Wake Turbulence Hazard When Landing With A Tailwind
- Jared VanLue
A few days ago, I was finishing an uneventful flight and landing on runway 26L at KLAS (Las Vegas, NV - USA). The weather was VMC around 2200L with wind 080 at 7 knots, so it was a direct tailwind. Due to a lot of operational restrictions, ATC doesn't like turning the airport around to land east unless the wind is greater than 10 knots. I operate out of LAS frequently, so I'm used to this and plan for it my landing calculations.
What I WASN'T ready for was how much the wake vortex of the aircraft ahead of me got pushed into my landing area. I was stabilized and just about to start the transition to flare at about 100 feet with a descent rate of 300 feet per minute, just the way my company wants it. With no warning, I noticed the ground rapidly rushing up to us, and the GPWS started squawking "Sink Rate!" It happened so fast all I could do was pull back harder on the stick to slow my descent. No time to go around, no time to spool up the engines, barely enough time to say "whoa!" At that point, we banged into the ground and the whole aircraft was shaking (and not from my landing).
It wasn't until I parked that I figured out it must have been wake from the aircraft in front of us getting pushed into the touchdown zone. It's a lose/lose situation when landing with a tailwind. We need to touchdown at the correct location because our performance is predicated on it, so I don't have the option of landing long. You could also say "I'll add a couple of knots to my approach speed in case I get into wake," but that doesn't work because your landing distance numbers are already dramatically increased when landing with a tailwind.
The only thing you can really do here is remain vigilant. When landing with a tailwind, be diligent for the signs that you are encountering wake turbulence near the ground such as shaking, a change in vertical speed or unusual pitch changes and be ready to control the aircraft through it. There might not be enough time for a go-around.
Check out Advanced Aircrew Academy's Wake Turbulence eLearning module for training.