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ICAO GRF &TALPA COMPLIANT
THE EFFICIENT AND COST-EFFECTIVE
WAY TO QUICKLY ASSESS AND REPORTON RUNWAY CONDITIONSWHITE PAPER

Case Studies & Resources Compilation

Every day, pilots, air traffic controllers and airport
operators work hard to make air travel as safe andefficient as possible. Before COVID-19 took control
over the world, 4.5 billion passengers entered aplane in 2019, more than ever before. These areabout 12.5 million lives to protect each day.
However, flight security also depends on external factors we can hardly
influence, especially referring to risky weather conditions: strong winds,
freezing temperatures, or heavy precipitation can have serious consequences.
Combined with increasing air transport, as shown in figure 1, the need forsafety measures grows in parallel.

ICAO GRF – The New Global Reporting Format for Runway Surface

To provide the necessary information to ensure the required safety level,
especially for takeoffs and landings, the International Civil Aviation
Organization introduces a global and standardized reporting format for
runway surface conditions, the Global Reporting Format (GRF). It has to be
implemented by 4 November 2021. This provides effective means toanticipate the airplane braking performance for airport traffic managers (2).
One step of the TALPA is the socalled NOTAM (Notice to Airmen) - a crucial
encoded report for airmen, which is determined by national authorities. The
code is usually sufficiently self-evident allowing a fast recognition of hazards
or obstacles (3).

2

(1)

© The World of Air Transport in 2019, ICAO, www.icao.int/annual-report-2019/pages/the-world-of-air-transport-in-2019.aspx(2)© European Organisation for Safety of Air Navigation (EUROCONTROL) (2016), www.skybrary.aero/bookshelf/books/3593.pdf(3)© European Organisation for Safety of Air Navigation (EUROCONTROL) (2016), www.skybrary.aero/index.php/NOTAM

Figure 1: Air transport, passengers carried© International Civil Aviation Organization of the World and ICAO staff estimatesCase Studies & Resources Compilation

Figure 2: Types of pilot related accidents in 2013 – 41 of 709 accidents were weather-related, © AOPASNOWTAM is understood as a special form of theNOTAM notifying the presence, or removal, ofhazardous conditions due to snow, ice, slush, orstanding water in a specific format (4).
From November 2021 onwards, the ICAO GRF andSNOWTAM (as TALPA already is in North America) will
become mandatory on airports, whereas until thenthe simpler RCC (Runway Condition Code) report,
which is a part of the SNOWTAM, is sufficient. The
trigger of this change was a Southwest Airline
Boeing-737 overrunning the Chicago-Midway Airport
runway in December 2005.

But what are the needed parameters andhow are they delivered?

Landing safety depends, among other factors, onthe runway grip or friction which needs to be3(4)included in the above mentioned reports. It ismainly influenced by different kinds of layers on therunway surface. Grip on dry surfaces can bemeasured by a grip tester, which has already beenused on airports for many years. But most of thefriction level estimations depend on experienced
airport traffic managers who are responsible for
informing airmen on the runway conditions via
radio communication or via printed reports for pilot
briefings. “Normally the first step of a runway
assessment is done visually from a patrol car. In
case of apparent frost, ice, or other dangerous
conditions, runway technicians sometimes use amechanic µ-meter, Skidometer, or a GripTester
issuing the data on a protocol printout”, explains
Michael Eberling, transport manager at Airport
Saarbrücken, Germany.

European Organization for Safety of Air Navigation (EUROCONTROL) (2016), www.skybrary.aero/index.php/SNOWTAM

Case Studies & Resources Compilation

Air traffic controllers record the runway weather
message onto an ATIS (Automatic TerminalInformation Service), which is an recorded taperetrieved by aircraft crews via a known radiofrequency. The ATIS is updated for every significant
change of (weather) conditions. The airport
operators also feed the MOTNE (MeteorologicalOperational Telecommunication Network Europe).
The latter is an appendix of the METAR(Meteorological Aviation Routine Weather Report)
distributed by the national aviation weather service,
such as the DWD in Germany, informing on current
data on the runway (RWY) designator (e.g. R27), typeof deposit, extent of contamination, depth ofdeposit and estimated braking conditions. TheMOTNE is part of a briefing package every airplanecrew has to read before the start of a flight. In turn,the pilot gives his or her feedback on the landing
conditions back to the tower (see workflow infigure 3).
Is the visual estimation of the runway conditions
sufficient for the high safety requirements on
airports? The figures speak against it: On average,
14.4% (see figure 2) of all aircraft accidents in 2013 (5)(Source: AOPA, see figure 2) and 63.1% of aviation
system delays in the US between 2003 and 2017(source: FAA (6) ) were weather-related. But, how canthis be prevented?

(5)Types of pilot related accidents, AOPA (2015),

www.aopa.org/-/media/files/aopa/home/pilot-resources/safety-and-p
roficiency/accident-analysis/nall-report/15-fn-0022-1-24th-nall-v6.pdf(6)Airline On-Time Statistics and Delay Causes, United States Departmentof Transportation (2017),

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www.transtats.bts.gov/OT_Delay/ot_delaycause1.asp?type=4&pn=1
Figure 3: TALPA Workflow

New technology for runway
weather assessment

One answer to improve aircraft takeoff and landing
safety is new technology in form of the mobile
runway weather sensor MARWIS (see figure 4). As
an addition to the usual AWOS (Automatic Weather
Observation System) equipment such as embedded
runway surface sensors and stationary weather
sensors, it improves the determination of runway(RWY) conditions and digitalizes the handling of
runway condition codes of traffic managers, pilots
and towers. It thus offers a new toolbox to digitalize
airport workflows for processing and transferring
the runway conditions in the right future-proof
coding such as the SNOWTAM or MOTNE. How
exactly does this change the landing preparation?

Case Studies & Resources Compilation

Fast and digital
The compact MARWIS can be mounted on all
kinds of airport patrol vehicles and directly
delivers the runway conditions dry, moist,wet, snow, slush, ice, chemically and criticallywet. It issues this data both on mobiledevices, such as a tablet, and stationary
output devices, such as in a control center(TWR). Therefore, it supports the trafﬁcmanager in the patrol car during the runway
assessment without detours. Moreover,
MARWIS issues a weather-related friction
value between 0.1 and 0.82 (low to high)which is similar to the CRFI (CanadianRunway Friction Index). This means, that thesmart sensor detects the friction for thedifferent runway contamination levels fromdry to water, ice or snow covered and feeds
them directly into the MDSS (MaintenanceDecision
SupportSystem)
softwareViewMondo in the right format of SNOWTAM– and this with a notably large number of
local high-resolved measuring points along
the runway thanks to the high data transfer
rapidity of 1.0 Hz.

Using MARWIS for the assessment is linked withtwo decisive advantages: Airmen get considerablymore information for their decision-making, andthe workﬂow takes less time, because by retrieving
the data automatically the runway is blocked for ashorter period. This frees precious time for theTALPA workﬂow, which must not exceed 10minutes. However, airport trafﬁc managers still
hold the reigns of the data, as the ViewMondo
software allows any modiﬁcation of the issued
runway condition codes directly on the mobile
output device in the patrol car, in case theobservations require it, or the feedback of thepilots calls for a level downgrade. The SNOWTAMand RCC/ RCAM reports can be printed, or sent bye-mail, e.g. directly from the patrol vehicle to thetower (see data ﬂow process in image 5).

especially important for the TALPA, where therunway states need to be reported for each of thethree sections (see ﬁgure 6).

In order to provide accurate location data,
individual spots of the runway can be stored in theroute’s master data and tracked by the outputdevices, such as a tablet, or a GPS module. This isOutlook on future aviation tasks

More efﬁcient de-icing

Within one week, one of the ﬁrst airport users in
Europe was able to save more than 10,000 Eurowith the help of MARWIS, achieved by a more
efﬁcient output of de-icing chemicals. By using thenew mobile sensor, the trafﬁc managers were able
to recognize chemically wet runway spots, wherede-icing chemicals were still active and needed
less, whereas especially critical spots needed moretreatment. Moreover, under certain conditions, theresidual de-icing chemical density can be estimatedquantitatively. This is not only decreasing costs but
also increasing the landing safety even more.

international standards yet. The introduction of theTALPA will be one step forward to a global
settlement. For the estimation or measurement of
runway conditions there is also no standard
available, forcing airport technicians to choose thebest method to go with individually.
The mobile sensor MARWIS from Lufft, issuing
weather-related friction values, water ﬁlm heights,
runway conditions, ice percentages, and dew
points as well as surface and air temperatures atonce, is the most versatile and future-proof
equipment for a successful TALPA performanceaccording to ICAO speciﬁcations.

As shown above, many different ways to assess andmaintain runways are prevailing in the airport
business, meaning that there are no ofﬁcially valid

Figure 6: Runway division and assessment according to SNOWTAM© Karl Schedler, MICKS

Figure 5: Principle data flow: runway condition monitoring

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