[Grammar] Usage of "Scarcely...when" and "No sooner did....than".

[shahjehansoomro]

Are the following sentences same according to English grammatical rules and meaning?

1. I scarcely reached the airport when the aeroplane took off.
or
2. No sooner did I reach the airport than the aeroplane took off.

 

[MikeNewYork]

There is no significant difference in meaning.