Sir Cliff Richard burst into a rendition of his hit Summer Holiday on board a Florida-bound plane carrying 192 seriously ill or disabled children this afternoon.
Now in its 27th year, Sir Cliff said the annual trip - which includes the opportunity for each child to swim with dolphins - is "probably one of the most exciting things that's happened" in the children's lives.
Having just jetted in from Miami to wave goodbye to the group - who are from all over the UK - he said: "Dreamflight is such a wonderful idea. The fact that these very sick children who have a dream of going to Disney, and suddenly, there's this plane.
"They have the most fantastic time.
"It's probably one of the most exciting things that's happened to them in their lives."
The children have left their families behind and will be looked after during the action-packed week of fun by 15 doctors, 50 nurses and 12 or 13 physios - all volunteers.
The total cost of the trip is around £750,000, all of which is funded by voluntary contributions and covers chartering a Boeing 747, medical equipment and medication, swimming with dolphins, police security and communications equipment.
Sir Cliff described the work of Dreamflight as "vital" and said it makes him feel positive about the world.
"All charity is vital. How do these people have a life? How do they get something as magical as this without a charity involved?
"It warms my heart, because it goes to show that with all the evil there is in the world, there are obviously people who will give their time, give their money, give their commitment and dedication to help young sick children have maybe one fabulous moment in their lives.
"I think it's worth every penny that it costs."