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Taking Flight with Interface Solutions for Aircraft Testing

As a top supplier of premium force measurement solutions for the aerospace industry, one of our critical areas requiring precision accuracy and high-quality products is for testing airplanes. Interface load cells, torque transducers, and instrumentation are used regularly in testing of all types of aerospace apparatus, components, and machines, along with embedding our force sensors in aircraft for ongoing simulation tests and inflight data acquisition.

Aircraft, spacecraft, military, and defense companies such as Boeing, Airbus, Lockheed, Northrop Grumman, Bombardier, Embraer, Gulfstream, NASA, and Cessna and many others in the supply and production lines utilize Interface load cells for thrust, wing, static, and fatigue testing. While structural test applications use many types of LowProfile™ load cells, Interface also offers a wide variety of load washers, load buttons and miniature tension and compression load cells for test, production, and control monitoring applications for aircraft.

Why do aircraft testing professionals prefer Interface solutions?  One reason is our moment and temperature compensated load cells use proprietary alloy strain gages for extreme accuracy and reliability that is unmatched by other brands. Using eight proprietary strain gages per sensor, our 4mV/V output well exceeds the performance requirements for testing these specialized aerospace vehicles.

In addition, before the airplanes are even assembled, every manufactured part and components must go through rigorous testing. There are hundreds of machines that are used on the production line for the hundreds of thousands of components needed to complete these specialized craft. Interface load cells and torque transducers are found on many of these production and test machines. Our products are used to provide a wealth of insight to guide manufacturers through research, development and final build. Because testing is so inherent for any of these parts, Interface products provide reliability and accuracy when there are no exceptions.

We recently developed several new application notes on ways our products are used to test airplanes. Included below is a preview of a few of the latest additions to our application notes catalog.

Jet Engine Thrust Test

A customer wanted to conduct a static jet engine thrust test that can accurately determine the engine’s thrust, burn time, chamber pressure, and other parameters, providing invaluable data to propellant chemists and engineers. They needed a high accuracy load cell with excellent repeatability to withstand thrust forces in very harsh environments. Interface offered a 1000 High Capacity Fatigue-Rated LowProfile™ Load Cell, which is ideally suited based on their performance for this application. The load cell reacts to the thrust forces produced by the jet engine and the signals are collected and recorded to create a “thrust curve” of the engine. The performance of an Interface LowProfile™ Load Cell allowed the engineers to be confident in the data acquired from the static testing. Additionally, the repeatability of the load cell results in reduced time between tests, making static jet engine thrust testing more efficient. Read the new Jet Engine Thrust Test application note here.

Aircraft Yoke Torque Measurement

An aircraft manufacturer wanted to measure the torque of their aircrafts yoke or control wheel. They also wanted to monitor the torque and forces applied to ensure that the aircrafts controls are operating properly. Interface suggested using the AT103 2-Axis Axial Torsion Load Cell to measure both torque and force within this single sensor. It can be installed inside of the yoke, and can measure the rotation of the yoke, and the forward and backwards movements. Data can be measured and paired with the SI-USB4 4-Channel USB Interface Module and displayed with the customer’s laptop. Using this solution, the customer was able to measure and monitor the torque and force of the yoke control. Read the Aircraft Yoke Torque Measurement application note.

Aircraft Engine Hoist

An aerospace company wanted to test their aircraft engine hoist in order to safely lift, remove, or install engines efficiently and safety. Interface’s solution was to install WTSSHKB-HL Wireless Bow Shackles to the aircraft engine hoist. A heavy load was added to the hooks where the aircraft engine would be. Results from the heavy load are then sent wirelessly to both the WTS-BS-4 USB Industrial Base Station attached to the customers computer or laptop, and the WTS-1-HS Handheld display for single transmitters. With these products, the customer was assured that the aircraft engine hoist was strong and secure enough to lift a heavy engine when installing or removing an engine inside of an aircraft. Learn more about the Aircraft Engine Hoist application here.

Our expert application engineers help our customers by providing technologies that provide exceedingly accurate measurement used in all types of testing, including structural, static and fatigue. For more information on Interface and its solutions designed for airplanes and other aerospace applications, please visit https://www.interfaceforce.com/solutions/aerospace.

Additional Aircraft Testing Resources

Aircraft Wing Fatigue App Note

Aircraft Screwdriver Fastening Control App Note

Aircraft Lifting Equipment App Note

Examining Interface Aerospace Industry Solutions

 

Understanding Uncertainty in Load Cell Calibration

In force measurement testing, accuracy is the most critical factor in ensuring the data you collect can help to identify challenges, failures and opportunities in the product design and development cycle. Here at Interface, we have mastered the art of load cell accuracy by employing a vertically integrated manufacturing process that allows us to control the development of our products most critical components.

Even the most high-end manufactured load cells and finely tuned components endure accuracy degradation over continued use. Therefore, we have also invested in equipment and talent with deep expertise in load cell recalibration, as well as offering gold and platinum standard calibration systems to customers. Recalibration is recommended on an annual basis, or of course, whenever our customers feel they need to confirm they are getting the right data out of their load cells.

One of the key factors of calibration and recalibration is understanding how to estimate practical uncertainty in load cell calibration. Measurement uncertainty is defined as an estimate of the range of measured values within which the true value lies or, alternatively, the degree of doubt about a measured value. In every application, there will be an uncertainty requirement on the force measurement. The equipment used to make the measurement must be traceable to a realization of the SI unit of force (the newton) within this required uncertainty.

Each application is different in terms of its uncertainty requirement. For instance, an application testing force in the aerospace and defense or medical sector will include a much more stringent uncertainty requirement than something like a commercial scale used to measure someone’s weight or food. It is critical to understand the uncertainty requirement on the application to ensure the force measurement device used is calibrated to handle the project.

How does one go about estimating uncertainty in load cell calibration? The first thing to understand is the GUM, a guide to the expression of uncertainty in measurement. This guide establishes general rules for evaluating and expressing uncertainty in measurement that are intended to be applicable to a broad spectrum of measurements.

Next, we have included a list of different considerations, as we measure uncertainty here at Interface. These factors will help guide you as you determine uncertainty for yourself. This list includes:

  1. Determine what parameter is to be measured and the units of measure.
  2. Identify the components of the calibration process and the accompanying sources of error.
  3. Write an expression for the uncertainty of each source of error.
  4. Determine the probability distribution for each source of error.
  5. Calculate a standard uncertainty for each source of error for the range or value of interest.
  6. Construct an uncertainty budget that lists all the components and their standard uncertainty calculations
  7. Combine the standard uncertainty calculations and apply a coverage factor to obtain the final expanded uncertainty.

It is also important to consider the different methods of load cell calibration. There are three different methods, and each has an approximate feasible expanded uncertainty. The different calibration methods include:

  • Direct dead weight – this method is the best for accuracy at 0.005% uncertainty, but it is slow, and the equipment is space inefficient.
  • Leveraged dead weight – middle of the road for accuracy at 0.01% uncertainty, and slow and space inefficient.
  • Hydraulic force generation comparison – this method has reasonable accuracy at 0.04% uncertainty and is also the fastest and most space-efficient option.

The final point is the sources of error in calibration. Error is defined as the difference between the measured value and the true value. There is a long list of different factors that can cause error and increase uncertainty. These factors may include drift, creep, misalignment, or environmental factors such as temperature. To compensate for this, it is important to understand the various formulas that can be used to find the true value based on the given measurement and the various factors for error.

To learn more about uncertainty and the different ways users can address uncertainty and overcome it, please give us a call at 480-948-5555, or visit our website to contact our Application Engineers.

Contributor:  LaVar Clegg, Interface

Source: NCLSI Measurement Training Summit 2014

Faces of Interface Featuring Dan McAneny

Our Faces of Interface series provides readers with an inside look at all the brilliant and talented people that work for our 52 year-old company.  There is also a team of experts and experienced individuals that are part of our sales engineering network. These representatives and distributors are integral to the work we do, and they are considered part of the Interface family.

In this post, we are featuring Dan McAneny, co-founder and sales engineer at Tritek Solutions, one of Interface’s sales representatives covering the Pacific Northwest. Dan has been working with Interface for many years, so we have gotten to know him pretty well and are grateful to have him part of our team.

Dan began his career as a design engineer in New York after graduating with a bachelor of science in Electrical Engineering from Lehigh University. He spent a few years in this design engineer role before quickly realizing that he had a passion for being out in the field and working directly with customers, rather than behind a desk.

His search for sales engineering positions took him out west to work for a rep company in Los Angeles, California, that sold electronic test equipment. This position helped Dan develop his proficiency in sales, as well as better understanding of the test solutions critical to the evolution of technology. When the LA company went out of business in 1988, Dan and his good friend and co-worker decided to start Tritek Solutions.

Tritek Solutions is a manufacturers’ representative with sales and administrative staff capable of providing a complete sales and support solution. The company focuses on test instruments, systems, specialized components and board-level products.

The company quickly ascended, growing into Northern California, the Rocky Mountain region, and the Pacific Northwest. And after 28 years in Southern California, Dan and his wife decided to take their talents to Seattle, Washington, where he could focus his work with Tritek in the Pacific Northwest.

Dan learned about the diverse and innovative technology ecosystem in this region and has developed a wide range of experience and expertise on how to serve customers in various industries such as aerospace and defense, medical, industrial, automotive and construction. In fact, this is the aspect of his job that he enjoys the most, working with customers in all of these different technology sectors in Seattle to learn about their challenges in bringing new innovation to market, and offering synergistic solutions available from the many manufacturers he represents.

“In a single day, I could be standing next to a 777X airplane for an hour, and then the next hour, I could be discussing a solution for developing delivery drones or ventilator production. The possibility of learning about and working with customers on hundreds of new technology is something I enjoy every day.”

When Dan began working with us many years ago, he noticed that our presence in the Pacific Northwest was mainly focused on large aerospace OEM’s and knew he could help us break into a larger variety of markets. Dan has been successful in proactively searching for and securing new opportunities for Interface force measurement products across new markets, innovators and advancing technology sectors.

“Working with Interface has been a pleasure. Their more than half-century in business has provided them with a deep understanding for efficiently working with reps like myself, and the quality of their products and engineering talent makes it easier because I know my OEM customers know and trust the Interface brand.”

When he is not making a killing helping original equipment manufacturers (OEMs) find test, engineering and manufacturing solutions for their product development process, Dan enjoys taking advantage of the beautiful outdoors in the Pacific Northwest. Dan’s wife of 30 years and two sons age 23 and 25 enjoy road and mountain biking, hiking and swimming together, as well as exploring the hidden gems the region has to offer.

Stay tuned to our blog for new Faces of Interface ForceLeaders profiles to learn more about our valued network and team members. You can subscribe to receive the blog weekly at www.interfaceforce.com/blog/.