McDonnell Douglas DC-10 VS Lockheed L-1011 Tristar

During my childhood years as an early aviation enthusiast in the 1980s, two exceptional planes caught my interest: the world’s most popular widebody trijets at the time, the McDonnell Douglas DC-10 and the Lockheed L-1011 Tristar. I remember having a kiddie airplane book about both, and I struggled to distinguish between them until I took notice of the position of engine #2 and its exhaust nozzle. But then, I kept pondering which of the two was the better aircraft.

While I did love the DC-10 because I had seen it in person countless times, the L-1011 Tristar held a certain appeal. I really didn’t know why; maybe it was the tail engine’s position? Or perhaps its size, even though they were similar. Oh well, let’s now talk about the DC-10 and the L-1011 Tristar.

The 1960s and 70s witnessed a period of immense innovation in commercial aviation. Amidst the race to develop faster, more efficient airplanes, two wide-body trijet contenders emerged: the McDonnell Douglas DC-10 and the Lockheed L-1011 TriStar. Both aircraft revolutionized long-haul travel, offering greater passenger capacity and range compared to their narrow-body predecessors. However, they also carved distinct niches in the aviation landscape, each boasting unique strengths and weaknesses.

Size and Capacity

The DC-10 and L-1011 were both sizeable aircraft, marking a significant leap from the prevalent narrow-body jets of the time. However, subtle differences existed in their dimensions. The DC-10 measured in at 182 feet (54.9 meters) long with a wingspan of 165.3 feet (50.4 meters). The L-1011 TriStar was slightly smaller, stretching 164 feet (50 meters) in length and boasting a wingspan of 164.4 feet (50.1 meters). While the L-1011 offered a marginally smaller fuselage, both aircraft offered comparable passenger capacities.

In standard configurations, the DC-10 typically accommodated around 250 to 400 passengers, depending on the cabin layout chosen by the airline. The L-1011 TriStar offered a similar range, seating 230 to 330 passengers. Notably, both aircraft offered the flexibility to be configured for either high-density seating arrangements or a more spacious layout with wider seats and increased legroom.

Range and Reach

Range was a crucial factor for airlines seeking to establish long-haul routes. The DC-10, particularly the later -30ER variant, emerged as the clear winner in this category. The baseline DC-10 offered a maximum range of around 3,500 nautical miles (6,500 kilometers). The DC-10-30 had a range of 5,200 nautical miles (9,600 kilometers) while the extended-range DC-10-30ER, on the other hand, could fly an impressive 5,730 nautical miles (10,620 kilometers), making it a popular choice for transatlantic and transpacific routes. The L-1011 TriStar, while boasting a respectable range of around 2,500 nautical miles (4,630 kilometers) in its initial variants, struggled to keep pace with the DC-10’s extended-range capabilities. Later variants of the TriStar, such as the L-1011-500, offered improved range of around 5,345 nautical miles (9,899 kilometers) but still fell short of the DC-10-30ER.

Technical Specifications

Both the DC-10 and L-1011 TriStar were powered by three high-bypass turbofan engines. The DC-10 primarily relied on various versions of the General Electric CF6 engine, and later on the P&W JT9D, known for its reliability and fuel efficiency. The L-1011 TriStar used one engine, the Rolls-Royce RB211, a powerful engine but one that was plagued by early reliability issues. Later versions adopted various models of the Rolls-Royce RB211-500, which addressed some of the initial problems.

In terms of cruising speed, both aircraft were fairly comparable, with typical cruising speeds hovering around 500 knots (926 kilometers per hour). However, the DC-10 enjoyed a slight edge in maximum takeoff weight, allowing it to carry more cargo on long-haul flights.

Avionics Technology

The DC-10 and L-1011 TriStar entered service at a time when aviation technology was transitioning from analog to digital systems. The DC-10, initially equipped with a mix of analog and digital avionics, underwent upgrades throughout its production run. Later variants incorporated more advanced digital flight control systems and instrument displays, offering pilots improved situational awareness and automation capabilities.

The L-1011 TriStar, on the other hand, boasted a more advanced avionics suite from the outset. It was among the first commercial aircraft to feature a fully digital flight control system, the Automatic Flight Control System (AFCS). This system offered improved stability and handling characteristics, particularly during autopilot operations. Additionally, the TriStar’s instrument displays utilized a mix of analog and digital components, offering pilots a clear view of critical flight information.

Safety Record

Safety is paramount in the aviation industry. Both the DC-10 and L-1011 TriStar have had checkered safety records, each experiencing a number of accidents and incidents throughout their service lives. The DC-10’s early years were marred by several high-profile accidents, some attributed to cargo door design flaws. Later model DC-10s with improved cargo door mechanisms had a significantly better safety record.

The L-1011 TriStar’s safety record was also tarnished by a few notable accidents, although not to the same extent as the DC-10’s early years. Some of these incidents involved engine malfunctions related to the Rolls-Royce RB211 engines used in earlier variants. Later models with improved engines experienced fewer safety issues.

It is important to note that safety standards and regulations have continuously improved over time. Both the DC-10 and L-1011 TriStar underwent modifications and upgrades to address identified safety concerns. However, their early safety records remain a factor to consider when evaluating these aircraft.

The Verdict

Ultimately, declaring a clear winner between the DC-10 and L-1011 TriStar is not a straightforward task. Both aircraft offered distinct advantages and disadvantages. Here’s a breakdown of their strengths:

• DC-10: Superior range (particularly the -30ER variant), good fuel efficiency, reliable General Electric CF6 engines. Higher capacity.
• L-1011 TriStar: More advanced avionics suite. Longer range.

However, the DC-10’s troubled early safety record and the complexities surrounding the Rolls-Royce RB211 engines used in the L-1011 ultimately played a role in their commercial fate.

The DC-10, despite its initial challenges, enjoyed a longer and more successful production run, with over 400 aircraft built. The L-1011 TriStar, plagued by engine development issues and fierce competition from the DC-10, only saw production of around 250 aircraft. Today, both aircraft are largely retired from commercial service, replaced by more fuel-efficient and technologically advanced airplanes.

DC-10 vs. L-1011 TriStar

McDonnell-Douglas DC-10-30		versus	Lockheed L-1011 TriStar 500
55.50 m	182 ft 1 in	length	50.00 m	164 ft
50.40 m	165 ft 4 in	wingspan	50.09 m	164 ft 4 in
367.70 m2	3,958 ft2	wingarea	329.00 m2	3,541 ft2
17.70 m	58 ft 1 in	height	16.87 m	55 ft 4 in
3		engines	3
240 kN	54,000 lbf	thrust per engine	222 kN	50,000 lbf
720 kN	162,000 lbf	total thrust	666 kN	150,000 lbf
263,085 kgs	580,000 lbs	MTOW	231,300 kgs	510,000 lbs
7,415 km	4,004 nm	ferry range	11,260 km	6,080 nm
M0.84		cruise speed	M0.84
250 passengers (3-class config)		capacity	230 passengers (3-class config)

The superior aircraft is always the one that most closely aligns with the customer’s needs. Different airlines have varying requirements for their fleets. Although the DC-10 and L-1011 were similar, both being wide-body, long-range trijets, the decision always hinged on which aircraft more effectively met their specific needs. Nevertheless, both the DC-10 and the L-1011 have made significant contributions to the advancement of more efficient long-range flight, especially in the development of the long-range twin-engine aircraft we see today.