My son received the Playmobil Leisure Jet (affiliate link) for his fourth birthday, and it has been brilliant. The best thing about it is that unlike most Playmobil sets it has very few small pieces. There is a pilot, a passenger and a suitcase, and the rest of the toy is the plane itself. This means that there are no parts to get lost or to present a choking hazard to smaller members of the family (although of course younger children should always be supervised around toys with small pieces).
It is very simple to operate. You can lift off the roof to access the passenger compartment and easily slot the people in and out of the seats. Underneath is a baggage compartment. It has three wheels on the bottom so it can be wheeled around the airport, and it's light enough to be lifted easily into the air for flying fun.
The tail fin and the wheels do detach quite easily but they are easily clicked back into place. I'd definitely recommend this Playmobil set, particularly for younger children that need a set which is a little more robust for them to play with.
I've made a short video of the Playmobil Leisure Jet so that you can see all the different parts.
You might also be interested in some of the other pieces from the Playmobil range. We were able to purchase the Playmobil airport second hand and it has been brilliant for encouraging role play with my son.