Currently a weight and balance procedure in a typical airline environment will only ‘calculate’ the gross weight. This calculation is based on historical survey data such as average passenger weight and average hand baggage weight. Similarly, the Centre of Gravity (CoG) is also calculated based on factors.
Crane Aerospace and Electronics is developing technology that could change the ‘calculation’ to a real figure. AirWeighs, it is a system that offers a real-time weight and balance and is being showcased at Paris.
Accuracy
“We have tested the system and have demonstrated an accuracy that is greater than 99%,” says Eric Haas, director, sensing and utility systems, “this system, although still in early development, has the potential to remove human error from weight and balance calculations. Thereby increasing safety and reducing turnaround times.”
The system converts the landing gear struts into on-aircraft-scales by using precise pressure sensors to monitor strut pressure, proportional to weight, at each of the struts. This technique alone cannot be used to accurately weigh the aircraft because of friction in the strut seals. To counteract the friction, hydraulic components are used to actively lift the aircraft by a couple of centimetres to exercise the seals. This breaks the seal friction and allows the weight to be determined using the precise pressure measurements at each strut.
“This technology has great potential for the future – presently weight and balance is done manually, but with our system it could be something that revolutionises despatch procedures,” adds Haas.
Because the system can accurately determine gross weight it can also work out CoG. For freighter operations this can prove beneficial – even though the occurrences of aircraft tipping due to improper loading are rare – the system comes complete with a ‘tip alarm’ to help avoid unsafe loading.
“Not only is the system highly accurate, but it requires no recurrent calibration. Current on-board weight and balance technology need regular maintenance and calibration. Our system is unique in its ability and no need for maintenance,” says Haas.
Benefits
Potential benefits of the system include a reduction in denied boarding as the aircraft weight is measured in real-time. Reducing turnaround times by up to five minutes because it cancels the need to do manual calculations.
Claims to help reduce gate delays through automation. Improving fuel efficiency with aft centre of gravity management as well as enhancing aircraft utility with multiple forward centre of gravity operations. It can also reduce the need for ballast to move the aircraft centre of gravity within the performance envelope, purely because the exact CoG and weight are known.
Source: Flight Daily News
