Crosswind Landings / "Impossible Landing" TE / Crosswind landing advice
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I’ve noticed that with the most recent BMS update, landing became a little bit different. It’s harder to find that sweet spot where the plane is gliding along nicely. I also noticed that there is a strange effect late in the approach where the plane suddenly gains altitude for a brief period. Is that something that was implemented intentionally?
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I’ve noticed that with the most recent BMS update, landing became a little bit different. It’s harder to find that sweet spot where the plane is gliding along nicely. I also noticed that there is a strange effect late in the approach where the plane suddenly gains altitude for a brief period. Is that something that was implemented intentionally?
That would be the turbulence buck introduced in U4. I set all the turbulence to 0 in the weather for all missions/campaigns.
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That would be the turbulence buck introduced in U4. I set all the turbulence to 0 in the weather for all missions/campaigns.
I think the turbulence that happens in the clouds is pretty cool. It help immersion and it resembles what I’ve experienced dozens of times on passenger flights. I am not completely sold on what happens during landing. Is that realistic?
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The turbulence in clouds is normal. The sudden increase in altitude followed by a sudden drop while on final is a bug. It wasn’t there in Updates 1, 2, or 3.
Looking at my original post……how did “bug” become “buck?” Maybe my iPhone invaded my computer…
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The turbulence in clouds is normal. The sudden increase in altitude followed by a sudden drop while on final is a bug. It wasn’t there in Updates 1, 2, or 3.
Looking at my original post……how did “bug” become “buck?” Maybe my iPhone invaded my computer…
Good to know. Thanks!
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@Duck:
Hi, guys…
I don’t know if I’m wrong, but it seems that the rudder automatically compensate directional control just before touchdown. Is it part of FLCS?
I mean it aligned itself parallel with the runway.
Thanks…:D
There is no such thing
However as soon as wheels touch ground the AC yaws itself to make wheel axis perpendicular to velocity vector
This is just basic physics that you can see in any crab landing video
Only consequence on landing like that is
- tire wearing
- gear damage it crab angle is too big
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There are three basic ways to land in a crosswind:
1. Crab into the wing wings level and yaw to align with the runway with rudder before touchdown.
2. Fly wing low and uncoordinated and touch down the mains sequentially.
3. Land the airplane crabbed and let the rubber take the punishment.I believe #3 is the preferred for the F-16 since FLCS will bite you if you try #1 or #2.
And of course there’s always #4, turn the wheels to align with the runway while flying crabbed; applies only to B-52s.
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For Duck Hawk:
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I think the turbulence that happens in the clouds is pretty cool. It help immersion and it resembles what I’ve experienced dozens of times on passenger flights. I am not completely sold on what happens during landing. Is that realistic?
I noticed that while inbound the runway we passed a small part of the city at I guess 300ft altitude, and you really felt how the warm floor was lifting your plane up, and once there was the grass again, you felt back down very strong, but that was in a Cessna 172 FR or 152 FR at ~60kts.
I guess less weight (no bombs, low fuel) on slow speed would be notable also in other planes, perhaps even more on big planes with big wings
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I’ve noticed that with the most recent BMS update, landing became a little bit different. It’s harder to find that sweet spot where the plane is gliding along nicely. I also noticed that there is a strange effect late in the approach where the plane suddenly gains altitude for a brief period. Is that something that was implemented intentionally?
I thought that is what most aircraft do on approach due to ground effect.
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Some info, just gee whiz
CROSSWIND LANDING
The recommended technique for landing in a crosswind is
to use a wing level crab through touchdown. At touch-down,
the ARI switches out. Undesirable yaw transients
may occur if roll control is being applied at this time.
After touchdown, perform two-point aerodynamic braking
using the rudder to maintain aircraft track down the run-way and
flaperon to prevent wing rise. In crosswinds, the
aircraft may drift downwind due to side loads imposed by
the crosswinds or travel upwind due to insufficient di-rectional
control inputs/availability. As the airspeed de-creases, increasing
amounts of rudder are required to
maintain track. Maintain two-point aerodynamic braking
until approximately 100 knots or until roll or directional
control becomes a problem. As the pitch attitude de-creases,
the nose tends to align itself with the ground
track.Aft stick and fully opened speedbrakes reduce stopping
distance. Apply brakes after nosewheel is on the runway;
however, if stopping distance is a factor, refer to SHORT
FIELD LANDING, this section. With all LG on the run-way, maintain
directional control with rudder, differential
braking, and NWS if required.
During landing rollout, the main concerns are wing rise
(roll control), weathervaning (directional control), and
downwind drift. Wing rise is controlled by flaperon into
the crosswind. Excessive flaperon deflection degrades di-rectional
control. Use rudder and differential braking to
control ground track, especially on wet or icy runways.
Engage NWS if required to maintain directional control
and to prevent departure from the runway. Excessive dif-ferential
braking may result in a hot brake condition. High
rudder pedal force may result in a yaw transient when
NWS is engaged. NLG strut compression is required to
engage NWS but sustained forward stick may result in full
horizontal tail deflection which decreases weight on the
MLG and thus reduces wheel braking effectiveness.Rudder Subsystem Theory of Operation. ISA
movement positions the rudder in response to commands from
the DFLCC. Yaw command signals from the yaw rate gyro
and the rudder pedals assembly are input to the DFLCC
. Additional inputs from the normal/lateral ac-celerometer, gun firing command, and YAW TRIM control
are also used to generate rudder position commands.
Aircraft yaw is controlled by inputs from the yaw
rate gyro assembly. This assembly is mounted to allow the
internal gyro spin motors to sense the rate of movement about
their axes. These motors generate four redundant yaw rate
signals to the DFLCC through their respective pickoff trans-formers. The Aileron-Rudder Interconnect (ARI) feature
counters the yawing moments produced by the roll control
surfaces. There is a wide variation in lateral control induced
yaw with flight condition and AOA. As a result, the ARI gain
is varied as a function of AOA and mach number. Sideslip
during roll maneuvers is minimized by combining the roll rate
signal and yaw rate feedback signal. The roll rate signal is
gain-adjusted by the angle of attack.
Normal/lateral accelerometer transducers sense lat-eral movement of the aircraft and generate input signals to the
DFLCC. These signals are combined with the yaw rate input
signals in the DFLCC. The resultant command is transmitted
to the rudder ISA to position the rudder control surface
accordingly.
A compensation signal is provided for the yawing
moment caused by firing the off-centerline mounted gun. The
gun firing compensation signal produces a static and dynamic
pressure adjusted rudder deflection command. This command
is also fed to the roll control system to compensate for the
rolling moment due to rudder deflection. An accelerometer
mount assembly is installed between the accelerometer and
the airframe. This mount isolates and inhibits
inadvertent lateral accelerometer input signals during gun fir-ing.
Yaw trim commands may be input through the
rotation of the YAW TRIM control. Deflection of the left or
right rudder pedals provides a nose left or nose right move-ment. Rotating the YAW TRIM control counterclockwise
moves the nose left and clockwise moves the nose right.
Markings adjacent to the control provide visual trim indi-cation. Yaw commands are summed electronically in the
DFLCC. These commands are applied to the coils of servo
valves SV1, SV2, and SV3 in the ISA. Under normal con-ditions, servo valves SV1 and SV2 are active and SV3 is in
standby. Active servos will port hydraulic fluid to position the
main control valve. This control valve then ports hydraulic
power to drive the ram in the desired direction. A mechanical
feedback nulls the main control valve and servo valves when
the ram has reached the commanded position. Each servo
valve coil contains two separate windings (SD 27-26-_ _).
Normal operation of the servos is possible with either the
primary or secondary winding. Outputs from the DFLCC
servoamplifiers are monitored by other DFLCC circuitry. A
malfunction will switch operation to the standby amplifier and
the secondary winding for that servo valve.
A hydromechanical monitoring and voting system
within the ISA monitors the outputs of the three servo valves.
A detected system failure in SV1 or SV2 will vote out the
malfunctioning servo and transfer control to SV3. A failure
will illuminate the MASTER CAUTION light and FLCS
caution light. A fault message will also appear on the Pilots
Fault List Display (PFLD). Failure detection/correction is
latched in after a malfunction. Reset is possible by placing
FLCS RESET switch to RESET and releasing. Reset cannot
be accomplished if the malfunction still exists. The flight
control panel is available in the forward cockpit only.
If a servo malfunction is indicated (rudder PFL),
positioning the FLCS reset switch to RESET will attempt to
reset the appropriate ISA. A recurring fail (same pressure
switch) will redisplay PFL (provided previous reset attempt
was successful). If an additional malfunction occurs, the
FLCS FAULT light will blink (if previous fail has not been
reset) to indicate additional FLCS fault(s) has occurred. The
ISA will continue to operate with one hydraulic system failed.
If pressure for both hydraulic systems drops below 720 psi,
the spring will command the ISA to neutral -
I thought that is what most aircraft do on approach due to ground effect.
Ground effect only occurs when your height above ground is equal to or less than your aircraft’s wingspan. So in an F-16 you would have to be around 30ft off the ground to experience ground effect.
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After touchdown, perform two-point aerodynamic braking
using the rudder to maintain aircraft track down the run-way and
flaperon to prevent wing rise. In crosswinds, the
aircraft may drift downwind due to side loads imposed by
the crosswinds or travel upwind due to insufficient di-rectional
control inputs/availability.…
With all LG on the run-way, maintain
directional control with rudder, differential
braking, and NWS if required.
During landing rollout, the main concerns are wing rise
(roll control), weathervaning (directional control), and
downwind drift. Wing rise is controlled by flaperon into
the crosswind. Excessive flaperon deflection degrades di-rectional
control. Use rudder and differential braking to
control ground track, especially on wet or icy runways.
Engage NWS if required to maintain directional control
and to prevent departure from the runway.Sounds like every other flight manual I’ve read. The only thing I can find are (supposed) pilots saying the aircraft waddles down the runway when landed in a crab, and it doesn’t waddle/bounce as much if you kick out of the crab before touchdown.
http://www.f-16.net/f-16_forum_viewtopic-t-9288-start-0.html
Are there any data available on the dynamics of crosswind f16 landings? I’d like to see some.
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There is an series of articles I always refer to from codeone magazine called “Semper Viper” where is a very good article about landing cross wind. If you can find it online it will say the same thing Dee-Jay and all the guys have been saying.
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This seems to be unique to the f16. Are there any other aircraft that right themselves while landing in crosswind? In BMS just now, landing in a 15 knot crosswind from left to right, the aircraft yawed itself to the right, while the rudder went hard left to try to arrest the yaw.
I’m just wondering what in the design makes it different.
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This seems to be unique to the f16. Are there any other aircraft that right themselves while landing in crosswind? In BMS just now, landing in a 15 knot crosswind from left to right, the aircraft yawed itself to the right, while the rudder went hard left to try to arrest the yaw.
I’m just wondering what in the design makes it different.
Juts my opinion, the landing gear. The way they landing gear compress, etc. Part of it. Aerodynamics and other things come into play.
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Wish I knew about this when looking for a project in my stability and control class. heh.