#1 is not accurate but for different reasons. A forward slip is absolutely required for a PPL checkride and has been for decades (if you'd like a source, see p

#1 is not accurate but for different reasons. A forward slip is absolutely required for a PPL checkride and has been for decades (if you'd like a source, see page 45 of the definitive FAA ACS: https://www.faa.gov/training_testing/testing/acs/media/private_airplane_acs.pdf https://www.faa.gov/training_testing/testing/acs/media/priva...). However, transport category aircraft (among other issues) have swept wings, which are far less stable in a slip - so slips are neither taught nor recommended for jets.