Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 6:39 am
by Colonel
The trick is to know when the mains are one foot above the runway ;D
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 12:46 pm
by cgzro
Humans judge distance by the relative size of objects that are of a known size to us. As you get down to 50' you can start to make out the individual blades of grass, the trees, the landing lights, rocks, stones etc. All of these things come into focus when they would not be resolvable at greater distances. Its the combination of many things coming into focus that gets you to the point of knowing how high you are so the answer is to look at those things. Look to the side and watch the grass at the edge of the runway, size of the landing lights, size of the houses and trees. Look at your angle relative to the roof of a house etc. There is no single answer because there is no single object. Of course if there are no objects on the surface then its like flat water or snow and its very difficult and you need to get very close to start to see the height.
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 1:39 pm
by Liquid Charlie
For me being "old" radar altimeter or radio altimeter >:D and a glide slope but when non of this is available I guess it's just muscle memory along with all the fucked up landings that finally teach you. Now to be taught by an instructor and eliminate all the trial experimentation would have been magic. I don't think that things are as they were 40 and 50 years ago where most of your flying skills were self taught with the odd kick in the ass my a mentor. On the other hand there is a grave shortage of career instructors and this certainly effects the over all knowledge level as well as misleading advice and instruction. The old phrase "babies having babies" comes to mind. Here's a thought, maybe all initial and private license instruction be done on tail draggers and nordo type aircraft. Get people away from their Ipads and looking out the fucking window. Sorry drifting rant -- haha
Seriously though, to find an instructor willing to teach something like this should be on every aspiring pilot's wish list. I go through this on a daily basis and try to explain to my IATRA qualified right seat, hit the fucking target first and forget the cosmetics. One example, which remains in my mind, on the voice recorder, "nice landing" and that was just before they ran off the end of the runway. Greased it on, catch was, too much runway behind them.
Change is good, technology is good but not at the expense of stick and rudder skills. I was recently talking to a truck driver. He was experienced and frustrated. He told me that they have drivers now that can't back up a rig, how fucking stupid is that. I'm afraid aviation has also taken that path in many areas.
Chuck, I'm totally interested in what you have to say. It might help me get the eye to wheel height explanations to my sexual advisors better.
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 2:44 pm
by Strega
[quote]I think I look about 300ft down the runway in front of me. I don't have any trouble judging my height above the runway to within a foot or two. I think it's mostly just down to experience.[/quote]
Flight sim doesnt count mr crunch.
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 4:17 pm
by Colonel
Landing an airplane is probably the most demanding
task a new pilot will tackle. All at the same time,
he has to
1) keep the aircraft on AND aligned with the runway
centerline (no simple task with a crosswind)
2) keep the aircraft on the correct glidepath
3) keep the airspeed + power correct
4) keep the yaw under control
5) flare the aircraft from the 3 degree glidepath
to level, one foot above the runway.
That's a lot of balls to juggle, and a lot of
precision to ask for, from a pilot. Heck, you
can get an instrument rating if you can fly
an airplane +/- 100 feet of altitude. Not so
landing!
Pilots often get behind the aircraft and when
the runway suddenly spreads wide, then try to
do task #5 - pitching from 3 degrees nose down
to level, one foot above the runway - in one
hell of a hurry. And that's not going to work
out, because first you get good, then you get
fast. Not the other way 'round.
With lots of practice, pilots have more percentage
of their brain left over for the flare, which I
encourage them to start a little earlier, and do
a little slower, to avoid a PIO in pitch which is
a trap that is all to easy to fall into, during the
flare.
We've talked about this before. Any time a
student has trouble landing, I tell them that
we are going to have some fun and do some
low flying, which TC says to never do.
I take the power on final, and I want them
to trim and just FLY THE AIRPLANE as low
as they can over the runway, but NOT TO
LAND THE AIRPLANE.
I want them to spend time - I bump the power
up, so we stay in ground effect and don't touch
down - at one foot, feeling how delicate the
pitch control is.
After a while, if you don't bump the power up,
they get a pretty good landing.
Just spend time, transitioning to, and then
flying one foot, down the runway. Try to stop
it from landing, which is pretty much what you
do with a little airplane anyways.
With a nosewheel aircraft, this gives a nice
mains-first touchdown, which is the objective.
-- EDIT --
Skip Stewart is one of the best pilots I know
of. He is an expert at flying at a height of
one foot!
[youtube][/youtube]
PS He got in all kinds of shit for doing that,
despite the fact that the paperpushers had
no authority in foreign soverign nations.
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 6:02 pm
by vanNostrum
Height is distance and it is judge by the relative size of familiar objects
Landing at night at YOW , poorly lit runways IMHO, sensing the transition into ground effect was an important cue and for the last
10' I used the relative size of the centerline stripe and runway markings
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 6:53 pm
by Colonel
[quote]Height is distance[/quote]
Sure is. A landing is a joinup and formation
(within one foot) of the runway. If you asked
most pilots to intercept and fly formation within
ONE FOOT of another aircraft, they would say
you are nuts.
[quote]distance ... is judged by the relative size of familiar objects[/quote]
Correct - beyond about 15 feet or so, your
stereoscopic vision doesn't work.
[quote]Landing at night[/quote]
Black night landings and glassy water landings
and zero/zero instrument approach landings are
often best done to a long runway/landing
area, where you don't really so much flare -
you set up a slow rate of descent with some
power on, and the aircraft enters ground
effect and flares itself. Works marvellously,
if you have the landing distance.
Many years ago, a pilot for a Company Which
Cannot Be Named was flying over Antarctica
and noticed an unusually large, flat area.
Because he was a thoughtful fellow, he punched
it into his newfangled GPS as a waypoint.
One day, wx went to shit. Chubby cube dwellers
don't think it ever will - they obsess about RVR
and whether or not the pilot got it before or after
the FAF (what bullshit) and exercising control
from the ground - but this pilot set up a long,
gentle descent to his waypoint and put his aircraft
down blind on the ice.
Better than crashing and everyone dying in my
opinion, but I am a [b]BAD PERSON[/b] because I want
to stay alive.
The chubby cube dwellers don't want you to use
your brain to stay alive - they will tell you that all
the answers are found in a stack of paper that they
produce.
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 7:15 pm
by vanNostrum
Black night landings and glassy water landings
and zero/zero instrument approach landings are
often best done to a long runway/landing
area, where you don't really so much flare -
you set up a slow rate of descent with some
power on, and the aircraft enters ground
effect and flares itself. Works marvellously,
if you have the landing distance
[/quote]
That was the " secret" I , a cero gold bars driver, used to impress my uninitiated passengers on the art of greassing landings ^-^
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 7:21 pm
by Colonel
Without a lot of experience at night - even
with all of the runway and aircraft lights
functioning perfectly - it's really easy for a
newbie to get into a PIO in pitch at night
during the flare, when things LOOK DIFFERENT.
A PIO in pitch near the ground is not always
a good thing. At my tiny airport, a couple
years back, a new PPL with a brand new night
rating (not from me) wiped the nose gear off
his RV-6A and killed his prop and engine and
cowling. A very, very expensive mistake.
Too bad no one ever taught him to do a black
night/glassy water/zero-zero landing.
People probably think I'm paranoid about
avoiding PIO's in pitch in the flare, but:
[youtube][/youtube]
That guy was landing the most docile nosewheel
aircraft ever, in perfect weather, and he killed
the poor thing. He approached too fast and tried
to force it onto the ground - both BIG mistakes.
Approach at the correct speed (see pitch attitude)
and try to stop it from landing - if you have the
skill to actually flare. Otherwise just set up a
gentle rate of descent and enter ground effect.
People don't believe me, but often your best
landings are achieved after doing the least
amount of heroics.
Re: How do you judge height from 50 feet to touch down?
Posted: Fri Mar 04, 2016 9:01 pm
by Chuck Ellsworth
Landings are only part of height judgement.
Crop dusting is probably requires the most skill in height judgement because of the accuracy required to drop into a field in a forty five degree angle of descent and level out at two feet and maintain that height for as long as the field is then pull up and turn around and do it all over again....thousands and thousands of times without killing yourself.
It is all about where you are looking to get the accuracy required and it is not at the far end of the field.