G500 FLIGHT TEST
flightglobal.com 22-28 May 2018 | Flight International | 27the G500, Claffy would call out speeds 10kt
faster than book to provide a little margin
should I be overly aggressive in rotation. The
engines advanced and stabilised at 91.2%N1.
Acceleration was brisk for the light aircraft,
our fuel load of 6,710kg (14,800lb) less than
half the maximum of 13,720kg. When Claffy
called “rotate” at 130kt indicated air speed
(KIAS), my initial pull was indeed a bit too
much, an action primed by what I had per-
ceived to be high forces needed during the
post-start control sweep. I immediately re-
laxed the back pressure with the G500 lifting
of the runway in an 8° nose-high attitude.
Once airborne with the gear and flaps re-
tracted, I followed the flight-director guidance
in the HUD for the 200KIAS climb. The flight-
director guidance cue is “winged diamond”
in both the HUD and on the panel-mounted
PFD. Flight-director guidance is intuitive
where one places the “winged circle” flight-
path marker over the flight-director cue. Once
above 3,000ft, I lowered the nose and acceler-
ated the G500 to 250KIAS in a left-hand turn
towards the Atlantic Ocean, where we would
work in one of the charted warning areas.
In the climb to flight level 400 (40,000ft), Ihand-flew the aircraft and would periodical-
ly execute bank-to-bank turns at speeds from
250 to 300KIAS, with my feet on the floor
and at bank angles of 30° to 45°. Aircraft re-
sponse in roll was crisp and predictable,
with desired bank angles easily captured.
During the higher bank-angle turns I found I
needed to add back pressure to keep the nose
from dropping; the G500’s flight-control
scheme does not include pitch compensa-
tion for banked turns, a feature found in
other FBW control schemes.HIGH-SPEED CRUISER
After levelling at flight level 400 the G500 ac-
celerated to and stabilised at M0.90, its high-
speed cruise condition. A total fuel flow of
2,920lb/h held M0.90 and an indicated air-
speed of 274kt. Static air temperature was
-61°C, about 5°C colder than standard, with a
resultant true airspeed of 510kt. Gulfstream’s
published NBAA IFR range is 4,400nm at
this speed.
Next, I slowed the G500 to M0.85 for a
long-range cruise condition. At an indicated
airspeed of 258kt, total fuel flow dropped to
2,400lb/h. On the cool test day, resultant trueairspeed was 476kt with a book range of
5,200nm. These are impressive figures; the
G450 had a maximum range of only 4,350nm
at M0.80. While this performance is a marked
improvement, it does just bring the G500 in
line with the capabilities of the Bombardier
Global 5000, one of its major competitors.
Once level at flight level 400, I noted a
differential pressure of 0.719bar (10.4psi)
with a cabin altitude of only 3,020ft. It is
well-proven that lower cabin altitudes are
less fatiguing. The G500 shares the G650’s
0.74bar maximum differential-pressure
cabin pressurisation schedule, which yields
a remarkably low cabin altitude of 4,850ft at
51,000ft.
For the flight test, I borrowed a lightweight
active noise-reduction headset from Gulf-
stream. The headset is the same one I use fly-
ing the Boeing 737NG. While it provides
some relief from the Boeing’s loud cockpit it
is by no means as effective as more expensive
ear-cupping models I have worn on other
business jet test flights.
What I noticed while setting up for upcom-
ing cruise performance points was how quiet
the cockpit was. I could have a conversation ❯❯Safety pilot Todd Abler joined Gerzanics
and Claffy for pre-flight walkaroundGulfstream