The subject of the invention is a Flight Data Recorder Protecting Device, whose task is to provide protection against physical damage of the flight data recorder during a plane crash and to assist its reliable separation as a result of ejection of the flight data recorder from the aircraft immediately before the crash.

So far, flight data recorders in aircraft have been installed in such a way that in the event of a plane crash they are all the time connected with the specific place in the aircraft in which they have been installed. The consequence of such a method of flight data recorders installation is that in the event of plane crashes, in particular over water, recorders sink with this part of the aircraft where they have been installed that makes their further functioning in numerous cases when they lie at large depths incorrect, and frequently the signals which they transmit cannot even be detected.

The purpose of the invention is to develop a device protecting a flight data recorder in such a way that directly prior to a plane crash the flight data recorder becomes separated from the aircraft through ejection by technical means independent of this device that can be implemented in many ways, and keeps afloat owing to floaters, which makes it easily identifiable by search and rescue teams. A device protecting the flight data recorder ejected prior to collision of an aircraft with bodies of water and the surface of the ground by technical means independent of the device according to the invention is characterised by that the flight data recorder is fixed on a plate surrounded on the perimeter with floaters, where punches and transmitting antennas are fixed to the plate.

The subject of the invention is presented in the embodiment in the drawing, where Fig. 1 presents the flight data recorder protecting device in the top view from the flight data recorder installation side, Fig. 2 presents the flight data recorder protecting device in the cross-section across its longitudinal axis, Fig. 3 presents the flight data recorder protecting device in the cross-section across its transverse axis, and Fig. 4 presents the punch of the flight data recorder protecting device.

As it is presented in the drawing, the flight data recorder protecting device is in the form of a plate 2 to which the flight data recorder is releasably/ unreleasably attached. The plate 2 is surrounded on the perimeter with floaters 3 attached to it releasably with clamping rings 4 and screws 5, whereby the displacement of the floaters 3 is significantly larger than the weight of the whole device. Example punches 6 are fixed to the plate 2 on the opposite side of the flight data recorder 1, and transmitting antennas 7 are fixed on both sides of the plate.

Functioning of the flight data recorder protecting device consists in that in the event of exceeding the specified g-load value, flight speed, sudden increase of speed/ acceleration which pilots cannot control after a specified time, sudden rotation about the longitudinal/ transverse axis, uncontrollable diving or when, for instance, the distance of the aircraft from the water surface does not allow, and there are no chances for the pilots to perform any manoeuvres saving the aircraft from a crash, or if all the above factors occur together, the ejection unit operating independently of the device being the subject of the invention is activated, owing to which the flight data recorder protecting device can effectively and inevitably punch the aircraft skin with the example punches 6, and thus it becomes physically separated from the aircraft and ejected together with the flight data recorder outside. In the event of crash over water, the flight data recorder protecting device 1 shall keep afloat which is possible owing to floaters 3, whereas in case of crash over land the floaters 3 shall play the role of an additional protection of the flight data recorder 1 against physical damage, whereby in both cases the antennas 7 located on both sides of the plate 2 shall allow the device to be located more easily.