Gap at top of side opening window

[markus250]

Hi there,
Recently inherited mother in laws house and just giving it a tidy up and fixing a few little things before selling.

Up in one of the bedrooms, there is a gap at the top of the side opening window. I can't see any adjustment on hinges etc. Its as if the opening part has dropped.
Is this a case of im missing some adjuster, or remove and replace hinges? Windows are around 30years old.

 

[crank39]

Window hinges or friction hinges aren't adjustable, the adjustment needs to be done by packing the frame square off the glass called 'toe and heel', it's a simple process to actually do but you need some specific tools, a sharp rigid scraper, a glazing shovel, a soft nylon hammer and a small selection of glazing packer