With launch dates 20 years apart, the Boeing 747-8 is the update to the iconic 747-400. With the immense popularity of the -400, Boeing had hoped for the same levels of success for the newer -8. The newer model hasn’t seen that success, despite being better in every way. Let’s look at the two models of 747 and the difference that 20 years of innovation can produce.
At first glance, you might notice the more obvious differences between the 747-8 and the 747-400. The engines of the newer -8 have engine cowlings with serrated edges, and where there was once a small winglet on the -400, no winglet exists on the -8. However, we can dive much more in-depth and look at some of the specification differences.
While the overall shape of the two 747s may look similar to one another, the dimensions have changed. The -8 actually has a larger wingspan, longer fuselage, as well as an extended upper-deck.
- Wingspan: The 747-8 has an additional 3.5 meters of wingspan
- Length: The 747-8 is 5.6 meters longer
- Height: The 747-8 is just 10 centimeters taller
For passenger versions, the 747-8 offers 51 additional seats over the 747-400. For the freighter variant, the increase in length equates to more cargo volume. In fact, with the 5.6 meters of extra fuselage length, the 747-8 offers 16% more revenue cargo volume. This equates to four additional main-deck pallets and three additional lower-hold pallets.
Quieter engines, better efficiency
While the 747-400 has three engine options from General Electric, Pratt & Whitney, or Rolls-Royce, the 747-8 exclusively uses the General Electric GEnx, which is the same engine used on the 787 Dreamliner.
This much newer engine has a much higher bypass-ratio. It also features composite fan blades and a composite fan case. It is also equipped with “a low-emissions combustor and a virtually maintenance-free fan module.”
So what is the result of a much newer engine? According to Boeing, the 747-8 reduces carbon emissions by 16% and is 16% more fuel-efficient. The more modern engine also gives it a 30% smaller noise footprint.
An advanced cockpit
Along with the newer engines, some of the most significant upgrades could be found in the -8’s cockpit. Here is a list of improvements that have come with the newer model:
- Vertical situation display (VSD): Giving pilots a clear view of the airplane’s current and projected flight path.
- Although the 747-400 had a flight management computer (FMC) as well, the -8 has an upgraded FMC
- Electronic checklist
- Airport moving map (AMM): An electronic map of airport taxiways, runways, and gates
- Liquid-crystal-display screen technology replaces cathode-ray-tube screens throughout the flight deck.
With advances in materials technology, engineering, and manufacturing, the -8 requires less maintenance than its predecessor. The maintenance intervals are longer, which means less time on the ground compared to the -400.
| Line Maintenance
1,000 flight hours
| A Check
600 flight hours
| Hangar Maintenance
10,000 flight hours, 24 months
| C Check
7,500 flight hours, 18 months
| Heavy Maintenance
8, 8, 6 years
| D Check
8, 8, 6 years
The most significant difference: Aircraft orders
Outside of the technical characteristics and specifications of the two jumbo jets, the number of orders of the two models varies greatly. For the 747-400 and its variants (including combi, extended-range, freighter, etc.), a total of 694 were ordered.
This overshadows the mere 137 deliveries of the 747-8 (both the intercontinental/passenger version and the freighter combined). While there are 16 more undelivered 747-8s, it’s unlikely the new jumbo jet will ever come close to the -400.
Furthermore, the ratio of freighter orders to passenger-variant orders is much higher with the newer -8. Some of its more notable customers have been cargo operators such as UPS.
In comparison, the 747-400 became the choice for many passenger airlines and their long-haul operations, including British Airways, KLM, Qantas, Japan Airlines, and many more.
While a lot has changed with the newer -8, it’s worth mentioning all the similarities between the two models. These include identical:
- Type rating
- Nose-door loading capability (industry-standard 3-meter pallets)
- Cargo-density capability of 10.3 pounds per cubic foot (165 kilograms per cubic meter)
- Ground-support equipment (including pneumatic start carts, ground power units, and potable water and lavatory service carts)
- Cargo-handling equipment
- Flight handling characteristics
- Door heights
Boeing notes that tow tractors used for the 747-400 can be used to move the 747-8 as well. However, the new airplane’s higher takeoff weight requires a larger towbar. Furthermore, its larger nose-landing-gear tire precludes the use of certain towbarless tow vehicles.
Having many of these commonalities was critical for Boeing in order to market the aircraft to passenger and cargo airlines that already had the 747-400 in their fleets. This can be clearly seen with commercial airlines like Lufthansa and Korean Air.
Interestingly, both variants have been selected by governments for VVIP transport. The Government of South Korea had used the 747-400 as its “Code One” presidential jet and will use the -8 for the same purpose next year. Additionally, the United States Government is currently working on retrofitting two -8s to be the new Air Force One.
Sadly, the most significant similarity is that both jets have fallen out of favor with passenger airlines as they seek the higher fuel efficiency and lower maintenance costs found with twin-jets.
With recent events, airlines like KLM have said their final goodbyes to the 747-400 for passenger operations, and British Airways is in the process of phasing out its fleet as well – replaced by the Airbus A350-1000.