Tailored to Trap
F-35C control laws give Navy pilots Integrated Direct Lift Control for easier carrier landings, and they open the door for future landing aids. Frank Colucci 01 Dec 2012
http://www.aviationtoday.com/av/militar ... 77964.html
"...Lockheed Martin test pilot Dan Canin at Patuxent River Naval Air Test Center, Maryland, explained, “What IDLC does is improve the flight path response of the airplane, allowing the pilot to make almost instantaneous corrections to glideslope while maintaining a constant angle of attack.”
“The landing approach in the F-35C is flown with the stick only,” noted Canin. “The throttle is automatic.” IDLC may someday facilitate hands-off landings and other possible F-35 shipboard enhancements.
F-35 System Development and Demonstration (SDD) plans now call for first arrested carrier landings in early 2014....
...Safe carrier approaches require the airplane be stabilized in the correct glideslope and attitude to touch down with the proper geometry and rate of descent. Carrier pilots maintain that glideslope with visual reference to an optical landing aid on the ship, or “meatball.” They make continuous power changes while holding the aircraft at a near-constant angle of attack (alpha). According to Canin, “If we’re going to hold alpha constant, then the only way to change lift is by accelerating or decelerating the airplane. We do this with power, but because of engine lag and aircraft inertia, there’s a lot of anticipation required, and a lot of corrections and counter-corrections. Doing that well requires skill, seat-of-the-pants [flying], and a lot of practice.”
He offered, “A much better approach would be to control the coefficient of lift itself, by changing the camber of the wing.”
All three F-35 versions have trailing edge flaps to change camber. In addition, the longer-wing F 35C has ailerons. The flaps normally droop 15 degrees in the landing configuration. However, active IDLC moves the flaps up and down from that reference point proportional to the rate of throttle movement. Canin said, “With IDLC, we change the symmetric deflection of the flaps and the ailerons in response to pitch and throttle commands by the pilot. The glideslope response is immediate, and doesn’t require a speed or alpha change. This is a tremendous advantage over a stiff-wing airplane.”...
...The JSF test program currently has no autolanding requirement, but plans call for an F-35C autolanding capability based on the Joint Precision Approach and Landing System. “The F-35 will take more of a self-contained approach — an internally generated glideslope from GPS.”
IDLC is just one part of the F-35 test program which will now include tests of a refined tailhook for arrested landings. “We look at approach handling qualities every chance we get,” said Canin. “Where the rubber meets the road, though, is at touchdown.
Until recently we haven’t had a loads clearance that allowed us to do carrier-type landings, but now we do, so now we’ll be able to look at our control precision to touchdown.”
I wonder what sort of
cushioned landings have been done up till recently? This is a very long article with a lot more information about carrier landings under this
'new' system with the HMDS II etc.
Go to these forum URLs (pages) for other relevant bits from same article:
http://www.f-16.net/f-16_forum_viewtopi ... t-105.html
&
http://www.f-16.net/f-16_forum_viewtopi ... t-315.html
A4G Skyhawk: www.faaaa.asn.au/spazsinbad-a4g/ & www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/videos?view_as=subscriber