What does an aircraft indicated as "H" for "heavy" signify regarding its wake turbulence category?

The designation of an aircraft with an "H" for "heavy" directly relates to its classification within the wake turbulence category. This category is crucial for ensuring safe separation between aircraft during takeoff and landing to mitigate the effects of wake turbulence, which can significantly affect smaller aircraft following behind.

When an aircraft is classified as "heavy," it indicates that the aircraft's maximum take-off weight is over 255,000 lbs (approximately 115,700 kg). One of the primary reasons this designation is important is that a heavy aircraft generates stronger wake vortices, which can pose a risk to smaller aircraft flying in its wake. As such, air traffic control applies greater separation distances between heavy aircraft and those that are smaller or lighter, to safeguard against the potential disruption caused by these stronger turbulence effects.

Considering the other choices, they refer to specific weight limits or passenger capacity, none of which directly define the wake turbulence category but rather reflect operational characteristics of the aircraft. Therefore, identifying an aircraft as "heavy" clarifies its significant impact on wake turbulence, reinforcing its classification as the highest in that respect.