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RR Engines Burn More Fuel Than GE.  
User currently offlineBOE773 From , joined Dec 1969, posts, RR:
Posted (7 years 9 months 1 week 1 day 22 hours ago) and read 14893 times:

According to SFC statistics, Rolls Royce engines burn more fuel than GE engines with comparable thrust. Is it because RR run with a lower pressure ratio than GE?

90 replies: All unread, showing first 25:
 
User currently offlineJetlife2 From United States of America, joined Jul 2006, 220 posts, RR: 25
Reply 1, posted (7 years 9 months 1 week 1 day 21 hours ago) and read 14904 times:

Well, this will generate a lot of responses! Everyone will have an opinion.

First point to answer, is it true, and based on what data? Are there any unbiased comparisons?

Probably the only people able to make a nearly accurate comparative assessment are the airframers where there are competing engines on the same aircraft. Both GE and RR submit cycle models to the airframer and they are audited for accuracy by the airframer. Then they run them side by side for the same airframe and mission. However the results are usually not made public to both sides. So RR would get the results of their analysis, but not the results for "the other guys".

Others who could make this assessment are customers who get competing proposals during sales campaigns. Fuel burn is often subject to financial guarantees so it is not in the company interest to wildly exaggerate claims. So customer evaluation teams are able to put them side by side and have some level of confidence.

Others are lease companies, and more rarely customers, who actually operate both versions.

So over the years these conclusions become known to all parties in the industry, since after all, this is a small town where everyone knows everyone else's business.

So yes it is broadly true that GE's SFC is better. Some might attribute it to better materials, higher temperatures, better cycle and aero design and more physics based understanding, vs empirical incremental changes.

Some might ask (at the risk of dragging the thread off topic) how this can be true if three spools are better than two. Some might conclude that might not be true after all.

But that would be just one opinion.


User currently offlineBOE773 From , joined Dec 1969, posts, RR:
Reply 2, posted (7 years 9 months 1 week 1 day 21 hours ago) and read 14897 times:

RR paid both QF and NZ airlines fuel penalties for the RB211s
on their 747-400s.

The CF6-80C2B1F engine has a SFC of 0.337 LB/HR. on the 747-400.

The RB211-524G and H engines have a SFC of 0.58 LB/HR on the 747-400.

So the Specific Fuel Consumption measured in Lb/HR. of a Rolls Royce
is quite a bit more than the GE engine for the 747-400.

Most RR engines are traditionally heavier and more 'maintenance
intensive' due to their three-spool layout, compared to the simpler
and lighter twin-spool of modern GE and P&W engines. This is also
why RR engines consume more fuel than the competition since a three
spool layout requires more power to drive and runs at a lower pressure ratio.

All four Trent engines (1000-A1, 1000-C1, 1000-D1 & 1000-E1)
for the Boeing 787 series aircraft will have a SFC of 0.506 LB/HR.

I do not have the SFC figures for the four GEnx engines for the 787s-
(GEnx-1A72, GEnx-1B54, GEnx-1B64 & GEnx-1B70).

But I expect the SFC of the GEnx will be lower than the RRs; most
likely in the 0.35 - 0.40 LB/HR range.


User currently offlineTepidHalibut From Iceland, joined Dec 2004, 209 posts, RR: 6
Reply 3, posted (7 years 9 months 1 week 1 day 13 hours ago) and read 14806 times:

Quoting BOE773 (Reply 2):
The CF6-80C2B1F engine has a SFC of 0.337 LB/HR. on the 747-400.

The RB211-524G and H engines have a SFC of 0.58 LB/HR on the 747-400.

I'm no expert, but I suspect you're comparing Cruise SFC with Take-Off SFC.


User currently offlineTristarSteve From Sweden, joined Nov 2005, 3930 posts, RR: 34
Reply 4, posted (7 years 9 months 1 week 1 day 13 hours ago) and read 14804 times:

Quoting BOE773 (Reply 2):
The CF6-80C2B1F engine has a SFC of 0.337 LB/HR. on the 747-400.

The RB211-524G and H engines have a SFC of 0.58 LB/HR on the 747-400

Try and use some common sense and ask yourself if these figures are true. Would you buy a car knowing that the fuel consumption was 72% higher for the same mission? This would mean that a CF6 engined B744 has 70% more range than an RB211!!!

Try comparing similar figures and start again,


User currently offlineManzoori From UK - England, joined Sep 2002, 1516 posts, RR: 34
Reply 5, posted (7 years 9 months 1 week 1 day 13 hours ago) and read 14803 times:

That's two threads now you've started bashing RR for no apparent reason... I wonder why?

First off, NO, RR will not end up being a sub-con supplier to GE & PW... for all the reasons explained in the other thread.

Secondly, where do you get these figures from? The three shaft engine design is actually lighter and smaller than the equivalent two shaft design so there goes that argument... I'll give this thread an F+ and a 'Must try harder'.

 Wink

Rez



Flightlineimages DOT Com Photographer & Web Editor. RR Turbines Specialist
User currently offlineAstuteman From United Kingdom, joined Jan 2005, 9834 posts, RR: 96
Reply 6, posted (7 years 9 months 1 week 1 day 13 hours ago) and read 14792 times:
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Quoting BOE773 (Thread starter):

If it helps, it might be worthwhile a) quoting actual figures, and the quoting the reliable source from whence they came, and b) ensuring that you're measuring "like-for-like".

If you're talking engines, it might also be worth "messaging" knowledgeable people like Lightsaber and Widebodyphotog.
They will have very reliable "back-up" sources for comparison.

Hope that helps.

Regards


User currently offlineWingscrubber From UK - England, joined Sep 2001, 845 posts, RR: 0
Reply 7, posted (7 years 9 months 1 week 1 day 8 hours ago) and read 14736 times:

Quoting BOE773 (Reply 2):
Most RR engines are traditionally heavier and more 'maintenance
intensive' due to their three-spool layout

Perhaps maintenance on a triple spool is more involved at the overhaul stage than a double spool, but I can tell you first hand that the engineers I spoke to who work on the 777s at Cardiff when I was working there preferred the trent to the GE90, and called the GE90 'Not a very good engine'.
I'd elaborate if I could but my personal experience with these is minimal.



Resident TechOps Troll
User currently offlineBrendows From Norway, joined Apr 2006, 1020 posts, RR: 4
Reply 8, posted (7 years 9 months 1 week 1 day 7 hours ago) and read 14728 times:

Quoting BOE773 (Reply 2):
The CF6-80C2B1F engine has a SFC of 0.337 LB/HR. on the 747-400.

Cruise SFC for the CF6-80C2B1F is 0.564 lb/hr/lb.

Quoting BOE773 (Reply 2):
I do not have the SFC figures for the four GEnx engines for the 787s-
(GEnx-1A72, GEnx-1B54, GEnx-1B64 & GEnx-1B70).

These engines will have a cruise SFC of about .495lb/hr/lb IIRC.

EDIT: many answers to the first question can be found in this post by Lightsaber Smile
http://www.airliners.net/discussions...general_aviation/read.main/2794875

[Edited 2006-07-14 16:01:04]

User currently offlineLMP737 From , joined Dec 1969, posts, RR:
Reply 9, posted (7 years 9 months 1 week 1 day 7 hours ago) and read 14708 times:

Quoting BOE773 (Reply 2):
Most RR engines are traditionally heavier and more 'maintenance
intensive' due to their three-spool layout, compared to the simpler
and lighter twin-spool of modern GE and P&W engines.

Actually the RB211 stays on wing much longer than the PW2000.


User currently offlineRichardPrice From , joined Dec 1969, posts, RR:
Reply 10, posted (7 years 9 months 1 week 1 day 6 hours ago) and read 14694 times:

Quoting BOE773 (Reply 2):

Most RR engines are traditionally heavier and more 'maintenance
intensive' due to their three-spool layout, compared to the simpler
and lighter twin-spool of modern GE and P&W engines.

Everything Ive read on this subject say that the triplespool RR engines are lighter than their twin spool counterparts from GE or P&W because the engine is a lot shorter.

BOE773 - its also good manners to quote your post considering you have lifted it directly and completely from this thread on Airdisaster.com:

http://www.airdisaster.com/forums/showthread.php?t=79049


User currently offlineTristarSteve From Sweden, joined Nov 2005, 3930 posts, RR: 34
Reply 11, posted (7 years 9 months 1 week 1 day 3 hours ago) and read 14641 times:

Quoting BOE773 (Reply 2):
Most RR engines are traditionally heavier and more 'maintenance
intensive' due to their three-spool layout, compared to the simpler
and lighter twin-spool of modern GE and P&W engines.

I must admit that the Roller has an extra spool. But to call the GE and PW engines simpler is going too far. Just go and look at a CF6 or a CFM56 sitting on a stand and compare it with a RR engine. The huge array of VGVs and VBVs and all their mechanism and actuators, and the HPTCC and LPTCC pipes and control valves that litter the outside of the casings. And the gearboxes hidden deep under the C Ducts while the RR accessories are all under the fan cowl. I dont think you have looked at them

Now a true story. In the mid 90s we looked after 3 L1011 with 22B engines. In the same hangar was a fleet of 5 DC10-10 with CF6-50s. After two years we had changed one engine for a time ex shaft. The others had changed 19 failed CF6 engines. They thought we must be flying them out for maint but NOT TRUE.
All the 8 aircraft were old, the Tristars ex Cathay and the DC10s ex Delta.


User currently offline411A From United States of America, joined Nov 2001, 1826 posts, RR: 8
Reply 12, posted (7 years 9 months 1 week 1 day 1 hour ago) and read 14617 times:

As far as Rolls Royce three-spool engines being heavier, yes 'tis true, when compared to similar weights of GE engines of the same (or nearly so) static thrust.

By about 1400 pounds, IIRC.

Having said this, generally speaking, the three-spool design is slightly more fuel efficient than its two-spool counterpart...and is also quieter, while at the same time generally having more time on the wing than others, before removal becomes required.

Rollers are REALLY good engines.


User currently offlineRichardPrice From , joined Dec 1969, posts, RR:
Reply 13, posted (7 years 9 months 1 week 1 day ago) and read 14606 times:

Quoting 411A (Reply 12):
As far as Rolls Royce three-spool engines being heavier, yes 'tis true, when compared to similar weights of GE engines of the same (or nearly so) static thrust.

Exactly how true is this? The Trent 900 (14,190lb) comes in nearly 600lb lighter than the EA GP7200 (14,798lb) for the A380, and a quick google around shows similair results for other comparable engines.


User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2532 posts, RR: 24
Reply 14, posted (7 years 9 months 1 week 1 day ago) and read 14595 times:

Quoting RichardPrice (Reply 10):
BOE773 - its also good manners to quote your post considering you have lifted it directly and completely from this thread on Airdisaster.com:

Except the thread starter on airdisaster.com kept coming back for more and even came up with this illogical gem:

Quote:
All the data quoted for GE engines is SFC measured at MAXIMUM power in LB/HP-HR.

All the data quoted for RR engines is SFC measured at CRUISE power in
LB/HP-HR.

Maximum power uses more fuel than Cruise power.
So this makes RR SFC even more than GE.

I wonder what planet he's on?



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineZeke From Hong Kong, joined Dec 2006, 8638 posts, RR: 75
Reply 15, posted (7 years 9 months 1 week 23 hours ago) and read 14577 times:

Quoting BOE773 (Reply 2):
The CF6-80C2B1F engine has a SFC of 0.337 LB/HR. on the 747-400.

The RB211-524G and H engines have a SFC of 0.58 LB/HR on the 747-400.

From memory the GE has about 4-5000lb less thrust than the 524HT, with a slightly lower MTOW.

The TSFC figures you are using are incorrect, nothing GE has on the market has a TSFC that low, the GEnx on the 748 will not even be that good.

Quoting BOE773 (Reply 2):
Most RR engines are traditionally heavier and more 'maintenance intensive' due to their three-spool layout, compared to the simpler and lighter twin-spool of modern GE and P&W engines. This is also why RR engines consume more fuel than the competition since a three spool layout requires more power to drive and runs at a lower pressure ratio.

Exact opposite of my understanding.

One of the reasons why CX has RB211s on every fleet (330/340/777/747), and last time I looked we were making billions in profit year after year.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineN8076U From United States of America, joined Jun 2006, 425 posts, RR: 9
Reply 16, posted (7 years 9 months 1 week 19 hours ago) and read 14530 times:

Does anyone know how the P&W engines on the 747 compare to the GE and RR engines, as far as fuel burn and weight? I can only assume it is worse than the other two.  Wink But I am curious, as it is the one I am familiar with.

Chris



Don't blame me, I don't work here...
User currently offlineCPDC10-30 From United Kingdom, joined Feb 2000, 4773 posts, RR: 24
Reply 17, posted (7 years 9 months 6 days 15 hours ago) and read 14420 times:

Quoting TristarSteve (Reply 11):
In the same hangar was a fleet of 5 DC10-10 with CF6-50s.

Don't mean to nitpick too much, but didn't the DC-10-10 use the CF6-6D engine? This was the initial version of the CF6 which was later improved upon. I thought the CF6-50 was for the 10-30.


User currently offlineMolykote From United States of America, joined Aug 2005, 1337 posts, RR: 29
Reply 18, posted (7 years 9 months 6 days 13 hours ago) and read 14404 times:
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Quoting Zeke (Reply 15):
One of the reasons why CX has RB211s on every fleet (330/340/777/747), and last time I looked we were making billions in profit year after year.

And the last time I looked the RB211 wasn't available on most of those airframes! (Perhaps you meant to suggest that the subsequent Trent line of engines was installed on the A330/A340/777?)



Speedtape - The asprin of aviation!
User currently offlineZeke From Hong Kong, joined Dec 2006, 8638 posts, RR: 75
Reply 19, posted (7 years 9 months 6 days 9 hours ago) and read 14376 times:

Quoting Molykote (Reply 18):
And the last time I looked the RB211 wasn't available on most of those airframes! (Perhaps you meant to suggest that the subsequent Trent line of engines was installed on the A330/A340/777?)

All the Trents are types of RB211s, eg the 345/6 has the RB211 Trent 500, see the TCDS http://www.caa.co.uk/docs/401/SRG_PRO_1056%20iss5.pdf



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlineReidYYZ From Kyrgyzstan, joined Sep 2005, 536 posts, RR: 1
Reply 20, posted (7 years 9 months 6 days 9 hours ago) and read 14369 times:

Quoting TristarSteve (Reply 11):
In the mid 90s we looked after 3 L1011 with 22B engines. In the same hangar was a fleet of 5 DC10-10 with CF6-50s. After two years we had changed one engine for a time ex shaft. The others had changed 19 failed CF6 engines.

Wow, talk about on wing reliability. I admit I'm biased towards RR, and saying that, upper management always said RR was a preferred engine, however the lease costs on GE were less. So it depends on your mission. From personal experience, the RR are prone to vib's (more spinning parts) GE's are prone to bleed probs (more air bleeds off for self accessory cooling/heating than actually goes to the back to promote combustion). RR use of EPR as a measure of actual power output is more accurate vs. GE and N1. As stated before, RR throws most of the accessories under the fan cowl, short of pouring oils, for the GE you open the C-ducts for everything else(PITFA). To be fair, RR is a delicate machine when treated properly, the GE is virtually indestructible in normal ops. According to the AMM, the fly-on damage limits are far greater in terms of blade damage et cetera...but that's what you get for building an engine for the military and then applying to commercial. (or so I've been lead to believe.)


User currently offlineGDB From United Kingdom, joined May 2001, 13042 posts, RR: 78
Reply 21, posted (7 years 9 months 6 days 5 hours ago) and read 14328 times:

BOE773, if they such shit engines then, why do so many people buy them?
Not all Commonwealth members, not that this ever mattered a damn.

Not bad going for a company that all those 'experts' in the finanicial services wrote off as being bound to exit the civil market in the early 1990's.
And selling such an inferior product too?

What's wrong with this picture?

The very title of the thread gives it away.


User currently offlineBOE773 From , joined Dec 1969, posts, RR:
Reply 22, posted (7 years 9 months 5 days 20 hours ago) and read 14268 times:

All four Trent engines (1000-A1, 1000-C1, 1000-D1 & 1000-E1)
for the Boeing 787 series aircraft will have a SFC of 0.506 LB/HR/LB.

All four GEnx engines (-1A72, -1B54, -1B64 & -1B70 )
will have a SFC of 0.495 LB/HR/LB.

So the GEnx series will beat the Trent engines in fuel consumption
by 0.011 LB/HR/LB. This fuel savings times two engines over one year will mean significant savings for an airline.


User currently offlineMolykote From United States of America, joined Aug 2005, 1337 posts, RR: 29
Reply 23, posted (7 years 9 months 5 days 18 hours ago) and read 14246 times:
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Quoting Zeke (Reply 19):
All the Trents are types of RB211s, eg the 345/6 has the RB211 Trent 500, see the TCDS http://www.caa.co.uk/docs/401/SRG_PR...5.pdf

Shame on me for not doing research before posting! I'm actually surprised to learn that. My experience is with the RB211-535 only so I had never looked at the TCs for the later Trents (although I was aware that they were quite similar in concept, I didn't know that they held on to the RB211 prefix). Thanks!

Do you know if the Trent 1000 is going to be certificated as an RB211 as well?

[Edited 2006-07-17 04:40:49]


Speedtape - The asprin of aviation!
User currently offlineManzoori From UK - England, joined Sep 2002, 1516 posts, RR: 34
Reply 24, posted (7 years 9 months 5 days 14 hours ago) and read 14224 times:

Quoting Molykote (Reply 23):

Do you know if the Trent 1000 is going to be certificated as an RB211 as well?

I believe we name all our three shaft engines as RB211s.

Rez
 Big grin



Flightlineimages DOT Com Photographer & Web Editor. RR Turbines Specialist
25 RichardPrice : Yes, all of the Trent series is derived from the RB211 so they all get the RB211 title as well.
26 TristarSteve : Well if that is the case, why does RR sell engines. According to you they are wasting their time. But airlines buy RR engines so there must be someth
27 DarkBlue : Not necessarily. Fuel burn rate is driven by both SFC and engine weight. Lower SFC benefits you the most over long flights since you're at cruise a l
28 BOE773 : Traditionally, RR engines have weighed more than GE.
29 LMP737 : You might want to look up the wieghts of the GE90 and the Trent.
30 BOE773 : All GE series engines prior to the -90 have been lighter than RR engines. Really, all Trent engines are warmed over RB211 engines without any radical
31 LMP737 : Which GE series engines are you speaking of? Becasue when it comes right down to it there are only two GE and two RR motors you can really compare. T
32 BOE773 : Taken from a thread about fuel consumption on Air Disasters. GE90-85B @ 84,700 lb.t. consumes 3.115 kg/s at take-off. 0.282 kg/s at idle. RR Trent 884
33 RichardPrice : I hope you realise that a thread on a forum is not a viable source to quote.
34 AirbusA6 : Hardly! There are major differences between early Tristar RB211s and later ones on the 747-400 never mind the advances on the various Trents.
35 BOE773 : So what are the major design differences between a Trent and a RB211?
36 Dougloid : We used to call the RR Spey on the G-II the Rolls Royce Spray because it sort of went aloft on a column of thrashed fuel like one of those water power
37 RichardPrice : The Trent name began with the RB-211-524L when RR realised it had differed significantly from the RB-211 series, and since then all versions have bee
38 Post contains images Manzoori : Richard, I wouldn't rise to it mate, he sounds like a troll! [sarcasm] Yes Boe773, that's right....all RR 3 shaft engines are basically warmed over RB
39 Post contains links RichardPrice : Both this topic and Modified C-5 To Airfreight The Aurora? (by BOE773 Jul 20 2006 in Military Aviation & Space Flight) were posted on airdisaster.com
40 Post contains images Manzoori : LOL! Thanks for the link! Very amusing! Cheers! Rez
41 BOE773 : The four Trent engines (1000-A1, 1000-C1, 1000-D1 & 1000-E1) for the Boeing 787 series aircraft will have a SFC of 0.506 LB/HR/LB. All four GEnx engin
42 RichardPrice : Evidence for the specific post please.
43 F14D4ever : How do you know? 'Cause they told you? How about applying some discernment, just a small adult dose, to your thinking?
44 BA787 : Just to clarify to the rest of you, this guy has been posting threads such as this in Civ Av and we are all tired of him. He seems to be anti British
45 HUYguy : I agree, I was about to say that too. BOE773 - get your facts right before you post, it makes you look a lot less stupid.
46 Post contains images DH106 : Allegedly
47 DarkBlue : And once again, fuel consumption is not driven by just SFC. An aircraft with heavier engines will burn more fuel than one with lighter engines. GEnx
48 BOE773 : GE. RR.
49 RichardPrice : Four letters, not including punctuation, does not a source make.
50 BOE773 : [quote=RichardPrice,reply=49][/q General Electric manufacture jet engines and are the best source for their engine data. Same goes for the other one.
51 RichardPrice : No, you have made the statements, you need to back them up.
52 Post contains links N8076U : For those of you who don't visit the "site related" forum, have a read... BA Bashing Threads Annoying (by BA787 Jul 24 2006 in Site Related) Chris
53 Bri2k1 : Why does anyone even reply? This is a lot like porn on the Internet. Everyone complains about it. It's annoying. You don't want your kids to see it. B
54 BOE773 : GE90-85B @ 84,700 lb.t. consumes 3.115 kg/s at take-off. 0.282 kg/s at idle RR Trent 884 @ 84,950 lb.t. consumes 3.56 kg/s at take-off. 0.31 kg/s at i
55 Post contains links and images Lightsaber : First, I'm a bit amused by this thread. A lot of discussion without good numbers until the end. But nothing is necessarily "apples to apples." I also
56 Zeke : " target=_blank>http://www.alair.com/Commercial/rb21....html The RB211-524 is not one engine, the one we have the RB211-524H-T-19 with takeoff thrust
57 Lightsaber : Correct. But I do not have every engines TSFC. If you have a source, Please inform. Just as any TSFC is fairly out of date. Most engines improve by 2
58 TepidHalibut : Just to be picky, RR fitted the 04 Module (HP System) from the Trent700 to the 524G/H. There were a few surrounding scenery changes (IPT NGVs being t
59 Zeke : I dont really, that sort of info has little practical application. Monitoring of engine airframe performance combinations is an ongoing effort and in
60 A520 : Gee! And I thought cryptic product name such as v03.1.5.beta02 had actually been invented by computer programmers!
61 Post contains images TepidHalibut : I was attempting to point out that the Trent 700 04 Module was used, not the whole Trent 700 core. It's even worse than that. Engine used on the BA 7
62 Baroque : Fantastic as always Lightsaber, I was just about to quit when I found your post. I presume this is a reference to the turbine description that shows
63 Post contains images Manzoori : LOL! If Lightsaber (PW) has access to this information then we (RR) have a security problem! One of my more experienced colleagues has asked me to ad
64 Baroque : Thanks for the information. The question was in the context of the link to the RR page for the T1000. As far as I could see, the description of the t
65 Manzoori : Sorry mate... we are of course bound by company policy not to give away information and I think it's a policy we can all agree we need to stick to. T
66 Baroque : Naturally, goes without saying and all that. But that still does not stop the non-RRers wondering what RR is going to do to get its SFC more competit
67 TepidHalibut : You mean the Trent ? ( Google and Wiki turns up "The designation was reused again in the 1960s for the RB203 bypass turbofan which was designed to re
68 Baroque : Thanks TH, that must have been the one I was thinking about. I looked at the Wiki entry, but last night did not persist through to the RB203 and now
69 Post contains images Jetlagged : Trent isn't the first river name RR have re-used. Tay is another. I don't think there's a criteria as such, other than being a UK river of reasonable
70 777236ER : Would be nice to have a Rolls Royce Aire, though.
71 TEAtheB : I like the sound of "Rolls-Royce Severn" Maybe they could build a really small engine with that many klbf thrust.
72 Boeing7E7 : Unless it's lighter and can provide the same performance with a lower thrust setting and has lower maintenance costs. There are more variables than a
73 Par13del : I have another question. It's mentioned thet RR engines typically stay on the wing longer than the PW or GE counterparts, what advantages do the other
74 Baroque : This is not generally known, but they did develop an engine called the Severn. However, it suffered short severe but periodic surge problems that are
75 Prebennorholm : Have you ever visited Bristol and watched the river Avon, a very narrow, fast moving and noisy river. What a perfect name for the RR Avon engine! PS:
76 Manzoori : LOL! You're right this thread is much improved since you know who got him/herself banned! :D Rez
77 TepidHalibut : In some ways, I miss his inane, stupid and ill-informed statements. As well as giving me a laugh, they could provoke some interesting discussions. Ba
78 AirbusA6 : Maybe the RB199 or EJ200 could have been given a European river name such as the Rhine? RR is based in Derby, whose river is the Derwent I believe, a
79 A520 : ... which also include Scotland ... so why not Fiddish, Livet or Morangie? More seriously, does anyone know the market shares in the narrow-body and
80 Jetlagged : There is a River Adur in the UK. Certainly large enough to justfiy being used as a name. Two rivers with similar sounding names. I assumed that the A
81 Baroque : Yes, I have been to both Avons. The Bristol one is famous around the world for the limestone section in the Avon Gorge (there is your bit of trivia f
82 TEAtheB : Maybe an engine to succeed Allison's engines? Possibly, but I reckon its the title that attracts the attention. How can you not click on the link?
83 Manzoori : Hmmm... I was under the impression that we (the British) wanted the 'e' adding... I don't think there is an E in the French spelling of Concord (apar
84 Post contains images David L : I believe Jetlagged is right. See Place de la Concorde.
85 Post contains images Manzoori : I Stand Corrected! Rez
86 Post contains images Jetlagged : As I recall the British suggested adopting the French spelling. I suppose on the basis that it would be better to concede, than wait for the French t
87 Baroque : That is my guess too, I had not realised there were quite as many others. And thanks for the meaning of Avon. While the Bristol Avon is the more inte
88 Jetlife2 : Saw the above. Not sure where you gained this impression, but FYI all FAA-certified engines have to meet the following requirement (quoting from FAR3
89 TristarSteve : Good answer but read the question. Yes we know that all jet engines accelerate from FLIGHT IDLE to near t/o in 5 secs. What Manzoori is saying is tha
90 Jetlife2 : Well I understand your point, and I suspect we are both right, but answering different questions. The text I quoted was that a difference in accel tim
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