Broken wing

[Stubby]

Way back, I believe the first jet passenger jet was the Lockheed
Electra. The plane mysteriously fell out of the air and very thorough
search for a cause was instituted. In the end, again if I remember
correctly, the conclusion was that the wing spar failed from fatigue
because the wing was nutating, a slight circular motion due to
gyroscopic effects.

Maybe that's the same thing caused the FL seaplane crash.

[Kev]

Stubby wrote:
> Way back, I believe the first jet passenger jet was the Lockheed
> Electra. The plane mysteriously fell out of the air and very thorough
> search for a cause was instituted. In the end, again if I remember
> correctly, the conclusion was that the wing spar failed from fatigue
> because the wing was nutating, a slight circular motion due to
> gyroscopic effects.

To jog your memory:

http://en.wikipedia.org/wiki/Lockheed_L-188_Electra

> Maybe that's the same thing caused the FL seaplane crash.

The Electra problem happened pretty soon after they came out. Those
seaplanes have been around a long time.

Cheers, Kev

[Capt.Doug]

>"Stubby" wrote in message
> Way back, I believe the first jet passenger jet was the Lockheed
> Electra. The plane mysteriously fell out of the air and very thorough
> search for a cause was instituted. In the end, again if I remember
> correctly, the conclusion was that the wing spar failed from fatigue
> because the wing was nutating, a slight circular motion due to
> gyroscopic effects.
> Maybe that's the same thing caused the FL seaplane crash.

The Electra wasn't a jet, it was a turbopropeller. Furthermore, the
Electra's design flaw was discovered early in it's life cycle. Grumman
Mallards are a mature design of 70 years starting with the Goose.

D.

[Matt Whiting]

Stubby wrote:

> Way back, I believe the first jet passenger jet was the Lockheed
> Electra. The plane mysteriously fell out of the air and very thorough
> search for a cause was instituted. In the end, again if I remember
> correctly, the conclusion was that the wing spar failed from fatigue
> because the wing was nutating, a slight circular motion due to
> gyroscopic effects.
>
> Maybe that's the same thing caused the FL seaplane crash.

Except the Electra wasn't a jet. Maybe you are thinking of the Comet.


Matt

[Bob Moore]

Matt Whiting >wrote

> Except the Electra wasn't a jet. Maybe you are thinking of the
> Comet.

Well...the Electras that I flew certainly had "jet" engines.
Even burned kerosene. :-)

Bob Moore

[Matt Whiting]

Hi I'm lonely, and I want my mommy...

[Matt Whiting]

I said the Electra is not a jet you pompous asshole...

[Stubby]

Kev wrote:
> Stubby wrote:
>
>>Way back, I believe the first jet passenger jet was the Lockheed
>>Electra. The plane mysteriously fell out of the air and very thorough
>>search for a cause was instituted. In the end, again if I remember
>>correctly, the conclusion was that the wing spar failed from fatigue
>>because the wing was nutating, a slight circular motion due to
>>gyroscopic effects.
>
>
> To jog your memory:
>
> http://en.wikipedia.org/wiki/Lockheed_L-188_Electra

Excellent article! Thanks. That Electra (maybe there are others) was
a turboprop rather than a turbojet as I had assumed.

[AES]

In article >,
Matt Whiting > wrote:

> Stubby wrote:
>
> > Way back, I believe the first jet passenger jet was the Lockheed
> > Electra. The plane mysteriously fell out of the air and very thorough
> > search for a cause was instituted. In the end, again if I remember
> > correctly, the conclusion was that the wing spar failed from fatigue
> > because the wing was nutating, a slight circular motion due to
> > gyroscopic effects.
> >
> > Maybe that's the same thing caused the FL seaplane crash.
>
> Except the Electra wasn't a jet. Maybe you are thinking of the Comet.

The Electra did, however, have a string of catastrophic early failures,
which were eventually traced to metal fatigue in the wing or fuselage
structure caused by a vibration or oscillation that occurred in flight
and was associated with the design of the plane; and the Comet had a
series of catastrophic early failures which were eventually traced to
metal fatigue and crack grown around the windows occurring after
multiple pressurization and depressurization cycles. Both were prime
examples of the learning process associated with civil aviation and
aviation technology.

Am I recalling this correctly?

[Robert M. Gary]

Are you thinking the English Comet? It had several inflight mysterious
breakups before it was discovered that the square windows created
stress fractures after several pressurization cycles. I believe it was
the first pax airline.

[Matt Whiting]

Matt Whiting wrote:
> I said the Electra is not a jet you pompous asshole...
>

Nice attempt at forging an email from me, but you aren't very good at it.

Matt

[Matt Whiting]

Bob Moore wrote:

> Matt Whiting >wrote
>
>
>>Except the Electra wasn't a jet. Maybe you are thinking of the
>>Comet.
>
>
> Well...the Electras that I flew certainly had "jet" engines.
> Even burned kerosene. :-)

Gee, Bob, you should know the difference between a turbine engine used
as a propjet from one used as a pure jet. :-)

Matt

[Ramapriya]

Matt Whiting wrote:
> I said the Electra is not a jet you pompous asshole...

Bob has remarkable consistency in posting incisive, telling stuff,
gleaned without doubt over years of flying. Notwithstanding that, don't
you think your invective isn't quite apropos for one past 70?

When he wrote jet under two quotation marks, it was obvious he wasn't
referring to the obvious.

Just my 0.02,

Ramapriya

[Darrell S]

Bob Moore wrote:
> Matt Whiting >wrote
>
>> Except the Electra wasn't a jet. Maybe you are thinking of the
>> Comet.
>
> Well...the Electras that I flew certainly had "jet" engines.
> Even burned kerosene. :-)
>
> Bob Moore

The ones I flew had jet turbine engines but they were geared to propellors
which makes a difference. They are generally referred to as turboprops
whereas the term jet normally refers to a jet engine without external
propellors. But the difference is decreasing since most high-bypass jet
engines now have internal rotors which produce more than half the thrust
using propellor type action but within the engine frame. That air doesn't
even go through the combutions chambers, it bypasses them, hence the term
high-bypass.

But you knew that, Bob, I just mentioned it for those who didn't.

--

Darrell R. Schmidt
B-58 Hustler History: http://members.cox.net/dschmidt1/
-

[Steven P. McNicoll]

"Stubby" > wrote in message
. ..
>
> Way back, I believe the first jet passenger jet was the Lockheed Electra.

The first jet airliner was the de Havilland Comet. The Lockheed Electra
you're referring to was a turboprop.

[Bob Moore]

Matt Whiting >wrote

> Gee, Bob, you should know the difference between a turbine
> engine used as a propjet from one used as a pure jet. :-)

Hey! Eastern Airlines called them "Prop Jets".
By the definitions posted here, there are no "Jet" airliners
currently flying, since they are all "Turbo Fans". Right??? :-)

Bob Moore

[Big John]

Kev

I'll use your post to add my comments on Electra.

Lockheed fixed the wing problem but bird had the bad name and airlines
didn't want to fly it.

USN bought a bunch (of the fixed birds) and put MAD gear and other
anti sub equipment in and have been flying them for years without any
wing problems.

Due to age and hours, Navy is starting to look at newer birds for
their mission. One being looked at is the 737.

2 more shopping days til Xmas 05 :o)

Big JOhn
`````````````````````````````````````````````````` ```````

On 22 Dec 2005 07:36:00 -0800, "Kev" > wrote:

>Stubby wrote:
>> Way back, I believe the first jet passenger jet was the Lockheed
>> Electra. The plane mysteriously fell out of the air and very thorough
>> search for a cause was instituted. In the end, again if I remember
>> correctly, the conclusion was that the wing spar failed from fatigue
>> because the wing was nutating, a slight circular motion due to
>> gyroscopic effects.
>
>To jog your memory:
>
>http://en.wikipedia.org/wiki/Lockheed_L-188_Electra
>
>> Maybe that's the same thing caused the FL seaplane crash.
>
>The Electra problem happened pretty soon after they came out. Those
>seaplanes have been around a long time.
>
>Cheers, Kev

[Matt Whiting]

Bob Moore wrote:
> Matt Whiting >wrote
>
>
>>Gee, Bob, you should know the difference between a turbine
>>engine used as a propjet from one used as a pure jet. :-)
>
>
> Hey! Eastern Airlines called them "Prop Jets".
> By the definitions posted here, there are no "Jet" airliners
> currently flying, since they are all "Turbo Fans". Right??? :-)

The still derive significant thrust from the exhaust jet, but I'll grant
you that it is getting much grayer as the bypass ratios keep increasing.
:-)

Then again, if it was black and white, what would we have to argue about
here? Things would get dull in a hurry.

Matt

[George Patterson]

Stubby wrote:
> Way back, I believe the first jet passenger jet was the Lockheed
> Electra. The plane mysteriously fell out of the air and very thorough
> search for a cause was instituted.

Sounds like you're confusing it with the DeHaviland Comet. The cause was
eventually determined to be the rapid formation of stress cracks around the
corners of the rectangular cabin windows.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[Jim Macklin]

They also used a high pressure sea level cabin, modern
pressurized aircraft use a lower differential pressure,
maybe 8-9 PSI for a 9,000 foot cabin at max cruise altitude.
The Comet was a victim of design, fabrication and
operational methods.


--
James H. Macklin
ATP,CFI,A&P

--
Merry Christmas
Have a Safe and Happy New Year
Live Long and Prosper
Jim Macklin
"George Patterson" > wrote in message
news:U7Jqf.50934$CL.50059@trnddc04...
| Stubby wrote:
| > Way back, I believe the first jet passenger jet was the
Lockheed
| > Electra. The plane mysteriously fell out of the air and
very thorough
| > search for a cause was instituted.
|
| Sounds like you're confusing it with the DeHaviland Comet.
The cause was
| eventually determined to be the rapid formation of stress
cracks around the
| corners of the rectangular cabin windows.
|
| George Patterson
| Coffee is only a way of stealing time that should by
rights belong to
| your slightly older self.

[RST Engineering]

No, the Lockheed Electra (turboprop, Allison engines) started falling out of
the skies shortly after their introduction. I believe the first one was
over Wink, TX and there were a couple more shortly thereafter. All sorts of
goofy reasons were tossed around, all the way from wrong rivet sizes to the
biffy leaking effluent onto the spar. The root cause was a peculiar
vibration of the engines called "whirl mode". THe fix was neither trivial
nor inexpensive. We had four of them at PSA and those damned things just
would NOT quit on you. They were also the easiest to work on transport
class aircraft I ever encountered.

Jim


"George Patterson" > wrote in message
news:U7Jqf.50934$CL.50059@trnddc04...
> Stubby wrote:
>> Way back, I believe the first jet passenger jet was the Lockheed Electra.
>> The plane mysteriously fell out of the air and very thorough search for a
>> cause was instituted.
>
> Sounds like you're confusing it with the DeHaviland Comet. The cause was
> eventually determined to be the rapid formation of stress cracks around
> the corners of the rectangular cabin windows.
>
> George Patterson
> Coffee is only a way of stealing time that should by rights belong to
> your slightly older self.

[Morgans]

"Jim Macklin" > wrote in message
news:jsJqf.30375$QW2.4649@dukeread08...
> They also used a high pressure sea level cabin,

I had never heard that. How did you dear about that?

I would imagine that a higher cabin would have slowed the cracks, but they
still would have formed.
--
Jim in NC

[Jim Macklin]

It was something I read many years ago, maybe during my A&P
course at Spartan, but I remember that the issues cited were
design of the windows and the quality of the joints and
rivets. The metal was an alloy that was prone to cracking,
but was strong. The extra pressure cause the metal to
expand and contract into the fatigue range of the alloy. It
all came together or should I have said apart on several
airplanes.


--
Merry Christmas
Have a Safe and Happy New Year
Live Long and Prosper
Jim Macklin
"Morgans" > wrote in message
...
|
| "Jim Macklin" > wrote
in message
| news:jsJqf.30375$QW2.4649@dukeread08...
| > They also used a high pressure sea level cabin,
|
| I had never heard that. How did you dear about that?
|
| I would imagine that a higher cabin would have slowed the
cracks, but they
| still would have formed.
| --
| Jim in NC
|

[jc]

Jim Macklin wrote:

> It was something I read many years ago, maybe during my A&P
> course at Spartan, but I remember that the issues cited were
> design of the windows and the quality of the joints and
> rivets. The metal was an alloy that was prone to cracking,
> but was strong. The extra pressure cause the metal to
> expand and contract into the fatigue range of the alloy. It
> all came together or should I have said apart on several
> airplanes.
>
>
Bit worse than that, in order:

The name - de Havilland aircraft had a habit of structural failure
The glue - Redux wasn't that good (note this was also a factor in the
convertible 737)
Fatigue - A mysterious new ailment for primitive people to blame the failure
of their "world beating" aircraft on. Strange that a novelist had written a
best seller on the subject 3 years earlier, stranger that Neville Shute had
worked for de Havilland 30 years before, had initially employed many of the
design staff after he founded Airspeed and presumably knew a lot that
wasn't didn't make the inquiry.



--

regards

jc

LEGAL - I don't believe what I wrote and neither should you. Sobriety and/or
sanity of the author is not guaranteed

EMAIL - and are not valid email
addresses. news2x at perentie is valid for a while.

[Steven P. McNicoll]

"Jim Macklin" > wrote in message
news:%xQqf.30408$QW2.23629@dukeread08...
>
> It was something I read many years ago, maybe during my A&P
> course at Spartan, but I remember that the issues cited were
> design of the windows and the quality of the joints and
> rivets. The metal was an alloy that was prone to cracking,
> but was strong. The extra pressure cause the metal to
> expand and contract into the fatigue range of the alloy. It
> all came together or should I have said apart on several
> airplanes.
>

The metal was quite thin. The skin of the 707 was about four times as thick
and Boeing employed ripstops as well.

[Dennis Mayer]

Morgans wrote:
>
> "Jim Macklin" > wrote in message
> news:jsJqf.30375$QW2.4649@dukeread08...
> > They also used a high pressure sea level cabin,
>
> I had never heard that. How did you dear about that?
>
> I would imagine that a higher cabin would have slowed the cracks, but they
> still would have formed.
> --
> Jim in NC


From what I recall from my younger Engr days:

Low cycle fatigue of metals is affected by:

1) Cyclic loading
2) Tensile mean stress
3) Local stress exceeding the material's yield stress

The bigger the values, the faster the crack initiation
or crack propagation...

[Michael Houghton]

Howdy!

In article >,
RST Engineering > wrote:
>No, the Lockheed Electra (turboprop, Allison engines) started falling out of
>the skies shortly after their introduction. I believe the first one was
>over Wink, TX and there were a couple more shortly thereafter. All sorts of
>goofy reasons were tossed around, all the way from wrong rivet sizes to the
>biffy leaking effluent onto the spar. The root cause was a peculiar
>vibration of the engines called "whirl mode". THe fix was neither trivial
>nor inexpensive. We had four of them at PSA and those damned things just
>would NOT quit on you. They were also the easiest to work on transport
>class aircraft I ever encountered.
>
....where the engine wobbles in a conical sort of motion. IIRC, the
turboprops had enough horsepower to get into that sort of vibration where
the classic round engines didn't. New turf with extra wrinkles, as it were.

yours,
Michael


--
Michael and MJ Houghton | Herveus d'Ormonde and Megan O'Donnelly
| White Wolf and the Phoenix narrowwares
Bowie, MD, USA | http://whitewolfandphoenix.com
Proud member of the SCA Internet Whitewash Squad

[James Robinson]

Bob Moore wrote:

> Matt Whiting wrote
>
>> Gee, Bob, you should know the difference between a turbine
>> engine used as a propjet from one used as a pure jet. :-)
>
> Hey! Eastern Airlines called them "Prop Jets".

The airline marketing departments purposely blurred the definitions in the
1950s. American called Electras "Jet Powered Flagships". Braniff called
them "Jet Power Electras". I seem to remember one airline declaring that
they had an all-jet fleet when they phased out their last piston aircraft,
but still flew turboprops.