Photo: From Eddie's Cockpit.
At home we leave this to the mechanic but on the road it is our responsibility. Checking the oil means more than just checking a 1/6th page before shutting down the APU.
Before you fill the oil, read the caution on the TRANSIT PAGE in the QRH. (Reproduced below.) If someone tells you your airplane has the new remote oil filler valve, proceed with caution. Though this issue has been known for many years, as of January 2013 no G450's have had the new valve installed.
Most of this comes from the G450 Aircraft Flight Manual, with a few comments in blue.
Figure:Transit Check, from G450 Quick Reference Handbook pg. NF-5.
[G450 Quick Reference Handbook NF-5] At intervals not exceeding 14 hours, check the oil, replenish as necessary, and examine the oil filter DPI to ensure there hasn't been any blockage.
How do you do that? Read on . . .
[G450 Aircraft Operating Manual §09-02-20 ¶3.A.] Preparation
Figure: Tay 611-8C Engine Oil Tank, from G450 Aircraft Operating Manual §09-02-20, Figure 6.
[G450 Aircraft Operating Manual 09-02-20 ¶3.B.] Level Check Using Sight Glass
Note that there are two scales, one for the left engine and the other for the right. The site glass is the same for both engines but the tilt of the engines makes the levels different.
Figure: Aircraft-Installed Oil Replenisher Panel, from G450 Aircraft Operating Manual §09-02-20, Figure 7.
[G450 Aircraft Operating Manual 09-02-20 ¶3.C.] Level Check Using Oil Replenisher
Can you trust this thing? You should compare its readings to the sight glass a few times and get a feeling for its accuracy. After a while you will learn if it is accurate or not. (Ours is.)
[G450 Aircraft Operating Manual §09-02-20 ¶3.C.] Servicing Using Aircraft-Installed Oil Replenisher
NOTE: The oil replenisher pump will stop automatically when FULL level is reached.
Check the sight glass level on both engines and note the amount required. Using the oil replenishing system, return the lower engine to its target level. If the following flight will be less than 7 hours, replenish the other engine after the next leg. If both engines must be serviced prior to the next leg, refer to the QRH Transit Check procedure, NF-5.
Experience has shown that most Rolls Royce engines operate normally at a value less than full without burning excess oil, but if filled to “full” will tend to burn oil more quickly. You should know what “target level” to shoot for when checking oil levels. This level is typically one or two pints low.
Photo: From Eddie's aircraft.
The DPI is viewed from the oil replenish access panel:
Even if you have determined the cockpit 1/6th page or the remote oil replenishing gauges are accurate, you will need to physically open the access panel and look at the DPI on each engine at least every 14 hours.
Photo: From Eddie's aircraft.
[G450 Aircraft Operating Manual §09-02-40 ¶1.A.] Hydraulic fluid servicing procedures for the Gulfstream G450 are included to enable the flight crew to supervise and/or assist ramp service personnel when the aircraft is away from its fixed base of operations. Servicing procedures provided in this section are general in nature and assume that no abnormality exists within the aircraft and/or hydraulic system. They are intended to allow routine servicing of hydraulic fluid by the flight crew.
[G450 Aircraft Operating Manual §09-02-40 ¶1.B.] Gulfstream recommends that flight crews use the Hydraulics / Summary synoptic pages when checking hydraulic reservoir quantities. Quantities shown on the Hydraulics / Summary synoptic pages are compensated for temperature, which provides for consistent servicing levels at varying ambient temperatures. When properly serviced, LEFT hydraulic system quantity should be no more than 2.75 gallons; RIGHT hydraulic system quantity should be no more than 0.70 gallons.
The quantity indicator is not accurate unless the system is pressurized. The cockpit synoptics are the most exact indication of fluid quantity. If you need to service, you will need to find a qualified mechanic and hand him this section from the AOM.
Gulfstream G450 Aircraft Operating Manual, Revision 35, April 30, 2013.
Gulfstream G450 Quick Reference Handbook, GAC-AC-G450-OPS-0003, Revision 34, 18 April 2013