Definition
A physics expression representing the gravitational potential energy stored in an object due to its height above a reference point. The value is calculated by multiplying the object's mass (m) by the acceleration due to gravity (g, approximately 32.2 ft/s² or 9.81 m/s²) by its height (h) above the chosen reference. In aviation, this expresses the potential energy an airplane holds because of its altitude.
Plain English
A simple way of measuring how much stored energy an airplane has just by being up high. The heavier it is and the higher it is, the more energy it has waiting to be used.
Context Anchor
Seen in energy management discussions, especially when comparing altitude energy with speed energy.
Derivation
The letters come straight from physics: m for mass, g for gravity, h for height. Multiplying them together gives the energy an object has stored simply because gravity is pulling on it from a height. Knowing the formula reminds you that altitude itself is a form of fuel — energy you've already paid for and can spend later.
Why Pilots Care
Recognizing mgh helps pilots see how altitude can be traded for airspeed or used to stretch a glide when engine power is lost.
Grounding Statement
An airplane sitting at 5,000 feet has real, usable energy stored in its altitude — energy that becomes speed the moment it noses down.
Intuition Check
Do not read mgh as a normal aviation abbreviation. It is a formula showing that height gives the airplane stored energy.
Example Sentence 1
When the instructor explained energy management, she pointed out that mgh is why a high, slow airplane and a low, fast airplane can have similar total energy.
Example Sentence 2
During the approach briefing the instructor pointed out that excess mgh could be converted to speed if the glidepath became high.