Prop Strikes

wrote in message
oups.com...
Anyone else here ever experience one? How did yours happen?

Mooney 201 main gear slipped down into a hidden drain while taxying on
grass. The aircraft tipped forward and the prop tip touched the turf. I
still remember the sound. It's a horrible sound... :-(

Julian

Many prop "strikes" are not sudden stoppages. Like when the prop slices
through a tow bar or digs a little ditch in the dirt. The Lyc and TCM
instructions, however, are that any incident that damages the prop to any
extent that cannot be repaired by simple gravel nick-filing requires a
teardown. Which seems like crazy overkill to me.

I can see that a sudden stoppage, a la WHANG! - (silence), might break
something inside.


"Hatz Lyman C" wrote in message
...
When the engine is started it goes from barely turning to suddenly
spinning
fast. Why can't it take a faster than normal deceleration from a prop
flailing against pavement or bashing a tow bar?

The difference is whether the acceleration or deceleration is constant or
sudden.

Lyman

Of seven propstrike teardowns, we've found two cracked cranks
and another bent. Bent cranks don't run properly in the bearings,
wearing them rapidly and ultimately resulting in failure. The undamaged
cranks were from more minor propstrikes.
Here's another reason to get it checked: An engine overhaul
shop had a crank with a crack through the front main, caused by a
propstrike. They tossed it into the scrap barrel, where it was spotted
by a guy building up an engine for his homebuilt. He wanted it, they
refused, and it disappeared shortly thereafter. A couple of years later
they heard of this same guy being killed in his homebuilt when the
front of the crank broke off and the prop came through the windshield,
believe it or not, killing him instantly. Investigators found that the
crack in the crank had been welded and remachined.

Dan

Dan

No. (Think about it ...)

Also I didn't belly in. Landed on mains only. Used the nose as a skid.
Big difference.

"steve" wrote in message
...
isnt it a given to have 2 prop strikes when you belly a twin?

"Dan Thompson" wrote in message
news
I had two prop strikes on a twin when the nose gear wouldn't come down and
I had to land on the mains. Will never forget the tick-tick-tick of the
prop tips on the concrete. Or the short rollout. Or the jaunty angle
when deplaning.

wrote in message
oups.com...
Anyone else here ever experience one? How did yours happen?
Mine have been ag related and hit ground, rocks, birds, and ?
Ever throw off a piece of the prop blade? I lost a piece during
climbout of a jungle strip in the Amazon in a C-185. Managed to dead
stick it back without any further damage but it took nearly two months
to get a replacement. IN the meantime, I used a field expedient and cut
off an equal amount from the other blade. We were about 200 miles from
civilization on the Rio Curaray.
Ah the fun old days....
Ol S&B

On Thu, 27 Jan 2005 03:31:38 GMT, George Patterson
wrote:



Corky Scott wrote:

Nothing happened right away, not at idle anyway. The prop missed the
still attached towbar. But when the engine was revved up for the
runnup, the lowered pressure in front of the prop sucked the tow bar
up and I guess caused a sudden stop.

Machado tells the story of a plane spotted taxiing with the towbar still
attached. Someone radioed to stop him from taking off.

A few years back, Joyce and I were headed over to Vassar MI from 3BS.
On the way we heard a guy in a Grumman Tiger ask a guy if he was in
the area. Hearing an affirmative he asked if the other plane could
join up with him. A different voice asked, "Forget something?".
There was a pause and as I recall the answer was, "Ahhhh Maybe".
Other voice, "something like a tow bar maybe?". Answer, "Not sure".

The second plane joined up and sure enough, "You have something
hanging from the nose gear. Kinda looks like a tow bar.

So, he headed back to Harry Brown airport. He set it down nice and
easy and the tow bar just skidded along. They removed the tow bar and
he went back out.


He had just landed.

I think I remember hearing some one radio this guy when he was on the
ground to tell him he still had the tow bar attached and to not take
off. He too, told them he'd just landed.


Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

George Patterson
He who marries for money earns every penny of it.

On 26 Jan 2005 06:57:39 -0800, "Paul kgyy"
wrote:


Upper Cowl separated on one side on my Arrow in flight - wind blew it
up on the windshield and since the other side remained attached, it
twisted and put about a 1/8 inch dent in the back of both blades.
Mechanic insisted I tear the whole #$&$ engine apart. One blade turned

As I recall, any strike that requires more than a minor dressing
requires an engine tear down according to Lycombing and Continental.

out to be out of spec, couldn't find replacement 2blade prop, ta da ta
da da da. That's how it goes with airplanes. At least I know the
engine is nice & clean inside and the new 3 blade prop looks nice.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

On 26 Jan 2005 12:58:17 -0800, "Gene Seibel" wrote:

Once. http://pad39a.com/gene/flypix0.html

When I was a primary student my instructors (two) did not figure any
wind less than the airplanes capabilities was an excuse for canceling.
I hated it at the time, but I was thankful they put me through that
when I did my first long cross country. A bunch of lake effect snow
storms popped up between "the straights" and TVC. Had I not been
thoroughly tested in those conditions it would have scared the crap
out of me.

My biggest fear was the wind getting under the tail when headed for
the transient parking ramp and doing what it did to you.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

"Gene Seibel" wrote in message oups.com...
I was pretty much right at the point where the wind went from tail to
head. Elevator control was something that simply wasn't instinctive to
me, and it happened in a split second.
--
Gene Seibel
Gene & Sue's Aeroplanes - http://pad39a.com/gene/planes.html
Because I fly, I envy no one.


Tricycle gear while taxiing; always dive into the wind or dive away from it...

steve wrote:
Hitting the tow bar would damage the prop enough to put any nick or stress
riser out of limits...a nick on the trailing edge would cause a chordwise
crack quite quickly...If i were flying that plane, I would refuse to fly the
aircraft until the prop was certified airworthy by at least a qualified
mechanic. A small scratch may seem irrelevant but at 9000g's it really is.



Bah, buddy of mine has a J5. He taxiied into a huge hole one day. Bent
the prop on both ends. We found a couple of wooden chocks and a big
mallet. We beat the prop back straight, more or less. He flew it home
and let the prop shop overhaul it. Sure it vibrated a little bit, but
it's a cub.

"Larry Dighera" wrote in message
.. .
On Wed, 26 Jan 2005 14:43:35 GMT, "Jay Honeck"
wrote in q0OJd.29738$EG1.8340@attbi_s53::

We went through the prestart checklist, and I engaged the starter only
to hear a loud clunk as the first blade went by. He had left the tow
bar on the front gear leg.

I saw a guy do that once.

Hitting the tow bar may not damage the prop, but it sure would damage
whatever the tow bar hit.

We were fortunate. The tow bar remained attached to the gear leg. I
presume this meant that the cylinder failed to fire in the first 180
degrees of prop rotation.


On Thu, 27 Jan 2005 19:28:02 -0500, "steve" wrote
in ::

Hitting the tow bar would damage the prop enough to put any nick or stress
riser out of limits...a nick on the trailing edge would cause a chordwise
crack quite quickly...If i were flying that plane, I would refuse to fly the
aircraft until the prop was certified airworthy by at least a qualified
mechanic. A small scratch may seem irrelevant but at 9000g's it really is.

We examined the prop and the tow bar and were unable to discern any
nick, scratch nor evidence of any impact at all. Of course the
trailing edge of the propeller wasn't involved in our incident.

If you consider that a 4-stroke IC engine requires two revolutions to
complete one full combustion cycle, then it would seem there is one
cylinder firing each half turn of a four cylinder engine.

Fortunately it was just the power of the starter motor that powered
the propeller that (probably less than) half turn. If the engine had
been running or even if it had fired a cylinder in that first 180
degrees, we would have considered scrubbing the flight.

Incidentally, what's a "stress riser?"