The days having our aircraft be able to tell us exactly what is wrong with them and where are still a ways off into the future, but while we wait for fully integrated smart aircraft, smart washers are filling some gaps.
Designed by JPB Système for Airbus Helicopters, smart washers work by providing the information of the bolt’s actual load, details Jonathan Beaumel, project engineer with JPB-Système.
“It allows you to know without touching the assembly, without interfering on the assembly, on the bolt, it allows you to know if it is correctly tightened or correctly torqued, without any intervention on it,” he said.
Inside the washers are electronics that provide the information on the force and relay the information to a communication module outside of it, with the benefit of being battery-less.
“When you’ve got the smart reader, she’s a product that we also developed, you just come closer from the washer and you push the button of the reader and it will communicate with the washer. It will provide the power to the washer and it will also give the power to the fuel system. And then the washer will talk to the reader and tell him if it is correctly torqued on it,” said Beaumel.
The washers also track what work has been done, who did it and even the GPS coordinates for said work.
“We can upload into the washer this information that at this day, Walker has been doing a check and the value of the check was this value. We can also provide information on, for example, the GPS coordinates, where you were at this time when you did this information. So this is pretty much all,” Beaumel said.
According to Beaumel, the information that really matters is the load information and how it might be differing under different circumstances.
“Let’s say you apply a torque with some kind of grease and you apply the same torque on the same assembly with another kind of grease. So you will try to have the same torque, but the resistance of the actual load won’t be the same. So with this value, with this data that we provide with the smart washer, it’s completely independent of the torque. And you get to the real value that you want, which is the actual load,” he explained.
The washers are recommended for use in spots where regularly maintenance is performed.
“If you don’t do maintenance that you know, that this kind of bolt never untightened due to vibration, that basically this bolt remained all the same during 10 years or whatever, it’s completely useless to install this kind of smart washer. But if you have to perform a regular maintenance on certain very critical parts, then I strongly recommend to use our device,” Beaumel said.
The project began three years ago at the request of Airbus Helicopter as they were looking for a solution to quickly know if bolts were installed correctly or not.
“Sometimes it means that to disassemble a lot of equipment all around the bolts. And when we are reaching the bolts, we have to remove the sealant, that could be all around the bolts. And then we take torque wrench, we uninstall it, and then we apply the torque again. And then we have to install all the equipment in front of the bolts. So it takes a lot of time and possibly it could lead also to mistakes because you will touch to an assembly that was potentially well installed. And potentially you will put some mistakes inside of it and into the bolts and also into all of the equipment that you have to move, to get access to the bolt,” Beaumel said.
The smart washer eliminates that work, providing quick and efficient information without the disassembly required of traditional washers.
The washers are in the process of being certified for use on helicopters, but once that is reached, Beaumel said the hope is to expand their use to other aircraft.
“Helicopters were actually the most critical for this kind of device because the vibrations are higher than in aircraft. And they also perform more torque checks than into the aircraft industry, which leads the parts to be more cost effective than the aircraft industry. So, it’ll give us the time to improve the industrialization of the product,” he said.
