£38,000 to £43,000 would be the UK rate for a permanent position, Mon-Fri 8am-4.30pm. Contracting rates for "independent consultant" tech services people are around £30 an hour. My most recent "off-shore" contract paid 35 Euros an hour.
Line Engineers may certainly earn more but their working conditions are much less attractive. Shift pay isn't paid for nothing and the long-term health effects of working shifts - especially nights - are well documented. (and check out the ages in the obituary columns of BA News.)
In any case, there are "Tech Services" type jobs available that work shifts and earn shift pay - Maintenance Controllers, Short-term Planners and Defect Analysts for example.