Re: How much "rust" is tolerated and landing light question?

Date:         13 Oct 98 02:48:31 
From:         mcl757@aol.com (MCL757)
Organization: AOL http://www.aol.com
References:   1
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>OK number one, flying UAL from Denver to San Antonio in an older 737S.
>First I noticed that the top (couldn't see the bottom) of both
>ailerons were nice shiny metal.  Thought that was an odd area to be
>replaced.

Perhaps they had been polished lately..?

> Then as flaps were extended for take-off I noticed rust
>stains running back approximately in the middle of the flap.  As we
>flew along, I reminded myself that most of the ac is not made from
>steel.  On landing, the source became clear.  Looked to be coming from
>perhaps a steel cover plate (screwed or riveted in place) on the flap
>and rust stains were evident all around it.  Also on deploying the air
>brakes, the undersides of those showed rust stains as well
>particularly at hinge points and hydraulic actuator connection points.

Sounds like you saw the lubrication for the flap tracks.  It is a rust
color and can get blown out from where it belongs and onto the flaps.
Since you mention seeing alot of this rust color at the hinge points,
that indicates to me that it was definately lubricant you saw.

>Number two, UA flight from San Antonio to Chicago.  As our 733
>arrives, I notice a hole in the starboard wing root where a landing
>light lens used to be.  As it came closer, I see the remnants of what
>looked like yellowed plexiglass shards.  The pre-flight picked it up
>and before long, both pilots were looking at it and trying to get a
>mechanic.  I knew my connection was shot at O'hare but hung around a
>bit to see the outcome.  Apparently, they found a local company that
>was going to make a temporary metal patch for the hole and it flew on
>a couple of hours late.
>
>Now my questions, I am assuming that the plane flew in at least part
>of the way with that condition.  What could have happened had the
>pilots either not noticed it (and it was almost missed by the 1st
>officer until he decided to take a second look) or decided to fly
>anyway?  What's behind that light and would the aircraft have flown
>any differently?

It probably didn't have much of an effect... especially since you had
been flying with it in that condition already.  Located behind the light
are electrical wiring, bleed air ducting, and of course the front wing
spar, but I don't think the airflow would displace the lights anyway.

I was fueling a 737 at SEA one time when I noticed the fairing piece on
the inboard edge of the inboard flaps, which keeps the airflow out of
the wing to body fairing, was missing.   I told the pilot who came and
looked at it, and they went with it.  Pilots have a MEL, which is a
Minimum Equipment List, which obviously indicates if the aircraft is
airworthy even with certain missing or failed equipment.

Matt in Seattle
Student Pilot
To most people, the sky is the limit. To those who fly, the sky is home.
--
EWR Tower: "NW 167, are you going around?"
NW 167(an A320):  "Wait um, uh, yeah, yeah I think it is...."