A fundraising drive has been launched to help pay for a second wedding - "less the heli ride" - for a bride and groom seriously injured in a wedding day helicopter crash.

The wedding day tragedy unfolded on a fairway of the golf course at Terrace Downs Resort in Windwhistle, 80km west of Christchurch on Saturday when the Robinson 44 came down while flying the newlyweds to a picturesque mountain spot for post-nuptial photos.

All four on board – the bride, groom, wedding photographer and pilot - were seriously hurt and rushed to Christchurch Hospital after the 3.05pm crash.

The couple have been named by friends as Fay El Hanafy and Mahdi Zougub, who have close links to the Al Noor Mosque in Christchurch and who postponed their wedding plans after losing friends in the March 15, 2019 terror attacks.

El Hanafy had surgery yesterday after suffering a broken back, foot, and legs. Zougub has a broken back and is due to undergo surgery today.

The photographer on board has been identified as award-winning Rachel Jordan who has suffered spinal fractures and also undergone surgery. She also has five fractured ribs, a lung laceration, fractured sternum, fractured arm in a few places, and fractured feet.

Investigations are ongoing into the cause of the accident.

Today, a Givealittle page has been set up to help raise money for a "wedding 2.0" after the young couple had the "best day of their life [...] flipped up side down into the most horrific day".

"Mahdi and Fay have been working hard and planning for a picturesque perfect wedding in Canterbury. As guests began arriving they were going up in a helicopter to circle the alpines and take the last photos before their wedding party," says the fundraising page launched by a close friend.

"We would like to get some money together to assist with organising another wedding for them as soon as they are physically able to. All the funds will be going directly to the groom and we are sure it will help with their mental recovery as well.

"We would like to get some money together to assist with wedding 2.0 - less the Heli ride."

Wyndon Aviation, which owns the helicopter, says while the injuries are serious, they are "grateful that all four are recovering in hospital".

A spokesman for the company said the pilot has undergone a number of medical procedures in the past 48 hours and is due for further surgery today.

"Their condition can be described as improving, albeit slowly."

Yesterday the company said it was "unaware of any causal factors in respect of this accident" and that it would "not only be counterproductive but inappropriate to speculate on the cause".

"We have, however, undertaken to work closely with the CAA [Civil Aviation Authority] and authorities who are investigating the circumstances behind yesterday's accident."

The Civil Aviation Authority had a team from its investigation and response unit at the accident site yesterday to begin "a thorough scene examination" and to gather witness statements.

"The initial focus of our investigation will be to build an understanding of the circumstances surrounding the accident," the CAA said.

"This will help us identify whether there are any safety issues which need to be promptly addressed by the CAA and helicopter operators."

The chopper was removed from the site yesterday afternoon.

Waleed Abaza, a close friend of Zougub who was not in Al Noor on March 15, 2019 but lost close friends in the mosque shootings, was one of the "traumatised" wedding guests.

He spoke about how he and his friends were driving into Terrace Downs, and excited to attend the big day, when they saw an ambulance and wondered what had happened.

They then met other shocked guests who told them that there had been a helicopter accident involving the wedding party.

At first, they thought people had lost their lives in the crash which happened just after take-off.

"It was like, 'Oh my god'," Abaza said.

"We were told it had just taken off and like ... just dropped from the sky."

About 10 minutes later, they heard that all had survived but had been badly injured.

"Everyone was in a state of shock – we were all just standing around, nobody knew what to do," Abaza told the Herald.

"We were all just trying to find out information.

He can't believe that tragedy has struck just two years after living through the Christchurch mosque attacks.

"We both lost many friends in March 15 attacks," Abaza said.

"It was supposed to be such a happy day, that is the irony.

"[Zougub] has been through a lot in his life and we were so happy for him."

Many of Zougub's friends killed in the terror attacks would have been at Saturday's wedding and supporting their close friend.

"It's so hard to believe that this has happened," Abaza said. He now wants answers and for someone to be held accountable for the crash.

"This should never have happened."

Ronnie Ronalde, director of operations for CPG Hotels, which owns the resort, says they've reached out to the newly-wed couple's family.

He says they would like to pay for a return visit when they're healthy again.