Economy of older and current turboprops versus old and current jetliners
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Scotbill/Proplinerman...Well they seriously looked at the next move from turboprops (Unducted Fans UDFs) after the 1970s Fuel price inflation but UDFs had development problems and the very efficient CFM-56 arrived. (There was an Air&Space article on the Boeing 737-300 in which a Boeing engineer said they only expected to sell a few hundred before UDFs became the norm 
)
Doesn't a high by-pass jet engine have a parts count advantage over a turbo-prop engine+propeller and less Mach number limitations too.
Another economic disadvantage of the Vanguard was having four engines rather than two (there wasn't a turboprop engine large enough to make it a twin)
It might be interesting to compare the costs of a 737-600 or A318 with the largest HS/BAE/'Avro' 146
)Doesn't a high by-pass jet engine have a parts count advantage over a turbo-prop engine+propeller and less Mach number limitations too.
Another economic disadvantage of the Vanguard was having four engines rather than two (there wasn't a turboprop engine large enough to make it a twin)
It might be interesting to compare the costs of a 737-600 or A318 with the largest HS/BAE/'Avro' 146
Another economic disadvantage of the Vanguard was having four engines rather than two (there wasn't a turboprop engine large enough to make it a twin)
Proplinerman
The 50% reduction probably applied to direct operating costs (fuel, maintenance, etc). At the time airlines had very high overheads (sales offices, station costs, general admin, etc). I was told that as a rule of thumb they added on 100% to DOC. Hence the reduction would only have been 25%. (I'm told that's one of the reasons the airlines got their sums wrong with the 747.)
It probably also assumed that passengers would be indifferent to the type of plane. Its long before my time but I'm told that the VC10 had higher operating costs than the 707 or DC8 but that it was more popular with passengers & had higher load factors (although its main operator BOAC never made much money). Doubtless the jets would have achieved higher load factors (yield was less important of those days of IATA agreed fares) than a prop.
With fuel costs increasing 50 seat regional jets are becoming uneconomic. The obvious solution is larger regional jets (DL is replacing many with 717s) but for feeder flights to small airports, particularly where there is minimal completion we may well see a return to prop jets.
As a matter of interest Pan Am (mainline, ignore their commuter carriers) never operated a turboprop going straight from piston aircraft to the 707/DC8.
The 50% reduction probably applied to direct operating costs (fuel, maintenance, etc). At the time airlines had very high overheads (sales offices, station costs, general admin, etc). I was told that as a rule of thumb they added on 100% to DOC. Hence the reduction would only have been 25%. (I'm told that's one of the reasons the airlines got their sums wrong with the 747.)
It probably also assumed that passengers would be indifferent to the type of plane. Its long before my time but I'm told that the VC10 had higher operating costs than the 707 or DC8 but that it was more popular with passengers & had higher load factors (although its main operator BOAC never made much money). Doubtless the jets would have achieved higher load factors (yield was less important of those days of IATA agreed fares) than a prop.
With fuel costs increasing 50 seat regional jets are becoming uneconomic. The obvious solution is larger regional jets (DL is replacing many with 717s) but for feeder flights to small airports, particularly where there is minimal completion we may well see a return to prop jets.
As a matter of interest Pan Am (mainline, ignore their commuter carriers) never operated a turboprop going straight from piston aircraft to the 707/DC8.
An interesting thread!
I cannot help thinking that if someone like Bombardier or ATR came up with a 150 seat turboprop,they could make thousands of them and a fortune, given the projected price rises in Jet A1 over the next couple of decades!
Pax may not like turboprops much, but the beancounters love em, and thats what counts!
I cannot help thinking that if someone like Bombardier or ATR came up with a 150 seat turboprop,they could make thousands of them and a fortune, given the projected price rises in Jet A1 over the next couple of decades!
Pax may not like turboprops much, but the beancounters love em, and thats what counts!
Pax may not like turboprops much, but the beancounters love em, and thats what counts!
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As a ex B.E.A. avionics man there were many reasons why the Vanguard failed . 1/ those 14ft 6ins props produced a great deal of interior noise and vibration ,we spent £1000s of pounds trying to cure this problem to acceptable levels and didn't cure it properly. 2/only the five 951s ever had Club seats and as the planes popularity waned they were converted to Tourist class 3/ they were very labour intensive the electrical system was over complicated as the tail de-icing was electric mats, the built in air stairs were heavy and fragile .we were glad when they were withdrawn and 9 were converted to freighters they made great freighters could carry 19metric tons of freight were fast and carried on flying until 1996 [freight and livestock don't complain] still love working to preserve the last remaining one at The Brooklands Museum though I would never have said that in the 60s and 70s.
the built in air stairs were heavy and fragile .we were glad when they were withdrawn
Landed one a.m. in a Merchantman with a complete hydraulic failure (no brakes or steering) and dutifully asked for a tug.to clear 28L (as it was then). When informed that it would take half an hour for a tug to reach me, decided to carry on and eventually parked on the stand using the props alone.
Part of base training syllabus for converting captains was practising three-point turns.
Happy days!
Back on topic; I think if you looked at like for like, in terms of kg/ seat mile terms the turboprop will generally beat the jet hands down. That would be the case for say, Vickers Vanguard vs Caravelle to Q400 vs A320.
Thing is, the fuel costs in the Vanguard days was such a neglible component of overall costs: legacy overheads and all that. Today it's somewhat different, that's not to say there aren't heavy engineering and technical costs with some of the turboprops, and yes, if you want to get there on the same day without stopping for refuel en route (additional costs), you fly on a jet.
But in a pure calorific value of fuel for work done basis; the turboprop wins.
Thing is, the fuel costs in the Vanguard days was such a neglible component of overall costs: legacy overheads and all that. Today it's somewhat different, that's not to say there aren't heavy engineering and technical costs with some of the turboprops, and yes, if you want to get there on the same day without stopping for refuel en route (additional costs), you fly on a jet.
But in a pure calorific value of fuel for work done basis; the turboprop wins.
