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  1. 1. Presume you have a direct head wind flying from point A to point B, and the identical wind velocity vector on the return. All other factors (airspeed, altitude, enviornment, etc.) are the same for both legs. You don't need an E6B; just select the correct answer.

    • Roundtrip flight time will be shorter than it would be if there were no wind.
      3
    • Roundtrip flight time will be the same as it would be if there were no wind.
      16
    • Roundtrip flight time will be longer than it would be if there were no wind.
      11


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Found on the 150/152 Club Website FAQ - How fast do Cessna 150-152's fly?

 

"On a round trip, the wind speeds cancel each other out like riding a bicycle up a hill and then back down on the return home. In practice, the winds typically vary from about 5 to 20 MPH, so the typical groundspeed of a Cessna 150-152 is between 90 MPH and 130 MPH. This is on the slow side for airplanes, but pretty impressive compared to automobile speeds."

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I don't know. I guessed longer because of drag you wouldn't get the full benefit of a tailwind push.

 

Just thought that it might also be the opposite and with wind total flight would be shorter because the aerodynamics of the plane are for forward moving. The aerodynamics would minimize the head wind, but tailwind would push more going opposite direction of design, like a sail.

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Okay, 64 views, 10 votes; I think that's enough. Congratulations to the 4 that got the right answer, and to the six that didn't, don't feel bad; you would be amazed at how many pilots will say the headwind and tailwind cancel out, just like someone wrote on the 150-152 website.

 

Think about it; you have the disadvantage of the headwind for a longer period of time than you have the advantage of the tailwind. That's why they don't quite cancel out, and the roundtrip flight time will be longer than if there were no wind.

 

And the bicycle analogy on the 150-152 website is way off base. The best comparison to how wind affects an aircraft in flight would be how the current affects a boat in a river.

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Sorry. I still don't buy it. You don't have the tailwind as long because you're flying FASTER than you were before. Headwind and tailwind being the same, it should cancel each other out. This is a question that we had in the 3rd grade.

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Sorry. I still don't buy it. You don't have the tailwind as long because you're flying FASTER than you were before. Headwind and tailwind being the same, it should cancel each other out. This is a question that we had in the 3rd grade.

 

Okay, I take it back... Maybe you should get out your E6B :rolleyes:

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Actually, their answer isn't true. It would take just slightly longer, because you suffer the effects of the headwind for a greater amount of time than you get the benefit of the tailwind. For example...assume a 100 mile round trip, with an airspeed of 100mph. We all know that the trip would take 1 hr. Now, do the math with wind...I'll use 10mph:

 

Going (tailwind): 50 miles/110mph = 27.3 minutes

Returning (headwind): 50 miles/90mph = 33.3 minutes.

33.3+27.3 = 60.6 minutes. The difference is small, but it is there. With higher winds the effect is magnified because the change is exponential. Now assume 40mph for the same trip...not unreasonable:

 

Going (tailwind): 50 miles/140mph = 21.4 minutes

Returning (headwind): 50 miles/90mph = 50 minutes.

Now the trip takes 71.4 minutes. So, at higher airspeeds, particularly in slower planes, the difference becomes substantial. If the above trip was a 4 hour round trip with no wind, it would take 4:45 with wind! If you assumed that the headwind/tailwind would cancel, that would really cause problems with your fuel calcs.

 

Now, do the math for a slow plane. Say a 65mph Cub. This is where the effect is really exaggerated (ask me how I know):

Going (tailwind): 50 miles/105mph = 28.6 minutes

Returning (headwind): 50 miles/25mph = 120 minutes.

If you think of the wind as a percentage of your airspeed, the result becomes more obvious. To the 65mph cub, a 40mph tailwind gives you a 62% increase in speed (105/65=1.62)! Meanwhile a 40mph headwind decreases your speed to only 38% of normal (25/65 = .38).

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Actually, their answer isn't true. It would take just slightly longer, because you suffer the effects of the headwind for a greater amount of time than you get the benefit of the tailwind.

 

that was their answer.

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that was their answer.

 

I think Steve was referring to the answer on the 150-152 website.

 

 

I'll always remember the first time I was asked the question, but it wasn't in the thrid grade :) It was just prior to my first solo cross country. I didn't give it a lot of thought and went with the "cancels out" answer. And I'll never forget my instructors reply; "You just ran out of fuel short of the runway". :huh:

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Ah... "I see" said the blind man.

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I think Steve was referring to the answer on the 150-152 website.

 

Yep...I didn't make that clear.

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