747SP numbers vs operators
Hey rog,
The QF SPs had C2 engines. The D4s were over the thrust limit certified. It actually gave QF a place to hang D4s which were getting a bit tired and could no longer make the D4 spec.
Originally the WLG operation forbade any derate or assumed temp operation so all T/O was full thrust. Imagine keeping the beast under control when your initial altitude limit was 3,000ft and you had a light SP??? Exciting!!! Flap limit speeds were a challenge.
One very frisky aircraft even at high TOW. The fuel feed configs at max TOW were simply a nightmare for the FEO.
The QF SPs had C2 engines. The D4s were over the thrust limit certified. It actually gave QF a place to hang D4s which were getting a bit tired and could no longer make the D4 spec.
Originally the WLG operation forbade any derate or assumed temp operation so all T/O was full thrust. Imagine keeping the beast under control when your initial altitude limit was 3,000ft and you had a light SP??? Exciting!!! Flap limit speeds were a challenge.
One very frisky aircraft even at high TOW. The fuel feed configs at max TOW were simply a nightmare for the FEO.
Thank you so much for sharing.
I was trying my best to ensure the RB211 Info I gave was correct as I could, as I kept reading variations on the engine types fitted from new build and then my source said that in 1982 the pair of SP's had the B or D variant engines fitted.
I flew on SAA SP's a few times - once was just the JNB-CPT hop and I was lucky to be sat upstairs in Biz Class. A lovely flight.
Thanks again.
and to AnotherFSO - what awesome video clips !!!
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I was scheduled to take my one and only flight on an QF SP back in early 1980 as SYD-LAX-SFO. However it was substituded with a brand new -400 at the last minute so I missed out on the chance. However as the 400 had only an SP load on board it was VERY comfortable - lots of room to stretch out!
Was the 747SP the first aircraft to fly the Pacific (LAX-SYD) non-stop? Did Pan Am do it first with that aircraft? The Pan Am - Qantas Pacific advertisement 'war' was certainty interesting back then!
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I did notice over the years various press articles about the 747SP which turned out to be (maybe) inaccurate - possibly either hopeful PR people or journalist misunderstandings.
The original Pan Am purchase was described as for their round-the-world flight, where it was stated that the Transatlantic sector needed an aircraft bigger than a 707, while the operation onward across Asia needed something smaller than a 747. In the event I don't think the SP was ever assigned to the round-the-world.
The different aerodynamic relationship between the back of the upper deck (original 747 length) and the wing leading edge was "discovered" to give an unexpected benefit, and led to the 747-300 and -400 having the upper deck extended to get the same benefit. I always thought Boeing were pretty good with aerodynamics, and can't quite relate to them suddenly discovering this after the event,
The Qantas SP was indeed originally said to be for serving Wellington. Qantas (international only then) was moving to an all-747 fleet, their last 707 ran Wellington, after which they chartered an Air New Zealand DC8 to cover their rigorously controlled 50% of flights on the route. There had likely been criticism they didn't use their own metal.
American bought the ex-TWA SPs for their Dallas to Tokyo route, but ended up using them on the very short Boston to London route they acquired from TWA. American were really short of intercontinental aircraft when they first bought the TWA London Heathrow network, and seemed to use one of everything for a while.
The SAA SP fleet were really just an insurance against losing their landing rights at Sal on European flights when the Portuguese colony got independence. In the end this didn't happen before the -400 came along, which could do without it anyway, and SAA, like other operators, ended up at a bit of a loss for what to do with them..
The original Pan Am purchase was described as for their round-the-world flight, where it was stated that the Transatlantic sector needed an aircraft bigger than a 707, while the operation onward across Asia needed something smaller than a 747. In the event I don't think the SP was ever assigned to the round-the-world.
The different aerodynamic relationship between the back of the upper deck (original 747 length) and the wing leading edge was "discovered" to give an unexpected benefit, and led to the 747-300 and -400 having the upper deck extended to get the same benefit. I always thought Boeing were pretty good with aerodynamics, and can't quite relate to them suddenly discovering this after the event,
The Qantas SP was indeed originally said to be for serving Wellington. Qantas (international only then) was moving to an all-747 fleet, their last 707 ran Wellington, after which they chartered an Air New Zealand DC8 to cover their rigorously controlled 50% of flights on the route. There had likely been criticism they didn't use their own metal.
American bought the ex-TWA SPs for their Dallas to Tokyo route, but ended up using them on the very short Boston to London route they acquired from TWA. American were really short of intercontinental aircraft when they first bought the TWA London Heathrow network, and seemed to use one of everything for a while.
The SAA SP fleet were really just an insurance against losing their landing rights at Sal on European flights when the Portuguese colony got independence. In the end this didn't happen before the -400 came along, which could do without it anyway, and SAA, like other operators, ended up at a bit of a loss for what to do with them..
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Didn't Clay Lacy set a round the world record in an ex Pan Am SP with United? And another one in a GIII?
The different aerodynamic relationship between the back of the upper deck (original 747 length) and the wing leading edge was "discovered" to give an unexpected benefit, and led to the 747-300 and -400 having the upper deck extended to get the same benefit. I always thought Boeing were pretty good with aerodynamics, and can't quite relate to them suddenly discovering this after the event,
When they shortened the fuselage for the SP, they pleasantly discovered that the upper deck 'fairing' provided favorable 'area ruling' as the upper deck now merged into the wing - which provided better transonic drag characteristics. When the 747 was originally designed (mid 1960s), the area rule concept was still quite new and novel, and so wasn't considered in the original design. I think the B-1 design was the first aircraft (early 1970s) that really took advantage of area ruling.
The 747SP gives a good example of how the large commercial aircraft business has changed. Back then, production runs of a particular aircraft design were quite a bit smaller than what's typical today - so when Boeing sold an aircraft, the price was set such that about 50% went to actually building it, and the other ~50% covered the development costs and cert, and hopefully left a bit over for profit. As a result, although the 747SP wasn't exactly a cash cow, it reportedly at least paid for itself, and aircraft like the 727 (~1,800 produced) were real cash cows.
Today, the development and cert costs have soared (despite all that went wrong with the 737 MAX cert, it's far more difficult and costly to certify a new design that in was even 30 years ago), and the pricing pressures mean that the built price is a much higher percentage of the overall sales price. As a result, in order to pay back all the development and cert costs - and have some profit left over, you need to sell a lot of that aircraft design.
As an example, Boeing didn't make any money on the 777-200LR (61 delivered). However, the -200LR paved the way for the 777F, which shares much of the design, and the 777F has been a commercial success (over 260 delivered and more than 50 unfilled orders).
Last edited by tdracer; 13th Apr 2024 at 02:32. Reason: fixed typo
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I flew Melbourne - Depasar - Singapore on a QANTAS SP, in about early 90's. It was by then a bit tired looking.
Was surprised they used an SP for that route. Not sure if it was a one off or regular.
Was surprised they used an SP for that route. Not sure if it was a one off or regular.
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I think the B-1 design was the first aircraft (early 1970s) that really took advantage of area ruling.
It is said in some quarters that the flap canoe fairings are an area rule application.
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From 1959, trans-Tasman flights were operated by Electras of Air NZ (then TEAL) and Qantas. When Qantas disposed of their Electras in 1967, the Wellington service was operated by Air NZ with Electras in Air NZ livery with added Qantas titles. When Air NZ retired their Electras in 1972, only their DC-8s could operate into WLG whereas Qantas 707s could not. With the imminent retirement of the DC-8s in 1981, neither airline would have an aeroplane able to operate into WLG. Qantas purchased two SPs for this specific purpose. The WLG problem was eventually solved in 1985 by the introduction of the B767-200 by Air NZ and Qantas. The Qantas SPs were then utilised exclusively on the longhaul routes for which they were designed. The greatest irony is that towards the end of their service, the Qantas SPs were routinely used on what was effectively a one-hour domestic shuttle between Sydney and Brisbane.
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"The large anti-shock bodies on the upper trailing edge of the wings, to increase the critical Mach by reducing transonic drag. The inboard shock bodies, which were larger, were also used for additional fuel tankage"
Don't think it was anything to do with the area-rule although they are associated with it
they were invented by Whitcomb & Kuchemann https://en.wikipedia.org/wiki/Anti-shock_body
"he extension beyond the trailing edge was considered secondary to the body on the wing surface, which slowed the supersonic flow to give a weaker shock and acted as a fence to prevent outward flow. The extension was only long enough to prevent flow separation.[5]: 52 Whitcomb stated that the anti-shock body was no longer required on the top surface of a wing when the supercritical airfoil was introduced[8] because they both decreased the strength of, or eliminated, the shock and its attendant drag."
Generally thought to only give a modest effect overall
Don't think it was anything to do with the area-rule although they are associated with it
they were invented by Whitcomb & Kuchemann https://en.wikipedia.org/wiki/Anti-shock_body
"he extension beyond the trailing edge was considered secondary to the body on the wing surface, which slowed the supersonic flow to give a weaker shock and acted as a fence to prevent outward flow. The extension was only long enough to prevent flow separation.[5]: 52 Whitcomb stated that the anti-shock body was no longer required on the top surface of a wing when the supercritical airfoil was introduced[8] because they both decreased the strength of, or eliminated, the shock and its attendant drag."
Generally thought to only give a modest effect overall
Hey Megan,
As I understand it the B747 canoe fairings were simply sized to cover the very complex mechanism for the flaps. They cost a lot in skin friction drag as I am reliably informed. TDRacer likely knows. There was a lot of stuff crammed into those fairings. The SP did not have nor need canoe fairings. The flaps were extremely simple to reduce weight and drag. The concept was that if a full sized B747 could operate out of a field an SP could too with simple flaps coz it was so much lighter and over thrusted.
The SP flaps were really easy to cock up when setting the T/O flaps. Unfortunately the F20, usual T/O setting, on the SP, was not in the same position on the flap gauge for the other B747s. In fact F10 on the SP was about the same position on the dial for F20 on the others. HF anyone?? Yes, many crews owned up to departing with F10 on the SP.
As I understand it the B747 canoe fairings were simply sized to cover the very complex mechanism for the flaps. They cost a lot in skin friction drag as I am reliably informed. TDRacer likely knows. There was a lot of stuff crammed into those fairings. The SP did not have nor need canoe fairings. The flaps were extremely simple to reduce weight and drag. The concept was that if a full sized B747 could operate out of a field an SP could too with simple flaps coz it was so much lighter and over thrusted.
The SP flaps were really easy to cock up when setting the T/O flaps. Unfortunately the F20, usual T/O setting, on the SP, was not in the same position on the flap gauge for the other B747s. In fact F10 on the SP was about the same position on the dial for F20 on the others. HF anyone?? Yes, many crews owned up to departing with F10 on the SP.
A UK business colleague had previously spent some years sent over to run the New Zealand office. He had all the stories about turbulent approaches into Wellington. He said more than once participants in national business meetings arrived from elsewhere with injuries and bleeding from being rolled around against the cabin wall on approach. He said it was accepted as a fact of New Zealand life. If I'm not mistaken they have never had an accident there.
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A UK business colleague had previously spent some years sent over to run the New Zealand office. He had all the stories about turbulent approaches into Wellington. He said more than once participants in national business meetings arrived from elsewhere with injuries and bleeding from being rolled around against the cabin wall on approach. He said it was accepted as a fact of New Zealand life. If I'm not mistaken they have never had an accident there.
Captain Speaking: Well, it looks pretty sporty down there, but we'll give it a try--you never know. Hold on tight.
As I understand it the B747 canoe fairings were simply sized to cover the very complex mechanism for the flaps
Aera ruling aims to make the sectional volume of the aircraft to smoothly increase from the nose and smoothly decrease at the tail. Some exmples.
F-102
F-106 - the F-102 redesigned with area ruling producing a 25% increase in speed
Concorde - having the "bump" reduced to fall inside the ideal line would have meant reducing the cabin diameter over those points, you can't satisfy all design criteria.
At the time of the 747 design area rule was well known and we have no idea of what was in the aerodynamic department minds. Positioning the under wing engine pods forward of the leading edge is another nod in the direction of area rule, But that positioning of engine pods was a feature on the B-47 and B-52 prior to Whitcomb coming out with his theory. The question is why Boeing adopted that particular feature, besides engineering issues such as wing bending relief etc. Did the post war Operation "Paperclip" give them some insight to what became Area Rule from the German research, or was the podded engine placement Area Rule effect just a serendipitous outcome resulting from other engineering concerns.
Whitcomb published his area rule paper in 1953 and it was classified "Restricted", in 1958 it was made public. His paper here,https://ntrs.nasa.gov/api/citations/...0050019402.pdf
Area Ruling is a means by which wave drag is reduced. Wave drag is a component of the aerodynamic drag on the aircraft wings and fuselage moving at transonic and supersonic speeds, due to the presence of shock waves. Wave drag is independent of viscous effects and tends to present itself as a sudden and dramatic increase in drag as the vehicle increases speed to the critical Mach number.
Aera ruling aims to make the sectional volume of the aircraft to smoothly increase from the nose and smoothly decrease at the tail. Some exmples.
F-102
F-106 - the F-102 redesigned with area ruling producing a 25% increase in speed
Concorde - having the "bump" reduced to fall inside the ideal line would have meant reducing the cabin diameter over those points, you can't satisfy all design criteria.
At the time of the 747 design area rule was well known and we have no idea of what was in the aerodynamic department minds. Positioning the under wing engine pods forward of the leading edge is another nod in the direction of area rule, But that positioning of engine pods was a feature on the B-47 and B-52 prior to Whitcomb coming out with his theory. The question is why Boeing adopted that particular feature, besides engineering issues such as wing bending relief etc. Did the post war Operation "Paperclip" give them some insight to what became Area Rule from the German research, or was the podded engine placement Area Rule effect just a serendipitous outcome resulting from other engineering concerns.
Whitcomb published his area rule paper in 1953 and it was classified "Restricted", in 1958 it was made public. His paper here,https://ntrs.nasa.gov/api/citations/...0050019402.pdf
Aera ruling aims to make the sectional volume of the aircraft to smoothly increase from the nose and smoothly decrease at the tail. Some exmples.
F-102
F-106 - the F-102 redesigned with area ruling producing a 25% increase in speed
Concorde - having the "bump" reduced to fall inside the ideal line would have meant reducing the cabin diameter over those points, you can't satisfy all design criteria.
At the time of the 747 design area rule was well known and we have no idea of what was in the aerodynamic department minds. Positioning the under wing engine pods forward of the leading edge is another nod in the direction of area rule, But that positioning of engine pods was a feature on the B-47 and B-52 prior to Whitcomb coming out with his theory. The question is why Boeing adopted that particular feature, besides engineering issues such as wing bending relief etc. Did the post war Operation "Paperclip" give them some insight to what became Area Rule from the German research, or was the podded engine placement Area Rule effect just a serendipitous outcome resulting from other engineering concerns.
Whitcomb published his area rule paper in 1953 and it was classified "Restricted", in 1958 it was made public. His paper here,https://ntrs.nasa.gov/api/citations/...0050019402.pdf
Positioning the under wing engine pods forward of the leading edge is another nod in the direction of area rule, But that positioning of engine pods was a feature on the B-47 and B-52 prior to Whitcomb coming out with his theory. The question is why Boeing adopted that particular feature, besides engineering issues such as wing bending relief etc. Did the post war Operation "Paperclip" give them some insight to what became Area Rule from the German research, or was the podded engine placement Area Rule effect just a serendipitous outcome resulting from other engineering concerns.
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The DC8 pod positioning looked similar to the 707 (apologies to the knowledgeable here but "looked similar" is as tech as I get), but the DC8-62 re-engineered both wing and pod positioning quite substantially, coming about 8 years later. So it appeared that the pods were generally seen as the way to go, but the detail needed a fair bit of refinement.
The initial reason for putting the engines in pods out in front of the wing was - interestingly enough - structural. Turns out that the engines can be used as 'tuned mass dampers' to reduced/eliminate flutter concerns. This had the additional benefit of giving physical isolation between the engines, so that something like an uncontained failure was unlikely to damage another, adjacent engine.
Boeing then discovered - using the Boeing Transonic Wind Tunnel (BTWT) referenced earlier - that it was important to put the engine well below wing - otherwise you would get 'interference' drag where the jet exhaust combined with the airflow around the wing to create areas of trans-sonic and supersonic flow (i.e. high drag). I don't ever recall hearing any reference to the engine pod placement with respect to 'area ruling'.
Way back when we were doing initial development of the 767, they did some BTWT testing that showed serious interference drag at cruise (as in ~2% of total aircraft drag). The setup for this testing was interesting - they did a 'blown nacelle', where high pressure air was piped up through the wing and strut and exhausted out carefully crafted core and fan nozzles (I was involved in some of the blown nacelle testing). Flow vis showed there was a 'pinch point' on the inside of the strut where the combination of fuselage, nacelle, and strut resulted in something of a nozzle effect with big shocks forming. They discovered that by reshaping the strut they could open that space up enough to make the resultant interference drag unmeasurable.
Megan - your points about area ruling are good, but remember the aircraft you referenced were designed to fly much faster than (subsonic) commercial aircraft. What wasn't well understood in the 1960s is how applicable area ruling could be in the low transonic region.
Boeing then discovered - using the Boeing Transonic Wind Tunnel (BTWT) referenced earlier - that it was important to put the engine well below wing - otherwise you would get 'interference' drag where the jet exhaust combined with the airflow around the wing to create areas of trans-sonic and supersonic flow (i.e. high drag). I don't ever recall hearing any reference to the engine pod placement with respect to 'area ruling'.
Way back when we were doing initial development of the 767, they did some BTWT testing that showed serious interference drag at cruise (as in ~2% of total aircraft drag). The setup for this testing was interesting - they did a 'blown nacelle', where high pressure air was piped up through the wing and strut and exhausted out carefully crafted core and fan nozzles (I was involved in some of the blown nacelle testing). Flow vis showed there was a 'pinch point' on the inside of the strut where the combination of fuselage, nacelle, and strut resulted in something of a nozzle effect with big shocks forming. They discovered that by reshaping the strut they could open that space up enough to make the resultant interference drag unmeasurable.
Megan - your points about area ruling are good, but remember the aircraft you referenced were designed to fly much faster than (subsonic) commercial aircraft. What wasn't well understood in the 1960s is how applicable area ruling could be in the low transonic region.
Originally Posted by Groundloop
I was scheduled to take my one and only flight on an QF SP back in early 1980 as SYD-LAX-SFO. However it was substituded with a brand new -400 at the last minute so I missed out on the chance. However as the 400 had only an SP load on board it was VERY comfortable - lots of room to stretch out!
Did you mean perhaps 1990?
I was scheduled to take my one and only flight on an QF SP back in early 1980 as SYD-LAX-SFO. However it was substituded with a brand new -400 at the last minute so I missed out on the chance. However as the 400 had only an SP load on board it was VERY comfortable - lots of room to stretch out!
Did you mean perhaps 1990?
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