Permitting heavy loads on state highways is no easy task  

Contribued Photo/Courtesy ADOT: After six nights of careful travel, the Philippine Mars fuselage and escort vehicles made it to State Route 86 in the Tucson area. It arrived at its new home at the Pima Air Museum early Saturday, May 17.

The recent transport of the Philippine Mars seaplane is an example of ADOT’s work

Contributed Article/Courtesy ADOT   

PHOENIX – Transporting a giant World War II-era seaplane from Lake Pleasant to the Pima Air and Space Museum in Tucson required detailed planning to protect state and local roadway infrastructure and to minimize inconvenience for other drivers. 

That’s where the Arizona Department of Transportation’s permitting process for oversized loads comes into play. Safely connecting Arizonans and empowering the economy includes helping companies transport loads ranging from transformers to prefabricated structures to wind turbine blades that can weigh hundreds of tons. 

Getting the Philippine Mars to Tucson required disassembling the aircraft and shipping the wings and engines as their own oversized loads. The greatest challenge was the fuselage, which at 26.5 feet tall, more than 137 feet long, and 15 feet wide created a made-for-television image as well as a logistical challenge for the haulers.  

“This was definitely one of the more unusual loads we’ve permitted in recent years,” said ADOT Permits Tech Christina Pippin. “We handle permits for many large cooling units, big mining vehicle parts, houseboats heading to Lake Powell, and even giant space rocket sections. Our goal always is to protect the public and minimize any impact to both state highways and local roads that often have to be used along transport routes.”

Contribued Photo/Courtesy ADOT: For safety reasons, most of the fuselage transport occurred at night when traffic is lighter.

Under what is known as a Class C permit for large or heavy loads issued by ADOT, the slow-moving transport vehicle carrying the fuselage made its way on a route that included Bell Road in the Northwest Valley and State Route 85 near Buckeye. For safety reasons, most of the fuselage transport occurred at night when traffic is lighter. It required law enforcement escorts and crews who moved utility lines as needed. ADOT issued an encroachment permit to allow contractors to adjust traffic control devices along the route. 

After six nights of careful travel, the Philippine Mars fuselage and escort vehicles made it to State Route 86 in the Tucson area. It arrived at its new home at the Pima Air Museum early Saturday, May 17.

Contributed Photo/Courtesy ADOT: Getting the Philippine Mars to Tucson required disassembling the aircraft and shipping the wings and engines as their own oversized loads.

As with all heavy loads, the private company handling this extraordinary aircraft haul was required to work with ADOT’s Statewide Permit Services office in applying for the appropriate permits. It was also responsible for keeping ADOT and other stakeholders, including cities and counties, up to date on plans since schedules and routes were subject to change.

While this was one of the more unusual oversized loads Arizona has seen in recent years, it followed processes designed to support these important shipments while protecting infrastructure. 

“In 2024, our office successfully processed over 6,500 oversized load permit applications,” said Courtney Mower, ADOT’s statewide permit services manager. “Though our permit technicians are not physically on the road with these heavy loads, their expertise is fundamental to ensuring these shipments reach their destinations efficiently and safely.”

To learn more about oversized permits and other permits issued by ADOT, please visit azdot.gov/permits. An ADOT Podcast featuring the oversized permits team is available at bit.ly/44VtJ5q.