No, it’s not the 1980s Scottish band – it’s a new measure to prevent runway excursions.
Runway excursions have been identified by ICAO as a key risk area globally. In many cases, the excursions are due to water, ice, or snow.
From 30 November 2023, to help to ensure safe landing and take-off, new rule 139.107 Assessment of runway condition and provision of runway condition report will require all controlled aerodromes in New Zealand to report to pilots the condition of their runway surfaces.
The runway condition report (RCR) provides the current surface condition of the runway described in thirds, over its length. The runway surface condition ‘thirds’ are provided to pilots in the direction the runway is being used.
A runway surface condition of DRY DRY DRY means there’s no visible discolouration over all thirds of the runway’s operational length.
The condition of each third of the runway is further described by numerical runway condition codes or ‘RWYCC’ codes. These are used mainly by jet pilots to describe the performance of the runway.
For instance, RWYCC 6,6,6 DRY DRY DRY means the entire runway is completely dry.
WET WET WET means there’s discolouration, or water present over all thirds of the runway’s operational length, and the depth of water is up to and including 3mm.
If a runway surface condition is not DRY or WET, it must be contaminated.
Runway surface contaminants include standing water deeper than 3mm, a slippery wet runway, snow, ice or slush, wet ice and wet snow.
The role of ATC
While the overall responsibility to assess and report runway conditions to pilots lies with aerodrome owner/ operators, they may delegate RCR responsibilities to air traffic control – but only as long as conditions are DRY (RWYCC 6,6,6) or WET (RWYCC 5,5,5).
Once there’s a possibility that conditions are contaminated, air traffic control will hand responsibility back to the aerodrome.
Airways’ senior air navigation specialist James Culleton says that regardless of the weather and runway conditions, air traffic controllers will maintain a lookout over the runway.
“Say, for example, a shower passes over the airfield. The runway, which was previously dry, becomes wet. If there’s no reason to suspect standing water or slippery wet conditions, there’s no need to wait for an inspection of the runway by the aerodrome.
“ATC will immediately advise any aircraft about to use the runway, and issue a new ATIS with ‘RWYCC 5,5,5 WET/WET/WET’.”
If, however, the rainfall is heavy enough that there’s the possibility of standing water or slippery conditions, air traffic control will hand back its delegated responsibility for reporting to the aerodrome.
When reporting, aerodromes can use a variety of tools to make assessments – rulers, vehicles with brake sensors, imbedded runway sensors1 and so on – and will then generate a detailed runway condition report. This report is sent directly to the ATIS, as well as being issued as a NOTAM.
In cases where air traffic control hands reporting responsibility back to the aerodrome, it’s possible the ATIS will, for a short period of time, state ‘RUNWAY ASSESSMENT IN PROGRESS’.
“This simply means the conditions are still being measured, and an accurate report will be available soon,” says James.
“Don’t forget that ATC will always verbally pass relevant ATIS changes to aircraft about to use the runway.”
RCR is being provided during the promulgated hours of the ATC service specific to each location. If the ATC service is off watch, there’s no mandatory requirement for aerodrome operators to provide an RCR.
Air New Zealand
Air New Zealand says it’s managed runway excursion risks through a range of measures, from pilot training to investment in new aircraft technology.
“But one aspect over which we’ve always had minimal control,” says Senior Manager of Aircraft Operations, Imogen Cullen, “is runway surface condition reporting, which has varied around the world.
“The accuracy and reliability of those reports are critical for safety during take-off and landing, but it’s been troubling how inconsistent and unreliable they can be.
“If pilots don’t have up-to-date, accurate data about the condition of a runway, they can’t accurately determine the expected aircraft deceleration performance, the runway distance requirements, and operational limitations such as wind limits for take-off and landing.
“Our flight crews are exposed to various local procedures and the full spectrum of weather and runway conditions at 50 airports around the world,” Imogen says.
“So we’re greatly reassured that come 30 November, aerodrome operators in New Zealand will provide reports more detailed than ‘wet’ and ‘dry’.
“This is because the new standardised runway condition report is based on the contaminant type, depth and coverage – and that data correlates directly with take-off and landing performance data provided by aircraft manufacturers, based on real flight tests in a range of runway conditions.
“That scientific correlation between reported runway condition and aircraft performance therefore removes subjectivity.”
Queenstown Airport already has a runway condition reporting programme but says the new requirement will further reduce risks, and improve operational efficiency, which will make air travel “safer for all”.
NZ Airports Association
Since the new rule was signed off by the Minister of Transport in May, NZ Airports has been working with its member aerodromes to understand what will be required from November, and how to go about that.
“It will improve aviation safety and bring New Zealand into line with ICAO SARPs (standards and recommended practices),” says Policy Director Steve Riden.
“Our focus has been on making the final rule and advisory circular something that’s practical, fit for purpose, and easily understood by airport staff.
“A key issue for airports has been how the data collected by airport staff then gets to the pilots that use it, in a timely, reliable, and traceable way.
“We’re looking forward to seeing the final roll-out of the Airways’ portal for aerodromes to enter their RCR data.”
To see the new draft advisory circular, see AC139-3 - Aerodrome inspection programme and condition reporting.
1 At Wellington, controllers can view data from runway sensors to support a dry or wet assessment.