Could Quadjets Make a Comeback in Aviation?

Introduction to Quadjets

A four-engined aircraft, often referred to as a quadjet, is a jet aircraft powered by four jet engines. These engines provide increased power, allowing larger aircraft to carry heavier loads and serve on heavily traveled routes. Quadjets gained popularity with models like the Boeing 747, Airbus A340, and A380. The first example of such an aircraft was the Havilland Comet, the world’s first commercial jetliner. Subsequent decades saw many other aircraft adopt the four-engine design. However, airlines today predominantly favor twin-engine aircraft for economic and sustainability reasons.

Characteristics of Quadjets

A standard quadjet features two engines on each wing, mounted in pods under the wings, reducing structural stress and allowing easier ground maintenance. Some configurations, like the Iluyshin II-62 and Vickers VC10, have engines attached to the rear fuselage to reduce cabin noise. The de Havilland Comet had its turbojets inside the wing, minimizing drag and foreign object ingestion, though complicating maintenance. Today’s prominent quadjets include the Airbus A380, Boeing 747, and Airbus A340.

The Decline of Quadjets

The idea of a quadjet resurgence in new-generation aircraft is presently unlikely. The Boeing 747 and Airbus A380 were giants in their time, but their heavier loads and higher operational costs diminished their business appeal. Both production lines are now closed, with only a few airlines still operating them. Even Emirates, the largest A380 operator, is transitioning to more cost-effective aircraft such as the Boeing 787 and Airbus A350. The evolution toward smaller, point-to-point flights over hub-and-spoke models has further reduced the demand for large quadjets.

Current Quadjet Operations

The COVID-19 pandemic accelerated the retirement of aging and surplus aircraft, including many quadjets. A few airlines, like Lufthansa, have returned some Airbus A380s to service. Historically, four-engine planes symbolized luxury, offering lavish amenities during intercontinental travel. Emirates and Etihad took this luxury further with features like onboard showers and private apartments. However, larger quadjets face challenges due to their inefficiencies and operational costs.

Advantages and Disadvantages of Quadjets

Advantages

• Improved safety with multiple engines, reducing risk if an engine fails.
• Higher power facilitating larger airframes and increased passenger capacity.

Disadvantages

• Higher fuel consumption compared to dual-engine aircraft.
• Increased maintenance costs due to four engines needing regular inspections.
• Financial liability when not fully occupied, prompting a shift to smaller aircraft for niche routes.

Future Prospects for Quadjets

Although reintroducing quadjets seems improbable, certain conditions might prompt a return. New propulsion technologies or regulatory changes on specific routes could necessitate larger, multi-engine aircraft. The potential future for quadjets includes innovative designs like the Boom Overture, a supersonic commercial quadjet under development, promising faster, safer, and sustainable travel.