Tory peer Lord Ballyedmond, 70, died in March 2014 when the helicopter came down near the estate he owned in Gillingham, Norfolk.
Pilot Capt Carl Dickerson, 36, co-pilot Capt Lee Hoyle, 45, and foreman Declan Small, 42, also died.
A jury inquest into their deaths has opened in Norwich.
The Agusta Westland AW139 crashed in thick fog shortly after take off from Gillingham Hall, near the Suffolk town of Beccles.
The hearing was told Mr Dickerson, of Thornton, Lancashire, had warned the helicopter needed to take off "no later than 7pm" because of the bad weather.
However, it did not take off until 19:22 GMT because Lord Ballyedmond, also known as Dr Edward Haughey, had been overseeing the hanging of pictures as part of his renovation of Gillingham Hall.
Ciara Cunningham, Dr Haughey's diary secretary, confirmed to the hearing he had received the message and would have had no problem following Mr Dickerson's advice.
"He very much valued the opinion of experts in their field," she added.
His personal assistant Madeleine Irwin, also said in a statement: "Lord Ballyedmond would never insist on flying when a pilot said they could not fly."
The peer lived at Ballyedmond Castle in Co Down, Northern Ireland.
He was chairman and founder of Norbrook Laboratories, the largest privately-owned pharmaceutical company in the world, and had a range of other business interests.
His son Edward told the inquest he last spoke to him as the helicopter was about to take off.
He added: "He was joking and said 'I better do what I'm told or I'll get in trouble with the boys'."
The timing of the flight had been arranged around Mr Small, of Mayobridge, Co Down, who was a valued employee and had a concert to attend the following day, he said.
Mr Dickerson's widow Paula said in a statement: "The accident shook my world and took the love of my life from me."
Mr Hoyle's widow Georgina, of Macclesfield, Cheshire, said the former soldier was a conscientious man who would not take chances with safety.
"He was my best friend and losing him left our family devastated," she added.
An Air Accident Investigation Branch (AAIB) report has already found the crash may have been triggered by an error in perception along with a lack of training and procedures to handle the flight.
The hearing continues.
One of Northern Ireland's richest men who died in a helicopter crash that killed three others had been warned about fog beforehand, an inquest heard.