The flight path in David Watson’s Flight Path is the one at Heathrow under which teenagers take menial jobs in the airport. One of them, Jonathan (Cary Crankson), is the focal figure in a fresh, authentic-sounding play about friendship and brotherly love.

Jonathan’s elder brother, 25-year-old Daniel (Scott Swadkins), has Down’s syndrome and a Harry Potter obsession. He has been farmed out to special schools but has developed a love of gardening. The boys’ parents have split up: Sean (Will Knightley, Keira’s dad) is a philandering academic; Susan (Mossie Smith) has found herself, apparently, as a social worker in Waltham Forest.

Watson is another promising product of the Young Writers’ programme at the Royal Court and his play shows all the signs of learning how to channel raw experience into structured theatre; criticism is all but disarmed by such patent evidence of the learning process.

Then a tender, touching scene in which Jonathan stumbles to express his affection for his mate’s girlfriend Lauren (Ashley Madekwe) flickers into hard evidence of talent. That mate, Joe (Jason Maza), is up to no good with his luggage handling, and Jonathan drifts into a position of danger with regard to his A-levels at sixth form college.

A subtle shuffling of partisan feelings finds Joe making positive contact with Daniel and Susan helping Lauren to articulate her ambitions as a singer. Without ramming home the point, Sean’s disembodied witterings about cultural demographics on the radio sound like alien codswallop.

The play is a co-production between the Bush and Out of Joint (it goes on a nice little tour next month to Birmingham, Tunbridge Wells, Cardiff, Wakefield, Guildford and Edinburgh) and should be even more effective with the right audience of youngsters. The integration of a likeable disabled actor, Swadkins, into a production of this quality – Naomi Jones’ direction is light and sensitive – is in itself an important statement.

“All my brother wants is a garden” becomes Jonathan’s overriding concern, and the manner in which the play shakes out, both in the writing and in Polly Sullivan’s neatly constructed design, is not the least of the short play’s pleasures, a modest fringe theatre echo of the ecstatic musical resolution at the end of Leonard Bernstein’s Candide.

- Michael Coveney