'George hasn't turned up,' said Nick. 'A nuisance his having to go back to Plymouth last night. He'll get over this evening sometime or other, I expect. In time for the dance anyway. I've got a man for Maggie. Presentable, if not passionately interesting.'
A faint roaring sound drifted in through the window.
'Oh! curse that speedboat,' said Lazarus. 'I get so tired of it.'
'That's not the speedboat,' said Nick. 'That's a sea-plane.'
'I believe you're right.'
'Of course I'm right. The sound's quite different.'
'When are you going to get your Moth, Nick?'
'When I can raise the money,' laughed Nick.
'And then, I suppose you'll be off to Australia like that girl-what's her name?'
'I'd love to-'
'I admire her enormously,' said Mrs. Rice, in her tired voice. 'What marvelous nerve! All by herself too.'
'I admire all these flying people,' said Lazarus. 'If Michael Seton had succeeded in his flight round the world he'd have been the hero of the day-and rightly so. A thousand pities he's come to grief. He's the kind of man England can't afford to lose.' (Peril at End House, Agatha Christie)
I suppose Moth here refers to an expensive brand/thing but can't figure out exactly what. The phrase in question is bolded.