While Boeing 747 is generally associated with large capacity, there is one variant of the 747 that’s an outlier in that regard – the 747SP.
This aircraft, developed to help airlines make long but thin routes profitable didn’t become a bestseller. In fact, only 45 airframes of the type were manufactured. That said, the “SP” has an important place in aviation history and is loved by many aviation enthusiasts.
In this article, I’ll take a look at how the aircraft came to be, how it’s different from the “regular” 747, and which operators had or still have the type among other things.
The Story of Boeing 747SP
The entry into service of the 747-100 in 1970 was a big milestone for Boeing and a historic milestone in commercial aviation as a whole. However, it also left the manufacturer with a large gap in capacity between the 747 and its next largest model – the 707.
To prevent losing the market completely to Lockheed L-1011 and Douglas DC-10, Boeing started looking for a way to enter the market. And, rather than starting from a scratch, creating a smaller version of the 747 – at that time named 747SB, with “SB” standing for “short body” – seemed like a good option.
At the same time, Pan Am was interested in acquiring aircraft that would be capable of flying long haul routes with limited demand non-stop. Iran Air was in a similar situation, being interested in launching non-stop flights between Tehran and New York.
In 1973, the combination of the circumstances above led Boeing to formalize its plan for a shortened 747 and its board to approve the development of the new variant. By this time, the aircraft was renamed to 747SP with “SP” standing for “special performance” and referring to its ability to fly non-stop further than any other aircraft at the time.
The same year, Pan Am placed ten firm orders with options for additional fifteen of the 747SP, becoming its launch customer. The first of those aircraft was delivered in March 1976 and entered into service a month later.
Just a bit more than six years later, in August 1982, the 747SP production line was closed after the 44th airframe of the type was delivered to the Government of Iraq. The production line briefly reopened about five years later when Boeing made one last, 45th, 747SP which it delivered to the Government of the United Arab Emirates.
The Differences Between the 747SP and the 747-100
Being based on the larger 747-100, the original Jumbo Jet and the 747SP are the same in many regards. However, there several notable differences between them as well.
The two main differences are, of course, that the 747SP has a longer range and a shorter body (and thus smaller capacity) than the 747-100. More specifically, rather than being 231 ft 10 in (70.66 m) long and capable of flying 4,620 nm (8,560 km), it is only 184 ft 9 in (56.3 m) long but has a range of 5,830 nm (10,800 km).
To achieve that, Boeing redesigned the aircraft’s wing. While there were other as well, the most notable modification to the wing is the use of single-slotted flaps instead of the triple-slotted ones of the original 747.
There are two other differences between the two 747s that I think are worth noting.
First, the 747SP’s tail is, at 65 ft 5 in (19.9 m), slightly taller than that of the other classic 747s which stands at 63 ft 5 in (19.3 m).
Second, the upper deck on the 747SP ends towards the middle of where the aircraft’s wing is. On the 747-100 (and -200), it ends around the place where the wing starts. The 747SP’s upper design was later used in the stretched upper decks of the 747-300s and 747-400s.
747SP Operators: The Past and the Present
As mentioned earlier, Pan Am was the launch customer for the 747SP. By the time Pan Am sold its Pacific routes to United in the mid-1980s, it had 11 airframes of the type. All of the 747SPs were transferred to United as part of that deal, tying both of the airlines for the title of the largest 747SP operator in history.
Other airlines that used to operate the 747SP included – among others – Iran Air, Korean Air Lines, South African Airways, Qantas, TWA, Air China, and American Airlines. Having kept the 747SP flying on its route between Tehran and Kuala Lumpur until 2016, Iran Air was the last commercial operator of the type.
With just 45 airframes produced, the 747SP was a fairly rare aircraft even during its heyday. Now, with only a dozen or so airframes remaining in service and the type being out of commercial service, it’s even rarer.
Most of the remaining aircraft serve as VIP transports. There is also a couple of engine test beds and even an airborne observatory using the 747SP, though.
The current 747SP operators include, among others:
- Government of Oman
- Government of Saudi Arabia
- Las Vegas Sands
- NASA / DLR (used as an airborne observatory)
- Pratt & Whitney Canada (used as engine testbeds)
Boeing 747SP Specifications
Finally, let’s take a look at some of the basic 747SP specs.
- Cockpit crew: 2 pilots + 1 flight engineer
- Length: 184 ft 9 in (56.31 m)
- Height: 65 ft 10 in (20.07 m)
- Wingspan: 195 ft 8 in (59.64 m)
- Wing area: 5,500 ft2 (511 m2)
- Maximum take-off weight: 670,000 lb (304,000 kg)
I talk more about the specifications of the 747SP as well as of the other 747s in this article.
While, at 45 airframes built, the 747SP was – from some points of view – not a successful airplane, it was still important at the time for the task it was designed for. It allowed airlines like Pan Am and Iran Air to connect very distant cities non-stop, something that we take for granted now but was new at the time.
I am fortunate to have been able to fly on the type twice. Once with Iran Air on a sightseeing flight around Tehran in 2014, and once with NASA on its SOFIA (Stratospheric Observatory for Infrared Astronomy).
Unfortunately, with no airlines using the type now, it cannot be flown on scheduled flights anymore. You can see one in the South African Airways Museum in Rand, though.