Tag Archive: acceleration

Tired eh! Physical Cost of AGSM

Fatigue is the cost of correctly performed Anti-G straining manoeuvre (AGSM) to fight against the +Gz forces during air combat. Being an isometric exercise, akin to a 50 or 100 m race or weight lifting, the muscles maintain sustained contraction during AGSM to generate energy anaerobically. Thus time “to fatigue” and of “fatigue recovery” determine …

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Protection against the ‘G’

Average relaxed ‘G’ tolerance of combat aircrew varies between 4 to 5G, although the range may be 3 to 8G. Yet, one must note there are large individual variations in G tolerance and even in the same individual, the tolerance may vary on different days or different times of the day. It is here that …

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G-LOC Demystified

G-LOC has been implicated in various combat aircraft mishaps. Incidence of in-flight G-LOC in India is 11%, while it is 12 and 19% in USAF and RAF, respectively. Interestingly, G-LOC is more likely to occur in a trainee pilot, co-pilot or weapon system operator, who is caught unaware by the sudden onset of G or …

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G-LOC – The Enemy within!

G-LOC is G-induced loss of consciousness, defined as a “state of altered perception wherein one’s awareness of reality is absent as a result of sudden, critical reduction of cerebral circulation caused by increased G force”.

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Air Combat Manoeuvres and +Gz Forces

During air combat manoeuvres* or while practicing basic fighter manoeuvres**, the pilots are exposed to the commonest type of acceleration encountered in aviation – +Gz. Interestingly, the aircraft are capable of pulling higher Gs and sustain it longer than an unprotected human being can tolerate. The effects of +Gz on the circulatory system, and in turn the blood …

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G Force – What is?

‘G’ is the ratio between a given acceleration and the acceleration due to gravity. The term ‘G force’ is used sometimes to describe a force, which produced acceleration, which is a multiple of the acceleration due to gravity (9.81 m/sq sec). Thus, an acceleration of 98.1 m/sq sec would be 10 G. High sustained G, …

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Exhilarating when Accelerating in Air!

A fast jet can move rapidly on ground, taking off into the medium of air where it can be manoeuvered in flight by the aerodynamic forces generated by the thrust of its engine and manoeuvrability by swift-responding control surfaces. Such movements of the aircraft affect its occupants, the aircrew (pilots and weapons system operators) due …

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G-LOC – Then and Now…

16 September 2011. Reno, Nevada saw the tragic crash of a P-51Mustang [1] during the Reno Air Races. The findings of the National Transportation Safety Board suggests that the pilot had lost consciousness due to ‘overwhelming’ G forces [2]. This occurrence in a modified 1940’s vintage aircraft is no surprise, considering its high thrust to …

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Aviation Medicine Quiz – Ejection and Ejection Seats

Here is a quiz on Ejection and Ejection Seats. Please answer to the best of your knowledge and understanding the following questions pertaining to Ejection.

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Eject! Eject! Eject! – Potential for Ejection Injuries

There are different phases of ejection, with potential for injury to the pilot. Sequentially, these phases are – (a) Canopy separation/ fragmentation; (b) Egress; (c) Ram Air/ Wind blast; (d) Wind drag deceleration; (e) Free fall; (f) Parachute deployment, and (g) Landing. As per the phase of ejection, a pilot can sustain various injuries with spinal injury being the commonest. 

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