Real Answers from Real Pilots

Wind Shear

Here’s a little change of pace guys, as I’m wondering about a little bit of general flying knowledge.
Today, flying into KBKW runway 28 the winds were listed as 310@17G25 with moderate-severe turbulence from the surface to 5500 or so on my descent. On half mile final I had the 172 stabilized at 80 knots with 10 degrees of flaps, but as I crossed the threshold (at about 30-40 feet), my IAS jumped to 110. This was pretty scary because there’s a huge cliff right at the threshold to the runway!
Being my first experience with wind shear, I improvised and extended my landing and landed safely. I was wondering what tips you all have for dealing with the hazards of wind shear? Thanks!

Kamrin,

That is a pretty significant airspeed gain and I bet was a little tough to handle, especially in a small airplane. Not second guessing your decision, and it has been a long time since I flew a 172, but a go around might have been appropriate in that situation, especially if you were concerned about runway length. On any approach, no matter what the weather, you should always be prepared to go around, doing so shows good judgement and is not a negative reflection on your pilot skills.

Beyond that, I would caution you not to chase the airspeed too much, meaning don’t make dramatic changes to the power settings. It is best to have a measured response, but to also allow the airplane to return to its natural state on its own. Remember that a gain of airspeed can oftentimes be followed by a loss in airspeed, no pulling the throttle all the way back to idle could cause you real problems if you need the power to get our of a loss of airspeed. This is more a problem in jets than it is in small airplanes as turbine engines take longer to respond to power changes than reciprocating engines do.

Good question.

Chris

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Hey Kamrin,

Yea windshear can DEFINITELY get your attention and has caused more than one pilot to have a bad day. Let me first preface this by saying I always recommend you talk to your instructor on areas of “technique”, as I never want to give conflicting information. Disclaimer aside the first thing to consider is what type of windshear are we talking about? Depending on the source, there’s increasing and decreasing performance windshear (decreasing performance is the REALLY bad one). What you experienced today was increasing performance as your airspeed “increased” (which actually “increases” your speed and lift, hence your “performance”). While I understand “this was pretty scary”, it’s MUCH scarier when it goes the other way! Obviously the concern here is you’re going much faster than you like and there’s a chance of landing long but the good news is you’re not falling out of the sky. When you have decreasing perf w/s the speed (and therefore the lift) drops off and if you’re low to the ground it could result in landing short, hard, or worse. Now again I don’t know where you are in your training but the most common technique used landing in gusty winds (which will usually cause increasing perf w/s vs say thunderstorm downdrafts) is to land with a lower flap setting. The idea being you can carry more airspeed to the ground while creating less lift. While your normal Vref might be say 65kts with full flaps, it will be higher (say 75 or 80, I’m guessing?) at a lower flap setting enabling you to still land in the touchdown zone. This btw is the reason you ALWAYS have one hand on the throttle vs 2 hands on the yolk. The biggest thing to remember is when in doubt you can ALWAYS GO AROUND. This continues all the way and including when you get to the airlines. ALL airlines have a “no-fault” go-around policy meaning if there’s ever a doubt you go. Most modern jets actually have windshear detection and at most airlines when it detects decreasing perf w/s (RED bells and whistles) you MUST go around. Increasing perf (yellow with less bells and whistles) you’re required to monitor.

Comfort and skill comes with experience and you’ll get better as with everything. Side tip try not to get freaked out by the numbers. I had an instructor tell me once all you need to know about wind is what direction and is there alot or a little. When I was doing my x-countries with my partner I noticed he would get really tense when he’d hear winds over say 15kts or the word gusty. He was actually really great at landing in gusty x-winds it was the thought (fear) that freaked him out. I then started editing the ATIS’ when I would get them. I’d give him direction but never say it was above 10-12kts. He’d land like a rockstar every time (even gusting to 30) and after say “man, that sure felt like more than 10kts!”. Gotta do whatcha gotta do :slight_smile:

Adam

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Hey Kamrin,

Like the rest said, windshear is no joke. Whether you are in a 172 or a 747, you must be very careful when you are approaching a runway with high gusty winds.

In a 172 however, once you get comfortable with the landings, you will see that the airplane is much more maneuverable than you thought it was before, and landing in heavy and gusty crosswinds is not all that bad. The trick is to always have in mind that you can go around at any point. If you keep that in mind and are ready with your hand on the throttle, you have mitigated most of the risk. I say that because many students (and not only at your level…I had the same trouble when I transitioned to the jet) will subconsciously pass a “point of no return” on the approach and decide for some reason that a landing is now mandatory (this is NEVER the case).

The most important rule is to keep yourself within your personal limitations. Never try to stretch them if you don’t have some sort of supervision.

Yarden

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