When approach guidance is established on final approach, a subsequent deviation may not recapture in a timely manner unless the approach button is rearmed.
THE SPEED BRAKE HANDLE MUST BE FULLY SEATED IN THE RETRACT DETENT TO PREVENT INADVERTENT EXTENSION.
FLAPS MUST BE SET AND EXTENDED TO 20° PRIOR TO SELECTION OF FLAPS TO DOWN.
APPROACH SPEED IS VREF + 5 KNOTS; HOWEVER, IN STRONG WIND CONDITIONS, ADD TO VREF 1/2 OF THE STEADY STATE WIND PLUS THE GUST INCREMENT TO A MAXIMUM ADDITIVE OF 20 KNOTS. APPROACH SPEED, INCLUDING ANY GUST ADDITIVE SHALL BE MAINTAINED TO THE THRESHOLD AND SHALL BE USED TO DETERMINE LANDING DISTANCE.
Notice this is no longer a recommended technique, it is procedure. So how do you do this? See VREF Additive, below.
AFTER TOUCHDOWN, PEDAL STEERING AND / OR RUDDER AERODYNAMIC CONTROL SHOULD BE USED TO MAINTAIN DIRECTIONAL CONTROL. DIFFERENTIAL BRAKING SHOULD AUGMENT PEDAL STEERING AS RUDDER EFFECTIVENESS DECREASES (IF REQUIRED). CONSIDER LIMITING T/R USE IF LANDING SURFACE IS DEGRADED OR CONTAMINATED TO PREVENT AIRCRAFT DAMAGE.
You must make the VREF additive called for by the AFM, it is no longer optional. This is a two step process. First, you have to make sure you have enough runway for the additional speed crossing the threshold. Second, you need to fly it. Fortunately, both of these steps can be done with a few key presses.
From the TSC FMS page select the "Perf Landing" page and enter the additive to the Threshold speed and Confirm Init to LDG Data. The computed landing distance will include this speed additive to your landing distance.
Photo: GVII Touch Screen Controller Perf Landing Page, with a 5 knot VREF additive
Click photo for a larger image
This automates the process of assuming you will be crossing the threshold with all of the additive so you can be assured you will still have enough landing distance. Many of us have been doing this manually for years. See: Gust Additives.
From the TSC FPLN page select "Flight Progress" and then "Departure and Approach Speeds" and enter the additive. The auto-throttle speed target will adjust automatically for you once you select the Flaps Down (39°) and will hold that until crossing the threshold.
In previous Gulfstreams we would MAN SPEED the target and you can do that with this airplane too, but don't. Keeping auto speeds will make a go around easier (one less button to remember).
[Ground and Flight Operations, pp. 243-244]
Minimum disengage height for the autopilot is 90 feet AGL from an ILS or LPV Approach (Flaps 39°), 130 feet AGL (Flaps 0°, 10°, 20°) and 200 feet AGL for all other operations. Maximum demonstrated altitude loss for coupled go-around is 50 feet. For limitations concerning use of the autopilot, see Section 01-22-20, Autopilot.
We are told that you can go lower with Flaps 39° because you will be at approach idle and not flight idle. I'm not so sure, according to the PAS, pp. 14-16 to 17, flight idle occurs with the gear up and flaps <22° while approach idle requires the gear down or flaps >22°. More about this: GVII Powerplant.
I don't agree with this technique. If you are at 100 feet on the correct glide path at VREF+5 and begin a power reduction, the airplane will lose more speed than the 5 knot additive or you will dip below glide path. Note this is above the height where ground effect takes effect. But even if you cross the threshold at VREF at the correct glide path, you will certainly dip below or go below VREF. This "best landing technique" has been preached by Gulfstream for a while now and I've noticed pilots tend to dip down into ground effect and then float, looking for the soft touchdown. I believe you can fly the airplane onto the runway using the autothrottle "Retard" function and end up in the touchdown zone and on speed.
Ground effect will only cause the exacerbated effect if you allow it to. The airplane should cross the threshold between 500 and 700 fpm, depending on approach speed, glide path angle, and winds. Allowing that to continue until 20 feet preserves the downward momentum.
I have long had a philosophy that the sooner you get the airplane to 80 knots, the better. When things go badly, you are better off at taxi speed than landing speed. But I also think hopping on the brakes to make an intersection after landing may be putting too much stress on the airplane and can even reduce directional control, so there is a balance to be had. The GVII autobrakes have been a game changer. I was warned that overriding the autobrakes took a lot of practice to do smoothly but I simply used my old Boeing 747 technique and things went well from my very first landing in the airplane. That technique: let the autobrakes do their thing until 80 knots, then apply just enough pressure to override and then maintain that pressure until you can reduce it. Easy.
Over the following months we started getting more and more aggressive to the point we were overriding almost immediately after touchdown and our braking became jerky. See: Smoothness for more about this aeronautical engineering concept. So then we thought, why wasn't this a problem before? Our solution: back to the basics:
Technique: Let the autobrakes do their thing until 80 knots, then apply just enough pressure to override and then maintain that pressure until you can reduce it.
Here is a video of our very next landing: GVII Autobrake Technique. I took time stamps of the video while looking at the airspeed on the PFD. We touched down at 121.5 knots and got to 80 knots 7.96 seconds later on autobrakes alone, using the Medium setting. That comes to a deceleration rate of 5.21 nm/hr per second, and that comes to:
This is a little less than the advertised autobrakes medium rate, but remember the autobrakes ramp up to that rate over three seconds.
Gulfstream GVII-G500 Airplane Flight Manual, Revision 5, March 3, 2020
Gulfstream GVII-G500 Ground and Flight Operations, released as part of the GVII-G500 AOM, §02-01-10
Gulfstream GVII-G500 Production Aircraft Systems, Revision 3, July 15, 2019
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