The pandemic lockdown has temporarily been shut down the cruise ship industry and drastically reduced passenger airlines travel and even railway passenger travel, with resulting reductions in service. Financial pressures caused by the pandemic have permanently closed several commuter plane services that connect between coastal cities and may just have opened a door of future opportunity for high-speed maritime transportation between selected pairs of coast cities. 

Introduction

Many intercity passenger transportation services have given notice that they are permanently closing some of their lesser traveled routes and selling off transportation vehicles so as to survive financially over the next few months. Prior to the lockdown, commuter planes were the choice for fast travel between coastal cities, with railways providing additional comfort and intercity buses appealing to the economy traveler with low-priced travel. At the present day, high-speed trains connect between very few pairs of coastal service, the prime example being Japan’s Tokyo – Osaka – Hiroshima service.

Elsewhere around the world, commuter airplanes offer much faster travel times between coastal cities than intercity passenger trains. Prior to the pandemic lockdown, companies in Singapore, Germany, Malaysia and Australia were developing wing-in-ground (WIG) vehicles aimed at fast transportation between coastal cities of up to 500-miles or 800-Kms apart. The prospect of faster-than-railway transportation at lower-than-commuter-plane ticket prices opens a potential market for ground effect commercial transportation. Internationally, there are several pairs of coastal cities located less than 800-kms apart and where the superior fuel efficiency of WIG vehicles would translate to lower tickets prices for passengers.

Engine Efficiency

Airline regulations require that commercial commuter passenger aircraft be powered by 2-engines. At the present day, twin-engine aircraft incur lower operating costs than 4-engine aircraft and regulations allow such aircraft to work trans-oceanic routes. A single large engine powers many large maritime vessels, setting a precedent for even large WIG vehicles to be powered by a single gas turbine engine, with potential to include a heat recovery regenerator in the engine to boost fuel efficiency. Various design constraints prevent the installation of a regenerator on commercial aircraft engines.

A single engine installed on a large WIG vehicle would involve a transfer drive mechanism driving twin or multiple propellers to maintain high propulsive efficiency by moving a much larger volume of air at lower relative speed. While a WIG vehicle could require 1/3rd the propulsive energy to travel at equivalent speed as a turboprop commuter airplane of equal weight, the addition of a regenerator could raise the energy savings advantage closer to a 4 to 1 ratio. Ongoing development of high-temperature, pressurized closed-cycle gas turbine engines provides a future option for efficient propulsion for WIG technology.

Maintenance Costs

While WIG vehicles are built to maritime structural standards, they spend most of their travel time skimming above the water surface. Operating as seaplanes that lift off from and touch down on seaplane runways, WIG vehicles save the maintenance cost of retractable landing gear. The ability of WIG planes to operate using a single engine while carrying the passenger compliment of a twin-engine commuter plane offers reductions in engine maintenance costs over twin engine planes. In the airline industry, a turbine engine experiences a breakdown for over 100-breakdowns involving piston-engine aircraft.

Advances are presently occurring in the development of solid-state batteries that promise to store more energy and deliver more deep-drain discharge/recharge cycles that present day lithium ion batteries. While the technology is still in the development stage in laboratories, the technology can purportedly offer equal or higher storage density than lithium-ion batteries and free from the risk of fire and/or explosion as has been the case for some lithium battery technologies. Solid-state battery technology offers WIG vehicles an operating range of up to 500-kms or better than double to operate range of a battery powered commuter plane.

Pilot Training

Automatic pilot technology is invaluable on long-haul commercial flights and can actually land an airplane on a runway. The tragedy of Air France flight 447 from Rio de Janeiro to Paris exposed a shortcoming on automatic pilot technology when post-crash investigations suggested that automatic pilot was unable to respond build-up of ice on the pitot tubes and returned airplane control to the pilots. The tragedy of Lion Air flight 610 involved an issue related to automatic pilot control. In both tragedies, pilots consulted flight manuals to respond to an unfamiliar situation.

Sadly, Lion Air flight 610 was within the operating range of WIG planes that fly just above the water surface. Pilot training for Class-A WIG technology is less complex, less costly and involves less time duration than commercial airline pilot training. Single wing Class-A WIG planes have 2-flight elevations, being 5% of wingspan to achieve peak fuel efficiency and 40% of wingspan to respond to waves when fuel consumption approaches that of a commuter airplane. The main training challenge for WIG pilots would be collision avoidance upon approach to and departure from terminals.

Arrivals and Departures

The ability to operate between seaplane runways greatly reduces airport service expenses. WIG planes equipped with retractable wheels can touch down on seaplane runways, then sail to a boat launching ramp to self-propel up the ramp and ashore for passengers’ convenience. Lifting off from suitable coastal runways where planes accelerate into a headwind would greatly reduce energy consumption caused by speed induced water drag, essential to enhancing future prospects for battery-electric WIG technology. Airline pilots who land planes on airport runways dislike the ground-effect phenomena as it greatly extends landing distance.

WIG planes generally touch down at lower speed than seaplanes and also commercial planes that land at airports. The combination of lower touch-down speed and ability of variable-pitch propellers to develop reverse-thrust offers the prospect of reducing touch-down distance, including when landing on coastal runways. Touching down a WIG plane while traveling into a headwind would further reduce touch-down speed and touch-down distance, unless the headwind exceeds the lift-off speed of the WIG plane. In such situations, touching down on water with a tail-wind or side-wind might be an alternative.

North America’s Great Lakes

Several potential Great Lakes WIG routes link cities around North America’s Great Lakes, with potential for weekday peak travel to occur between mid-September and mid-June of each year, when majority of pleasure craft and recreational boats are out of service. Coastal breakwaters at lakeside cities such as Chicago, Milwaukee, Cleveland, Erie and Buffalo provide protection from waves and allow seaplanes and WIG planes to touch down and lift off. Detroit, Buffalo and Kingston (Canada) are located on rivers that connect to the lakes and away from the severe “November Witch” wave conditions that occur on the Great Lakes.

On the Canadian side, a 250-km/hour WIG plane service is possible between Toronto and Kingston, located at the western entrance to the St. Lawrence River. In the western of Lake Ontario where gentle wave conditions prevail, 30-minute trans-lake commuter service is possible between Toronto and Niagara/St. Catharines, using tandem-wing WIG technology.

The pandemic lockdown has greatly reduced the number of passengers who travel on short-haul and commuter planes, with airlines having closed several such services. During the post-pandemic period, other entrepreneurs could re-examine future potential for business using WIG planes between coastal cities, along former airplane commuter routes.