A trip to Wellington took 35 minutes and to Auckland a little more than 40 minutes.
Quieter inside than a commercial jet, its twin engines can quickly lift it to find still air for a comfortable flight.
Certified to fly higher than most commercial aeroplanes, it can retain sea level air pressure to 21,000 ft.
"That is well above all of the weather and the other traffic," Mr Toogood said.
"Patients who are post-surgery, suffering serious neurological or cardiac conditions require a sea level cabin.
"The King Airs are good to about 13,000 ft or 14,000 ft. That is not always completely out of the weather and is certainly at the same flight level as a lot of the domestic air commuter traffic."
He said it would be a clinical decision when the single-patient plane would be used.
"Because there is no cost penalty they can simply decide what is best for each patient."
It took three months to fit out the jet with medical equipment certified for the Mustang and for chief pilot Alex McHardy to upskill.
He has already flown several medical missions.
"It is certainly less stressful for the patient and passengers," he said.
"Once the medical team has flown on this they don't want to get on the other plane."
Built in 2008 and bought from an Auckland businessman, it has 880 hours of flight time "which in aviation terms is new".
Mr Toogood said it would be available for lease but because it was additional to requirements of the air ambulance service "there is no step down in resource" should it be unavailable when requested.
"If the HBDHB like this aircraft - if it works well for them - then we are happy to make it a dedicated air ambulance. But for now it is just baby steps - we want to see where it fits in the fleet and where it sits in the service.
At $2.5million it was twice the cost of a turboprop equivalent but had greater longevity due to fewer moving engine parts and newer technology and better design.
While the cost to the HBDHB for the jet was the same as a turboprop "it will actually cost them less in the bigger picture because their clinicians will spend less time on a mission".
At a ribbob cutting ceremony yesterday HBDHB chief executive Dr Kevin Snee said he saw nothing but benefits from the jet due to smooth rides for delicate conditions and greater speed.
"When somebody is very ill, time is of the essence," he said.
Cessna Citation Mustang specs
Crew: one or two pilots
Capacity: 4 to 5 passengers
Length: 12.37 m
Wingspan: 13.16 m
Maximum speed: 777 km/h
Cruise speed: 630 km/h
Range: 2,161 km at maximum weight
Service ceiling: 41000 ft
Cost new: $4.7 million
•Source: Wikipedia