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The dangerous "downwind turn" in aircraft


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A popular piece of wisdom passed down generations of pilots, is to be wary of airspeed loss when turning away from the wind, as airspeed is a vital piece of maintaining lift, and losing too much of it and/or losing it too quickly, is a hazard that could get you in trouble. An example goes like this: Let's say we're flying South to North at 100 knots, and the wind is blowing West to East at 20 knots. If we turn West, we're turning into a 20 knot headwind so our airspeed increases to 120 knots. Good. On the other hand if we turn East, we lose those 20 knots, and our airspeed becomes 80 knots. What do you think about this hazard?

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It depends. Once an aircraft is in flight, all the forces on the aircraft are relative to the airmass it is in, and that includes wind. If the aircraft is at altitude, the ground exerts no influence on the aircraft’s performance, with the exception of what the pilot is concentrating on.

For example, if the pilot concentrates only on airspeed, as well as his turn and bank indicators, he can turn and bank all day long without reference to the ground, including turning the “dangerous” downwind turn, without any problem.

Problems can arise if the pilot pays too much attention to the ground, and tries to make his “lazy eights” with reference to some reference on the ground. I experienced this myself in my very early years of training for my private pilot’s license. When trying to do a “lazy eight” over a particular ground reference, in wind, it is possible to over compensate for the wind drift by making a steeper banked turn than if the pilot was paying attention to his airspeed.

So, there is some truth in the “dangerous downwind turn” but only because some pilots are focusing on the wrong frame of reference, the ground instead of the air mass they are flying in.

The closer to the ground the aircraft is, the more dangerous the downwind turn becomes, simply because the inexperienced pilot is more inclined to follow a track over the ground and less inclined to be paying attention to his instruments.

This can result in the pilot needing to over correct his course by “crabbing” into the wind, risking a cross-controlled stall, where the aircraft's rudder and ailerons are working in opposite directions.

I have known some private pilots who thought that crabbing into a landing was perfectly good practice!

Unfortunately, at least one of them died in a spin because of using this technique once too often.

My answer to your question is: No, the so-called “dangerous downwind turn” is not dangerous to an experienced pilot who is not distracted by the ground, and knows how to make a coordinated turn even in windy conditions.

 

 

 

 

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21 minutes ago, sluggo said:

You monitor your airspeed to avoid a dangerous stall.

Most aircraft flying today have some form of stall warning system.

The point is, unless the pilot is focusing on a ground reference, the plane's airspeed does not change much if at all. Only the ground speed changes, which has no effect on the aircraft's performance with respect to the air mass it is flying in. You should always be paying attention to your air speed and other instruments such as turn and bank indicator and altimeter. But as I wrote earlier, once an aircraft is in flight, all the forces on the aircraft are relative to the airmass it is in, and that includes wind. If the aircraft is at altitude, the ground exerts no influence on the aircraft’s performance. The aircraft will not stall in a downwind coordinated turn.

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My reply was specifically for airspeed, without regard for the ground or type of maneuvers. In a cloud you lose your sense of direction, without instruments.If you have winds in whatever direction, as a trained pilot, you know how to compensate.
I am also minimizing the danger proposed be ECM. There are greater risks like loss of power, bird strikes, severe weather, pilot error.

 

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forum;

I attended air shows in the past. The only one where I witnessed an accident was 1995 at Toronto Canada off the shore of Lake Ontario. A maritime patrol aircraft (a converted 4 engine British Comet airliner) was finishing a maneuver, and climbing in preparation for it's next one. I looked down at the program to see what was next. There was a muffled explosion, I looked up to see a cloud of water a few hundred feet high full of dark pcs of debris. The crew of 7 perished.

A little research provided the result of the investigation, which I hadn't done until now.Pilot error, not monitoring his airspeed, resulting in a stall, without adequate altitude for recovery.Aircraft and lives have been lost for lesser seemingly insignificant details.

My intention was not to disagree with what was posted, but emphasize aviation is much more complex than the principles of flight. It involves aircraft mfr., air traffic control, weather service, navigation aids, etc.

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