Can a commerical jet fly into a tropical cyclone? There is little doubt on whether planes can fly over a tropical cyclone as clearly demonstrated by this video of a Gulfstream jet flying over hurricane Katrina in 2005 to drop weather instruments.

I do not know the intensity of cyclonic wind at 10km above sea level, but my limited understanding on the subject suggest that the wind is strongest near the surface and weakens with height. If a small plane with high service ceiling can fly over such a powerful storm. Is it possible for a larger plane with a lower service ceiling to fly into a cyclone unscathed?

Considering that most pilots would try to go around a cyclone and that safety regulations may also forbid pilots from putting their passengers in any kind of risk that airlines do not want to bear, by just strictly looking at the aerodynamics and aeronautics of the aircraft, is it feasible for large commercial planes like 747 to fly into a tropical cyclone?
If the wind shear (sometimes called wind gradient, which in my opinion is the better term) encountered in that part of the cyclone the aircraft is penetrating is less than what the aircraft can handle, then, yes, an aircraft can safely fly into a cyclone.

What the aircraft can handle varies greatly depending on the speed at which it is being flown. Large aircraft have a recommended turbulence penetration speed, both in terms of knots and mach. In the absence of such a recommendation, V speeds that are relevant are Va, Vb, and Vo. http://en.wikipedia.org/wiki/V_speeds is a good V speed terminology reference.

I do not know what typical wind gradient values within a cyclone are or what their distribution within the cyclonic area is. However, I would be surprised if they were significantly greater than gradients within tropical thunderstorms, and aircraft do penetrate such.

In season there's a roughly north-south line of thunderstorms that regularly develops between Sumatra and Sri Lanka with tops greater than 50,000 feet. Lacking the fuel to go around the line, we would regularly go through it using radar to avoid the worst. However, with those old radars (back in the 1990s in 747s), it was not uncommon for us to wind up in a cell.