Why does Vmc decrease with altitude?
Im currently doing my multi rating and am completely confused when it comes to Vmc
Why does Vmc (indicated) decrese with an increase in density altitude?
As per my knowledege Vmc is the minimum speed at which directional control of the A/C can be maintained with one engine failed, max power on the operating engine and 3-5* bank away from the failed engine. Vmc has nothing to do with climbing or decending..only directional control.
My explaination to the above question is that with the thrust reducing with altitude, the moment decreases and therefore less rudder input is required to maintain directional control, but it was shot down by one of the instructors, he said that the rudder effeciency too will decrease with altitude.
Another question that I have is if i am producing 'X' thrust at 5000 feet and 10000 feet, will my IAS be same? (The TAS will increse (right?)) or in other words..is less thrust required at 10000 feet as compared to 5000 feet to maintain the same IAS?
Last edited by DJ Flyboy; 14th Feb 2011 at 00:36.