Regulations & Safety
NTSB Urges FAA to Update Runway Condition Assessment Matrix for Heavy Rain
NTSB recommends FAA revise runway condition assessments and expand rainfall reporting after 11 runway overruns linked to heavy rain from 2008 to 2022.
This article is based on an official press release from the National Transportation Safety Board (NTSB).
On May 26, 2026, the National Transportation Safety Board (NTSB) issued a press release urging the Federal Aviation Administration (FAA) to overhaul how runway conditions are assessed during heavy rainfall. The safety board warns that the current framework leaves flight crews vulnerable to runway overruns by failing to capture the true impact of severe weather on aircraft braking performance.
Stemming from investigations into 11 runway overrun accidents and incidents that occurred on wet runways between 2008 and 2022, the NTSB has issued three new safety recommendations. These directives focus on updating the Runway Condition Assessment Matrix (RCAM) and expanding aviation weather reporting standards to better equip pilots with accurate data.
According to the NTSB, the current system fails to adequately account for the progressive loss of wheel braking friction as rainfall intensity increases. This creates a critical blind spot for pilots and dispatchers when calculating safe landing distances during intense storms.
The Limitations of Current Weather Reporting and RCAM
The RCAM is a standardized framework utilized by airport operators and flight crews to evaluate and report runway surface conditions. As noted in the NTSB release, it plays a vital role in calculating required landing distances, particularly on wet or contaminated runways.
However, the NTSB’s Aviation Investigation Report 26-04 (AIR-26-04), titled “Accounting for the Progressive Decrease in Runway Friction Associated with Increasing Rainfall Intensity,” highlights a significant flaw. The current matrix does not factor in the progressive decrease in runway friction that correlates with heavier rainfall.
Expanding Rainfall Descriptors
Currently, aviation weather reports cap the “heavy rain” threshold at 0.3 inches per hour. The NTSB points out that this limitation prevents flight crews from accurately assessing runway slipperiness when rainfall exceeds this rate.
To address this, the NTSB recommends that the FAA add new rainfall intensity descriptors to aviation weather reports. This would allow pilots to identify rainfall rates that surpass the 0.3 inches per hour mark, enabling more accurate landing distance calculations and better aeronautical decision-making.
Case Study: Miami Air International Flight 293
The NTSB’s recommendations are heavily informed by historical data, notably the crash of Miami Air International Flight 293. On May 3, 2019, a Boeing 737-81Q carrying 142 passengers and crew overran ungrooved runway 10 at Jacksonville Naval Air Station in Florida, coming to rest in the shallow waters of the St. Johns River.
While there were no serious injuries, the aircraft sustained substantial damage. The NTSB investigation determined that the probable cause was directly linked to the runway conditions and the intensity of the precipitation.
Extreme Conditions and Pilot Decision-Making
Crucially, the NTSB found that rainfall intensities during the Miami Air incident were two to eight times higher than the FAA’s heavy rain threshold of 0.3 inches per hour.
“an extreme loss of braking friction due to heavy rain and the water depth on the ungrooved runway, which resulted in viscous hydroplaning”
In its official report, the NTSB attributed the above cause to the Jacksonville overrun. The safety board noted that under such extreme conditions, braking effectiveness is reduced so severely that pilots should not even attempt to land.
NTSB’s Three Core Recommendations
Based on these findings, the NTSB has formally issued three safety recommendations to the FAA to mitigate future risks and improve operational safety.
First, the FAA must revise the RCAM to account for the progressive decrease in the wheel braking friction coefficient associated with increasing rainfall intensity. The NTSB advises that progressively higher rainfall intensities should correspond to progressively lower runway condition codes.
Second, as previously noted, the FAA should expand rainfall intensity descriptors in aviation weather reports to capture data beyond the current 0.3 inches per hour maximum.
Third, the NTSB emphasizes the need to improve flight crew awareness. By providing a broader range of descriptors, pilots will be better equipped to associate heavy rainfall with lower runway condition codes, preventing the dangerous underestimation of required landing distances.
AirPro News analysis
We view these recommendations as a necessary and overdue evolution in aviation safety protocols. If the FAA adopts these changes, it will fundamentally alter how pilots and dispatchers calculate landing performance during severe weather events, likely leading to an increase in weather-related diversions but a significant decrease in runway excursions.
The NTSB’s findings underscore that pilots are currently forced to make critical landing decisions based on incomplete weather data. Providing accurate descriptors for extreme rain will empower flight crews to confidently divert flights rather than risk a catastrophic runway overrun. Furthermore, the specific mention of an “ungrooved runway” in the Miami Air case highlights the ongoing need for airports to evaluate their infrastructure. The interaction between pavement types (grooved versus ungrooved) and heavy rainfall remains a critical variable in RCAM calculations that airport operators must prioritize.
Frequently Asked Questions (FAQ)
What is the RCAM?
The Runway Condition Assessment Matrix (RCAM) is a standardized framework used by airport operators and flight crews to assess and report runway surface conditions. It is essential for calculating safe landing distances.
Why is the NTSB recommending changes to the RCAM?
The NTSB found that the current RCAM and weather reporting standards do not adequately account for the progressive loss of braking friction during rainfall that exceeds 0.3 inches per hour, leading pilots to underestimate required landing distances.
How many accidents prompted this NTSB report?
The NTSB based its recommendations on data gathered from investigations into 11 runway overrun accidents and incidents that occurred on wet runways between 2008 and 2022.
Sources
Photo Credit: NTSB