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View Full Version : Economy of older and current turboprops versus old and current jetliners


Proplinerman
22nd Jun 2013, 14:41
From my Pprune name and previous posts, you'll know I'm a propliner fan, especially of the Vickers Vanguard.

So, can I call upon the technical knowledge of my fellow PPrune users in this forum, to ask just how economical the Vanguard was compared with contemporary jetliners in the late 1950s. In this film clip from 1959 on YouTube: "BEA Vickers Vanguard"-1959 - YouTube of the aircraft when it was new, the commentator says "Vickers claim its design, with Rolls Royce Tyne engines, could cut many passenger fares by 50%."

I believe the above was not just sales talk by Vickers, but of course this economy did not prevent the Vanguard from being a near total commercial failure, largely due to it coming onto (I believe, I was a baby at the time) the market just at the time when the first jetliners (bar the false start with the Comet 1 six to seven years earlier) were coming on the scene, and passengers' very clear preference at that time, for pure jets over turboprops (let alone piston engined airliners).

So just how economical was the Vanguard in its day please? I believe it did allow BEA to cut the fares on the routes the aircraft was used on, in some cases quite sharply, though please correct me if I'm wrong. And with the 50+ years of progress with turbine engines since 1959, how economical are modern day jetliners compared with the Vanguard and present day turboprops please?

GOLF_BRAVO_ZULU
23rd Jun 2013, 06:54
You may have seen it already but Flight, 3 MAR 61 edition, made some interesting economic comparisons for the Guardsvan.

eg


TOTAL CQSTS PER SEAT-MILE (pence)
Viscount 200

701 sixty-three seats 3.7
802 seventy-two seats 3.9

Vanguard

951 one hundred and thirty-eight seats 3.6
953 one hundred and thirty-eight seats 3.8


vanguard | 1961 | 0275 | Flight Archive (http://www.flightglobal.com/pdfarchive/view/1961/1961%20-%200275.html)

scotbill
23rd Jun 2013, 07:20
BEA originally thought there would never be a requirement for jets in Europe and the Comet was a hurried shortgap replacement when the Caravelle proved them wrong. As a result of V951 teething problems the Comet came into service first - 1960 as against 1961
.
Can't remember much about the fuel flows but the old lady was one of the fastest prop driven planes ever. Although the cruise speed was only 360 mph she could descend at over 300 knots indicated (Vne at low level 331K!) and as a result London ATC had to have a notice at West Drayton pointing out that Vanguards descended at jet speeds.
(In fact it is said that, above 400 knots IAS, Vickers test pilots preferred the Vanguard's handling to the Valiant). With all-manual tab-assisted flying controls the handling seemed to become more delicate the faster she went.

With their better short field performance, Vanguards on domestic flights often had chock to chock times better than achieved by the jets of today. (eg Glasgow - LHR 1.05 hrs) And she carried the same load as the Trident 3b.

So there never was a compelling case for jets on short sectors but the simple fact is that the public never came to love the Vanguard.

scotbill
23rd Jun 2013, 07:23
And the cheapest domestic fare I can recall was £3.15 on the (very) late night services to Glasgow , Edinburgh and Belfast.

Krystal n chips
23rd Jun 2013, 07:38
" So there never was a compelling case for jets on short sectors but the simple fact is that the public never came to love the Vanguard."

Without going too far off track, a sentiment that was duly repeated, if not expanded on, with another venture into turbo-props some years later.

Enter, the A.T.P.

Fuel economy was a positive feature of the type.

The only positive feature.

grollie
23rd Jun 2013, 07:59
What the Advanced Technical Problem. I worked on them at Manx Airlines years ago. One problem after another.

ATNotts
23rd Jun 2013, 10:07
scotbill

And the cheapest domestic fare I can recall was £3.15 on the (very) late night services to Glasgow , Edinburgh and Belfast.

Crickey! Yesterday I took the bus from Beeston (Nottingham) to Derby and it cost me £ 3.20! BEA were obviously the real "low fares airline"!

Proplinerman
23rd Jun 2013, 10:23
Thanks for all the replies so far guys-very interesting.

John Farley
23rd Jun 2013, 12:01
Proplinerman

You pose a very interesting question but one that I am not sure it is possible to answer without access to specific information which I doubt is available.

Let me try and explain why I say this.

Consider what it costs airline A to fly a particular type:

The total cost is made up of a huge number of factors some of which are company related such as manning levels for the aircraft type specific tasks, plus any culture/union factors, through to simple type related fuel burn in the cruise and more complicated maintenance man hours per flying hour.

Then consider airlines B and C which could clearly have different company related costs and depending on cultural issues could even have different maintenance man hours per flying hours.

Whether airline A can get pax to climb up the steps in sufficient numbers to be profitable clearly depends on their underlying costs as well as the fuel that will be used on the trip. As others have pointed out if pax in general don’t like riding a particular type then you really are up against it.

It is clearly possible to find out the fuel burn in the cruise for the sort of types you have mentioned but taken in isolation I am not sure they alone necessarily show which type was better commercially.

But you probably realise all that!

The SSK
24th Jun 2013, 08:24
A propos of nothing, BEA's Vanguards were scheduled for 70 minutes Amsterdam-Heathrow. BA's current schedule is 75 min.

And the cheapest domestic fare I can recall was £3.15 on the (very) late night services to Glasgow , Edinburgh and Belfast.

I can recall that BEA would fly you in a Herald from Glasgow to Edinburgh for 12s6d, and Dan-Air from Newcastle to Carlisle in an Ambassador for 18s.

tornadoken
24th Jun 2013, 08:28
So: 1955. Pax then as now do not flatly prefer jet to turboprop. They prefer a convenient schedule at a sensible fare. See, today, Dash 8/ATR well able to compete with 146/ERJ/CRJ on sectors upto say 150 mins. It was entirely sensible in 1955 for Vickers Ltd. to assign Corporate funds to do a Viscount Major to build upon spectacular V.700 market performance, V.800 market interest. It was entirely sensible for the 2 launch customers to welcome big belly cargo capacity, to extend utilisation into pax-unfriendly nights. So: Q: why did such Viscount customers as Ansett/TAA, KLM take L.188, and Capital/United, Indian A/L take Caravelle?

As JF infers, the A is not a simple number like fuel burn per seat-mile. Nor is it some politico-conspiracy as often favoured by those seeking to explain Brit business "decline": clearly in US boardrooms L.188 would have advantage v.some alien product...but only a bit: if an import makes bottom-line sense, it will fly. When pitching 707-100 v. DC-8/20, Boeing's civil reputation was hugely inferior to Douglas': Pan Am's launch orders were for 20 707, 25 DC-8. But the market found greater customer-care in Seattle. And greater in Toulouse, Burbank, than in Weybridge. This was the secret of F27 success over Herald: perception that the Supplier cares for his customer.

In 1978 HAECO in Hong Kong had in for heavy maintenance an ancient Vanguard and an ancient 707, both second, was it third operator, long out of any new build warranty. Parts and repair advice: from Weybridge: slow or worse; from Seattle: 24/7 (expensive; but Aircraft on Ground would be moreso). Here is the reason Qantas rejected Britannia:
“(A negative impression during QF’s 7/55 visit) to assess Bristol(’s ability to meet schedule and to demonstrate) an organisation adequate to service the aircraft”. J.Gunn,High Corridors,QUP,1988,P69.

Vickers took a loss of £16.7Mn. on Vanguard. I submit the reason for customer flight was their perception that it would be just too hard to capture the attention of prime and/or vendors when a tyre blew in Timbuktu. Vickers' attention would be on Valiant and on stroking the man in Whitehall about to award the next big thing. That is why Aer Lingus (then a BEAC Associate Co.) launched F27 in preference to playing second fiddle to Victor at Radlett.

vctenderness
24th Jun 2013, 08:34
The Vanguard had a First Class cabin at the rear of the aircraft which is pretty unusual compared to today.

Also you could fly First on domestic routes with a very high level of cabin service.

Noyade
24th Jun 2013, 09:25
So just how economical was the Vanguard in its day please?Hopefully I have them in correct order mate. :) Descending down we have the...
1) Vanguard
2) Boeing 720-420
3) Douglas DC-8-30

http://i44.tinypic.com/20jqlvn.jpg

http://i39.tinypic.com/2mwwm81.jpg

http://i40.tinypic.com/2iiuypt.jpg

Proplinerman
24th Jun 2013, 10:08
Thanks for the further replies.

I'm pretty sure the reason the Vanguard's First Class cabin was at the rear was because it was there on all propliners, due to it being rather quieter behind the prop's, instead of in line with or ahead of them. Reverse applies to jets.

Flight times of the Vanguard versus current jetliners: I'm pretty sure it was 50 min's Manchester to London in the 1960's, whereas now it's 60 min's. Some of this however could perhaps be put down to much busier air routes nowadays.

The SSK
24th Jun 2013, 10:37
I'm pretty sure the reason the Vanguard's First Class cabin was at the rear was because it was there on all propliners, due to it being rather quieter behind the prop's, instead of in line with or ahead of them. Reverse applies to jets.

We've been discussing this recently on another thread. Mainline Dash 8s (Austrian, Croatia etc) have their business class at the (noisier) front end - because passengers expect that's where business class should be.

Some of this however could perhaps be put down to much busier air routes nowadays.

These are sectors into LHR - include contingency for holding in the stack, presumably.

gruntie
24th Jun 2013, 10:42
Some of this however could perhaps be put down to much busier air routes nowadays.

In days of yore (or at least the Shuttle) I was told that it was so that they could serve a hot meal to all the passengers and so justify the high fare as it was "Club".
The first class train fare meanwhile was exactly the same. Funny that.

Proplinerman
24th Jun 2013, 11:14
"We've been discussing this recently on another thread. Mainline Dash 8s (Austrian, Croatia etc) have their business class at the (noisier) front end - because passengers expect that's where business class should be."

How strange: when I flew recently on a Flybe Dash 8, I actually moved from a seat just ahead of the wing to one behind the wing, because I felt the forward seat was a bit noisy from the prop's. Tho in saying that, I'm in no way decrying the Dash 8-an admirable aircraft in my view.

Rail v plane to London from M/C: nowadays, I always take the train-cheaper and better service and quicker door to door to central London. The only time I fly to/from LHR from M/C is on the odd occasion I have to take a flight out of LHR, when convenience etc (especially if it's BA/T5) outweighs cheaper rail fare.

thetimesreader84
24th Jun 2013, 14:05
In terms of fuel burn, I believe a reasonably modern 737 (cfm engines) will burn around about 4,500lb fuel per hour in the cruise (correct me if I'm wrong).

On the Electra, we used to plan on about 5,000lb for the first hour, reducing to 4,500 thereafter - so a little more, but not drastically, considering the 40-odd years of extra development involved - I don't have fuel figures for the "straight jet" 737.

Oh, and over a 2 or 300 mile stage length, the Electra is no slower than the jet. In fact, before they put the speed restrictions on it, I'm told it was faster over the ground than the 737.

And it has a lovely sound, and handles like a dream.

TTR

A30yoyo
24th Jun 2013, 22:55
Proplinerman....Flight quotes a 600gal/hr fuel burn for the Vanguard in
http://www.flightglobal.com/pdfarchive/view/1996/1996%20-%203052.html

which I think converts to about 4,900lbs/hr (with Kerosene S.G.=O.82)

737-800 fuel burn seems to be around 4,500-5,000lbs/hr but it can carry about 180 pax? (and faster), Vanguard was ca.140 pax?

scotbill
25th Jun 2013, 06:45
A30yoyo

Yes - but you are comparing a 50s technology Tyne with state-of-the-art.

Had there been any demand for big turboprops the engine/prop technology would presumably have made similar progress.

As a matter of interest my best chock to chock time BFS-LHR on a Vanguard was 59 minutes. Equalled on jets but never surpassed.

The competitive block times of both Viscount and Vanguard had nothing to do with first class service times and much more to do with less congestion. And the first class cabin was in the rear for noise reasons.
Had the disadvantage that the chief steward was also at the back.

The basic point is that jet speeds confer little advantage the shorter the sector. However, the jet obviously has much more flexibility in terms of getting above the weather

A30yoyo
25th Jun 2013, 11:52
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

VX275
25th Jun 2013, 14:07
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)

I wonder if anyone will think of designing a twin turboprop using the A400M TP400 engines. At 11000 shp they are more than twice the power of a Tyne.

Peter47
28th Jun 2013, 10:31
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.

ATSA1
30th Jun 2013, 16:13
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!

DaveReidUK
30th Jun 2013, 16:40
Pax may not like turboprops much, but the beancounters love em, and thats what counts!

The beancounters who were around in the late 1950s and early 60s would have told you that it's not just about DOCs.

avionic type
30th Jun 2013, 17:10
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.

scotbill
30th Jun 2013, 19:27
the built in air stairs were heavy and fragile .we were glad when they were withdrawnI'm sure you're right about the Vanguard problems but in the industrial atmosphere of 70s (when it was a question of whose turn it was to go on strike today) there was many a time that we were glad of those airstairs and the reversing props which made us independent of tugs and stair drivers.

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!

siftydog
30th Jun 2013, 21:05
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.