How a seaplane travels by land across Arizona

Oversize/overweight loads are a really big deal, literally. You can see that in the video below by ADOT Videographer Joe Larger. He followed the massive Philippine Mars seaplane on part of its recent journey from Lake Pleasant and shares not just the sights and sounds but how ADOT’s Statewide Permits staff helped make it happen.

You’ve probably seen one before on the road: A large truck carrying a boathouse, part of a windmill or even an aircraft, and accompanied by one or more escorting vehicles. Also referred to as heavy or wide loads, ADOT’s Statewide Permits Services process thousands of oversize/overweight permit applications each year.

Recently, the Philippine Mars seaplane was transported from Lake Pleasant north of Phoenix to the Pima Air & Space Museum in Tucson. The Philippine Mars was one of only five flying boats of its kind used by the US Navy during World War II. It later served as a waterbomber to fight wildfires and is now one of the only Mars aircrafts remaining today, according to the Museum.

The drive from Lake Pleasant to Tucson would usually take about three hours using I-17 and I-10. But, at 137 feet long, 26.5 feet tall and 15 feet wide, the Philippine Mars was too large to travel on the interstates and had to take a winding route over the course of 6 days. 

“This was definitely one of the more unusual loads we’ve permitted in recent years,” said ADOT Permits Technician 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.”

Oversize loads, which can be up to 300 feet long, are often transported at night to reduce impact to the public. Permits Services coordinates with departments across ADOT to determine the best time and route for each specific load based on roadway characteristics and condition, size and weight of the load and other related factors.

To learn more about oversize/overweight permits and other permits issued by ADOT, such as film permits and the Adopt a Highway program, please visit azdot.gov/permits.