Section 2.3.3
Despite not reaching this portion of the Engine Dual Failure checklist, the captain stated during postaccident interviews that he thought that he had obtained green dot speed immediately after the bird strike, maintained that speed until the airplane was configured for landing, and, after deploying the flaps, maintained a speed “safely above VLS,” which is the lowest selectable
airspeed providing an appropriate margin to the stall speed. However, FDR data indicated that the airplane was below green dot speed and at VLS or slightly less for most of the descent, and
about 15 to 19 knots below VLS during the last 200 feet.
The NTSB concludes that the captain’s difficulty maintaining his intended airspeed during the final approach resulted in high AOAs, which contributed to the difficulties in flaring the airplane, the high descent rate at touchdown, and the fuselage damage. (See additional discussion in section 2.7.1.)
2.3.2
Simulation flights were run to determine whether the accident flight could have landed successfully at LGA or TEB following the bird strike. The simulations demonstrated that, to accomplish a successful flight to either airport, the airplane would have to have been turned toward the airport immediately after the bird strike. The immediate turn did not reflect or account for real-world considerations, such as the time delay required to recognize the extent of the engine thrust loss and decide on a course of action. The one simulator flight that took into account real-world considerations (a return to LGA runway 13 was attempted after a 35-second delay) was not successful. Therefore, the NTSB concludes that the captain’s decision to ditch on the Hudson River rather than attempting to land at an airport provided the highest probability that the accident would be survivable.
NTSB: Sully Could Have Made it Back to LaGuardia - CBS News
If you're prepared, and have practiced dual engine failures, an immediate turn would have made the airport. But it's a high risk event especially if you're not prepared or haven't practiced it. I think the success rate to RTB to rwy 13 was 6/7 or 7/8. Rwy 22 about 50/50 and 31 was 0/1 or 0/2.
Unfortunately even professional pilots have chosen the movie as their base for information instead of the NTSB report.