For author Kersten Hamilton and illustrator Valeria Petrone, things got rolling with 2008’s Red Truck, a Viking picture book for the toddler set spotlighting a plucky tow truck that rescues a school bus stranded in a rainstorm. A board-book edition of the title has made impressive sales tracks since its 2012 release, and now that still-chugging red truck has a whirling companion: Yellow Copter, just out from Viking.

The book that paved the way for Yellow Copter presented Hamilton with new creative challenges. She had previously written YA novels and picture books for older readers, but Red Truck is aimed at preschoolers. “I wanted to write a book that very young children would ask to hear over and over again – something both onomatopoeic and heroic,” she said.

Although pulling that off was trickier than Hamilton had anticipated, she found inspiration from an innate source. “To write Red Truck, I had to connect with my inner three–year–old,” she explained. “Fortunately, that kid who enjoys the sound of individual letters and letter combinations is never very far away. Still, I found it so difficult to craft a satisfying story on this level, that when I finished Red Truck I put on my YA novelist hat and sent my picture-book self a box of truffles.”

It didn’t take long for Hamilton to polish off those chocolates and switch hats yet again. When it became evident that Red Truck (whose board book sales “are closing in on six figures,” according to Viking senior editor Kendra Levin) clearly had wheels, the author decided to write another vehicle-themed book. Yet her first stab, a tale about a yellow school bus, fell flat. “The onomatopoeia never felt right, and I didn’t want to repeat words I had used in Red Truck,” explained the author. “And that left me with nothing but the hiss of hydraulic brakes. Adult test readers simply did not enjoy hissing at their children!”

Copter to the Rescue

After deciding to get off the bus that “just wasn’t going anywhere,” Hamilton recalled, “I went back to my building blocks: letter sounds. To me, the most fabulous phoneme in ‘yellow’ is the sound of the letter ‘o.’ I decided to find a machine with an ‘o’ in its name, which left me with an oil tanker or a helicopter. The choice was obvious. Helicopters make lovely sounds and they have rotors, booms and skids. Fantastic!”

Levin (who became Hamilton’s editor at Viking after Catherine Frank, who acquired Red Truck, left the company) immediately took to Yellow Copter when the author delivered the manuscript. In the story, the title character makes a loud “whup whup whup” noise as it takes off to rescue a teacher stranded at the top of a Ferris wheel.

The editor appreciated the fact that the follow-up book, like its predecessor, “has an addictive, recitable quality that makes it perfect for reading aloud. Parents often tell me that their kids have the words to Red Truck memorized, and want to hear the book read to them over and over again. One thing I especially love about these books is that they are both concept books and storybooks. Each tells an engaging story with a hero, a conflict, and a satisfying resolution, while also subtly conveying concepts like color and movement.”

Levin also credits Petrone’s digital illustrations for enhancing the appeal of Red Truck and Yellow Copter, noting, “the friendliness of Valeria’s art – the smiling faces on the vehicles and the people, and the gentle way it portrays each conflict so readers are absorbed without being frightened – is crowd-pleasing. Kersten and Valeria know their audience so well and are able to speak their language, whether that means through text – bouncy rhymes and clear-cut vocabulary – or through art with bold primary colors, appealing faces, and speech bubbles.”

Petrone, an Italian artist whose illustrations have also appeared in magazines and newspapers, said she enjoyed working on Red Truck and Yellow Copter, because they gave her a chance to create what she called “vehicles with personalities. There is a great tradition of this kind of character, starting with The Little Engine That Could, and it was a challenge for me to create several in my own style. When illustrating for very young children, I try to communicate a lot through graphic composition, shapes and colors, and characters’ expressions. I smile a lot while I draw, and I like to think that my young readers smile too when they see my characters.”

The illustrator recently delivered final art for her third collaboration with Hamilton, Blue Boat, starring a salvage tug, which Viking will publish in summer 2016. Due that same season is a board-book edition of Yellow Copter.

Hamilton, who does extensive research for her vehicle-centric books to ensure that the details are accurate, said Blue Boat is “the most intensely researched of the three. I am a desert creature, and I have never walked a deck or been awash in anything but sand. It turns out that salvage tug work is fascinating – addictive even. Which is good, because if I don’t love something, my inner three–year–old refuses to rhyme about it!”

Yellow Copter by Kersten Hamilton, illus. by Valeria Petrone. Viking, $16.99 May ISBN 978-0-451-46991-5