CANOPY BURSTING SYSTEM

Abstract: A hood detonation system for blasting two hoods in a two-seated aircraft is described. It comprises a first detonation cord (3) detonable by means of initiation and attached to the first, front hood (1), and a second detonation cord (4) detonable by means of initiation and attached to the second, rear hood (2). The hood detonation system is in particular characterized by a protective balloon (19) inflatable by initiation of a gas generator essentially simultaneously with the initiation of the detonation of the second detonation cord (4), and adapted to prevent splintered parts from the second hood (2) to move into the space inside the second hood.

Description: Canopy bursting system The present invention relates to a hood detonation system for blasting two hoods of a two- seated aircraft comprising a first detonation cord, detonable by means of initiation and attached to the first, front hood and a second detonation cord, detonable by means of initiation and attached to the second rear hood. Hood detonation systems for one-seated military aircraft are previously known and have in recent years been developed at the same time as equipment for ejection of the pilot sitting in the seat by means of a powder charge. In order to provide a free way for this ejection the hood of the aircraft must be blasted. Thus, in one-seated aircraft a detonation cord has been used, which is initiated to detonate at the same time as a number of charges for, amongst other things, adjustment of the position of the pilot in the seat and the powder charge itself is initiated for the ejection. In two-seated aircraft where the second pilot is sitting behind the first, beneath a second rear hood, problems occur in blasting the rear hood due to the pressure distribution in the axial direction of the hood. Hence, during the detonation, splinters from the hood can move into the space inside the second hood and injure the pilot during the ejection. The object of the present invention is to obtain a hood detonation system of the kind mentioned in the introduction, which provides full security against injuries from splinters from the rear hood during ejection of the second, rear pilot. Such a hood detonation system is according to the invention mainly characterized by a protective balloon inflatable by initiation of a gas generator essentially at the same time as the initiation of the detonation of the second detonation cord, the balloon being arranged to prevent blasted parts from the second hood to move into the space inside the second hood. In a preferred embodiment of the invention, the gas generator together with the inflatable protective balloon is placed below the front part of the second hood, beneath an oblique pane arranged therein, which during inflation of the protective balloon imposes thereon a motion component directed backwards, into the second hood. Another advantageous embodiment of the invention involves that the protective balloon is designed so that it during inflation at least partly fills the space that is located backwards, below the second hood. The invention is described in the following with reference to the accompanying schemati Figure, which shows an embodiment of the hood detonation system according to th invention with a part of a two-seated military aircraft. Only parts of the aircraft that hav relevance in the context are shown in the Figure. In the Figure a front hood is denoted 1 and a second hood 2. Both are manufactured fro aery late resin. The front hood is equipped with a first detonation cord 3 extending along th lower edges of the hood and along its topmost part, and the rear hood is in a corresponding manner equipped with a second detonation cord 4. The first detonation cord 3 is initiated to detonate in connection with initiation of a powder charge for ejecting the first pilot, through a gas conduit 5 extending to a gas triggered igniter 6 that operates a transmission device 7 activating a charge 8 that initiates a detonation of the first detonation cord 3. The rear detonation cord 4 is initiated to detonate in a corresponding manner through a gas conduit 9, a gas triggered igniter 10, a transmission device 11 , a charge 12, which initiates detonation of the second detonation cord 4 as well as it initiates an igniter line 13 connected to a pressure switch 14 energizing an electric switch 15. An electric impulse is thereby transmitted through an electrical line 16 to an electrical igniter 18 located in a protective balloon container 17 that ignites a gas generator containing sodium azide. Thereby a protective balloon 19 is instantaneously inflated and fills the space below the rear hood, so that blasted parts thereof, i.e. splinters, are prevented from penetrating into the space below the second hood and injuring the second pilot. In the hood detonation system shown, the protective balloon container 17 is located under the front part of the second hood 2, beneath an oblique pane 20 arranged therein, which during inflation of the protective balloon 19 imposes thereon a motion component directed backwards, below the second hood 2. The protective balloon 19 is moreover designed so that it during inflation partly fills the space located backwards, below the second hood 2.

Claims: Claims 1. A hood detonation system for blasting two hoods in a two-seated aircraft, comprising a detonation cord (3), detonable by means of initiation and attached to the first, front hood (1), and a second detonation cord (4), detonable by means of initiation and attached to the second, rear hood (2), characterized by a protective balloon (19) inflatable by initiation of a gas generator essentially simultaneously with the initiation of the detonation of the second detonation cord (4), and adapted to prevent splintered parts from the second hood (2) to move into the space inside the second hood. 2. A hood detonation system according to claim 1 , characterized in that the gas generator together with the inflatable protective balloon (19) is located below the front part of the second hood (2), beneath an oblique pane (20) arranged therein, which during inflation of the protective balloon imposes thereon a motion component backwards, below the second hood. 3. A hood detonation system according to claim 1 or 2, characterized in that the protective balloon (19) is so designed, that it during inflation at least partly fills the space located backwards, below the second hood (2).

Inventors: OLSSON GEORG, OLSSON, GEORG
Applicants: SAAB AB, SAAB AKTIEBOLAG
Application year: 1995
Main classification: B64D25
IPC codes: B64D25