Unsealed Runways in F27’s
There were simply no restrictions – if it was serviceable it could be used!
The only totally unsealed airfield in the Melbourne-based network was Flinders Island; published as being “crushed limestone” it was like landing in talcum powder, a smooth landing was virtually assured.
Many on-line ports had alternate (crossing) runways that could be used if the crosswind on the sealed runway was excessive; Portland, Warrnambool, King Island, Hamilton and Wagga Wagga spring immediately to mind.
There was a trick to Hamilton, where overflying was distinctly frowned upon. If the forecast indicated a strong crosswind, you could ring ahead and get a flarepath laid on the cross (gravel) strip. Inevitably on arrival, peering down at the illuminated windsock would reveal no such crosswind, but you were sort of obliged to land on the gravel just to justify the time and effort to lay out the flares!
As Griffo says, many charters were to unsealed airfields also. From my own experience to Deniliquin once (FIVE F27’s; the sealed runway wasn’t available for some reason), several charters to airfields in the Qld coalfields and also to Mt Tom Price and Laverton in WA.