Power settings

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RAF_Quantum
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Power settings

Post by RAF_Quantum »

Hi Guys,

I've been asked the question about range for the 1-11. The longest route we have programmed is Manchester EGCC - LGRP Rhodes which as the crow flies is just over 1600nm. Looking at some of your flight logs for 1-11 trips, there isn't any sort of pattern regarding fuel consumption. I guess we all need to be singing from the same hymn book so I think we need to come up with some economical cruise settings.

I've never really looked hard at the fuel consumption aspect of flight sim prior to this way of flying within FlyNET. It certainly gets you thinking about things more and how to operate your aircraft efficiently.

I guess we need the 'gurus' of the different types to give some guidance here. Please post below.

Rgds

John
Last edited by RAF_Quantum on 29 Jun 2006, 00:21, edited 2 times in total.
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Rick Piper
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Post by Rick Piper »

Hi John

no offence ment but you will never get any hard and fast rule for any of these aircraft.

It's a simulator and range etc is not the same as real range.

In FS the higher you cruise the less fuel you will use.

You can fill in all this info but it will get you nowhere.

I notice that all the 1-11 specs on flynet give different crusise speeds.

TAS or Groundspeed is all we need as anything else is of no use.

As soon as you switch on real weather the numbers gathered are a mile off anyway.

Regards
Rick :wink:

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RAF_Quantum
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Post by RAF_Quantum »

Hi Rick,

Thanks for that. It's just a rule of thumb as a start point. Looking at actual kgs used between different pilots, it's obvious that different power settings are being used and probably cruise altitudes. On one particular flight you got another 200nm further than another pilot for a similar fuel burn. Someone might be pottering around at 20,000ft with a particular power setting when they really should be at 30,000ft with a different power setting. Is Manchester - Rhodes 'do-able' in the 500? If it's not, I'll have to build in a tech-stop.

Rgds

John
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Chris Trott
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Re: Power settings

Post by Chris Trott »

Okay, for the pistons and turboprops, it's fairly straightforward. I'll list the ones I can get offhand and update later when I get home. Rick, I've found the numbers on most of the models we've used to be close enough to work off the checklists and real-world information for your power settings for pistons and turboprops and/or cruise speeds in the case of turbojets. This should give everyone an idea of where they should at least be shooting for.
RAF_Quantum wrote: ==============================================
Vanguard/Merchantman

Normal cruise - 12,500 RPM

Max range cruise - 11,500 RPM

Cruise altitude - 19,000 - 22,000 Feet

==============================================
Viscount 700srs

Normal cruise - 14,000 RPM

Max range cruise - 13,300 RPM

Cruise altitude - 16,000 - 20,000 Feet

==============================================
Viscount 800srs

Normal cruise - 14,200 RPM

Max range cruise - 13,500 RPM

Cruise altitude - 16,000 - 20,000 Feet

==============================================
Argosy

Normal cruise - 14,200 RPM

Max range cruise - 13,500 RPM

Cruise altitude - 10,000 - 16000 Feet

==============================================
HS 748

Normal cruise - 14,200 RPM

Max range cruise - 13,500 RPM

Cruise altitude - 10,000 - 16,000 Feet

==============================================
DC-3

Normal cruise - 32" MAP, 2000 RPM

Max range cruise - 31" MAP, 1800 RPM

Cruise altitude - 3,000 - 10,000 Feet

Note: These numbers are general numbers and MAP actually varies by engine, temperature and altitude.
Last edited by Chris Trott on 09 Aug 2006, 16:32, edited 3 times in total.

cstorey
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Post by cstorey »

In real life manchester -rodos was just about possible in a -400,if winds were nothing out of the ordinary but it is absolutely vital to get FL350 or you will not make it. bear in mind that in reality you could were not permitted to go above this because of no drop down oxygen. So econ techniques are necessary - no faffing round terminal areas ; careful monitoring of the balance between climb rate and fuel consumption, and a long range cruise rather lower than normal i.e. about Mach 0.71 or just over 420kts TAS, together with maintaining cruise level to the last possible minute

I have no direct knowledge of the -500 but Peter Mcleland probably can help with that

Chris

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Viscount Cornbank
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Post by Viscount Cornbank »

The Viscount cruise power settings are incorrect; The 700 series, all of which had Dart 6 engines, has a maximum continuous RPM of 14000. Likewise for the 800. The 810 series, with Dart 7 engines, has a max cont of 14500RPM but more normally 14200RPM . In the last panel releases, which are getting long in the tooth , that equated to a 90% throttle setting.

Fraser
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Chris Trott
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Post by Chris Trott »

Fraser,

Looking at your panel document, you show 14200 as normal cruise RPM, which is what is stated. The 13500 is based off of another set of charts I have for the same engine that refer to 13500 as "alternate cruise power".

I didn't find any 700 panel or documents so I simply copied and pasted. I can use the 802/806 numbers and use them though which would be 14000 and 13300.

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MALTBY D
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Post by MALTBY D »

On the 1-11 I usually cruise at mach .72
Shorter routes 21-25000 ft, longer routes 30-33000 ft.
Climb at 290-300 kt, RPM 93-94%.

From the figures for the 400 series doing CYYR-BIKF, 7823kg fuel was used for a flight time of 3.3hr
7823kg / 3.3hr = 2370kgph average.
Average ground speed (inc takeoff & land) was 1318nm / 3.3hr = 399kt
So very roughly a max fuel load of 11000kg / 2370kgph = 4.6 hours max flight time (landing on vapours)
399kt x 4.6hr = 1840nm max range if the maths is right? :think:

Average ground speed should rise the further you travel, so there is some error. But then I did have a 25kt tail wind so that may balance it out.
Tricky stuff init :dunno:

------------------------
On the Trident I do mach .84 - .86 at 27-36000 ft
Climb at 270-290 kt, 93% RPM.

------------------------
VC10 long range cruise mach .84 at 31-38000 ft.
Climb at whatever speed I fancy, 92-93% RPM.

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Post by bigred1970 »

just my 2 cents but if you have questions if the 500 would make it, could you use the 475, it is lighter but has the same fuel load as teh 500 as far as I can tell.

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johnhinson
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Re: Power settings

Post by johnhinson »

RAF_Quantum wrote: DC-3

Normal cruise - 32" MAP, 2000 RPM

Max range cruise - 31" MAP, 1800 RPM

Cruise altitude - 3,000 - 10,000 Feet

Note: These numbers are general numbers and MAP actually varies by engine, temperature and altitude.
I'm new around here so excuse me for jumping in on an old item, but
I believe I can correct these figures. The established cruise settings for
a DC-3 are 30" MAP/2050 RMP.

As it happens this yields a lot less than the 140-odd IAS that the
various FDEs around give you. At 3000 feet it gives you about 120, but
it may be a tad more at higher altitudes.

John

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