Simplify the following text for a Grade 9 native English-speaking person.
Original: London City Airport has a CAA Public Use Aerodrome Licence ( Number P728 ) that allows flights for the public transport of passengers or for flight training .
Simplified: London City Airport has a CAA Public Use Aerodrome Licence ( Number P728 ) that allows flights for the public transport of passengers or for flying instruction , subject to an aircraft being approved for a 5.5 degree or steeper approach .