What is the longest over-water route of flight with no alternates?

Few realize that San Francisco/Monterrey, CA are closer to Hawaii than Los Angeles or San Diego because of the curvature of the earth. The longest over water route in the world is the stretch between the U.S. mainland and Hawaii. Even between Hawaii and Tokyo there are alternate airports available, such as Midway Island (hence the name “Midway”). Going across the North Atlantic, alternates include Iceland and Greenland. Even more southerly routes would make the Azores a possible alternate.

Nautical-mile distance to Honolulu, HI (PHNL) from:
San Francisco (KSFO) 2081.1
Monterrey, CA (KMRY) 2087.5
San Diego, CA (KSAN) 2266.7
Seattle, WA (KSEA) 2324.5
Scottsdale, AZ (KSDL) 2535.8

The distance from Scottsdale to San Francisco is 563.4, nearly identical total mileage 2535.8 for flying directly from Scottsdale to Honolulu 2535nm vs flying from Scottsdale to Honolulu via San Francisco 2644 – a difference of only 109nm or 4.3%. All distances shown are with great-circle routing in mind. Great-circle distance explained.

Most do not realize just how far south Hawaii really is. Honolulu at N 21° 19’ is nearly the same latitude as Mexico City, MX N 19° 26’.

On October 7th 2011, a highly experienced ferry pilot ran out of fuel before he reached his destination, Hawaii. The 300-series Cessna came up only 13 miles short and landed safely in the Pacific Ocean. The pilot was immediately rescued by a Coast Guard helicopter and rescue swimmer. Dramatic video released by the Coast Guard shows the plane gliding low over the water and then splashing down. Within seconds the pilot climbs out onto a wing as a helicopter lowers a rescue swimmer, who helps him enter a basket and is hoisted to the hovering aircraft. The 65-year-old man, who was not seriously injured, was flying solo from Monterey, Calif., when he radioed authorities Friday afternoon that he was running low on fuel about 500 miles from his destination of Hilo, Hawaii, the Coast Guard said.

NOTE: a Ferry Flight requires a special permit from the FAA and by definition carries with it a higher degree of risk as the aircraft is being operated outside of its certified design envelope. It is certainly the norm for an aircraft being operated under a ferry permit to safely reach its destination. Whether it be for transporting the aircraft for repairs or making a journey that is 200%-300% longer than what the aircraft was originally intended for, these flights are performed under strict guidelines where only minimum required crewmembers are onboard and additional precautions have been taken.  Aircraft designed for extended twin-engine operations (ETOPS), i.e. long-range overwater flights, are governed by very conservative, thus more restrictive, fuel requirements and would have resulted in an aircraft having ample fuel even in the case of diverting for weather or flying on one engine.

According to one very seasoned pilot, anex-airline captain & former Naval Fighter Weapons School “Top Gun” Instructor, Professional crews flying ETOPS aircraft will carry enough fuel for “All contingencies including engine loss and cabin depres.  At every waypoint we made position reports which included our fuel state.  If we had burned more than our flight plan we would go to our alternate.  Generally our alternate was our original departure point, but alot depended on the winds aloft as that would determine where you went.  On the HNL to LAX route our alternate was SFO for almost 2/3rds of the flight.”

So if you are considering flying to Hawaii or any other destination that takes you beyond gliding distance from land, make sure you do it in an aircraft designed for ETOPS and follow the related ETOPS procedures. You will nearly be guaranteed to stay both high and dry.

Posted on in Flight Training