Lab Ch3 'Using $lookup' - Filtering by airplane

Please, take care when filtering by airplane, as field ‘airplane’ can contain multiple values in a string, i.e 333 380 321 787 330 332, not just one single value as I was expecting.

Because of this I got different results than proposed solution. I took me a lof of time to figure out what was happening, until I realised and I got the same results.

Thank you very much for pointing this out!