The 160th Special Operations Aviation Regiment (Airborne) has this to say about the Chinook:
The MH47 conducts overt and covert infiltrations, ex filtrations, air assault, resupply, and sling operations over a wide range of environmental conditions. The aircraft can perform a variety of other missions including shipboard operations, platform operations, urban operations, water operations, parachute operations, forward aerial refueling point (FARP) operations, mass casualty, and combat search and rescue operations.
With the use of special mission equipment and night vision devices, the air crew can operate in hostile mission environments over all types of terrain at low altitudes during periods of low visibility and low ambient lighting conditions with pinpoint navigation accuracy.
The MH-47E is a heavy assault helicopter based on the CH-47 airframe, specifically designed and built for the special operations aviation mission. It has a totally integrated avionics subsystem. This avionics package combines a redundant avionics architecture with dual mission processors, remote terminal units, multifunction displays and display generators to improve combat survivability and mission reliability.
The "Echo" model also has an aerial refueling (A/R) probe for in-flight refueling; external rescue hoist; and two L714 turbine engines with Full Authority Digital Electronic Control that provides more power during hot/high environmental conditions.
The MH-47D Adverse Weather Cockpit (AWC) Chinook is a twin engine, tandem rotor, heavy assault helicopter that has been specifically modified for long range flights.
It is equipped with weather avoidance/search radar; aerial refueling (A/R) probe for in flight refueling; Personnel Locator System (PLS) for finding downed aircrews; Forward Looking Infrared (FLIR); secure voice communications; Fast Rope Insertion Extraction System (FRIES) for insertion of personnel/equipment and extraction of personnel; defensive armament system consisting of two M-134 machine-guns and one M-60D machine-gun; and internal rescue hoist with a 600 lb. capacity.