You are starting two very expensive engines and the FADEC is not even good enough to realize you left your engine bleed switches on during the quick turn and will happily allow you to torch the engine and your paycheck in the process. Reciting starting events after they happen is useless. I've seen more than my share of sim partners routinely state "LP, HP, fuel, ignition . . ." start after start only to miss something when it doesn't happen.
Get in the habit of reciting (at least in your head) the events before they are supposed to happen. When you put the fuel switch to run, for example, look for the IGN icon followed by fuel flow, followed by TGT rise. Do this every time and the time one of those three is missing, you will notice.
You will, more than likely, never have to do anything other than press the START switches and watch the magic happen. But if that isn't the case, you might also want to look at:
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Speaking of abnormals, we've found it helpful to video some of these things as they normally happen, so if you ever have something that doesn't seem right, you have something to compare it to: G450 Engine Start.
Everything here is from the references shown below, with a few comments in blue.
[G450 Airplane Flight Manual §2-03-40]
Once hydraulic pressure is up, it will be almost impossible to disengage the gust lock.
Ensure the engine bleed valves are OFF. Otherwise, the APU load control valve will close once the engine reaches 20% HP rpm and that may result in a hot start. The EEC might auto abort the start in time to avoid an exceedance, but it might not. More: G450 Systems / APU Load Control Valve Logic.
If engine control is not in EPR mode, there will be a blue “L-R Engine ALT Control” Engine 1/6 page and an amber ALT annunciation on the CAS Page. You must change the engine back to EPR mode using the display controller: SENSOR / ENG ALT CTRL / toggle LSKs as applicable. Procedure shown here: G450 Abnormal Procedures / FADEC Reverts to ALT.
I look at this page to check the bleed air pressure and never look at it again.
Check that residual TGT is less than 200°C. If not, perform engine crank cycle to reduce residual TGT. You can do a normal engine start, just delay placing the fuel switch to RUN until 200°C.
If tailwind exceeds 10 knots, allow engine to achieve maximum cranking rpm and verify that positive LP RPM is achieved prior to selecting fuel control to run. If the tailwind or crosswind exceeds 25 knots, the aircraft must be turned into the wind prior to engine start.
Using the START MASTER provides FADEC protection and one igniter for normal ground starts. The right ACS pack will shut down whenever the START or CRANK master switches are depressed.
Continuous use of the starter is limited to three crank cycles with a 15 second delay between each. After three cycles delay use of the starter for 15 minutes.
You really ought to check the engine bleed air valves are off for every engine start. It is easy to get rushed when doing a quick turn and the price of failure here can be high. Some pilots say "Start Master, three ambers" for every start, checking for three amber lights on the bleed air panel when pressing the start master switch. This ensures you have turned off the two engine bleed switches and that the start master switch works and has shut off the right pack.
The right engine is normally started first to provide a test of the PTU. When the button is pressed the left ACS pack will shut down. You should first notice “SVO” icon and then a positive LP RPM indication. (If not, execute the G450 Abnormal Procedures / SVO Fails to Open procedure.
R FUEL CONTROL . . . RUN
Ensure you have HP rotation first, then LP rotation — this will keep you out of trouble for most opening conditions.
The FADEC will automatically schedule fuel and the “IGN” icon will appear when determined by the FADEC. If you don't see the IGN icon, execute the No Ignition procedure. TGT and both RPMs should slowly increase.
If the FADEC detects a problem the start will be aborted and “Autostart Abort” will appear on the CAS. Select START MASTER to OFF and the fuel control to OFF.
SVO/IGN . . . OUT AT APPROXIMATELY 44% HP RPM
You should see the IGN go out at 41% HP, followed by the SVO a few percent later. The Starter Air Valve includes a clutch which automatically disengages at 41% HP RPM. The SVO light indicates the closure is complete, usually 3% later. The operating manual also mentions 42% but this is a G-550 number.
If the SVO fails to close, turn the Start Master OFF, all bleeds OFF, and time for 30 seconds and turn the fuel control switch off once bleed air pressure stabilizes at a minimum value or by 30 seconds. See the G450 Abnormal Procedures / SVO Fails to Close procedure.
Idle HP RPM . . . CHECK 49% HP RPM MINIMUM
EVM . . . Check
The only reason we wait for this CAS message is to ensure the left system check valve works, preventing PTU hydraulic pressure from reaching the flight controls. See this in action: Hydraulic System Synoptics Video (Engine Start).
Repeat process for left engine. Process and indications are the same except: as the left system hydraulic pressure comes up the PTU pressure will drop to zero and the Single Rudder message will go out.
Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.
Gulfstream G450 Airplane Flight Manual, Revision 36, December 5, 2013