Sabena aircraft 1938?

[QDMQDMQDM]

My mum came as a refugee out of Germany in September 1938 on a Sabena aircraft to London from Berlin. They made an unscheduled stop in Duesseldorf where all the passengers had to get off and be searched. Then they continued on to London, coming low across the channel and landing on a drizzly evening in Croydon.

She thinks it was a corrugated biplane. Is this possible? Anyone know what it was likely to be?

Thanks,

QDM