The Boeing 747 is a very unique aircraft. At that time 747 was considered ageless meaning it could be used forever. But what made it this unique? So today we will look into it. But before we start, you need to read my previous blog on it.
So as Boeing started work on the 747 hey took the CX-HLS design. They took the HUMP design and converted it into an upper deck. Hey also changed some designs of the CX-HLS. At the time of development of the 747 the concept of SST (Super Sonic Transport) was widely spread as the development of CONCORDE started. Another reason why Boeing took the CX-HLS design is that they wanted a plane which could be used as a cargo lifter too. CX-HLS design was perfect in all sense. Boeing decided to to built an aircraft which could easily carry standard shipping containers. Containers are 8 ft (2.4 m) square at the front (slightly higher due to attachment points) and available in 20 and 40 ft (6.1 and 12 m) lengths. This meant that it would be possible to support a 2-wide 2-high stack of containers two or three ranks deep with a fuselage size similar to the earlier CX-HLS project and thus, took and redesigned the CX-HLS design.
CX-HLS was a high wing design which is most common for HEAVY LIFT CARGO but rare on PASSENGER aircraft. And MIDDLE wing is used for speed. And HIGH wing isn’t great for passenger comfort. So they decided to make a LOW wing design. If there is a great roll on the left or right and thus, will try to level itself.
Although we cannot say that the Boeing 747 is the CX-HLS completely as it had the high wing and the 747 had a low. We can say that it was inspired by the CX-HLS.
There’s a interesting thing that the original design included a full-length double-deck fuselage with eight-across seating and two aisles on the lower deck and seven-across seating and two aisles on the upper deck. However, concern over evacuation routes and limited cargo-carrying capability caused this idea to be scrapped in early 1966 in favor of a wider single deck design.The cockpit was, therefore, placed on a shortened upper deck so that a freight-loading door could be included in the nose cone; this design feature produced the 747’s distinctive “hump”. ( As mentioned in my previous blog)
Now we got a design but what about power? Boeing called Pratt & Whitey to built a high-bypass turbofan engine which at that time was a concept. After years of ‘trial and error’ Pratt & Whitey developed the JT9D engines to power the 747.
At that time planes didn’t have the hydraulic. 747 was a huge aircraft and thus, it can’t be oprated by cables. This was the initial concept of FLY-BY-WIRE ( 747 wasn’t a fly-by-wire it gave the idea of it ).
At the time of its production Boeing didn’t have a large plant, to built a new production line it had to built a new factory in Paine Feild, Everett. A interesting fact about it is that while the factory was under construction, at that time also Boeing was building it. People say that it was snowing during it and the roof wasn’t built untill that.
FACT: early 747s used URANIUM as their counter weights.