Granted it would take a hell of a parachute for a 20k + lb helo vs. a 1,500 lb plane.
Interestingly enough, it has more to do with true airspeed rather than with weight. Yes, weight is a consideration for the actual decent rate after deployment, but getting the thing slowed down enough to deploy is the big issue (obviously not so much on a helo, but on a FW the airspeed is the big driving force).
BRS, the company who makes the parachute for Cirrus and many other aircraft (mainly ultralights, however I spent 3 years working with BRS to implement a chute into the Lancair Evolution), has many different versions of chutes for different weight categories and true airspeeds flown. The chute for a 5000 lb plane weighs nearly 200 lbs itself...that's without any sort of pyro for timed/sequenced deployment of the chute. They have some chutes for dropping cargo in the range of 20k+ lbs, via static line and staged charges, but they are stupid heavy and expensive.
BRS is a good company, and after 3 years they finally changed my thinking about having a parachute on an airplane. I was completely against it for a very, very long time, but that's for another thread.