Leg - I refer you to page 48 of the 2011 / 2012 annual report.
The Walker Trust holds its shares via Rosedale Aviation Holdings Ltd.
The annual report states that the company's share capital is made up of 75.2 million shares - ie these are the sole shares that give ownership of Flybe.
The same page states that Rosedale owns 48.1% of the company or 36,146,250 shares - so yes, by far the largest shareholder. At a current price of 55.75 pence per share, the Walker trust's stake in Flybe is worth 36,146,250 x 0.5575 = £20,151,534.38 or approx £20.2 million pounds.
There is no magic or other class of shares used for ownership as per the annual report. Flybe as a company in its entirety is worth £41.5 million pounds. It may be large in terms of fleet, number of employess or flights operated but it is not a particularly valuable company.