Low Power on Approach Events

Energy management is an important element of approaches and has a direct influence on maintaining positive aircraft control and stability. The stabilized approach events utilized by Omni’s Flight Data Analysis (FDA) program are configured to match Omni Standard Operating Procedure guidelines and allow the FDA team to gain insight into the energy-related complexities of our flight operations. One significant energy management-related event monitored by the FDA team is the Low Power on Approach event. This event triggers a notification when the aircraft engines are set to idle power for over 30% of the approach phase below 1,000 ft. The Low Power on Approach event is crucial because it allows the FDA team to identify approaches that were potentially conducted in a high-energy state. There has been a small increase in approaches this year which have been accomplished with these low power settings. Some of these approaches have been flown with idle power for over 50% of the approach phase of flight. To put it in perspective, that’s approximately 30 seconds at idle power below 1,000 feet.

High-energy approaches often occur when Air Traffic Control (ATC) directs the aircraft to maintain a high airspeed or altitude. This places the pilots in a challenging position to manage a “hot and high” approach to the runway. The situation can be compounded in a light aircraft, where ATC instructions make it difficult to achieve the desired approach profile.

The primary concern associated with low power settings for substantial portions of an approach is the increased time required for the aircraft’s engines to spool up to full power, which could potentially take between seven and 15 seconds. In situations where go-around thrust is required, the delay in full power could lead to a dangerous situation. A thorough approach briefing, and effective crew resource management is essential to mitigating the risks associated with high-energy approaches. Discussing the conditions and expectations of an approach can help in anticipating and planning accordingly to respond to these circumstances. The Flight Crew Training Manual states that, “If an approach requires a sink rate greater than 1,000 feet per minute, a special briefing should be conducted.” Some mitigation strategies that should be discussed include descent rates and gates to determine when aircraft speed will be reduced. The crew should also establish the maximum acceptable descent rate they consider appropriate for the situation, such as 1,200 feet per minute. Ultimately, a well-coordinated approach strategy and proactive crew resource management can significantly enhance safety and is vital to reduce the likelihood of hazardous situations.