Please Don't Do That

[Colonel]

A cringeworthy moment.

Had the misfortune to watch a PPL try to
land the mighty C172 on a paved 4000
foot runway.  His challenge was a 10
knot wind, right down the runway.

On final, I could see the nose tucked down
low, to compensate for the treacherous
headwind.  First facepalm.

Despite the 10 knot headwind, he burned
the first 2000 feet of runway and instead
of overshooting, forced the mighty 172
down on the runway on it's nosewheel,
which popped the nose up, so the mains
hit, which popped the ass up, so the nose
hit again, and then the mains hit again,
and the nose hit again.  Serious porpoise.

I know no one gives a shit about oscillations
but it looked just like this:



Somehow the poor 172 managed to keep
it's nosegear attached to the airframe.

Personally I would have entered a hard landing
in the journey log but he didn't.  The aircraft
needs an inspection IAW CAR 625 App G( 8 ):

[quote]( 8 ) Heavy or Overweight Landings

An aircraft landing gear is designed to withstand landings at a particular aircraft weight and vertical descent velocity. If either of these parameters is exceeded during a landing, it is then probable that some damage can be caused to the landing gear or its supporting structure. Overstressing can also be caused by landing with drift or landing in an abnormal attitude (e.g. [b][i]nose or tail wheel striking the runway before the main wheels[/b][/i]). [/quote]

In particular, the rivets on the nose gear
need to be examined - they can pop right
off under shear - and the firewall for wrinkles.

But none of that legally required maintenance
will occur.

Instead, our intrepid PPL came in after his
ace landing and parked the 172 by taxiiing
off the pavement onto rough ground with
the elevator hanging down.  He didn't give
a shit about the prop hitting, either.  Maybe
he figured he'd completely trashed the 172
during his landing so there was no worry
about a prop strike and destroying the engine.

Now, I understand that I am a [b]BAD PERSON[/b]
because I might hurt someone's feelings by
mentioning that gee, maybe pilots shouldn't
wreck the hardware.

And the bonehead PPL is a "Good Person" because
he is having lots of "learning experiences".

And I'm ready for [u]Rui and the Four Bars[/u] (sounds
like an off-key doo-wop band from the 50's) to
start crapping all over for me, for daring to
mention this.

But please guys, try to work just a little bit on
your stick and rudder skills.  The aircraft will
last a lot longer.  Maybe that doesn't matter
to you but it sure as hell does to me.

I will be kind this morning and not mention
the millions of dollars spent on rwy 07/25
at CYOW because four-bars kept pulling the
same stunt, approaching high and hot and
refusing to overshoot, touching down long
and running off the end of the runway with
no thrust reversers, of course.

[Colonel]

[img]https://bobchoat.files.wordpress.com/20 ... nbrain.gif[/img]

Look at that massive primate brain.

Those huge frontal lobes.

And it's all nearly useless, because
under pressure, when it really counts,
what's flying the airplane is that tiny
lizard brain.

[Chuck Ellsworth]

How do they get to fly solo with such abysmal flying skills and total lack of how serious these events are?

It was the same in Europe, a never ending record of damaged nose gears and firewalls.

Oh, by the way Colonel we are getting mentioned over on the Canada forum of Pprune...seems we have found a new home here to pat each other on the back.

Here......pat, pat, pat. :)

[Slick Goodlin]

I have never porpoised a trike, nor have I seen it happen.  I've watched a lot of airplanes come and go and somehow it's never come up.  To me the whole affair is just words on paper which kind of makes me feel like I'm missing out.

[Chuck Ellsworth]

It is all about height above the runway judgement...or lack thereof.

[Slick Goodlin]

Taildraggers can porpoise too

Been there.  Did not like.

[Chuck Ellsworth]

Been there.  Did not like.

Can you elaborate a bit more.

When these things happen we should find out why and how to not let it happen again.

There are some of the best tail wheel pilots in the industry here who are more than willing to help you out.  :)

[Colonel]

Shot in the dark:

https://en.wikipedia.org/wiki/Pilot-induced_oscillation

[quote]Pilot-induced oscillations may be the fault of the aircraft, the pilot, or both. It is a common problem for inexperienced pilots, and especially student pilots, although it was also a problem for the top research test pilots on the NASA lifting body program. The problem is most acute when the wing and tail section are close together in so called "short coupled" aircraft.[/quote]

An important part of your job as a "stick & rudder"
pilot is to learn to damp out oscillations:



Those interested in the history of jet aircraft
can look at all of the small-tail variants of the
first swept-wing aircraft which suffered from
divergent dutch roll.  This includes the B707.

There is a funny story as to why the F-86
never had a "small tail" variant.

Oscillations are often very bad - see 2nd
order ODE's for more information.

As a pilot, we can see annoying oscillations
on the LOC (GPS track solves that one)
and on the GS inside 500 AGL as the cone
narrows.

As a tailwheel pilot, we can see terrifying
oscillations in yaw when the tires are on
the ground.  Tailwheel aircraft are certainly
not immune to oscillations in pitch during
landing, more often during wheel landings:

www.pittspecials.com/articles/Wheel_landings.htm

However, you can still get an oscillation in
pitch even with a three-point landing in a
taildragger. 

I have seen this in single-seat (but not
two-seat) Pitts.  This fairly rapid oscillation
in pitch, with a small amplitude, undoubtably
due to the short coupling of the very short
fuselage, while unsettling is not divergent
and as such is not a control issue.

[HiFlyChick]

Scary!  Not even so much that he did it but also that he cares so little about the person flying it next...

We had this happen once at the flying club that I learned at - it was such a shame because the person that did it was a super nice guy, but I think he panicked at the first thwack of the nose and just let it have its own way (porpoising and striking the prop).  I think he was so shook up that he gave up flying (but at least he owned up to it).

I always tried to drill into my students and later on my F/Os (yes, I wear 4 bars, wonder if I am one of those terrible 4-bars that keeps getting talked about? :) that the overshoot is always an option, and that extending the flight time is no biggie compared to damaging the aircraft.