via the MONTE reporting system.

Automatic Terminal Information Service, ATIS

One inherent weakness in the ATS system is the currency of the information. This is due to the fact that flight crews generally listen to ATIS on arrival, some twenty minutes before landing, and in rapidly changing weather; the runway conditions may vary dramatically in such a time span. Alaska FSS AFIS provides a continuous broadcast of recorded non−control information at airports in Alaska where a FSS provides local airport advisory service. The AFIS broadcast automates the repetitive transmission of essential but routine information such as weather, wind, altimeter, favored runway, braking action, airport NOTAMs and other applicable information. The information is continuously broadcast over a discrete VHF radio frequency (usually the ASOS frequency).

Air Traffic Control, ATC

ATC is the only entity one that is able to provide timely information to flight crew, especially in rapidly changing conditions. In addition to being timely, information disseminated through ATC may contain additional information associated with weather observed by MET personnel as well as information gathered by other flight crew, such as braking action reports.

Pilot Reports, PIREPS

Pilot Reports provide likely braking action the aircraft may experience but these are subjective and depend on what aircraft type is reporting the braking action.

USAF Runway Condition Reporting

FAA ATC will Issue the runway surface condition and/or the Runway Condition Reading, RCR, if provided, to all USAF and ANG aircraft. ATC will issue the RCR to other aircraft upon pilot request. The USAF has established RCR procedures for determining the average deceleration readings of runways under conditions of water, slush, ice, or snow. The use of the RCR code is dependent upon the pilot’s having a “stopping capability chart” specifically applicable to their aircraft. USAF offices furnish RCR information at airports serving USAF and ANG aircraft.

Expected Pilot Actions on Wet or Contaminated Runways

Preflight planning requirements for Part 91 operators are governed by 91.103 and 91.605. It is highly recommended that part 91 operators, and pilots calculate pre-departure landing distance performance requirements based on the guidance contained in their AFM. RCAM usage is recommended fort Part 91 operations and is required to be used by commercial operators.

Landing distances in the manufacturer-supplied AFM provide performance in a flight test environment that is not necessarily representative of normal flight operations. For those operators conducting operations in accordance with specific FAA performance regulations, the operating regulations require the AFM landing distances to be factored to ensure compliance with the pre-departure landing distance regulations.

Manufacturers do not provide advisory landing distance information in a standardized manner. However, most turbojet manufacturers make landing distance performance information available for a range of runway or braking action conditions using various airplane deceleration devices and settings under a variety of meteorological conditions. This information is made available in a wide variety of informational documents, dependent upon the manufacturer. Manufacturer-supplied landing performance data for conditions worse than a dry, smooth runway is normally an analytical computation based on the dry runway landing performance data, adjusted for a reduced airplane braking coefficient of friction available for the specific runway surface condition. Most of the data for runways contaminated by snow, slush, standing water, or ice were developed to show compliance with European Aviation Safety Agency and Joint Aviation Authority airworthiness certification and operating requirements. The FAA considers the data developed for showing compliance with the European contaminated runway certification or operating requirements, as applicable, to be acceptable for making landing distance assessments for contaminated runways at the time of arrival.

Pilots now are advised to make a landing assessment before initiating the approach landing phase of the flight. To ensure that an acceptable landing distance safety margin exists the FAA recommends a Part 91 operator add a 15 percent safety margin to the actual airplane landing distance. The 15 percent safety margin is a minimum safety margin to be applied after accounting for all known variables, such as the meteorological, runway surface conditions, landing with a tailwind, airplane configuration and weight, runway slope, threshold crossing height and airspeed, and the timely utilization of ground deceleration devices. Be prepared, know the landing conditions, divert to an alternate, or go around, but do not risk a runway overrun.

BottomLine

  1. 1. FAA has tried to harmonize with ICAO and EASA
  2. 2. FICON reports just got more informative and harder to read
  3. 3. Pilots’ are to use a new source of information, the RCAM “Matrix”
  4. 4. AC 25-32 has published this “Matrix” with Mu reading for advisory information only.
  5. 5. SAFO 06012 and AC 91-79 need to be read and understood along with this new information source
  6. 6. Take a read on my blog entries titled "Cold WX Restricted Airports" and "Aircraft Deicing/Anti-Icing"