Engineer Officer (Aerosystems): moved every couple of years and did a wide variety of jobs. You won't really be getting your hands dirty, but you do need to have a good understanding of the technical side as you can be making - sometimes explaining, sometimes defending - decisions that could have a major impact on life and limb. Hence I sometimes got my coveralls on and went out with my guys to see what jobs involved. I've done normal office hours and nominally 12-hour (usually longer) days/nights. I've run shifts of 50-60 personnel maintaining and repairing equipment and during 2 tours on aircraft squadrons (fast jet and transport). I've also done office-based jobs where I've written technical documents; managed contracts; overseen the introduction into service of new aircraft; run a project for upgrade of aircraft radars; and saved the RAF a fortune and stopped a lot of aborted missions by solving a major problem on Tornado engines. How much you travel is a bit of a lottery; the fast jet squadron was only on UK-based exercises during my time, but got regular trips to Oman with TriStar and that led to a deployment to the Falklands. Even with the office jobs I got out and about to other stations and visits to industry.
As an officer you'll also have wider responsibilities such as management of any staff (their welfare, discipline and career progression), quality assurance and health and safety.