Aerospace

Meggitt provides products for flight test, inertial measurement, and pressure profiling including flutter testing, engine testing and static and dynamic vibration testing.  Our complete range of extreme environment accelerometers, microphones, airborne amplifiers and pressure transducers are used during ground, in-flight and on-board monitoring of aircraft engines.  We play a significant role as new engines are developed, certified and placed into production.

Our design and manufacturing engineers recognize that the world of transducer technology centers around engineering tradeoffs. Generally, the compromises are between the performance characteristics of the transducer and its environmental requirements or the constraints imposed by the phenomenon being measured. For aerospace testing, typical performance requirements are high sensitivity, wide-band frequency response and wide dynamic range. Common environmental problems are high and low temperature extremes, shock, vibration, moisture and thermal transients. Constraints are typically size and weight. Consequently, to meet the unique challenges faced by many of our customers, Meggitt routinely designs custom products using a wide range of technology platforms.

TYPICAL APPLICATIONSREPRESENTATIVE MODELS
Engine testing6237M70, 6243M1, 6233C, 522M17, 522M37A, 2271A, 7722, 2777A
Flight test65, 7290E, 7298, 8515C, 2680
Ground vibration test (GVT)2221F, 7251A
Flutter test7290E
Component qualification testing2220E,35B, 8510B
Aerodynamic flow8515C, 8507C
Stage separation2255B, 7280A, 8540
Vibroacoustic2510, 2510M4A, 8510B
Launch vehicle testing7293A, 2222C

Application considerations

Ground vibration test (GVT)

Ground vibration tests obtain vibration data on the complete aircraft structure and are typically performed very late in the development.  As access to the structure is often limited, time pressures on testing is severe leaving no room for re-testing should equipment malfunction.  Both the 2221F and the 7251A are reliable, through hole mount accelerometers.  They are lightweight, have a 360  degree ͦ cable orientation and are hermetically sealed.  The PE 2221F operates to 500 ͦ F and requires no power while the IEPE 7251A operates to 257 ͦ F.

Flutter test

Aerodynamic forces, inertial effects and structural elasticity can cause an oscillation on aircrafts that is referred to as flutter.  If the vibrations are not damped, structural failure can occur.  The 7290E is a unique variable capacitance, DC accelerometer designed to measure the low g, low frequency characteristics of flutter phenomena.  This device has a frequency response of 0-15 Hz at a range of ±2 g’s and 0-2000 Hz at ±100 g’s at its highest range.  ESD sensitivity meets Class 2 requirements of MIL-STD-883/Method 3015 while state-of-the-art digital temperature compensation electronics provide for precise compensation over a wide temperature range.  Choose the watertight M5 option if moisture is anticipated during testing.

Aerodynamic flow

Aerodynamics is the study of air flow and key to its understanding is the low pressures exerted by the air flow on the surfaces it encounters.  Of critical importance is the use of miniature sensing technology that integrates with the structure under test without disrupting the surrounding air flow.  Both the 8515C and 8507C are low range pressure sensors with miniature footprints that are adhesively mounted.   The 8515C has a flat, round profile while the 8507C is tubular shaped.  Both units feature an active four-arm strain gage bridge diffused into a sculptured silicon diaphragm for maximum sensitivity and wideband frequency response.

Related topics

Ask the Experts

Variable capacitance accelerometer phase shift

Eliminating noise in a measurement system

Understanding noise specifications

Sensor features that may be critical in aircraft/space vehicle testing

  • High temperature operation up to +760°C
  • Low temperature operation down to -269°C
  • Hermetically sealed
  • Low acoustic sensitivity
  • High full scale output
  • High over range protection
  • High stability