Mastering the crosswind
Author: Colin Aro
Article extracted from LightspeedAviation.com
The original article has been divided into four to facilitate the reader’s reading.
Configured and Stable
A good landing is the result of a well flown, stabilized approach. We’ll go over the basics for good configuration and
stabilized speed control.
The Approach – The Set Up
A good landing is the result of a good approach. As the aircraft is established on final, it should be configured for landing, trimmed, and stabilized. In particular, the airspeed should be stabilized at the proper approach speed. Good speed control is best achieved by flying the appropriate pitch attitude for the desired airspeed. Therefore, good speed control is the result of good attitude control. This is especially true in gusty conditions. Having the aircraft configured and stabilized at the proper speed will go a long way in making the perfect touchdown “automatic”, but don’t be too much of a slave to “stabilized”: The April, 2020 issue of AOPA Pilot has an excellent discussion of aircraft configuration on approach (‘Landing like a Pro’, pp. 94-96). This article humorously points out that ‘straight down’ is a perfectly stable approach.
AOPA follows this up with an excellent recent article ‘Finishing Strong’ which breaks down a three-step transition from the air to the ground (October, 2020 AOPA Pilot, pp. 76 – 83). This material is light on crosswind discussion – “How has something so simple become so confused?”
We hope to expand on the effect of and correction for crosswinds on landing. It truly is a relatively simple skill, and we hope to shed some understanding of it here.
What is the “proper approach speed”? Generally speaking, the approach speed listed in the POH for a typical GA aircraft is 1.3Vs0. Whatever the POH dictates, this is the appropriate speed to be flown on the approach. There may be more than one suggested speed based on configuration and/or desired performance. I cannot stress enough how important it is to fly pitch attitude and not chase the airspeed indicator – especially when it’s gusty.
Regarding gusty conditions, it is advisable to adjust the approach speed if the surface winds are gusty. If gusts are present, a good rule of thumb is to add half the gust factor to the approach speed. For example, say the surface winds are at 12 knots gusting to 20. In this case, we have an 8 knot gust factor and would add 4 knots to the approach speed.
In summary, upon establishing the aircraft on final approach, we need to
- Have the aircraft properly configured for landing.
- Have the aircraft stabilized at the proper approach speed, possibly adding a gust factor.
- Have the pitch attitude trimmed for the appropriate speed, especially in gusty conditions.
If the approach is stabilized with the correct airspeed, attitude, and configuration then a good landing and rollout are very nearly an automatic result of the properly flown and stabilized approach.
As for stabilized, I personally like to hold my crosswind slips to landing relatively early on final – other instructors whom I respect immensely believe the opposite: crab into the wind until the flare and add the slip at that point because the crosswind component will change as you descend to the runway.
And to bring the dreaded “taildragger” into the discussion: we will discuss the prospect of estimating crosswind component based on the aircraft’s crab angle. In my humble opinion, the only good argument for wheel landing a taildragger is when the crosswind is unknown. It is better to run out of control authority and execute a go-around with the mains firmly on the ground as opposed to minimum controllable airspeed a few feet off the runway.
The remainder of this eBook will focus primarily on proper crosswind correction during landing. Loss of control is our primary source of accidents in the landing phase and for short final/touchdown/rollout a large factor here is proper crosswind correction and control. The major issue with landing in a crosswind is, of course, the aircraft’s crabbed flight path when the longitudinal axis is aligned with the runway centerline. In the next chapter we will add a discussion of crosswinds and crab angles in preparation for slips-to-land.