I have another theory. Herts AA put out a press release Monday to mark 900 missions in a tad over three years. So that's 300 a year roughly.
Let's compare to other UK AAs.. Here's one - I found a story from Warwickshire & Northants celebrating their 9,000th mission on 2nd September 2010 having started in 2003. So that's 9,000 in 7 years, so 1,285 a year, say four times Hertfordshire's rate.
How do other UK air ambulances compare? Is Hertfordshire a "low utilisation" operation and thus ripe for their Explorer to be shipped to Dubai for an airshow?