Undershoot Vs. Overshoot airport landing accidents

On Wednesday, April 17, 2019 at 8:28:44 AM UTC-7, wrote:
I always assumed that there are more overshoot airport accidents than undershoot ones. That is mainly due to our general knowledge that it's better to be too high than not high enough.
Am I correct here ?
Dan

You are not correct. We make impacting short a habit -- too clean, too low, too late on baseleg turn, too often undercalling the wind, Not Understanding How to Descend. Thus the typical belief is that an approach should be shallow.
"I'm in a 45:1 glider, I have to make a longer approach....."
This is Wrong.
If you ever find yourself having to clean up on Final,
you are doing it Wrong. You should be progressively dirtying-out.


soaringsafety.org
click on Flight Safety Programs, Accident Prevention, SSF Annual Reports

Pick a Year and begin reading. It is hugely enlightening.

In 2017 - (most recently available results):
Hit Object on Final - 2 (too low)
Stall/Spin - 1
Hit Object on Ground - 1
Land Short - 1
Land Long - 0
Other - 1

2016
Hit Object on Final - 3 (too low)
Stall/Spin - 1 into trees on approach(too low)
Hit Object on Ground - 2
Land Short - 0
Land Long - 1 asw28 over trees+long into trees
Other - 1 (lost-hit trees during outlanding=short)

2015
Hit Object on Final - 2 (too low)
Land Short - 2
Land Long - 1 (failed to open spoilers, three passes)

The majority of the US accidents are screwups on takeoff. PT3s
are the typical result of the screwup. This is why I offered my
SSA Webinar on Takeoff Dangers and How to Avoid Them. I would like to reduce this category of wreckage.
Go see it free anytime on the SSA website.

The second most common accident is landing short/hitting obstacles
short of the HOME runway. Trees, wires, fences, crops. Then the same
problem at outlandings .... being short of the targeted landing space.

I fully believe this comes from a failure to teach effective descent skills.. The The S's allow us to descend massively.
Spoilers, Slips, Speed.

Use the ones you are comfortable employing. Get training to expand your
personal envelope to include more tools. A normal approach should be half-dirty.

Drag increases exponentially with an increase in airspeed.
The truth is -- that exponent doesn't disappear after it has exhausted the
potential energy (altitude). When you round out fully dirty (all flaps or all spoilers or both/all) at speed -- the next thing to be scrubbed away exponentially is the kinetic energy. The speed WILL dissipate very quickly,
and even students realize that this has suddenly become a very normal looking landing.

Pilots who are 'handicapped' with flaps-only ships understand this.

Manufacturers shifted away from true landing/drag flaps, and the creation of landing-short accidents by pilots, to a more forgiving tool - spoilers. A reduction in landing flaps only creates a loss of lift and falling further below glide slope. Spoilers allow the reduction or return of lifting qualities to the airfoil for those oft-found occasions of being too-low on final approach.

I wish I could find my video on an old hard drive of a diving approach full dirty in a DuoDiscus (plain-Jane early one) that I had used in a landing training talk for an SSA Convention in about 2004. FULL Dirty with speed works. And Pete B knows it (as do my students).

Thanks,
Cindy B