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BAK questions
finallyflying
Topic Author
finallyflying created the topic: BAK questions
Hi everyone,
After re reading Bob's BAK study guide again, there are a few things I have picked up that I can't quite get a grasp on. I wonder if someone might be able to shed some light on these subjects.
I'm a little confused about figure 5.6 and 5.7 in balancing the turn (page 5.4) where it says the motion is not all yaw nor is it all pitch, it is a combination of both, what about roll??? Why is roll not considered?
In regards to the battery compartment, when the battery is being charged and hydrogen gas is formed as a by-product, where does the hydrogen gas go? And if hydrogen gas and air form and explosive mixture, if air comes in through the vent, how does this not cause an explosion?
Figure 7.28 (page 7.36) aren't the headings 060 deg and 120 deg? Isn't 240 deg and 300 deg at the tail of the plane?
To answer your first question, whilst it is true that you have to roll the aeroplane in the first place to establish an angle of bank, once the bank has been established, there is no further roll occurring during the turn. If roll was occurring during the turn, the angle of bank would be changing. The bank remains constant during the turn so you cannot be rolling.
The main function of the vent in the battery compartment is not to allow air in, it is there to let the hydrogen out so that there is no build up of hydrogen. The rate of hydrogen production during the charging process is quite small, so as long as it can escape as it forms, it cannot build up to a dangerous level.
In the diagram showing the various headings, you should imagine that you are sitting behind the scale, so what you see from the cockpit is what's on the bottom of the scale. I must admit that it is a bit hard to draw that on paper, but remember that it is not the scale that is turning when you change your heading. The scale is remaining fixed in relation to north and the aircraft is turning around the scale.
