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777 Autostart: Wrong logic.

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Hello all.The Autostart system of 777 PSS are incorrect. In PSS 777 when i select ING START (Overhead, left or right ingnitors) engines comes to start before the CUTOFF SWITHCES are in RUN position. The EEC waits the command of pilot (CUTOFF IN "RUN" POSITION) to start the engine. This is correct way.Actually, the 777 PSS are modeling an MANUAL START (Not AUTOSTART). You can disable AUTOSTART bottom or not in overhead: PSS 777 will dont make an correct Autostart.Ernest

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Very true. I was just about to make a post about this. I hope this gets address soon with a patch. Just for reference here is the correct way to start the engines. Auto & Manually.The AUTOSTART switch must be OFF to accomplish a manual start. Ignition and fuel are provided as soon as the FUEL CONTROL switch is positioned to RUN.The engines can be started using the autostart system or manually. Autostart is the normal starting mode. Selecting OFF on the AUTOSTART switch disables autostart and allows manual, pilot-monitored, starting. Bleed air powers the starter motor, which is connected to the N2 rotor. The starter air source is normally the APU, but air from ground carts or another running engine can be used.The START/IGNITION selectors control the starter air valves and provide continuous ignition capability. Ignition and fuel flow are controlled through the FUEL CONTROL switches. At approximately idle N2 RPM, the EEC commands starter cutout, and the START/IGNITION selector moves to the NORM position.The Autostart allows the EEC to control fuel and ignition and automatically abort the start for certain malfunctions. With the AUTOSTART switch ON, the autostart sequence is initiated by rotating the START/IGNITION selector to START and moving the FUEL CONTROL switch to RUN. The START/IGNITION selector opens the starter air valve to begin dry motoring the engine. Moving the FUEL CONTROL switch to RUN opens the spar fuel valve, but not the engine fuel valve. The proper sequencing of fuel and ignition is controlled by the autostart system. With the FUEL CONTROL switch positioned to RUN, the EEC opens engine fuel valve and energizes the ignitor(s) at the appropriate N2 RPM.

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I waiting for explain.This is a *BIG ERROR*. Must be corrected ASAP if possible. Thanks,Ernest

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>this was mentioned during testing, it will not be changed>>John>PSS SUPPORT>support@phoenix-simulation.co.uk>>http://www.avsim.com/pss/phoenix.jpgIt will not be changed? GREAT SUPPORT! :-erks"PSS 777 Professional?" Sorry but this is a joke. :-xxrotflmaoIm dissapointed, very dissapointed.Ernest

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I thought it was wrong too. On the 747-400 nothing happens until you have both the fuel switch in run and the start switch pulled. However according to a post by a Cathay 777 pilot on Airliners.net, the procedure is to select start, wait until oil pressure is indicated (which means the engine is turning over presumably), then select fuel to run. This is because the only thing FADEC does not monitor during start is oil pressure.I'm not that familiar with the 777, but I'll keep an open mind for now. Not all aircraft work the same, and it would be wrong to criticise the 777 because PSS have not programmed it to work like a 747 :)If you want it to work the 747 way, then select fuel to run first, then select engine start.Edit: My apologies, it seems the 777 procedure only requires a valid INDICATION of oil pressure, which is not available until the start switch is put on. It does not imply the engine begins cranking. So the crew select start, check the oil indications, then select run. At that point the engine begins to crank. So, it does appear the PSS 777 is incorrect. However it's relatively small issue. I'm more concerned with things not simulated at all. How very PSS like to immediately refuse to fix it :)

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Selecting the start switch to start opens the start valve and turns the engine.When the fuel control switch goes to run the spar valve opens and the engine valve is armed for operation by the EEC. Also the ignition is armed at this point.So the start valve logic is correctly modelled.Cheerio Sjaako

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>Selecting the start switch to start opens the start valve and>turns the engine.Negative. EEC waits the CUTOFF "IN RUN POSITION" and begins turn the engine.

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auto start sequence isautostart to onEEC monitors the engine parameters, this is not modelledstart selector to startstart valve opens provided bleed air to rotate the starter motorfuel control switches moved to runspar valve opens, engine fuel valve still closed, only spar valve modelledwhen engine rotation speed appropriate, EEC opens the fuel valve and energizes and ignitoras mentioned no changes will be made to the programming of autostartJohnPSS SUPPORTsupport@phoenix-simulation.co.ukhttp://www.avsim.com/pss/phoenix.jpg

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>Negative. EEC waits the CUTOFF "IN RUN POSITION" and begins>turn the engine.Not according to Boeing 777 Tech manual Section 20 Engine/Autostart.Might want to read up on that.Cheers

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