Position Measurement & Control - Fall 1996 (FA96)

Contents

• Application Note for Aircraft/Aerospace
  
• New Product: Series 175 Extends Range
  
• Medical Industry Likes the Series 150
  
• Alligator, Inc. Has and Uses the "Right Stuff"
  

Firstmark Controls position transducers were first developed in 1968 to monitor aircraft flight control surfaces. Since that time, these products have been used in a broad range of aircraft/aerospace applications for test, measurement, and control purposes.

Recently, we have worked with several users to develop an Application Note that focuses on the use of Firstmark Controls position transducers in aircraft and aerospace applications. Six pages in length, the Application Note covers typical uses, actual application descriptions, mounting and installation tips, and other technical information of value to the aircraft/aerospace instrumentation engineer and technician

To request a copy of the Application Note for Aircraft/Aerospace, please complete and submit the Request More Information form or view it online.

To meet the requirements of customers with displacements greater than 4 inches (101.60 mm) and with subminiature size needs, Firstmark Controls has introduced the Series 175 position transducer with a maximum displacement of 5.25 inches (133.35 mm). With dimensions of 1.990 inches diameter by 0.490 inches width, the Series 175 unit is still smaller than the Series 160 product line.

The Series 175 has one model, the Model 175-0421, available with 2K or 5K ohm potentiometer resistance. Like the Series 173 and 174 products, the Series 175 has a bearing-mounted shaft for reduced moment of inertia, longer lifetime, and easier repairs. Left- and right-hand cable pull is available. This product replaces the specialty Model R171-0421 position transducer that has been provided to a limited group of customers.

Firstmark Controls's Series 150 position transducer has been selected for the MPMN 100: Readers' Choices for the Top Products of the Year. Awarded by Medical Product Manufacturing News, the MPMN 100 comprises the 80 new product and 20 new literature releases that generated the highest reader-service response during 1996.

The Series 150 position transducer's small size, high precision, long life, and ease of mounting make it ideal for the high-performance, high-reliability requirements of medical products. It has a 1.5 inch (38.10 mm) stroke and is only 0.75 inch by 0.75 inch by 0.38 inch (19.1 mm by 19.1 mm by 9.7 mm) in size.

For more information on Medical Product Manufacturing News, please contact:

Did you realize that commercial pilots can be FAA-certified to fly a specific type of aircraft without ever having flown in it? If this seems amazing, you'll want to learn more about Alligator, Inc., a Firstmark Controls customer dedicated to solving flight test challenges.

One challenge that Alligator, Inc. recently met was to obtain the complete flight test data required to construct FAA Level C and D flight simulators for the British Aerospace BAe 800 and 1000 aircraft. FAA Level C and D simulators provide the highest fidelity performance of any class of flight simulators. These flight simulators make PC-based flight simulator programs seem like the rudimentary 1970's video game of Pong.

Alligator, Inc. was contracted by Reflectone, the simulator manufacturing division of British Aerospace, to assist in the development of a flight simulator for the BAe 800 and 1000, two medium-range business jets. The company's objective was to obtain flight control and air data information for modeling the aircraft's performance. This data would then be used in the development of the simulator.

One key challenge of this task was that the data was required in only 3 months time. While most simulators are built over an 18- to 24-month time period, the BAe 1000 simulator was to be fully developed and certified in 10 months.

To obtain aircraft control data, over 20 Firstmark Controls position transducers were mounted on each aircraft to monitor ailerons, elevators, trim systems, rudders, rudder pedals, landing gear, control wheels, and control columns. Displacements ranged up to 36.75 inches. The data from the pilot controls was particularly important for this project due to the high-fidelity requirements of Class C and D simulators. The transducers were mounted to the aircraft using either existing mounting holes or by using clamps. The displacement cable was attached to the moving flight control mechanisms by looping the cable end and attaching the looped end to a separate cable section that had a swivel. The swivel attached to the flight control mechanism.

The flight test program took about 6 weeks to instrument the aircraft and finetune the data acquisition system, 4 weeks to conduct the testing, and another week to restore the aircraft to its original condition. The data was collected in 60 flight hours.

Ron Renz of Alligator, Inc. noted that they chose Firstmark Controls position transducers because they are “small, easy to use, robust, reliable, and relatively inexpensive.”

Alligator, Inc. also used a Firstmark Controls Model 100600 straight-nose air data boom to acquire angle-of-attack, sideslip, static pressure, and total pressure information. The Model 100600 air data boom was mounted to the nose of the aircraft using a custom-designed adaptor. Calibration of the pressure transducers was done using a trailing static cone. According to Renz, “We used the Firstmark Controls air data boom because it performs, is available quickly, and is affordable.”

Data from all transducers was acquired on-board the aircraft using an in-house C and C++ application and a real-time operating system running on a ruggedized computer. Maximum speed during the flight test was Mach 0.84.

The Alligator, Inc. flight test team was started in 1983 to meet the growing requirements for flight test data acquisition, FAA certification, and simulator development with active customer involvement. The company employs a team approach to their projects and specializes in being highly responsive and operating within high-pressure test schedules. The company has completed 17 simulator data acquisition projects to date as well as 41 certification flight test programs. To learn more about Alligator, Inc. and its capabilities, contact the company at:

ISSN 1527-5108