A CLOSE CALL! - Low Level Wind Shear and Stall on Takeoff

Summary

The pilot recounts a turbulent flight from Tacoma Narrows Airport to Packwood, Washington, on July 16, 2020. Despite safe landing, takeoff was fraught with wind shear issues and severe turbulence due to mountainous terrain. The video offers a dual perspective analysis, including a point-of-view camera and wing-mounted camera, detailing the stall warnings and fluctuating airspeed. Post-flight analysis covers weight and balance, density altitude calculations, and performance data, emphasizing the perils of valley flying in summer.

Takeaways

• 🛫 The flight took off from Tacoma Narrows Airport to Packwood, Washington, encountering turbulence during landing but managed to land safely.
• 🌬️ Wind shear and turbulence occurred during takeoff due to wind gusts of 27 knots and mountain-induced turbulence near the Packwood area.
• 📸 The pilot recorded the takeoff with a camera mounted on the left wing and a point-of-view camera for detailed flight analysis.
• 🚨 The stall warning horn was triggered multiple times due to sudden airspeed losses caused by wind shear during takeoff, especially near the treetops.
• 🛰️ The flight path was programmed into the ForeFlight app, showing a 77 nautical mile route with an estimated time of 49 minutes and fuel burn of 8.6 gallons.
• 🌄 Packwood Airport is surrounded by mountains, and the winds coming from the southwest created severe turbulence as they funneled through the valley.
• 📈 Windy.com was used for flight planning, showing real-time and forecasted wind speeds. However, it couldn't predict the impact of local terrain features on turbulence.
• ⚖️ Weight and balance data were reviewed, showing the plane was well within its weight limits, but density altitude increased to 2,580 feet, reducing climb performance.
• 🛬 The plane’s climb performance was degraded due to wind shear, with the vertical speed indicator fluctuating between flat to 400 feet per minute before stabilizing.
• 📊 After analyzing the flight, the pilot concluded that taking off at a different time of day with more stable air conditions could have avoided the turbulence issues.

Q & A

When did the pilot experience the flight with turbulence and wind shear?

The pilot experienced the flight on July 16, 2020.

From which airport did the pilot take off and where was the destination?

The pilot took off from Tacoma Narrows Airport and the destination was Packwood, Washington.

What kind of weather conditions were reported during the takeoff?

During the takeoff, the wind gusts were reported at 27 knots and there was a lot of turbulence coming off the mountain and interacting with the trees and other terrain features in the valley.

What was the total flight distance and estimated time for the flight?

The total flight distance was 77 nautical miles and the estimated time was 49 minutes.

What was the fuel burn estimated for the flight?

The estimated fuel burn for the flight was 8.6 gallons.

What tools or apps did the pilot use for flight planning and analysis?

The pilot used apps like Windy.com for weather information and ForeFlight for flight planning, weight and balance data, density altitude calculations, and airplane performance data.

What was the airport's elevation and its impact on the flight?

The airport's elevation was 1057 feet. The density altitude at the time of takeoff was calculated to be 2580 feet, which significantly affects the climb performance of the airplane.

What was the rate of climb performance of the PA28140 under normal conditions?

Under normal conditions, the rate of climb performance of the PA28140 was about 700 feet per minute.

What was the pilot's total takeoff weight and center of gravity?

The pilot's total takeoff weight was 1787 pounds, and the center of gravity was within the acceptable range as indicated by the weight and balance data.

What were the wind conditions like at the time of takeoff according to Windy.com?

According to Windy.com, the wind velocity on the ground was about 7 to 10 knots, but it showed 27 knot gusts, which is what was experienced just after takeoff.

What was the pilot's conclusion about the flight and what would they do differently next time?

The pilot learned a great deal from the flight and concluded that they would not take the flight under similar conditions. They would choose a more stable time of day like early morning or a time of year with more stable air, avoiding summer midday flights.