EASA Mandates Takeoff Safety Systems for Large Aircraft by 2027

Enhancing Takeoff Safety: EASA’s Push for Take-off Performance Monitoring Systems (TOPMS)

In July 2025, the European Union Aviation Safety Agency (EASA) released Notice of Proposed Amendment (NPA) 2025-01, aiming to mandate the integration of Take-off Performance Monitoring Systems (TOPMS) in certain large aeroplanes. This move represents a significant shift in aviation safety strategy, targeting a long-standing vulnerability in commercial flight operations: erroneous takeoff performance calculations. By focusing on real-time monitoring and predictive analytics, EASA intends to reduce the risk of runway excursions and loss-of-control incidents during takeoff, two of the most frequent and dangerous types of aviation accidents.

This proposal is not only about adding another layer of safety but also about modernizing aircraft systems to match the capabilities of current sensor and computing technologies. The regulation applies to both new aircraft designs and in-production aircraft still being manufactured and used in commercial air transport. With this initiative, EASA is attempting to close a safety gap that has persisted for decades due to technological, regulatory, and economic constraints.

Understanding TOPMS: Functionality and Certification

How TOPMS Works

TOPMS integrates several subsystems to monitor and validate takeoff performance in real-time. At its core, the system relies on a combination of sensors, predictive algorithms, and pilot interfaces. The sensor array collects data on acceleration, thrust, and speed using inertial measurement units (IMUs), engine pressure ratio (EPR) sensors, and wheel tachometers. This data feeds into a predictive algorithm that compares actual performance against pre-calculated models based on aircraft weight, flap settings, and environmental conditions.

If the system detects a deviation, for example, thrust output that is 8% below the expected value within four seconds of brake release, it triggers an alert. These alerts are displayed via head-up displays (HUDs) or electronic flight bags (EFBs), providing pilots with a visual cue on whether to continue or abort the takeoff. The system can also detect incorrect runway entry points before the aircraft reaches 60 knots, further enhancing situational awareness.

TOPMS does not replace pilot judgment but augments it with real-time data and decision support. By acting as a last line of defense, it helps prevent errors that might otherwise go unnoticed until it’s too late.

“This technology closes a critical gap in our decades-old reliance on pilot calculation accuracy, finally giving crews real-time decision support against one of aviation’s most persistent killers.” — David Learmount, FlightGlobal aviation safety analyst

Certification and Implementation Requirements

EASA’s proposal outlines specific technical and operational requirements for TOPMS certification. For new aircraft designs seeking CS-25 approval, compliance will be mandatory starting in 2027. For aircraft still in production and operated under EU Part-CAT rules, retrofitting will be required by 2029. The system must detect thrust deviations of 8% within four seconds of brake release and identify incorrect takeoff positions before reaching 60 knots.

Additional requirements include integration with Terrain Awareness and Warning Systems (TAWS) and continuous updates on runway friction coefficients using wheel-slip measurements. These features aim to ensure the system provides meaningful, timely alerts without overwhelming pilots with false positives.

Manufacturers are expected to demonstrate a false alert rate of less than 1% during certification trials, a crucial metric given the potential for nuisance alerts to distract or confuse flight crews.

Safety Impacts and Industry Implications

Reducing Runway Excursions

Runway excursions remain a significant concern in aviation safety. According to the International Air Transport Association (IATA), runway excursions accounted for 24% of all accidents prior to the COVID-19 pandemic. Over the past decade (2012–2021), there were 138 runway excursion incidents worldwide.

Several high-profile accidents could have been prevented with TOPMS in place. These include the 2008 Spanair Flight 5022 crash, where incorrect weight calculations led to insufficient thrust, and the 2022 Cargolux 747 incident, where a thrust-setting error resulted in a high-speed aborted takeoff. EASA estimates that TOPMS could reduce takeoff-related runway excursions by up to 40% among equipped aircraft.

Financially, the potential savings are substantial. The International Air Transport Association (IATA) estimates that runway excursions cost the industry $900 million annually. A 40% reduction could translate to $360 million in avoided costs per year.

Operational and Technical Challenges

Despite its benefits, implementing TOPMS is not without challenges. For one, the system adds complexity to cockpit operations. A United Airlines trial reported a 22% increase in pilot scanning time during high-alert scenarios. This raises concerns about workload and potential distraction during takeoff, a critical phase of flight.

Data security is another concern. TOPMS relies on wireless data transfers for performance validation, creating potential cybersecurity vulnerabilities. Ensuring secure, encrypted communication channels will be essential for widespread adoption. Additionally, ICAO estimates that pilots will require around eight hours of simulator training to become proficient in handling TOPMS alerts and failure modes.

From a technical standpoint, retrofitting older aircraft poses significant hurdles. Airbus, for instance, has flagged compatibility issues with legacy A330 models. Embraer estimates an 18-month certification timeline for its E-Jets E2 series, highlighting the time and resources required for integration.

Cost-Benefit Analysis and Industry Readiness

EASA’s cost-benefit analysis projects a 20-year net present value (NPV) of €290 million, with a benefit-cost ratio of 3.8:1. Development costs are estimated at $2.1–$4.8 million per aircraft type, with recurring maintenance costs of around $18,500 per aircraft. These figures suggest that the safety and financial benefits far outweigh the implementation costs.

Major manufacturers are already preparing for compliance. Airbus is developing a TOPMS that integrates with EFBs for real-time validation, while Boeing’s OPTIM system uses GPS and thrust monitoring to achieve similar objectives. These developments indicate that the industry is moving toward readiness, even as regulatory frameworks are still being finalized.

However, discrepancies remain between global regulators. While EASA is pushing for mandatory retrofits, the U.S. Federal Aviation Administration (FAA) favors voluntary adoption. Similarly, ICAO recommends a 7% thrust deviation threshold for alerts, compared to EASA’s 8%. These differences could complicate international harmonization efforts.

Conclusion

EASA’s proposal to mandate TOPMS in large commercial aircraft marks a pivotal moment in aviation safety. By leveraging advancements in sensor technology and predictive analytics, TOPMS provides pilots with real-time decision support, directly addressing the root causes of many takeoff-related accidents. The system is not a silver bullet, but it represents a significant step forward in mitigating one of aviation’s most persistent risks.

Looking forward, successful implementation will depend on harmonized global standards, effective pilot training, and financial support for smaller operators. If these conditions are met, TOPMS could become a cornerstone of modern flight safety, aligning with ICAO’s goal of reducing runway excursions by 50% by 2030. The technology is ready, now it’s up to the industry and regulators to act.

FAQ

What is TOPMS?
Take-off Performance Monitoring Systems (TOPMS) are onboard systems that monitor aircraft acceleration and performance during takeoff to detect anomalies such as incorrect thrust settings or takeoff positions.

Why is EASA mandating TOPMS?
EASA aims to reduce the number of runway excursions and loss-of-control incidents during takeoff, which are often caused by performance calculation errors. TOPMS provides real-time alerts to help pilots make informed decisions.

When will the regulation take effect?
For new aircraft designs, the mandate will apply starting in 2027. For in-production aircraft still being manufactured and used in commercial transport, retrofitting will be required by 2029.

Is TOPMS already in use?
Some manufacturers like Airbus and Boeing have developed prototype systems, but widespread implementation is pending regulatory approval and certification.

Will all aircraft be required to install TOPMS?
The current proposal applies to large aeroplanes over 60,000 kg MTOW. Smaller aircraft are not currently included, though some regulators are considering broader applications.

Sources: EASA, FlightGlobal, ICAO, IATA, MDPI, NBAA