Hello everyone,
Now I know that the book "Ace the Technical Pilot Interview" contains many mistakes and is not very reliable but I have still read it and corrected the errors checking the explanations with my ATPL manuals. There are a few questions which I'm unsure of and would appreciate if I could get some help on:
Q1) Why does a jet aircraft climb as high as possible?
The book mentions the following two: minimum cruise drag and best engine SFC. I will quote the minimum cruise drag from the book as I'm not sure if it is totally correct:
Minimum cruise airframe drag. This is experienced at high altitudes because drag varies only with EAS, i.e. as EAS decreases drag decreases. At very high altitudes the MN speed becomes limiting and therefore EAS and TAS are reduced for a constant MN with an increase in altitude. Therefore the lowest cruise EAS is at the highest attainable altitude (service ceiling) and because drag varies only with EAS, airframe cruise drag is also at its lowest value at high altitudes. Consequently, our thrust requirements are lower at high altitudes because our thrust value must only be equal to our drag value.
Q2) Why is the risk per flight decreased with a reduced-thrust takeoff?
The book gives three reasons but it's only the first one that seems confusing:
The assumed/flexible temperature method of reducing thrust to match the takeoff weight does so at a constant thrust-weight ratio, making the actual takeoff distance and takeoff run distance from the reduced-thrust setting less than that at full thrust and full weight by approximately 1 percent for every 3ºC that the actual temperature is below assumed temperature.
Q3) What is the wind direction around a high-pressure system?
I have no problem in understanding this but the books says:
However, it should be rememberd that above a surface high there is an upper low system. Therefore, the wind direction will reverse at height in a high-pressure system.
I've researched the ATPL manuals I have and it basically says that in the atmosphere we have "compartments" of areas of convergence and divergence, which I would take to be as low and high pressure systems, and that between them you have a level where divergence/convergence is zero, which occurs at the 500 hpa pressure surface (FL180). Now when I look at current surface weather charts and upper level weather charts, I do not see this theory confirmed.
Thanks in advance and happy holidays!