Helicopter at Angelus Hut

Looks like no, unless it; for management purposes - i.e. hut maintenance, restocking, etc. "Motorised air access Motorised air access detracts from the peace and tranquility of the park. The park is closed to motorised aircraft landings except for special purposes, in accordance with by-laws. The special purposes, defined in the by-laws, are mainly for essential management, emergencies and wild animal control" http://www.doc.govt.nz/Documents/about-doc/role/policies-and-plans/4.%20use%20and%20accessibility.pdf

In other words not until some pays extra for a concession along with a paper handshake

commercial helicopter flights are allowed to land at Kepler hut with walkers...

The above document is part of the management plan for Nelson Lakes National Park (only) - does not apply to other parks such as Fiordland, Mt Cook. Each have their own plan: some allow landings in specified places/areas, some do not.

Wasnt aspiring park a similar rule? But as mentioned by waynowski that rule is not applied

Not so: Helicopters are permitted in Aspiring. " 6.6.5 Aircraft
 Aircraft, including helicopters and fixed-wing aircraft, may be used in the park for a number of purposes, including:
 Conservation management63 Emergency or search and rescue operations
 Commercial hunting/wild animal recovery operations (WAROs) Servicing concessionaire infrastructure
 Scientific research—including servicing of infrastructure and access for research
 Recreation activities
 Tourism and other commercial activities
 Management of pounamu by Ngai Tahu.
 " http://www.doc.govt.nz/about-us/our-policies-and-plans/national-park-management/mount-aspiring-national-park-management-plan/6-park-objectives-and-policies/6_6-public-use-and-enjoyment/#665aircraft

Interesting. No doubt there will be some Armed Forces act, or something, which allowed the use of an air force helicopter up the Travers Valley (NLNP) one holiday weekend last year. No matter where I was in the area I could hear it thrashing around. It sure did "detract(s) from the peace and tranquility of the park"

DOC and volunteer groups use iroquois from NZRAF for a lot of stuff. Both heavy lifting for DOC and free transport for traps etc for volunteer groups. Makes sense: NZAF get training, conservation work gets free transport. Will almost certainly fall under "management purposes" clause

no helicopters allowed in aspiring, apart from the regular flights up and down the routeburn to service the guided walkers huts... and to ferry the walkers between huts when rain and wind threaten...