The DFCS does not give pilots the same unlimited authority in pitch because the human could stall the airplane on the low end, or overstress the airframe on the high-speed side. If you pull the stick back to a flight path that there is not enough energy to sustain, the DFCS will yell at you and flash an urgent message on the PFD, but if you insist on pulling back it will automatically deploy the wing slats to keep the ailerons active at low airspeed. If you still persist and the autothrottle is engaged, it will automatically add power. If the autothrottle is not engaged, the DFCS will lower the nose to keep the 7X flying even though you are holding full aft stick. Other jets have stick pushers that grab the yoke out of a pilot's hand to shove the nose over and prevent a stall. The DFCS accomplishes the same with total smoothness and always keeping the airplane near, but on the safe side, of the stalling angle of attack.
With the stick full aft the 7X has very positive and smooth roll control in any configuration. The DFCS is really helpful in a wind shear encounter because you simply add full power and full aft stick and the system keeps the 7X flying at the maximum safe angle of attack with no risk of a stall.
On the high-speed end the DFCS limits indicated airspeed or Mach to just a hair over the red line by raising the nose no matter how much you push on the stick. The autothrottle does its best to keep the airplane flying within the limits, but raising the nose to keep the 7X right on the limits is the final protection for the airframe. Again, not a new concept -- many Learjet models had stick pullers to prevent an overspeed -- but the DFCS protects the airplane with perfect smoothness and precision.
The 30-knot-plus winds were waiting for my return to the runway, but were blowing within 20 degrees of runway heading, so it was gusts and bumps, not a crosswind that would be the test. Thanks to its very effective leading edge slats and big flaps the 7X has very low Vref approach speeds, around 105 knots at typical weights. With the gusty conditions I maintained about 15 knots above Vref and found that the less I did with the stick, the better the approach was. I pushed over to aim the flight path marker at the touchdown zone and to match the VASI, and then left the stick alone. It is hard at first not to jump in and try to correct for every temporary attitude change made by the gusts and turbulence, but if you set it and watch, the DFCS does a spectacular job on approach.
As the radio altimeter calls out the height above touchdown you reduce power to idle and pull back on the stick to reduce the descent rate. My touchdowns were great on the trailing link gear and the spoilers deployed automatically to keep the wheels on the runway. Unlike other jets where you need to continue pulling back on the yoke, or at least hold back pressure to keep the nosewheel from banging down, the DFCS has a "de-flare" logic so you immediately release backpressure on touchdown and the system automatically and very smoothly lowers the nosewheel.
We pulled an engine back on takeoff and made another approach and landing, but again, the third engine means this was just an "abnormal" procedure, not an emergency as in a twin, so you use the same speeds and flap configurations as with all three turning. The rules require that it must be possible to hold the wings within 5 degrees of level using rudder only after an engine failure in a transport airplane, but the DFCS helps here, too. Even though the pilot only moves the pedals after an engine failure, the DFCS uses aileron and spoiler along with the rudder to hold the wings level so the rudder and fin can be smaller, lighter and create less drag than on a conventional airplane.
With its big cabin, 5,950 nm IFR range and 5,505-foot runway requirement for a max weight takeoff, the 7X is a remarkable airplane. As a pilot it's easy for me to become absorbed in the technology of just how the 7X delivers so much runway performance, speed, range, comfort and safety, but the people who buy large business jets have also noticed and the airplane is sold out for several years in advance. The first all-new Falcon in many years is truly something special in every respect.
