A look at the differences between Boeings two twinjets, the 777 and 787

Battle of the twin-jets: Boeing 777 vs. 787 Dreamliner

If you have ever taken a longhaul flight, there’s a 50/50 chance you’re familiar with one of Boeings newest twin-engined longhaul aircraft! These two models form a staggering 52% of the global wide body aircraft fleet.

Boeing’s 777 and 787 Dreamliner have helped modernise the aviation industry. The two twin-engined jets have sped up the retirement of 3 and 4-engined aircraft, who simply cannot compete with their efficiency.

So, what’s the difference between them? 

For the average casual observer, you can be forgiven for mixing both the aircraft up. They are both highly efficient, twin-engined aircraft from the same manufacturer, after all. In fact, they are deemed so similar, both aircraft share a common type-rating. This means pilots have minimal training to learn the differences and switch between flying them.

However, scratching beneath the surface, and we will see that these are essentially entirely different aircraft. There are huge generational differences, with significant implications for both passengers and pilots. This is to be expected. Despite remaining a leading longhaul aircraft type, the B777 is beginning to get pretty old! The 787 entered commercial service in 2011, nearly two decades after the initial 777 flights back in early 1995.

In this article, we will compare and contrast these two aircraft, and hopefully leave you more informed on the key differences between them. It might even influence your decision when booking your next flight!

B777 vs B787 : A Pilot’s Perspective

Modern avionics showing systems display in new Boeing 787 Dreamliner

The Boeing 787 has ultra-modern avionics & systems management

Aircraft handling

From a pilot’s perspective, both the 777 and 787 Dreamliner offer state-of-the-art avionics, fly-by-wire controls, and advanced navigation systems. In fact, the 777 was the first commercial aircraft to feature fully digital fly-by-wire controls, which have been further refined in the 787 Dreamliner.

Both aircraft share a similar screen layout, autopilot modes, and familiar yoke and moving throttle combination. As a result, any commercial airline pilot rated on one aircraft will feel pretty comfortable seated in the cockpit of the other, in a very short amount of time.

This handling similarity is a key selling point for Boeing. The 787 and 777 share a flying manual, known as a Flight Crew Training Manual or FCTM, as the majority of handling techniques will work for both aircraft.

However, the similarity extends far beyond similar manuals and admin costs. The real reason the aircraft are designed to operate so similarly is, so they can share a common type rating. This is the hugely expensive — and time-consuming — course that pilots undergo to switch between operating different aircraft models.

This means that while some type rating courses may take up to 3-months to complete, pilots switching between the B787 and B777 can do so in as little as 7 days! Five days of ground school differences training learning about the differences in aircraft systems, and only 2 days of simulator training to fine tune their handling nuances.

This commonality gives airlines a huge amount of flexibility, and saves significant amounts of pilot training costs.

Onboard technology

Both aircraft share Boeing’s EICAS aircraft management — short for Engine Indicating and Crew Alerting System. Essentially, when something goes wrong, the system alerts the pilots, and after safely securing the flight path of the aeroplane, pilots are presented with an electronic checklist to work through to try to resolve the problem.

It’s a clever system, and replaces the “old days” of printed paper checklists and flight engineers looking after engine systems.

  • The newer 787 Dreamliner has a more modern systems architecture and display layout, which is simpler, more functional, and more efficient than its counterpart in the 777.
  • As an example, the 787 has onboard health-monitoring systems that self-monitor and report systems maintenance requirements to ground-based computer systems in real time. This feature not only streamlines maintenance, but also enhances safety by ensuring that potential issues are detected and addressed proactively.
  • B777 pilots will perform take off or landing calculations on separate tablet computers, or send off digital messages to perform the calculations remotely, or even sometimes complete the maths manually with pen and paper.
  • Pilots on the B787 have all this functionality inbuilt. The aircraft has an integrated performance calculation tool known as an electronic flight bay. This allows the pilots to perform complex takeoff and landing calculations, read airspace restrictions and notices, even to see detailed airport maps to help taxi, all on the main screens in the aircraft.
Modern avionics showing systems display in new Boeing 787 Dreamliner

Where pilots notice the main difference between the B787, and it’s older counterpart, the B777, is how the electronic systems integrate with the flight. Here, the generational gap between the two aircraft really begins to show:

The electric jet

The 787 is often dubbed by pilots as “the electric jet” or the “plastic plane” — owing to its high reliance on electronics and largely composite construction.

This short quip hides arguably one of the largest differences between the 787 and the 777 — the fundamentally different electrical systems

Aircraft have a giant variety of systems that need powering, and the Boeing 777 is no different. It powers these systems electronically, hydraulically, and some via a process known as bleed air.

What’s bleed air? Well, it’s high pressure and temperature air, taken directly from an intermediate stage of the engines. This source of air is then used by the B777 for a huge number of different applications:

  • Cooled and conditioned bleed air helps pressurise the cabin and maintain a comfortable temperature.
  • Ducted towards the leading edge of the wings, and around the engine inlets, bleed air in the 777 helps melt ice and keep the aircraft safe whilst operating in icing conditions.
  • Bleed air from the APU (or another engine) is also used to start the engines themselves

In contrast, the 787 forgoes bleed air entirely, using a hugely powerful electronic system instead. Everything above, from starting the engines to pressurising the cabin — even anti-icing the wings — is done via a combination of electric heaters and pumps.

This saves weight, among other advantages, but it’s a hugely important difference for the pilots, and the electronics system differences play a big role in the training differences between the aircraft. On the ground the B787 needs more ground power units to be attached, and in the air the 787 provides over 5 times more electrical power than the B777.

Ergonomic cockpit and head up display

At first glance, the cockpits look similar, but on closer inspection, the 787 Dreamliner’s cockpit has been designed to be more ergonomic and comfortable for pilots. In contrast to the 777, Boeing has incorporated larger displays, better lighting, and an enhanced field of view via a significantly larger wrap-around cockpit window.

This supposedly helps to reduce pilot fatigue and improve situational awareness for pilots on long-haul flights.

787 Dreamliner head up display (HUD) during the cruise

One of the most noticeable differences between the two aircraft in the cockpit is the addition of a head up display (HUD). Once solely fitted in fighter jets and other military aircraft, Boeing has offered HUDs as an optional extra for many years, but most airlines haven’t taken any interest in paying additional fees for them.

You can elect to have a HUD fitted on the B777, but I don’t know any commercial operators that have chosen this option. Contrastingly, the B787 is the first aircraft where having a HUD is mandatory, and it forms an integral part of operating the aircraft. It provides pilots with the ability to fly extraordinarily accurately, and has some additional features to help pilots handle some uniquely difficult characteristics of the B787 — such as flying an engine failure after takeoff.

While it does take some getting used to, it is one thing that pilots who have flown the B787 say they really miss when switching back to flying the B777.

B777 vs B787: The Passenger Experience

Passengers disembarking from Uzbekistan airways boeing 787-8 Dreamliner

It’s nice to know your pilots are having a more comfortable flight, but I’m sure it’s not a dealbreaker when booking your next ticket! However, there are some significant differences in the passenger experience that might sway your next booking!

The 787 Dreamliner has been specifically designed to enhance the passenger experience, with a focus on factors such as cabin altitude, humidity, air quality, lighting, sound, and space.

Air Quality: 6,000 vs 8,000 ft

The 787 Dreamliner has a maximum cabin altitude of 6,000 feet (1.83 km), compared to the typical cabin altitude of around 8,000 feet (2.44 km) in most airplanes, including the 777.

It goes without saying that the conditions in the atmosphere at a typical airline cruise altitude of around 40,000 ft (ca. 12 km) are pretty inhospitable! Aside from being a rather chilly -60 degrees Celsius, the average human will find it difficult to keep conscious much above 12,000ft.

To combat this, passengers in both aircraft are kept safe by pressurising the inside air. But there are significant differences between the 777 and 787 in how they achieve this:

  • Both the 777 and 787 Dreamliner are equipped with advanced air filtration systems to ensure optimal air quality and humidity levels for passengers.
  • Like virtually all other aircraft, the 777 achieves this by tapping bleed air from the engines.
  • However, the 787 Dreamliner goes a step further by removing this bleed air, using fresh air from outside ducts, before electrically pressurising and heating this air.

The other major difference, is that due to the B787s construction, the cabin altitude at cruising altitude on the B787 is nearly 2,000 ft lower than the B777, only reaching altitudes of 6,000ft.

The lower cabin altitude in the 787 is possible due to its advanced composite materials, which do not fatigue in the same way as metal-based fuselages, and can handle increased pressurisation. This results in a more comfortable experience for passengers, reducing the likelihood of altitude-related discomfort.

Alongside the lower altitude, at 6,000ft air can retain more moisture, so the cabin air inside a 787 is more humid. Spending 10 hours in an aircraft with a lower altitude and higher humidity is noticeable, and helps to reduce jet lag!

Windows: Size matters!

777-300ER windows with conventional window blinds unlike the 787s electrochromatic blinds

Another notable difference in the passenger experience between the 777 and 787 Dreamliner lies in both the size of their windows, and how they operate.

The 787 Dreamliner features the largest windows of any current commercial aeroplane, providing passengers with unparalleled views. These larger windows are made possible by the aircraft’s composite materials, which allow the fuselage to handle the loads from larger window cutouts. In contrast, the 777, with its aluminium fuselage, has smaller windows, which are more typical of commercial aircraft.

Frequent fliers might also notice the windows on the 787 are subtly higher than their counterparts on the 777. They are also designed to be more aligned with the average passenger’s eye line, so there’s less straining to look out of them.

While slightly better views are certainly an improvement, the most noticeable difference between the two aircraft windows from a passenger perspective are the blinds. Or, the lack of them! The 787 has removed window blinds altogether, instead opting to use special electrochromatic glass, that dims when an electric current is passed through it.

For airlines, the lack of blinds saves weight. But it also gives the possibility for fine-tuning the light that is allowed through the window, in a way that basic window blinds can’t achieve. Pre-set waking-up and going-to-sleep modes gradually reduce or increase the outside light over a set timespan, to mimic dawn and dusk. These features are also claimed to reduce passenger jet lag.

Turbulence tricks

As we’ve mentioned, the 777 was the first large commercial airliner to have full fly-by-wire. Essentially, instead of any cables and pulleys between the pilots and the flight controls, inputs are routed via a series of computers.

This offers two added benefits. Firstly, fly-by-wire enabled safety features such as a roll and bank limits and speed protections — helping to prevent pilots accidentally manoeuvring too sharply and putting the aircraft under additional stresses.

The second benefit is of far more interest to passengers! It enabled clever computer additions to the flight controls to help smooth out turbulence. When the 777 hits turbulence, without pilot input, the fly-by-wire computers can make minute adjustments to the flight controls to help counter the bumps, enabling it to ride turbulence well.

But the fancier computers in the 787 have a few even cleverer tricks up their sleeve that arguable mean it provides a smoother ride in turbulence. 

Turbulence smoothing features are a closely guarded secret. But, in a step up from the B777, the 787 has an innovative turbulence-detection system that uses sensors to counter the effects of turbulence by slightly adjusting the control surfaces, before the aircraft actually hits the turbulence.

This clever tech results in a smoother ride and reduced motion sickness, always a passenger favourite!

Shhhhh — peace and quiet

Qatar Boeing 787 engine with noise reducing chevrons

VS

Emirates boing 777 freighter

Keen observers might have noticed zigzags on the back of the engines. Known as chevrons, these distinctive shapes highlight the 787 Dreamliner greater emphasis on sound quality.

This specific technology helps with the mixing of hot jet engine air, and the cooler stream of air by passing it, and by blending them together more smoothly, reduces engine noise significantly.

The new Boeing 787 is among the most modern jets, relying on chevrons to reduce engine noise levels. It sports chevrons on the nacelles, or fan housings.

NASA Helps Create a More Silent Night

It’s one of many technologies in use to help keep the noise down and provide a quieter experience for passengers, ground crews, and communities near airports.

That’s not to say that the 777 is a particularly loud aircraft, either. Yet, the combination of a significantly heavier aircraft requiring more thrust, a large aluminium — versus composite — body, alongside older air conditioning and onboard technology, means that the 787 is undoubtably quieter onboard.

In fact, the B787 is so quiet, that our senior flight attendant Alissa reports that during the introduction of the Dreamliner they had to make a special note of this in cabin crew briefings. It’s reported that for flight attendants flying the B787 for the first time after flying the B777 were told to make sure they don’t comment about any rude passengers and to keep the gossip to a minimum!

Because the cabin was so much quieter, airlines had had complaints that customers could hear the galley conversations several rows away!

Conclusion: The technology gap is beginning to show

Both the Boeing 777 and 787 Dreamliner are exceptional aircraft that have made significant contributions to the aviation industry. From a pilot’s perspective, both aircraft are hugely capable, with advanced avionics, and fly-by-wire controls.

However, there are some fundamental differences between the two, owing to the near two-decade difference in their design ages. These differences not only affect the pilots operating them, but have a significant impact on customers, so much so, that some might even adapt their time or journey routing to fly on one versus the other.

Between both aircraft, there is familiarity to the cockpit layout, and both aircraft share a common type rating. However, pilots operating the 787 Dreamliner, will notice a considerable reliance on electricity versus traditional systems such as bleed air. They also benefit from a modern systems architecture and a more ergonomic cockpit design, including a head up display fitted as standard.

For passengers, while the 777 offers a comfortable and spacious cabin environment, the 787 Dreamliner has taken the passenger experience to the next level with its focus on a lower cabin altitude allowing higher air humidity and quality. In addition, larger windows, smoother ride quality, and lower sound levels help to ensure a more relaxing flight.

While the 777 remains a popular and reliable aircraft for long-haul flights, the 787 Dreamliner has pushed the boundaries of passenger comfort and efficiency, setting a new standard in commercial aviation.

Despite this, the Boeing 777 remains the most produced longhaul aircraft ever, and its larger passenger size makes it the current most efficient aircraft to operate for airlines. Due to its extensive route network and ease of flying, the 777 is arguably still a pilots favourite.

But, age is beginning to show, and modern technology sets the Dreamliner apart. The 787 offers better fuel efficiency than the 777, using at least 20% less fuel due to its advanced composite materials, lighter weight, and more efficient engines from General Electric and Rolls-Royce. The 777, however, still maintains an edge in terms of passenger capacity and range.

To help the aging B777, and to keep both aircraft at the forefront of technology, Boeing is currently developing the 777X. This is a redesigned version of the B777 which will incorporate many of the newer technologies and cabin improvements that were implemented on the 787, albeit in the considerably larger 777 aircraft size.

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Josh

Flyingbynumber’s Resident Airline Captain — Josh

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