Abstract: An aircraft (10) comprising a fuselage (12), the fuselage (10) comprising at least first and second inwardly tapering portions (20, 22) extending in a generally rearward direction from an aft end of the fuselage (12), each inwardly tapering portion (20, 22) comprising a boundary layer ingesting propulsor (36) mounted thereon.

Abstract: A method is disclosed for surveying drill holes with a drilling arrangement and borehole survey assembly. The method can include providing a drill tool having at least one drill rod and a drill bit assembly, and providing a borehole survey tool having a sensor) for measuring a borehole. In the method a drill tool having a central flushing channel for conducting flushing fluid to the drill bit assembly is used, and the borehole survey tool is arranged in the central flushing channel so that flushing fluid can flow in the central flushing channel past the borehole survey tool.

Abstract: Drill assembly for making a hole into a soil or rock which arrangement comprises a pilot bit (10) drilling the middle part of the hole and a ring bit (1) drilling the outer circle of the hole in which case in the drilling situation the ring bit (1) is adjusted around the pilot bit (10) and rotary movement and drilling impacts are directed from the pilot bit (10) to the ring bit (1) with the help of the mentioned surfaces (4-6);(7-9),(15, 16) adjusted between the bits and conveying power and that the ring bit (1) can be removed around the pilot bit (10) and can be installed to it and that further a coupling ring (2) belongs around the ring bit (1) in order to join a casing pipe, which can be pulled to the drilled hole, to the ring bit (1) with the help of the mentioned coupling ring. The coupling ring.

Abstract: A bit assembly in a drilling apparatus working by hammering and for rotating said assembly comprising of a pilot bit (1) drilling the central part of the hole and a ring bit (2), fitted in connection with said pilot bit(1) and furnished with cylindrical inner surface drilling the outer surface of said hole, and further, between the pilot bit (1) and ring bit (2) a blocking arrangement of mutual rotation and axial movement, whereby opening of said blocking arrangement makes it possible to pull the pilot bit (5) off the hole, while ring bit (2) remains in the hole, and the bit assembly comprises a casing tube and its extension (6) and an interlocking system, which is through a ring-shaped device (8) from the extension (6) of the casing tube adapted to transfer pulling force from the pilot or ring bit to the casing tube extension (6) and said interlocking system can be opened in order to continue drilling with the ring and pilot bits (1, 2) when the casing tube remains in its place.

Abstract: A bit assembly for a drilling apparatus working by impact and rotation or merely by rotation, and comprising a pilot bit (1) drilling the hole centre and in connection with the pilot bit a ring bit (2) is arranged to drill the outer circle of the hole and, further, between pilot bit and ring bit surfaces are arranged to transmit impacts and/or rotary motion from the pilot bit to the ring bit, and the bit assembly also including an arrangement for pulling protection tube into the hole on drilling. In the bit assembly between ring bit (2) and pilot bit (1) at least an arrangement transmitting rotation is jointly fitted in the ring bit shirt portion (5) by forming the rear edge of the shirt portion seen in the drilling direction to comprise surfaces with different directions, which with one of their portion (4) can transmit rotary motion force to the ring bit (2) and with their adjacent part (3) force to pull said ring bit off the hole.

Abstract: A bit assembly for a drilling apparatus working by impact and rotation or merely by rotation, and comprising a pilot bit (1) drilling the hole centre and in connection with the pilot bit a ring bit (2) is arranged to drill the outer circle of the hole and, further, between pilot bit and ring bit surfaces are arranged to transmit impacts and/or rotary motion from the pilot bit to the ring bit, and the bit assembly also including an arrangement for pulling protectino tube into the hole on drilling. In the bit assembly between ring bit (2) and pilot bit (1) at least an arrangement transmitting rotation is jointly fitted in the ring bit shirt portion (5) by forming the rear edge of the shirt portion seen in the drilling direction to comprise surfaces with different directions, which with one of their portion (4) can transmit rotary motion force to the ring bit (2) and with their adjacent part (3) force to pull said ring bit off the hole.