"Securing" the aircraft, if you follow the QRH (which agrees with the AFM), takes you from stopping the APU to a dark cockpit, the gust lock on and the parking brake released. But there is more to it than that. The AOM picks up from there and gets you to the point you can walk away from the bird. Of course you have got another list of concerns if in cold weather.
What follows comes from the references shown below. Where I think it helpful, I've added my own comments in blue.
[G450 Airplane Flight Manual, §2-06-40]
- Before you press the stop switch, consider a few things:
APU . . . STOP
Boost Pumps . . . OFF
Bleed Air (ENGINE / APU) . . . OFF
- AC Power — if you don't have an external AC power cart hooked up and available, you will need to turn off the DU's, just about every bit of avionics that has a power switch, and anything that relies on the 60 Hz power converter. This will be a break power transfer from power to no power, and that isn't graceful.
- Brakes — Make sure the wheels are chocked and release the parking brake. You should do this first because there is no guarantee how long the brake accumulator will hold those brakes so you want the APU running until you've done this. See G450 Systems / Landing Gear Wheels and Brakes for more on this.
- You may also want to pull up the GND SVC synoptics before you shut down the APU to get an indication of your engine oil levels. See G450 Normal Procedures & Techniques / Post Flight Servicing for more on this.
- You may also want to check your APU run time now since that information on the CMC is not available without AC power.
Turning the APU bleed off really doesn't matter but you really need to be vigilant about turning the engine bleeds off. See G450 Systems / APU Load Control Valve Logic for an explanation on why this is critical.
APU Master . . . OFF
[G450 Aircraft Operating Manual §03-02-30 ¶4] Monitor APU indications until APU RPM is less than 5%.
Cockpit Lights . . . OFF
CABIN PRESSURE CONTROL Panel . . . SELECT MANUAL / VERIFY TROV CLOSED
After a flight the TROV should close on its own, selecting MANUAL ensures it stays closed the next time battery power is turned on.
LEFT / RIGHT BATTERIES . . . OFF
Gust Lock . . . ON
Make sure the hydraulic pressure has spun down to zero to avoid putting stress on the individual locks and latches. You may need to move the yoke and rudder pedals to center to ensure the gust lock is engaged. If you skip this step the engage point can become worn and eventually will not work. More about this: G450 Systems / Gust Lock.
IRS “ON BATT” Lights . . . CHECK OUT
Parking Brake . . . AS REQUIRED
Photo: From Eddie's aircraft.
Of course we don't have IRS batteries; the light in question indicates the IRU's are drawing off the E-Batts.
[G450 Aircraft Operating Manual, §09-01-40, ¶3.]
- Installation of Ground Safety Locks:
- Main Landing Gear: The main landing gear safety lock is a pip pin that is placed in the lower end of the left and right side brace actuators. The pip pin prevents the internal locking feature of the retraction cylinder from unlocking.
- Nose Landing Gear: The nose landing gear safety lock is a pip pin inserted through the lock hook on the trunnion which prevents the nose landing gear over center down lock linkage from unlocking.
- Gust Lock: A gust lock is provided to enable the flight crew to lock all flight control surfaces without the use of external locking devices. The gust lock protects each flight control surface in winds of up to sixty (60) knots. With the gust lock engaged, movement of the engine power levers forward of the idle detent is not possible.
- Ensure gust lock is engaged (ON).
- Check parking brake accumulator pressure, located on the copilot's flight panel or left side of nose wheel well, for available pressure. The indicator should read 3000 psi for full charge to 1700 psi minimum for setting the parking brake. If below 1700 psi, charge the accumulator using the AUX pump.
- Set parking brake by pulling PARK/EMER brake handle in cockpit. Rotate handle until handle locks in detent.
- Chock main landing gear wheels fore and aft.
- After wheel chocks are in place, release parking brake by pulling and rotating PARK/EMER brake handle in cockpit. Maintain gentle restraint while allowing handle to return to the "brakes off" (released) position.
- Gulfstream recommends installing engine inlet covers and pitot static probe covers when the aircraft is to be left unattended for any period of time up to one overnight stay. If aircraft is to be left unattended for a period longer than one overnight stay, or if weather conditions make it advisable, install all protective covers.
- Close, latch and lock main entrance door and external baggage door.
- Disconnect main aircraft battery connectors if aircraft is to be parked for three days or more.
I have never done this on a Gulfstream and have never had a problem. I failed to do this once on a Challenger and the battery was dead within a week. Your call.
- Ensure that a good electrostatic ground is available and that the aircraft is properly connected to it.
- Moor aircraft if weather conditions make it advisable.
- If wind is expected to exceed thirty (30) knots due to a severe storm or wind condition, the aircraft should be housed. If housing the aircraft or flying the aircraft to a safe location is not possible, the aircraft should be moored.
- Mooring provisions for the Gulfstream G450 are incorporated through the use of spring-loaded mooring rings arranged as follows:
- Main Landing Gear: One ring on outboard face of each main landing gear strut.
- Nose Landing Gear: Two rings, one on each side of the nose landing gear strut, just above the taxi lights.
- All mooring rings are made to pivot and, when not in use for mooring, are held down by a torsion spring against the strut in order to clear lines and structure in the wheel wells when the landing gear is retracted. It is recommended that the mooring rings be lock wired against the strut when not in use as an added safety precaution.
CAUTION: THE GROUND ATTACHMENT POINTS AT THE NOSE LANDING GEAR MUST BE CAPABLE OF A MINIMUM LOAD OF FIVE THOUSAND (5000) POUNDS EACH. THE GROUND ATTACHMENT POINTS AT THE MAIN LANDING GEAR MUST BE CAPABLE OF A MINIMUM LOAD OF FIFTEEN THOUSAND (15000) POUNDS EACH.
Figure: G450 Mooring Rope Attachment, from G450 Aircraft Operating Manual §09-01-40, Figure 8.
Remember your airplane is basically a kite, albeit a 75,000 pound kite. In high winds a set of chocks on each wheel might not be enough.
Additional Items (Technique)
There are additional items you may want to add to your checklist, some for convenience and some to prevent possible damage to the airplane:
- EFB . . . Turn off
- Window Locks . . . Install (Without these installed, the lock on your main cabin entrance door is useless.)
- External Baggage Door . . . Lock (Same as the window locks. You may need a ladder to reach the lock or you can simply open the door, lie on the floor with your shoulders outside the door, and lock it with your body mostly inside.)
- Galley Faucet Guard . . . Install (Most galleys do not have floor sensors to prevent the faucet from turning on. If the faucet is accidentally placed on with power off the aircraft, the next time power is applied you may not notice the sink overflowing until it is too late.)
- V-6 Valve . . . Close (When we bought our airplane in 2009 we were told this wasn't necessary as the software fix was complete, there was no chance the water tank valve would creep open and overflow the aircraft toilets while the aircraft sat overnight. And yet we continued to hear stories about this very thing happening. A brand new G-550 at our airport showed up in 2013 and it has had this happen several times. We close the V-6 when the aircraft is unattended.)
- Water tank pressure relieve valve . . . Relieve pressure. If you press the pressure relief valve you will hear a loud hissing sound; this is the residual pressure in the tank. By getting rid of this pressure you further prevent the problem closing the V-6 valve is meant to address.
- Gear Pins . . . Install (There is no way your main gear are going to retract without hydraulic power. The nose gear is another story, you need those gear pins installed. See G450 Systems / Landing Gear Uplocks and Down locks for why.)
- Steering Link . . . Stow (A little paranoia here, I've heard of pilots returning to their aircraft and the steering link was missing. We hide our in the door when parked overnight.)
- Pitot Covers . . . Install (Especially if you are parked some place dusty or buggy)
Additional Items (Cold Weather)
When you expect the aircraft will be left outside with temperatures below freezing, you have many additional considerations:
Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.
Gulfstream G450 Airplane Flight Manual, Revision 35, April 18, 2013
Gulfstream G450 Quick Reference Handbook, GAC-AC-G450-OPS-0003, Revision 34, 18 April 2013