Method for installing a blind fastening device (100; 100a) in a bore (28; 28a) provided in a structure (20; 20a), the structure (20; 20a) having a first side and a second side, wherein the method comprises steps of: - inserting a sleeve (31; 31a) into the bore (28; 28a) from the first side of the structure (20; 20a); - using a core element (36; 105; 36a; 105a) arranged in a longitudinal passage (32; 32a) of the sleeve (31; 31a) and accessible from the first side, forming a deformed sleeve zone (33; 33a) engaging the structure (20; 20a) on the second side thereof to install the sleeve (31; 31a) in the structure (20; 20a); - removing the core element (36; 105; 36a; 105a) from the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a'); the method being characterised in that it further comprises steps of: - inserting at least one inspection device (64; 76) at least partly into or through the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a'), performing inspection of the installed sleeve (31'; 31a') or of at least a portion thereof using the inspection device (64; 76), and removing the inspection device (64; 76) from the longitudinal passage (32; 32a); and/or inserting a working device (84; 91) at least partly through the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a'), performing additional work, on the second side of the structure (20; 20a), on the installed sleeve (31'; 31a') and/or in the vicinity thereof using the working device (84; 91), and removing the working device (84; 91) from the longitudinal passage (32; 32a); and - inserting a core bolt (105; 105a) into the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a') and tightening the core bolt (105; 105a) with respect to the installed sleeve (31'; 31a'), wherein the core bolt (105; 105a) in particular is or corresponds to the core element or is another element. - inserting a sleeve (31; 31a) into the bore (28; 28a) from the first side of the structure (20; 20a); - using a core element (36; 105; 36a; 105a) arranged in a longitudinal passage (32; 32a) of the sleeve (31; 31a) and accessible from the first side, forming a deformed sleeve zone (33; 33a) engaging the structure (20; 20a) on the second side thereof to install the sleeve (31; 31a) in the structure (20; 20a); - removing the core element (36; 105; 36a; 105a) from the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a'); - inserting at least one inspection device (64; 76) at least partly into or through the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a'), performing inspection of the installed sleeve (31'; 31a') or of at least a portion thereof using the inspection device (64; 76), and removing the inspection device (64; 76) from the longitudinal passage (32; 32a); and/or inserting a working device (84; 91) at least partly through the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a'), performing additional work, on the second side of the structure (20; 20a), on the installed sleeve (31'; 31a') and/or in the vicinity thereof using the working device (84; 91), and removing the working device (84; 91) from the longitudinal passage (32; 32a); and - inserting a core bolt (105; 105a) into the longitudinal passage (32; 32a) of the installed sleeve (31'; 31a') and tightening the core bolt (105; 105a) with respect to the installed sleeve (31'; 31a'), wherein the core bolt (105; 105a) in particular is or corresponds to the core element or is another element.