when do downwind takeoffs become acceptable?

[McBiggles]

thought of this today as i watched some guys in the bay takeoff downwind in gusty conditions in a buck 80. even though we have always been taught to take off into the wind a lot of guys still go with the wind at their backs to save a 15-20 min taxi. we all know it can be done but where do you draw the line and decided to spend that extra time getting set up into the wind. 5 knots? 10 knots? more? i know different planes can do it better than others so give me your thoughts and maybe a story or two...

[AuxBatOn]

I would follow what the Aircraft Manual says about recommended tailwinds. Ever heard of a perimeter flight last year that went off the end of the runway because he took off in a tailwind??

AuxBatOn

[just curious]

It becomes acceptable to me when it's someone I don't like, who doesn't work for us, especially when I can salvage the aircraft clock to add to my collection.

[Adam Oke]

I was always told that they couldn't give two shits how long it took me to taxi, get comfortable, and warm up the air craft. But they would be seriously pissed if I cracked a cylinder, put 'er into the trees, or did somthing stupid.Why take off down wind?

I mean if its light and variable I've taken off numerous times "downwind" at a busy airfield. You can't have 9 students in the right hand circuit, and a glider operation on the left hand flip flopping back and forth on a 3000ft runway .... someone is bound to bump into someone. Light and variable ( I think its defined around 3kts? ) and the sock limp as Michael Jackson in an old age home ... not going to matter.

[AdamB]

At the flight school i did my initial training at there was a noticeably sloped runway. We would tend to take off downwind with tailwinds of up to about five knots. Anything considerably above that, and we would take off uphill, into wind.

[xsbank]

The POH gives max tailwind components. Laziness, unwillingness to take time to taxi, are not good enough reasons to go downwind, but topography and water conditions are.

Is downwind departures covered in basic flight training? Do newbies have to do one?

How many clocks ya got now, JC?

[Cat Driver]

I must be very, very careful how I comment on how to fly airplanes otherwise I end up in pissing matches with pilots who do not agree with my flying decisions.

So here is how I handle the down wind take offs on water.

A down wind take off on water is a last resort decision and done only when there is no other way due to terrain and only if the tail wind is within acceptable limits for the airplane I am flying.

A tail wind that is at or beyond the airplanes performance capabilities is the same no go decision as a take off in below safe visibility conditions.

There are several downsides to a down wind takeoff the most signifigant of which is as speed increases hydrodynamic drag increases exponentially and your take off run is extended with the added risk of pounding the airplane at excessive speed over the waves and risking engine over heating among other things.

And of course there is the added problem of once airborne you will be starting your journey at low airspeed down wind with a reduced climb gradient.

If you are driving a flying boat another issue may come into the equation which is the possibility of a down wind porpoise developing due to the wave action...and it will not be pretty.

Please do not become offended by my explaining how I personally make my decisions on down wind take offs on the water, and do not feel that I am dissing your personal decisions should you have a different opinion on this subject.

[Ref Plus 10]

That was quite Politically Correct, Cat. Well done

[North Shore]

A number of years ago, I was flying a turbine otter somewhere in the northlands. On camp change day, I took a load of turkeys into a camp on the upwind side of a lake. Nice, long, rock free landing/takeoff area. Unloaded, and then loaded up the return trip. Flashed up, and looked at the water - calm, so I turned away from the shore, poured the coal to 'er, and we were off. Some time later, when I realized that the flat calm of the protected water next to the shoreline had changed into the wavelets of a 10-15kt tailwind, the otter was getting a little squirrely, and I was dancing a quickstep on the rudders trying to keep it straight. Eventually, we got into the air, and I shook my head all of the way back to base.

Simple, basic lessons reinforced: 1.) Always take off into the wind unless absolutely impossible to do so. 2.) Dont let time pressures get in the way of safety. (it was camp change day, and we had a lot of work to do, and so I didn't want to spend the extra 5 mins for the taxi to the into-the-wind run)

That's my war story...

Currently, the plane that I fly doesn't really take well to tailwinds, either on the land or the water, and can be a real bear in x-winds on the water. As we aren't really in a hurry at any time, an extra widening of the circuit to get into the wind, or an extra 2 - 3 minutes to take a headwind on a runway isn't even worth thinking about, and so we take the time.

As an adjunct to that, I always think of myself in front of an inquiry, trying to justify my actions to some non-flying lawyer type, as to why I chose to take off downwind or whatever, and crashed doing so...

[AdamB]

Please do not become offended by my explaining how I personally make my decisions on down wind take offs on the water, and do not feel that I am dissing your personal decisions should you have a different opinion on this subject.

Too late. I'm calling TC on you

[Cat Driver]

That was quite Politically Correct, Cat. Well done.

Thanks Ref Plus 10, I'm trying to disprove that old saying you can't teach an old Dog ( Cat ) new tricks.

Did you notice I didn't even come close to mentioning flight instructors. ....soon I'll be loved by everyone.

Another suggestion is if you are really worried about saving a few minutes you should think about the time it will take to retrieve the wreck if you miss judge the conditions.

Bottom line is good airmanship demands you learn to slow down your need to get going.

[AdamB]

Wow Cat.

That was way the hell out of line. Good job, you had us all going there for a minute.

[Kzanol]

I think it depends on the airplane. My boss tells me never to do anything(takeoff or land) downwind in the Cessna, however he flys the Beech 18 and I don't think he even looks to see where the wind is, unless the backs of the floats are under the water.

[lazyboy]

Wow,I agree with cat on that one,and no mention of T.C....most likly why its only 7 degrees in cental manitoba

[Adam Oke]

Please do not become offended by my explaining how I personally make my decisions ... , and do not feel that I am dissing your personal decisions should you have a different opinion on this subject.

Might as well slap that in your signature . . Keep on posting your good material.

[Big Pistons Forever]

Is downwind departures covered in basic flight training? Do newbies have to do one?
?

I will post my thoughts on this question in the flight training forum.

[x-wind]

POH first (landing and takeoff distance charts) . Then only if there's a slope in the runway or really big obstacles at one end.

ATC never clears anything to Land or T/O with more than a 5 knot tail wind.

[brokenwing]

what about a finger lake where you have the wind funneling in both ends, north wind at one end, south wind at the other? do you start the takeoff with a tailwind and climb with a headwind or vice versa?

[Cat Driver]

what about a finger lake where you have the wind funneling in both ends, north wind at one end, south wind at the other? do you start the takeoff with a tailwind and climb with a headwind or vice versa?

[Cat Driver]

I think it depends on the airplane. My boss tells me never to do anything(takeoff or land) downwind in the Cessna, however he flys the Beech 18 and I don't think he even looks to see where the wind is, unless the backs of the floats are under the water.

What does he do when the the backs of the floats are under water?

[Doc]

Runway slope has been mentioned several times. Now, I'm a flatlander, but the only sloped runway I've had to deal with is in Baker Lake. I'm sure there are some out west. Down wind take offs and landings are when there just is no other choice. Ever watched a raven on a fence post? He always turns into wind to launch. I wonder why.....

[Cat Driver]

Down wind take offs and landings are when there just is no other choice. Ever watched a raven on a fence post? He always turns into wind to launch. I wonder why.....

For the same reason they land into wind???

Ever seen a duck take off or land down wind?

[Doc]

No, but I watched some ducks try to take off from a lake (large pond) in Mexico City. Funny as hell. Poor things had to wait till the evening to depart! Good lesson on hot and high.

[brokenwing]

Cat,..... nothing? I was hoping for some insight on the double wind situation. It's not uncommon in my line of work, and was hoping for a logical method and reasoning. Screw the newfound PC bullshit, you're old enough to have written the 10 commandments, so you survived long enough to figure something out.

[xsbank]

Runway slope? What slope?

There was a narrow little bay near Port Hardy where we did camp runs - you had to land into the bay, it was closed and no chance to overshoot; the camp was at the head of the bay and you had to take off inside the bay downwind because the bay was one-way and the water was too rough outside. Ergo bingo, routine downwind takeoffs.

In a perfect world, you would always take off into wind or crosswind at least, but even the Gooses (Geese?) took off downwind there. Part of being a coastal float pilot. Often the only useful water will not conveniently point into wind.