For pipe flow I came across the information that the onset of turbulent flow occurs at approximately $Re=10^3$ to $Re=10^4$, while for boundary layers on the airfoil the onset occurs in between $Re=10^5$ and $Re=5\cdot 10^6$. Therefore, since the onset of turbulent flow ranges greatly, is theoretically still possible in some cases to have the laminar flow above $Re=10^7$ on the airfoil, disregarding the laminar sublayer in every turbulent flow above the surface?
Any reference to books would be highly appreciated.
