Pitot Static Testing on the Flightline
Years have gone by without significant advancements in the more commoditized testing functions of aircraft. Old faithful still rings true for most wrench turners grinding it out everyday to play their part in the safest aircraft regulatory environment ever. For aircraft transponder and pitot-static system tests, as required by FAR 91.411 and 91.413, these certifications cannot be performed using automation. The inspector is required to perform leak checks and accuracy verification by commanding the air data test set to each set of the required set point, then visually verify the readings on the instrumentation and readouts. But, wouldn’t it be nice to perform some of these functions at the same time, thereby saving an immense amount of time as compared to sequential testing operations with limited equipment.
The use of semi-automated pitot static test equipment offers significant advantages over manual testing methods for commercial aviation and maintenance repair organizations. Pitot static systems are critical components of aircraft, providing essential data for airspeed, altitude, and vertical speed measurements. Additionally, some newer aircraft equipped with SmartProbes can test other parameters, such as Angle of Attack (AoA). Ensuring the accuracy and reliability of these systems is paramount for flight safety and regulatory compliance. And doing them all simultaneously is a huge time-saver for the maintenance teams at MROs around the globe.
One of the primary benefits of semi-automated test equipment is the efficiency it brings to the testing process. Compared with manual testing, which involves manually entering each pitot and/or static set point and rate(s) setting, semi-automated equipment can streamline the testing procedure by allowing the operator to run pre-programmed tests for these tasks. This automation reduces testing time and minimizes the risk of human error, allowing technicians to perform tests more quickly and efficiently.
Semi-automated pitot static test equipment also enhances the precision and consistency of test results. These advanced systems use precise sensors to measure and analyze air pressure and velocity, ensuring accurate testing, troubleshooting malfunctions, and the certification of pitot static systems. By eliminating variability associated with manual adjustments, semi-automated equipment produces more reliable and repeatable test outcomes enhancing the overall quality of maintenance and repair activities.
Raptor Scientific’s ADTS-3250 air data test set was designed specifically for the general aviation and commercial aviation markets. It features many safety features, both software and hardware to protect the aircraft during testing and includes a few semi-automated test functions. The test sets are built upon 25 years in developing and manufacturing high-accuracy, ruggedized pitot static test sets and air data calibration equipment for the military sector. And they always meet or exceed the ranges and accuracies required for testing with the convenience and technologies civilian users want.
From initial startup, the operator is presented with a list of installed aircraft profiles. These profiles set the tester up with the maximum ranges and rates for the aircraft under test. This ensures that the operator cannot inadvertently exceed the limits of the aircraft during testing. Profiles are pre-installed at the factory, chosen from a standard list of aircraft or custom lists from a database of hundreds of commercial and general aviation aircraft.
A decade ago, most of the testing required two operators — one controlling the test set on the ground connected to the aircraft, and the other in the cockpit performing the checks. Today most air data test sets can be controlled using a handheld remote. Newer test sets, like the ADTS-3250, feature a WiFi-direct enabled 7.0-inch touchscreen remote control unit for untethered operation of the test. The remote can also be operated using a wired connection when wireless features cannot be used due to security protocols, or if signal strength is diminished. A remote control unit offers great versatility for the operators. These more recent advancements in ground testing allow organizations to standardize testing procedures across their fleet at different locations.
Another feature on most modern pitot static test sets that has improved testing for operators has been the digital display and graphical user interface. The days of analog thumbwheel and toggle switches are long gone and replaced with digital systems. Test sets like the ADTS-3250 feature an intuitive software interface, which lowers the operator learning curve. This is extremely helpful whether the operator has utilized a pitot static test set before or not. Data is presented in an easy-to-understand format and a status bar tells the operator exactly what is happening with the tester. Modes of operation, like control, measure or leak test can easily be selected and operated without having to refer to a user manual.
Semi-automated tests can be derived from the Aircraft Maintenance Manuals (AMM), Technical Orders (TO), or other testing documentation. Raptor’s ADTS-3250 is capable of storing thousands of aircraft profiles and a virtually unlimited number of test sequences for each aircraft separately. This standalone application allows the end user to easily add, remove, or edit aircraft profiles and test sequences to the ADTS. With the Profile Builder software, operators can easily create a subset of tests with set points, rates, and tolerances. It can all be managed, created, and edited from any PC. This also allows any custom profiles or test sequences to be installed across multiple testers or multiple locations without having to set up and program each individually.
With aircraft profiles and test sequences, semi-automated testing now enters into the equation. The operator must now select the aircraft from the menu, then the test sequences desired. Any programmed test sequences will be displayed in the menu. The operator will select the test needed and then hit start — and the unit will start controlling to the first set point in the sequence. During the test, the ADTS will allow the operator to continue to the next set point, return to the previous set point, or safely control the system to the ambient pressure (ground).
The image below (Image C) shows the actual test sequence list for the HC-130H aircraft. As you can see, there are six test sequences programmed into the tester for this aircraft. The end user manages these test profiles, along with its other aircraft using the profile builder software. If any updates are required, they can quickly deploy these updates to the field as needed.
The adoption of semi-automated pitot static test equipment can also improve documentation and regulatory compliance efforts. The ADTS can store test reports and data logs if enabled, providing a record of testing activities for audit purposes. This documentation not only demonstrates compliance with regulatory requirements but also aids in troubleshooting and trend analysis, helping maintenance organizations identify recurring issues and implement preventive measures.
Air Data and Pitot Static Testing for Calibration Laboratory
Automated pitot static and air data calibration equipment can contribute to cost savings for maintenance repair organizations. Raptor Scientific’s Air Data Calibrator (ADC) product line is used by both commercial and military test and calibration laboratories around the world. These systems provide fully automated test and calibration for the ADTS-3250 and several other OEM test sets through apps installed on the system. Semi-automated calibration can be performed for other test set manufacturers. By reducing testing time and enhancing efficiency, these calibrators minimize equipment downtime and labor costs associated with manual testing.
The ADC Series calibrators are considered secondary standards and can also be used to bench test altimeters, airspeed indicators, gauges, transducers, air data computers, and more. They have an accuracy ratio three times greater than the flightline test set and are traceable to the National Institute of Standards and Technology (NIST). In addition, they include an accredited ISO 17015:2017 calibration certificate at no additional charge.
In conclusion, the benefits of using automated and semi-automated test equipment for commercial aviation and maintenance repair organizations are too numerous to list. From improving efficiency and accuracy to enhancing diagnostic capabilities and regulatory compliance efforts, these advanced testing systems play a crucial role in ensuring the safety, reliability, and cost-effectiveness of pitot static systems in aircraft operations. As technology continues to advance, the adoption of semi-automated equipment will likely become increasingly prevalent across the aviation industry worldwide, not just in the United States.