Weight and balance calculations can be a challenge in flight planning. Yet every aircraft ever certified is built around strict limits for a reason. They define how safely, predictably and easily it can fly. Staying inside those limits is one of the most effective ways a pilot can protect themselves.
Why weight and balance limits exist
Weight limits are far more than arbitrary numbers, as flight instructor and industry expert Thomas Turner explains, ‘Weight and balance is all about aircraft performance, stability and control’, he says.
An aircraft can only lift a certain amount of weight with the power available. Even before reaching an absolute structural limit, performance begins to degrade. ‘A desirable performance envelope requires the aeroplane’s weight to be at or below maximum, well less than that absolute limit,’ Turner says. Flying above this limit reduces take-off and landing performance, cuts climb ability and increases the risk of overstressing the airframe.
Balance is equally critical. Turner says both stability and control authority depend heavily on where the centre of gravity sits. If the centre of gravity is too far forward, the aircraft may not have enough elevator authority to raise the nose at slower speeds. If it is too far aft, the aircraft may pitch up uncontrollably into a stall. ‘Put it all together and you’ll see how important it is to remain within the aeroplane’s weight and balance limits,’ he says.
The risks of operating outside the envelope
Flying overweight or out of balance removes layers of safety that pilots may not appreciate until something goes wrong. A forward or aft centre of gravity can rob the aircraft of stability at the worst possible moment, such as during an engine failure or go-around. More weight also increases stall speed and lengthens take-off and landing distances.
Turner says many pilots focus only on take-off calculations and forget that balance changes throughout the flight. ‘Most pilots are taught how to compute weight and balance for take-off. Far fewer are taught to compute weight and balance as it will exist at landing,’ he says. In many aircraft, the centre of gravity moves as fuel burns. If pilots do not check the zero-fuel condition, they may unknowingly land outside the envelope.
His advice is clear: ‘Check your take-off, landing and zero-fuel centre of gravity are all within limits. If the zero-fuel centre of gravity is not within limits, plan to land before it moves outside the centre of gravity.’
How EFBs support accuracy and reduce error
Electronic flight bags (EFBs) have transformed the way pilots plan loading, but only if the data going in is correct. Alex Hart, product manager at OzRunways, says the app uses multiple layers of safeguards to catch mistakes. Live animations and automatic colour changes show immediately when a weight, centre of gravity or limit is exceeded. ‘If the aircraft’s loading falls outside the approved envelope, the weight and balance line turns red, providing instant visual feedback,’ he says.
Once a weight and balance profile is checked by a weight control officer, they lock it and send it to all pilot devices. This means everyone uses the same information.
Digital tools also cut out common maths mistakes. ‘They make the numbers more accurate and reduce simple errors,’ Hart says. He says EFBs link fuel use and other parts of flight planning. This makes updates easier and more reliable than using a paper load sheet.
Using performance charts the right way
Performance charts are another area where pilots must be cautious. They are built on worst-case conditions and require specific techniques to achieve the published figures. Turner says pilots often forget the charted numbers assume precise speeds and attitudes.
‘You won’t get the performance the chart says you will if you use another technique,’ he says. The safest approach is to build generous margins. Turner uses at least 50% beyond book numbers, noting that factory data already assumes ‘average pilot technique’.
He also encourages students to compare performance at different weights. Even a reduction of 50 kg can significantly improve climb performance and safety.
Your best safety margin
Weight and balance may seem simple, but it still needs care. Check your take-off, landing and zero-fuel centres of gravity. Use performance charts the right way. Use the safety tools in your EFB. These steps help you keep strong safety margins on every flight.
Resources for flight planning
Flight planning resources are a focus of CASA’s Your safety is in your hands campaign. For more guidance, tools and tips, be sure to visit the pilot safety hub.
