Changing or canceling a RFS
 

I hve a QR flight SIN - DOH - OSL coming up, with a 90 minute stop in DOH and about 4hrs in OSL before the connecting RFS back to Heathrow.

I have noticed that the SIN - DOH flight is a serial late arriver and am concerned that I may miss the OSL flight and associated BA connection back to LHR (BA 763 departing 11:40am). So say for example:

• I am in SIN airport and the DOH flight is going to depart too late to make the connection to OSL, or
• I am in DOH having just missed the connection

In either scenario I should get onto the later QR flight to OSL. However, can I change the OSL - LHR leg of the RFS to a later flight (say BA 767 departing 17:05) while sat in either SIN or DOH airports? I assume if not (cannot find anything about cut off timing for altering a RFS) I assume it would be best to just book another RFS for the later flight?

RFS bookings are not changeable within 24 hours of departure.
There have been a few reports of exceptions being made and I recall one post where QR were kind enough to reroute a person in a similar position from DOH to LHR instead of OSL but they are exceptions and shouldn't be relied upon to solve a problem that arises.
The problem you highlight is the big draw back of ex-EU bookings and the associated positioning flights.

Also consider whether it's better value to book a revenue Plus ticket and use the Same Day Change provision on that.