Another Blow to Airbus

On Aug 12, 12:16*pm, wrote:
a wrote:
With several thousand hours of SEL PIC, I can't remember once when
after leaving the ramp going back because the control excursions were
unusual. I have come back because RPM drop was not right, because VOR
tests showed failure, a DG that wasn't 'crisp'. etc etc. Have not yet
had the prop not cycle correctly. Did see someone in a 680 Commander
get out to take off a rudder clamp, that would have been found because
the excursions were not 'free'. That brings up an interesting topic
for aviators -- when and why did you last return to your tiedown
without taking off on a planned flight? Or, not left the tiedown or
hanger because the airplane was not, in your view, airworthy?

Two years ago right after annual; no carb heat.

Turned out to just be an air duct coming loose 'cause the clamp wasn't tight.

--
Jim Pennino

Remove .spam.sux to reply.

I used to fly a Mooney Ranger (Joe-bar retraction of the gear!) that
had normal aspiration -- not injected -- and had the carb heat cable
break during an approach in actual, with carb ice buildup. There was
no engine response when I tried to fly the miss, tried everything and
it turned out leaning the engine gave me enough power to limp to an
alternate. That was a big snow storm in the northeast, had I gone down
in the mountains of eastern PA I would not have been found until
spring. (VOR approach into an uncontrolled airport, then got to
Scranton for a full ILS that I was NOT going to miss!).

I wish the damn thing had broken during run-up. That airplane would
grow carb ice in the wink of an eye -- first indication was the CHT
gauge would start falling.

In article e717c6e3-261a-4a7e-91f4-447fcd3eb048
@c10g2000yqi.googlegroups.com, says...

On Aug 11, 3:08*pm, Richard wrote:
On Aug 8, 10:05*am, a wrote:



On Aug 8, 9:25*am, " wrote:

On Aug 8, 7:05*am, a wrote:

The more I fly and the older I get the more I want to be gentle with
the flight controls. Remember, fellow aviators, there are demons
lurking near the edges of the envelope.

Which begs a question on runup process.

My brother in law "vigorously" checked controls free and clear to the
point they banged at the stops. *I was quite more gentle, taking them
to the stops on free and clear. *In some ways, I could see why he did
what he did, but since my normal flight regime didn't abruptly take
control inputs to the stops I elected my way.

http://www.youtube.com/watch?v=ki79yX4bhJ4Runupstarts6 minutes into
the video.

I wonder how others did it?

As you, I move the controls to the limits, but gently. *You'll see
elsewhere recommendations that throttle advancement be slow as well,
and there's little reason to be abrupt with the prop for that matter.
If one pays for the repairs on a personal airplane, gentleness usually
equals lower bills as well as more comfortable passengers.

One wonders if in fly by wire airplanes pilots might assume the
software will *protect the mechanical parts. Speaking of that, if you
watch films of advanced jets landing (these airplanes are by design
unstable) you'll see very busy stabilizers, lots of flipping, but the
pilot will tell you he's just applying smooth back pressure to the
stick. The computers know the attitude the pilot wants and makes it
happen actively.

I did a test on our cars, in neutral or park full throttle will
accelerate the engine but it self limits well below redline. That and
the ABS mentioned in an earlier thread add a layer of protection. If
you extrapolate that sense of protection into taking a 1.1 g turn in
tires that can support only 0.9 gs you'll bend metal.

.

I've seen it done both ways too and as a jumper (non-pilot) I always
wondered if a more gentle approach might be more useful to detect a
subtle problem since (it seems to me) that a full force slam to the
stops would overcome any momentary resistance and could mask a problem
in a linkage. *Conversely, I suppose it could force a *break* in a
weak link while on the ground. *So then, YMMV.

On airplanes without 'augmented' controls, the feedback forces on the
yoke and rudder are significantly greater in flight than on the
ground during run up, so if there's going to be a failure it might
very well be aloft. The good news is, it's rare to the best of my
knowledge that moving the controls to the extremes,. either fast or
slow, will uncover a problem, or that they fail in flight.

With several thousand hours of SEL PIC, I can't remember once when
after leaving the ramp going back because the control excursions were
unusual. I have come back because RPM drop was not right, because VOR
tests showed failure, a DG that wasn't 'crisp'. etc etc. Have not yet
had the prop not cycle correctly. Did see someone in a 680 Commander
get out to take off a rudder clamp, that would have been found because
the excursions were not 'free'. That brings up an interesting topic
for aviators -- when and why did you last return to your tiedown
without taking off on a planned flight? Or, not left the tiedown or
hanger because the airplane was not, in your view, airworthy?

My only experience is way way back in my student training days - so, in
a Traumahawk. The Tommy has an auxilary electric fuel pump as well as
the std engine driven mechanical pump. The aircraft checked out fine to
me. However (IIRC, it was 25 years ago), just prior to startup (upon
turning on the electric fuel pump (ON for startup, T/O and landings) it
sorta kept ticking. I didn't think too much of it, until I started up,
and noticed a very strong fuel smell. I shutdown and looked under the
engine cowls and noted a hell of a lot of fuel in there. I switched the
electric pump on and had another looksee - only to see fuel absolutely
****ing out! Got someone from the club to take a look and it was
grounded - I grabbed another Tommy and headed up for an uneventful
flight.

I hate to think what could have been!

(The problem was later found to be a broken 'T' connector - or
somethin' like that - in the fuel line.)

And the pre-flight checks did not, essentially, catch the problem.

--
Duncan.

a wrote:
On Aug 12, 12:16Â*pm, wrote:
a wrote:
With several thousand hours of SEL PIC, I can't remember once when
after leaving the ramp going back because the control excursions were
unusual. I have come back because RPM drop was not right, because VOR
tests showed failure, a DG that wasn't 'crisp'. etc etc. Have not yet
had the prop not cycle correctly. Did see someone in a 680 Commander
get out to take off a rudder clamp, that would have been found because
the excursions were not 'free'. That brings up an interesting topic
for aviators -- when and why did you last return to your tiedown
without taking off on a planned flight? Or, not left the tiedown or
hanger because the airplane was not, in your view, airworthy?

Two years ago right after annual; no carb heat.

Turned out to just be an air duct coming loose 'cause the clamp wasn't tight.

--
Jim Pennino

Remove .spam.sux to reply.

I used to fly a Mooney Ranger (Joe-bar retraction of the gear!) that
had normal aspiration -- not injected -- and had the carb heat cable
break during an approach in actual, with carb ice buildup. There was
no engine response when I tried to fly the miss, tried everything and
it turned out leaning the engine gave me enough power to limp to an
alternate. That was a big snow storm in the northeast, had I gone down
in the mountains of eastern PA I would not have been found until
spring. (VOR approach into an uncontrolled airport, then got to
Scranton for a full ILS that I was NOT going to miss!).

I wish the damn thing had broken during run-up. That airplane would
grow carb ice in the wink of an eye -- first indication was the CHT
gauge would start falling.

I fly a Tiger in SoCal and it would take some weird (for here) weather
to actually get carb ice, but I don't launch unless EVERYTHING feels
right.


--
Jim Pennino

Remove .spam.sux to reply.

On Aug 9, 12:41*am, a wrote:
John Smith wrote



"After being buffeted by the wake from a jet ahead of them, the pilots
made several sharp rudder movements." Note the key word "several".
"Several" sharp rudder movements may break any aircraft at any speed,
especially big ones, as any pilot sould know, especially after the
American Airlines crash from 2001.

True enough, but absent any conflicting factual information, if the
NTSB is indicating the controls are too sensitive and airframe damage
can happen even when special training is given. I'd call it a design
weakness or flaw.

The Airbus is a fly by wire airplane, pilot inputs for all intents are
'suggestions' to the software, and we've read elsewhere of accidents
caused because the software chose to ignore those inputs. A reasonable
person might find, then, that inputs that might damage the airframe
would be moderated by the programming. A jury made up of such
reasonable persons might be inclined to think harshly of Airbus.

If I was the plaintiff in such a lawsuit I'd ask for a change of venue
to, oh, Seattle comes to mind.

Typical litigous mentality. The plane passed certification but any
pilot can break a plane. Control surfaces have the power to break
wings, tailplanes and rudders -fact. I believe NASA had to use a test
plane recently to examine the increase in tail fin load induced by
rapid reversal of rudder input after significant yaw had developed and
the found the structural load could be more twice the design load -if
I remember correctly.

Cheers

On Aug 9, 1:49*am, Mxsmanic wrote:
a writes:
A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit.../2010/08/ntsb-...

Hmm. The whole purpose of having computers that fly the airplane, and ignore
the pilots' inputs if they find them contrary to what French engineers have
decided, is to prevent exactly this sort of incident. Why don't the
all-knowing, all-wise computers prevent any rudder movement that might
endanger structural integrity?


Because the computers don't know actually know the relationship
between yaw, airspeed and allowable rudder input/structural load and
they are not required to. Neither do most pilots when they step on the
rudder pedals. Think about it...

Cheers

On Aug 9, 2:23*am, brian whatcott wrote:
On 8/8/2010 7:05 AM, a wrote:

A couple of days ago the NTSB found the 320 series to have too
sensitive a rudder, it can be torn off with peddle pressures. What's
especially of interest is the problem seems to persist even when crews
are given special training about the problem.

There are some details here.

http://content.usatoday.com/communit.../2010/08/ntsb-...

The more I fly and the older I get the more I want to be gentle with
the flight controls. Remember, fellow aviators, there are demons
lurking near the edges of the envelope.

I am not going to act all shocked that pilots can pull pieces off of an
airframe: these pieces include
1) Wings
2) horizontal elevator/stabilator
3) vertical stabilizer, and pieces hinged or connected to the above.

That includes EVERY plane that has a certificate of airworthiness.

It is more troubling if pilots can get into the danger area (maneuver
speed plus as you know) and still inadvertently pull bits off if
correctly trained. * *A very troubling thought: how many incidents had
ex military fighter pilots at the yoke?

Good points. It is possible that fighter trained pilots may have a
lower awareness of the fragility of aircraft since their planes are so
strong. The fact remains that full opposite rudder deflection in a yaw
can produce very large fin loads with increased bending moment perhaps
the biggest problem. After all, Va is not defined for the fin but only
for the wings.

Cheers

Cheers

On Aug 9, 2:30*am, John Smith wrote:
brian whatcott wrote:
It is more troubling if pilots can get into the danger area (maneuver
speed plus as you know) and still inadvertently pull bits off if
correctly trained.

The most troubling part is that many pilots think the cannot pull bits
off below maneuver speed.

Make that most pilots.

Cheers

On Aug 10, 7:15*am, Dudley Henriques wrote:
On Aug 9, 1:47*pm, RST Engineering wrote:

On Sun, 8 Aug 2010 05:05:50 -0700 (PDT), a wrote:

. Remember, fellow aviators, there are demons

lurking near the edges of the envelope.

Or as my first flight instructor told me, "The envelope has airspeed
going horizontal and altitude going vertical. *Pushing the envelope
puts you into the upper right corner of the envelope. *That's also
where the stamp gets cancelled."

Jim

Actually, if the truth be known, not that exceeding the right side
won't get you killed, it's the LEFT side of the envelope that gets
most pilots in trouble. :-))
Dudley Henriques

So true. As far as I know the the real flight "envelope" looks nothing
like an envelope... But the safest place is also on the left side,
drinking tea... ;-)

Cheers

On Aug 11, 1:11*am, a wrote:
On Aug 9, 3:15*pm, Dudley Henriques wrote:





On Aug 9, 1:47*pm, RST Engineering wrote:

On Sun, 8 Aug 2010 05:05:50 -0700 (PDT), a wrote:

. Remember, fellow aviators, there are demons

lurking near the edges of the envelope.

Or as my first flight instructor told me, "The envelope has airspeed
going horizontal and altitude going vertical. *Pushing the envelope
puts you into the upper right corner of the envelope. *That's also
where the stamp gets cancelled."

Jim

Actually, if the truth be known, not that exceeding the right side
won't get you killed, it's the LEFT side of the envelope that gets
most pilots in trouble. :-))
Dudley Henriques

We SEL GA aviators don't get to play in the coffin corner, Dudley. I
can't get the Mooney to those altitudes and speeds (dammit!).

Strap on a JATO =:-O

Cheers

On Aug 11, 2:44*pm, "Peter Dohm" wrote:
"Dudley Henriques" wrote in message

...
On Aug 9, 1:47 pm, RST Engineering wrote:

On Sun, 8 Aug 2010 05:05:50 -0700 (PDT), a wrote:

. Remember, fellow aviators, there are demons

lurking near the edges of the envelope.

Or as my first flight instructor told me, "The envelope has airspeed
going horizontal and altitude going vertical. Pushing the envelope
puts you into the upper right corner of the envelope. That's also
where the stamp gets cancelled."

Jim

Actually, if the truth be known, not that exceeding the right side
won't get you killed, it's the LEFT side of the envelope that gets
most pilots in trouble. :-))
Dudley Henriques

--------------------

Or, to put it in a grossly understated way, the part of the envelope where
you would write "Attn: *Whomever" is likely to get your attention!


You put the return (to sender) address on the left side or sometimes
the backside... How apropos.

Cheers