When you combine that load transfer with the crosswind component of a quartering tailwind, you could put yourself in a situation where one of your main gear has little or no weight on it, affecting your ability to keep the plane under control and on the runway.
When it comes to landing accidents, how much tailwind is too much? Ultimately, it depends on your proficiency. Below, we've picked three landing accidents where the pilot faced less than 10 knots of tailwind. In each of them, there were different factors at play, but all three led to an accident. Read the NTSB report here.
The airplane, which was near max gross weight, reportedly touched down within the first few hundred feet of the 3,' runway. However, the pilot wasn't able to bring the aircraft to a stop, and it overran the runway, coming to rest on a 45 degree downslope past the departure end of the runway.
According to the NTSB, at maximum gross weight in the weather conditions of the airport at the time of the accident, the airplane had a calculated ground roll of about 1, feet, with a total landing distance of about 2, feet.
Taking into account the 5 knot tailwind and the 1. So what happened here? First, runway 22 was being used by other aircraft, which may have pressured the pilot to use the same runway. The pilot's decision to land with the tailwind, combined with the fact they only had a ' margin of error on landing distance, ended with the plane going off the end of the runway. It only took 5 knots of tailwind, but had the pilot chosen to land with a headwind instead, they most likely would have had enough runway to safely stop.
Anyone who flies a tailwheel aircraft knows how challenging it can be to land in any kind of wind. And when there's a tailwind, landing safely is even more difficult. In this accident, a Cessna was making a landing with a 5 to 8 knot tailwind.
During landing, the airplane touched down hard, and the pilot lost directional control. The aircraft began side-loading, causing the left main gear to collapse and the left wing to strike the runway, substantially damaging the aircraft. As with any hard landing or porpoise landing , maintaining control of the aircraft is the first priority. But in this case, the tailwind increased the aircraft's ground speed, and amplified directional control problem.
Landing into the wind may not have prevented the hard landing, but it would have made maintaining directional control and going around much easier. Based on radar data, the approach was unstabilized from the final approach fix inbound, and the aircraft broke out of the clouds significantly left of the runway. The pilot made a right turn and maneuvered the aircraft toward the runway.
But because of the aircraft's position and the 7-knot tailwind, the pilot touched down approximately halfway down the wet runway. Even though the pilot had 40 degrees of flaps in, they were unable to bring the aircraft to a stop on the remaining portion of the runway. The aircraft overran the departure end of the runway at approximately 45 knots, and impacted terrain, collapsing the nose gear.
I have been spending some time in analyzing the impact of tailwind on the ground speed of the aircraft. I am using the simplified lift equation to quantify the aerodynamic lift on the aircraft wings :. Assuming the aircraft takes off with no wind at a speed of kmph V AW. In other words indicated airspeed is same as ground speed.
Now if we assume that the aircraft is cruising at a speed of kph, and it encounters tailwinds at 50 kph. By the above equation, the ground speed of the aircraft V AG should be kph. This is where my intuition starts working against me. I am somehow not able to correlate it with the situation of a boat moving in a steam of river, where the stream velocity impacts the velocity of the boat directly - some kind of tight coupling between boat and water surface.
In the case of airplane, it is difficult for my brain to imagine a similar "tight coupling". My understanding says that a tailwind will cause a reduction in V AW , which will decrease lift.
Can anyone help me to clarify the real reason behind the increase in the ground speed of the aircraft? In normal flight, the two forces cancel, so the plane travels in a straight line not necessarily level - it could be climbing or descending, but the line is straight.
A sudden headwind, as you can see, has the opposite effect. You can see this if you take a flying lesson. In straight-and-level flight, just give the yoke a short shove forward. The plane goes down, then up, and gradually returns to straight-and-level. There's a "trim wheel". This controls a tab on the elevators. It essentially functions as if it applies a continuous pressure, fore or aft, to the yoke.
So if the pilot wants to go fast, she applies "nose-down-trim". Since the plane will then be headed in a straight line sloped downward at a higher speed, she applies power, which moves the slope from downward back to level. This is flying The power does not control speed, it controls climb. The elevators do not control climb, they control speed. All of this is in airspeed - relative to the air, not to the ground.
A sudden increase in tail wind a gust will reduce the lift, as experienced when an aircraft hits turbulence. If you wish to access the latest content from the SKYbrary team, please visit and bookmark www. Tailwind Operations in fixed wing aircraft are considered to be takeoffs or landings with a performance diminishing wind component — that is, a tailwind. Air Traffic Services will often determine preferential runways based on noise abatement or traffic flow criteria and will not change the active runway until the tailwind component exceeds a predetermined value — normally in the order of 5 knots.
It is up to the aircraft commander to ensure that the aircraft can be safely operated with this tailwind component.
0コメント