CRV-7i Instrumented Rocket

Project Outline:

To carry out design, certification and manufacture of an instrumented CRV-7 rocket.

Project Description:

Vibration data gathering trials of munitions in the captive flight carriage environment provide evidence towards the Safety and Suitability for Service Assessment that allows release to service for weapons. For CRV-7, those data gathering trials have previously used traditional methods to obtain those data, utilising accelerometers on the rocket and its launcher with signal conditioning units, data recorders and batteries housed elsewhere, e.g. for a helicopter, within its cabin or for fast jets, within an adjacent pod. Such trials are relatively expensive to conduct and require use of the host aircraft for several days to allow the instrumentation to be fitted.

In the case of CRV-7 on a helicopter (Apache) there are some further considerations. Helicopter vibration is known to vary significantly according to the state of its rotor blades’ (track and balance) and from airframe to airframe. Consequently, to ensure the most realistic qualification test severities and hence optimum air carriage life, it is desirable to conduct several vibration data gathering trials to enable a statistical approach to be developed. Unfortunately, such an approach is not practicable using traditional data gathering methods due to the length of time that the aircraft are required and associated costs.

An assembled drill CRV-7 rocket was modified to meet this requirement be means of the addition of three Cranfield Aerospace Air Countermeasure Data Loggers (ACDLs). To operate the installed ACDLs the rocket was also fitted with a purpose built control module. As required, the Instrumented CRV-7 rocket is capable of recording nine channels of wideband vibration data. The design of the Instrumented CRV-7 Rocket allows vibration to be measured on itself and on adjacent structures. Due to the minor nature of the mechanical modifications a MAA F100A Certificate of Design can be raised by read across to the existing drill rocket F100A.