BMS F-16C/D 4.34, Руководство по эксплуатации самолета, Страница: 227 / 234

T.O. BMS1F-16CM-1 BMS 4.34 Change 2.00
BMS 4.34 Dash 1
© Red Dog 2012-2019
Page: 227
4.1 Limit Cycle Oscillation
Complex buffeting & stores flutter (Limit Cycle Oscillation) code has been added to the Flight Model.
These are both based off real-world F-16 studies & technical papers.
A limited amplitude constant frequency oscillation (commonly referred to as limit cycle oscillation or
LCO) may occur with certain stores loadings. LCO (typically 5 -10 cycles per second) may occur in
level flight or during elevated g maneuvers. LCO may appear as buffeting or turbulence at a constant
frequency, lateral acceleration from side-to-side, or in some cases vertical acceleration up and down.
The magnitude generally increases with increasing airspeed and/or load factor.
Other indicators of LCO include significant vertical movement of the forward area of wing stores,
especially wingtip launchers and missiles; this motion is typically up and down, but may also follow a
circular pattern. In addition, cockpit instruments may become difficult to read as LCO amplitude
increases from moderate to severe. LCO in BMS is not detrimental to the aircraft and mostly happens
with air-to-surface configurations (external tanks and AGMs, General Purpose or Guided bombs).
If LCO is encountered and is uncomfortable or distracting, reduce airspeed.
4.2 Descent Warning Advisory
Descent Warning After Takeoff (DWAT) provides an audio warning of an unintended dive or descent
during the departure phase of flight. The Voice Message Unit (VMU) descent warning advisory
“Altitude, Altitude”, will occur when all the following conditions are met:
•
The landing gear handle is up.
•
The time from takeoff is less than 3 minutes (from WOW).
•
The aircraft has climbed at least 300 feet above the runway elevation referenced to Mean Sea
Level (MSL), but not yet gained 10,000 feet above runway elevation.
•
There is a descent rate present such that the aircraft will descend to the runway MSL
elevation within the next 30 seconds.
•
The DWAT message has not previously occurred since takeoff.
If for whatever reason you want to start the 3 minute timer before takeoff selecting ENABLE on the
GND JETT switch starts the DWAT timer as well.
Predictive Ground Collision Avoidance System (PGCAS)
In addition, the CARA ALOW code was rewritten in 4.32 so that it behaves more like the real one.
Specifically, the
‘AL <alt>’ label will flash when you are below the selected <alt> value as measured by
height AGL. If you descend through the ALOW limit, you get the VMS warning once unless and until
there is a CARA reset.
Resets happen if you go back above the limit altitude, or if the RALT reading is lost (like when you roll
inverted and the radar can't see the ground). A reset also occurs if your rate of climb
as measured by
the radar altitude exceeds 1200 feet per min. Note this last one means that you can hear the VMS
message even when flying along in level flight or even climbing if the terrain below you has sudden
significant slope. Normally though you should only hear one VMS altitude warning per trip below the
limit value.