Simviation Forum - Lockheed Electra engine management

Apr 17^th, 2012 at 7:43am

reachva Offline
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Greetings all,

Lately I've been enjoying flying the Electra model available for FSX. I've tried to read as much as I can find about operating this airliner correctly but I'm at a bit of loss when it comes to some of the finer details of turboprop management.

Looking at the gauges in the VC, I can see the typical oil pressure, oil temperature, exhaust temperature, engine RPM and thrust settings. I haven't however been able to find much good material as to what settings I should be looking for when it comes to particular phases of flight (taxi, climb, cruise, descent, etc). I'm sure this has to be somewhere but I can't find the documentation.

The other issue I'm having is that I can't seem to find any indicators as to what the propeller RPM is. As mentioned I can only seem to find the engine RPM gauge measuring I'm assuming the turbines revolution speed but nothing from the propellers. As a result I'm having to guess what settings I think they should be in during flight; not the most realistic approach!

Does anyone have any experience with how to handle these or knows about where I can find more?

By the way I'm flying the Team FS KBT Electra.

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Reply #1 - Apr 17^th, 2012 at 8:14am

DaveSims Offline
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Clear Lake, Iowa

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While I don't know the correct numbers to use, I can tell you most turboprops don't give you the prop rpm, instead it is in a percentage, as is the turbine engine speeds as well. Why turbine manufacturers use percentages instead of actual rpms, I'm not really sure.

Dave

www.flymcw.com

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Reply #2 - Apr 17^th, 2012 at 10:10am

Flying Trucker Offline
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Not sure this Link will help or not...think it is for FS2004 (not sure) and not to be used for the Real Aircraft.

Scroll about a third of the way down on the below Link and there is some published information there.

Sorry if I wasn't much help but will see what else I can find for you as per Real Aircraft Settings.

http://www.fseforums.com/forums/thread-view.asp?tid=60883

Cheers...Happy Landings...Doug

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Reply #3 - Apr 17^th, 2012 at 8:57pm

aeroart Offline
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The Electra had constant speed engines that were geared down at a 10:1 ratio. So when the turbines are turning at 14,750 rpm, the props are doing 1,475 rpm.

Art

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Reply #4 - Apr 17^th, 2012 at 9:10pm

DaveSims Offline
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Clear Lake, Iowa

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aeroart wrote on Apr 17^th, 2012 at 8:57pm:

The Electra had constant speed engines that were geared down at a 10:1 ratio. So when the turbines are turning at 14,750 rpm, the props are doing 1,475 rpm.

Art

I guess I was forgetting, but if I recall correctly, the Electra has the same engines as the C-130 Hercules. And if I also recall correctly, those engines always turn at 100% RPM, with power settings being torque settings, which effects the prop pitch, not rpm.

Dave

www.flymcw.com

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Reply #5 - Apr 18^th, 2012 at 6:21am

reachva Offline
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You're right, I just took a look and the gauges do indeed measure in % torque. Seems a bit unusual to me considering my normal aircraft is an ERJ-170/190 but I'm slowly getting there. I'm pretty sure the default King Air 350 had gauges for both the prop and engine speeds which is what is causing the confusion.

The below is from the link posted which seems to confirm (as far as I can tell) that there is no direct method of determining the exact prop rpm but instead working it out based upon the engines. It also seems to state that the prop positioning was automatically determined by thrust setting.

Quote:

2. ENGINE CONTROLS AND INSTRUMENTS.

The Allison 501-D13 is a constant speed axial flow turbine
engine, driving a 13 foot diameter propeller though a two
stage reduction gear. Fourteenth stage compressor bleed air
valves are provided for anti-icing and starting.

The Power Levers have Start, Ground Idle, Flight Idle and
Takeoff detents. During ground operation, the power lever
controls both fuel flow and propeller pitch. RPM Selector
Switches enable both Normal and Low taxi RPM to be selected.
In the Low position, the engine will operate at 9900-10300
RPM. When the switches are moved to Norm, the idling RPM will
accelerate to 13150-13750. As a safety feature, the switches
will automatically trip to Norm when the power levers are
moved beyond the ground, or Beta range.

During flight, the power lever affects fuel flow only, the
propeller governor maintaining constant engine speed. In
flight, once the power lever has been positioned above
approximately 60%, the fuel control system will maintain
selected Turbine Inlet Temperature (TIT) automatically.

The TIT is the primary datum for selecting engine power,
provided in doing so limitations on maximum shaft horsepower
are not exceeded.

1. TURBINE INLET TEMPERATURE GAUGES.
The presentation of the TIT gauge is in the form of a
pointer against a scale from 0-1200 ‘C. Additionally an
electronic display shows the precise TIT. The gauges are
normally powered by the Essential Bus, or in an emergency
or when the Essential Bus is not powered, by the standby
inverter. The inverter is normally set to Emerg. before
take off and landing.

MAX TAKEOFF……………………………………….971’C
MAX CONTINUOUS……………………………….895’C
MAX CRUISE………………………………………….847’C

2. SHAFT HORSEPOWER GAUGES.
Four LCD shaft horsepower gauges show the power output from
the engines in both digital and pictorial form. These gauges
may be substituted for the original analogue type by editing
the gauge names in the panel cfg. from No1_HP_LCD to
No1_HP and so on for each gauge.

MAX TAKEOFF……………………………………4000 HP
MAX CONTINUOUS……………………………3400 HP
MAX CRUISE………………………………………3200 HP

Note that the SHP reading is affected by ambient conditions,
a minimum of 1500 SHP is required when the power levers are
set to takeoff.

3. ENGINE RPM GAUGES
Engine RPM is displayed on dual pointer gauges, the inner
displays 1000s of RPM, the outer 100s of RPM. The system
is self contained, requiring no electrical power.

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Reply #6 - Apr 22^nd, 2012 at 7:40pm

C Offline
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Doh! I ignored this because I thought it'd be about radial engine handling (wrong Lockheed Electra), of which I have precisely Zero experience!

Quote:

And if I also recall correctly, those engines always turn at 100% RPM, with power settings being torque settings, which effects the prop pitch, not rpm.

Indeed - sensible turboprops are like this. Power is controlled by varying the prop pitch and fuel entering the turbine, which is always rotating at the same RPM (other than on the ground, where a lower %RPM can be selected - in my experience of the Garrett TP331, it was via a simple switch).

Quote:

I'm pretty sure the default King Air 350 had gauges for both the prop and engine speeds which is what is causing the confusion.

The King Air (yes, even the 350) and its "wonderful" 1930s vintage engine controls are an entirely different beast, as you have the throttles controlling the tq and the prop levers doing the RPM. I suppose that's the limitation of it being a "free turbine"(the prop isn't physically attached to the powering gas turbine) or whatever it's called. Either way, IMHO, ahving operated both styles, it's a PITA; 6 levers in a small cockpit when 2 power levers and two small fuel cut-off levers could have sufficed!

As someone pointed out to me, it was probably due to the pilots of the time refusing to fly a twin with less than 6-levers! Grin

« Last Edit: Apr 23^rd, 2012 at 3:44am by C »

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Reply #7 - Apr 22^nd, 2012 at 8:04pm

Flying Trucker Offline
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Hi "C"

As someone pointed out to me, it was probably due to the pilots of the time refusing to fly a twin with less than 6-levers!

Well we had to make it look like we were earning our Pay "C"... Grin

Cheers...Happy Landings...Doug

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Reply #8 - Apr 23^rd, 2012 at 12:09am

reachva Offline
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Fly Reach Airways Virtual!
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Alright now I think I understand how to operate the Electra reasonably realistically. Need to revise my VOR and DME navigation skills but I'm getting there (been quite a while since I flew airline routes in anything other than an E-jet).

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Reply #9 - Apr 23^rd, 2012 at 3:45am

C Offline
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Flying Trucker wrote on Apr 22^nd, 2012 at 8:04pm:

Hi "C"

As someone pointed out to me, it was probably due to the pilots of the time refusing to fly a twin with less than 6-levers!

Well we had to make it look like we were earning our Pay "C"... Grin

Lol. Real airliners have flight engineers to look after such trivial tasks! Grin

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Reply #10 - Apr 23^rd, 2012 at 11:30am

Flying Trucker Offline
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Seems like today they are going back to where the Pilot had to be the Flight Engineer also...

The Air Force Manuals my son uses are all beyond me... Grin

Cheers...Happy Landings...Doug

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