In a nod to some of the current discussion on this forum over sustained turn rates and maneuverability (or claimed lack thereof in the case of one hotly debated aircraft), and the excellent posts over at Elements of Power Blog, it’s time for a thread about which performance metrics will/ do matter in modern air combat. In the age of HOBS missiles, BVR missiles with active guidance and unquestionably better Pk than the much maligned sparrow, which metrics matter most? Is it traditional maneuverability, agility, supermanuverability?
It would be nice to keep this discussion non-platform specific, without x can turn better than y tail chasing.
Part I- first off- the research on the topic:
http://www.idearesearch.in/Papers/AP_aesi_agility.pdf
The idea of Combat Cycle Time- i.e. the ability of an aircraft to perform a 180* maneuver and return to the original mach number. The general idea here is that high AOA leads to quick initial turn rate with a degradation of speed. Comparing the F-18, and F-16, the F-18 had higher initial turn rates, the F-16 had superior CCT due to AOA limit, less energy loss.
The paper also goes into the F-18/ x-31 which will be discussed below. Lastly, the impact of situational awareness on pilot’s decision making. In essence, pilot action or inaction affects the potential the agility of an aircraft.
Next- Axial Agility Metrics vs Longitudinal Vs Lateral
(Fighter Agility Metrics-Randall K. Liefer)
General idea of this paper was to study transient agility metrics other than traditional turn rate etc.
Axial- ability to rapidly increase or decrease energy state, accelerate/ decelerate/climb etc.
Longitudinal- pitch rate (maximum load factor to unload- nose up and down) The paper also discusses the difference between pitch rate and AOA.
Lateral- (Loaded Roll) – time to bank 90*
And Next- Agility: History, Definitions and Basic Concepts: Patrick LE BLAYE ONERA System Control and Flight Dynamics Department (DCSD) Base Adrienne 701, 13 661 Salon Air, FRANCE
This paper looks at new measures: supermanuverability, system agility, weapon agility, operational agility
Supermanuverability- paper discusses how TVC increases pitch rates and AOA, TVC controlling pitch allows control surfaces to attain maximum roll rate as well.
system agility (avionics)- HMD, MFD etc speeds up OODA loop
weapon agility- new weapons with off-axis, midcourse guidance, Expanded envelope, improve the weapon system agility
operational agility- the sum of all parts. Examples: lack of airframe agility offset by HMS off-bore sight missiles, lack of system agility can offset airframe agility (example I can think of is the BVR firing sequence for early Mig-29)
Part II will deal with operational impact
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February 14, 2014 at 2:30 am