Members of the Hawkes Bay and East Coast Aero Club took the routine call just after 11am while the Tomahawk plane was just over halfway through an expected 60-minute flight.
A visitor from Britain, who was fully qualified, was flying the aircraft, and was on a training exercise before having his pilot's licence validation exam today.
He and his experienced instructor from the club were killed when the plane crashed into the Ngaruroro River.
A routine call back to the club was made a few minutes before the emergency locator beacon went off, aero club president Bruce Govenlock said. There was no indication anything was wrong.
"I understand it was routine ... that he was advising they were going to fly lower," he told the Herald. "It was not many minutes from the last radio transfer that we noticed the beacon ... It doesn't appear there was any chance for a distress call and the last radio transmission indicated there was nothing wrong."
After the emergency beacon went off, another club plane already in the air went to investigate.
The crash site was close to the small settlement of Maraekakaho and State Highway 50 but was not visible from the road and difficult to access.
Mr Govenlock said it had been a harrowing day for the small club and its members, especially the ones who heard the beacon go off and realised the plane with their friend on board had crashed.
"They acted professionally and did what they needed to do ... It would have been very hard as they all know the pilot," he told the Herald.
Club members visited the home of the local man after the crash.
The plane reportedly appeared to stall before it nosedived into the river.
Alison Arthur was tending to her horses on her farm in Crownthorpe near Hastings when she spotted the plane in the air.
"We see planes come up the river all the time, but I first noticed these pop sounds before I spotted the plane.
"I've never seen one that low around here before, then it started swerving from side to side before it tilted heavily."
Mr Govenlock said the aircraft was 30 years old and had been well maintained.
Civil Aviation Authority investigators would arrive at the scene this morning.
- Andrew Koubaridis, NZ Herald, Additional reporting: APN
