Centre of Gravity (Cofg)

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Take off - climb angle

Definition: An aeroplane or helicopter becomes airborne and then climbs rapidly.

Bush Talk: "Jez - that thing can climb like a homesick angel"

Fixed Wing:

The higher the power to weight ratio, the more the nose can be raised above the horizon to increase the angle of climb after becoming initially airborne. The best RATE of climb (feet per minute) is a combination of max available engine power to give thrust from the propeller and the most efficient wing angle. An example of a high power to weight ratio is the space shuttle. It can point its nose to the sky and go straight up.

Helicopter:

As we now know, the helicopter "propeller" is the Rotor disc. Unlike a propeller producing thrust longitudinal to the fuselage, the helicopter rotor disc produces thrust nearly vertical to the fuselage. Therefore, a high power to weight ratio helicopter does NOT point its nose to the sky to climb. Rather, the fuselage remains in a comparatively level attitude as the rotor lifts it up. Helicopters do not always have the ability to hover and then climb vertically up over a spot due DA and weight limitations. Any reduction in weight or DA is of benefit to a helicopter's vertical climb rate.

Hint: Helicopter: Don't put the pressure on a pilot to land and pick you up from a spot surrounded by tall trees or close obstacles. He may get in OK (only low power is needed for a descent and landing) but may have to work the machine a lot harder to get out vertically against gravity. It is better to walk a 100 meters to a wider clearing to allow the helicopter to fly through transition (see next item) and have more available power to climb safely up and out.