Bird wings are not the only reason birds can fly

 

أَوَلَمْ يَرَوْا۟ إِلَى ٱلطَّيْرِ فَوْقَهُمْ صَـٰٓفَّـٰتٍۢ وَيَقْبِضْنَ ۚ مَا يُمْسِكُهُنَّ إِلَّا ٱلرَّحْمَـٰنُ ۚ إِنَّهُۥ بِكُلِّ شَىْءٍۭ بَصِيرٌ ١٩

Translation: Have they not seen the birds above them, spreading and folding their wings? None holds them up except the Most Compassionate. Indeed, He is All-Seeing of everything. SURAH AL MULK 19 

The birds fly by moving their wings up and then down towards their bodies. Up till today, human beings have failed to create bird wings. To fly in the sky, human created continuous non stop 

motor for either planes or helicopters. 

Nothing holds them up in the sky except Allah.