If an engine fails during takeoff and no lateral guidance was armed, what will the roll bar command?

In the scenario described, when an engine fails during takeoff and no lateral guidance is armed, the roll bar will command the existing heading at nosewheel lift-off. This is crucial for maintaining aircraft control as it allows the pilot to stay aligned with the runway during a critical phase of flight.

The reasoning behind this is that at the point of nosewheel lift-off, the aircraft is still closely aligned with the runway centerline. By commanding the existing heading, the roll bar ensures that the aircraft does not inadvertently bank or roll away from the runway, which could lead to a loss of control or deviation from the required flight path.

In the absence of armed lateral guidance, the system relies on the existing heading to maintain stability and control, facilitating a safer response to engine failure during takeoff. This approach is particularly important during this high-stress moment, where precise aircraft control is essential for safety.