Hover performance, loading and margins
Helicopter performance requires comparing actual required power and control capability with what is available under the stated conditions. A successful hover in one place does not prove that every departure, climb, landing or emergency option is available. Keep weight, pressure altitude, temperature, wind, surface and configuration tied to the correct rotorcraft flight manual chart.
Hover conditions and density
Hovering in ground effect and hovering out of ground effect are different performance conditions. Ground proximity can reduce induced power required when the surface and geometry permit the effect. A pinnacle, roof edge, slope or confined area may not provide the same conditions as the charted model. An aircraft that can hover in ground effect does not automatically have adequate out-of-ground-effect power or a safe departure path.
High density altitude generally reduces available rotorcraft performance, with the actual powerplant and installation determining the available power. A density-altitude approximation is a planning model, not a substitute for performance charts. Use the temperature appropriate to the stated pressure altitude when finding an ISA deviation. For example, confusing field elevation with pressure altitude or assigning the wrong standard temperature can produce a misleading result.
Mass, moment and control margin
Center of gravity is total moment divided by total weight using one consistent datum. Adding fuel or payload changes both quantities; moving an existing load changes moment without adding weight. Retain the units and distinguish longitudinal from lateral calculations. A value within one center-of-gravity boundary does not prove that maximum weight or every other boundary is satisfied.
A forward or aft center-of-gravity limit also concerns remaining control authority. Exceeding a limit cannot be justified by assuming more cyclic will always be available. Actual loading and operating envelopes govern the decision. A classroom arithmetic answer is not an approval to fly.
Planning before committing
The height-velocity diagram identifies combinations and conditions in which an acceptable landing following a power loss may not be assured. It is not a universal curve shared by all helicopters. Consider the actual chart and procedure rather than choose a route solely because it looks clear.
Wind, obstacles, surface, reconnaissance, escape options and available power all matter to a proposed operation. A running or no-hover departure is not automatically a safe answer to inadequate hover capability. The correct method requires the actual aircraft, site, training and approved procedures. This bank provides no generic confined-area maneuver or emergency recovery sequence.