Just my luck, headwind both ways - every dang time!

k9medic

k9medic

Line Up and Wait
Joined
Sep 27, 2018
Messages
929
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N Central FL and GTC Bahamas when off work
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ATP-H, CMEL, CSEL, CFI/CFII Airplanes and Helicopters
My wife made a comment last night after we returned from the Bahamas that the flight seemed to take a little longer. I justified it by saying that it just felt longer since we were now landing after dark.

In reality, this comment got me to thinking. This trip was a day trip over and back to drop off more supplies. My best speed in level flight going over was 122kts - in both directions!

The past few trips over, I have seen a general decrease in GS which is apparently backed up by my flight time records.

Overall, the flights area a canned route and I am rarely vectored all over. The average distance flown is 680nm round trip. Based on my logs, I come up with 6.4 hours round trip as an average flight time. Mathematically, I'm flying 106kts overall. The fastest was 5.2 (130kts) and the slowest was 6.9 (98kts!) Yes, I know climbs and taxi time add into this equation

For an aircraft that trues out at 130kts, the trip just seems like it should be faster.

Is this just all in my head?
 
Even with a partial tailwind, if it’s not directly on your tail, you have to compensate for the drift, so ANY crosswind component is slowing you down, even with a tailwind. You can’t break even, you’ll always lose. Unless the tailwind is exactly the direction you are going.
 
Salty said:
Even with a partial tailwind, if it’s not directly on your tail, you have to compensate for the drift, so ANY crosswind component is slowing you down, even with a tailwind. You can’t break even, you’ll always lose. Unless the tailwind is exactly the direction you are going.
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I don't agree with that.

According to my E6B, a 12kt, quartering tailwind in a 130kt TAS airplane will give an you additional 8kts. At 12kts, once the wind moves about 10 degrees aft from a direct crosswind, you will start seeing some benefit.
 
k9medic said:
For an aircraft that trues out at 130kts, the trip just seems like it should be faster.

Is this just all in my head?
Click to expand...

Have you calculated your TAS on any of these legs?
Does the forecast winds aloft agree with your groundspeed vs TAS?
 
Yes. I use the GPS' TAS calculation function and it always seems to come out at or around 130kts. I'm normally cruising between 7 and 9K. Even hand jamming the TAS conversion is comes out to 130ish TAS.
 
Well the winds aloft reports should have shown a headwind in each case then......unless you spent a long time in the climb or maneuvering, right?
 
donjohnston said:
I don't agree with that.

According to my E6B, a 12kt, quartering tailwind in a 130kt TAS airplane will give an you additional 8kts. At 12kts, once the wind moves about 10 degrees aft from a direct crosswind, you will start seeing some benefit.
Click to expand...
Of course you see a benefit, but it’s always less than if it’s a straight tailwind. But when it’s a headwind, you get the short end of the stick again.
Use the e6b and calculate groundspeed for a 45 degree tailwind, then do it for a 45 degree headwind. The gain is not as big as the loss the other way.
 
Salty said:
Even with a partial tailwind, if it’s not directly on your tail, you have to compensate for the drift, so ANY crosswind component is slowing you down, even with a tailwind. You can’t break even, you’ll always lose. Unless the tailwind is exactly the direction you are going.
Click to expand...
I would say this differently: For a round-robin flight, any wind will increase the elapsed time because you spend more time with a headwind component than you spend with the off-setting tailwind component.
 
Always seems I have a headwind when I’m in a hurry.
 
dtuuri said:
I would say this differently: For a round-robin flight, any wind will increase the elapsed time because you spend more time with a headwind component than you spend with the off-setting tailwind component.
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That’s also true, but that’s an additional reason, not the one I’m describing.

With the 45 degree 15 knot headwind you’re losing 11 knots, with the tailwind you’re only gaining 10. The steeper the crosswind or the higher the wind speed, the worse this problem gets. A 90 degree crosswind has a pretty steep penalty.

695DDFBB-9292-4DAE-9E5C-997D23794E84.png 3042CDF3-AFCA-421E-B7D2-1C48196F5B74.png
 
Bet you walked to school uphill both ways in the snow in bare feet too. :)
 
Driving across Wyoming on I-80? Back when we lived in Colorado I was sure you could be fighting a headwind, exit and go the other way and still have a headwind.
 
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