Aircraft Electrical Systems: A320/A321 Briefing

 

Technical Safety Bulletin: Aerodynamic Risks and Mechanical Constraints in Low-Altitude Go-Arounds

1. Strategic Overview of the Near-Ground Go-Around Environment

A go-around initiated during the flare or following a bounce is a high-stakes, time-critical maneuver. Transitioning from a landing mindset—where the aircraft is decelerating and losing energy—to a high-energy climb requires precise coordination and a rapid shift in tactical priorities. This transition often occurs under extreme pressure, such as a sudden runway incursion or a destabilized bounce. The "Textbook Answer" regarding the limits of this maneuver is absolute: the selection of thrust reversers is the "point of no return." Once reverser deployment is initiated, the aircraft is committed to the full stop; any attempt to return to the air is unsafe.

WARNING: Once a go-around maneuver is initiated, the flight crew MUST commit to and complete the maneuver. There is no provision for reversing this decision once the transition to TOGA (Take-Off/Go-Around) power has begun.

Adhering to this commitment is only possible if the flight crew understands the specific hardware limitations and system logic that govern the aircraft in this state.

2. Analysis of System Logic and Hardware Limitations

A320 system architecture—specifically engine physics and flight control laws—dictates pilot technique during a rejected landing. Success depends on the pilot's ability to fly the aircraft according to its current logic state rather than relying on automated protection.

CRITICAL CONSTRAINT: Thrust Reverser Limitation Do not initiate a go-around after thrust reversers have been selected. Reverser deployment disrupts airflow over the rudder, drastically reducing directional control efficiency, and creates a significant drag profile that prevents a safe transition to flight. The Pilot Monitoring (PM) must verify reverser status immediately before a go-around is called.

The Reality of Flare Law Below 100 feet, the aircraft transitions into Flare Law. This logic provides a direct stick-to-elevator relationship. The system provides no longitudinal stability or auto-trim in this law; the Pilot Flying (PF) is the sole provider of pitch control and must manually compensate for all aerodynamic changes.

System Logic Realities

• Engine Spool-up Delays: High-bypass turbofans require several seconds to spool from idle to TOGA. Expect the aircraft to continue losing altitude or settle onto the runway during this interval.
• Runway Contact: Temporary landing gear contact with the runway is acceptable and safer than an aggressive, premature rotation.
• Transient CONFIG Alerts: If TOGA is applied while wheels are on the ground, disregard any transient "CONFIG" alerts that trigger during the transition.
• PM Oversight: The PM is the primary gatekeeper of the "Reverser Status" check, as they maintain the capacity to monitor system states while the PF focuses on the runway environment.

These system constraints necessitate a manual management of the physical forces generated during the transition to full power.

3. The Mechanics of TOGA Transition: Pitch and Power Dynamics

The transition from landing idle to TOGA thrust near the ground introduces significant longitudinal forces. Because the engines are mounted under the wings, the sudden application of thrust creates a powerful "pitch-up" moment that must be actively managed by the PF.

Managing the Pitch-Up Effect Application of TOGA thrust drives the nose upward aggressively. In Flare Law, you must anticipate this and apply positive forward sidestick pressure to prevent the nose from pitching through the flight director bars. Failure to counteract this moment increases the risk of a tailstrike and a dangerous loss of airspeed.

The Spool-up Gap During the delay between moving the thrust levers and achieving full power, the aircraft lacks the energy to arrest its descent immediately. Maintain the pitch attitude and allow the airspeed to increase up to VAPP. Do not attempt to "yank" the aircraft off the ground; wait for the energy to be established.

Physics vs. Instinct: Transition Technique

Feature	Pilot’s Instinctive Reaction	Required Aerodynamic Technique
Rotation	Rapid, aggressive "pull" to avoid the ground.	Smooth, deliberate rotation to the go-around pitch target.
Altitude Loss	Panic if the aircraft continues to sink.	Accept that the wheels may touch the pavement while engines spool.
Airspeed Target	Attempting to climb at low speed.	Maintain pitch attitude until airspeed increases up to VAPP.
Sidestick Input	Pulling and holding the stick back.	Applying forward pressure to counteract under-wing engine thrust.

These technical requirements are often compromised by human-factor traps identified in high-stress training environments.

4. Instructor’s Corner: Mitigating Operational "Gotchas" and Traps

Simulator insights reveal that most failures during balked landings stem from the "startle response" and a reliance on muscle memory over situational awareness.

Deconstructing the "Startle Tailstrike" The "Startle Tailstrike" occurs when a pilot reacts to a sinking aircraft with an aggressive, rapid pull on the sidestick. This high rotation rate, combined with the compression of the landing gear oleos upon contact with the runway, creates a physical pivot point that reduces tail clearance to near-zero. Technique: Set TOGA and rotate smoothly to the pitch target, regardless of runway proximity or gear contact.

The "Premature Gear Up" Trap Never retract the landing gear immediately upon the "Go Around, Flaps" call. If the gear is retracted while the aircraft is still settling or in the spool-up gap, any runway contact will be catastrophic.

"Established in Go-Around" Criteria Before making configuration changes, the PM must verify the aircraft is "Established" using this checklist:

1. Positive Rate: Confirmed on the VSI and altimeter.
2. Safety Margin: The aircraft is safely climbing away from the ground. Only after these are met should you retract flaps one step and raise the gear.

Professional flight management requires a return to foundational principles during these critical moments.

5. Standardized Recovery Techniques and the Golden Rules

Adherence to core piloting principles is the only way to ensure safety during time-critical maneuvers.

Synthesizing the Golden Rules

1. Fly, Navigate, Communicate: Manage pitch, thrust, and wings-level flight first. Ignore ATC and routing until the climb is stable.
2. Take Action if Things Do Not Go As Expected: A high bounce or runway incursion is your cue to take action (Go-Around), provided reversers are stowed.

Step-by-Step Recovery Flow

• Thrust: Move levers to TOGA.
• Pitch: Rotate smoothly to the target attitude; use forward stick to counteract the pitch-up moment.
• Configuration: Maintain current gear and flap settings. Energy management and pitch control take absolute precedence over "cleaning up" the aircraft.

THE THREE COMMANDMENTS FOR PF/PM

1. PF FOCUS: Remain entirely focused on the runway centerline and pitch attitude; do not reach for configuration controls.
2. PM VERIFICATION: Instantly verify that thrust reversers have not been selected before calling "GO-AROUND" or confirming the PF's decision.
3. TASKSHARING: The PM acts as the safety buffer and system monitor, while the PF manages the physical flight path.

Safe operations in the near-ground environment require disciplined pitch control and constant situational awareness of the aircraft’s reverser status.