Pilots - is this a fuel leak in an MD-80 - PeachParts Mercedes-Benz Forum

spdrun · #1 08-23-2013, 07:33 PM

I was on an MD-80 flight today and noticed a fluid leaking from a fuel pump cover (marked "boost pump") on the wing. Mentioned this to the flight attendant, she had the co-pilot come back and check. They announced that a passenger had noticed a fluid leaking from the wing area, and that "fuel sometimes collects" around the pump cover on the wing, it's normal, and we were continuing on to the destination airport.

After we landed, out of the pilots said thanks, that it was "just de-icing fluid" and that they couldn't have legally flown the aircraft with even a minor fuel leak. TSOR shows that MD-80s do not carry de-icing fluid internally, and it's summer in both NYC and the destination.

Pictures attached, not very clear, but you can see that the anti-slip tape is wet and there's a streak of fluid to the rear of the cover. Was this actually de-icing fluid, or was this a convenient lie? Granted, the leak didn't look very severe, but was this a dangerous situation, or merely one out of the ordinary?

http://s23.postimg.org/sdyv8gq63/IMG_1597.jpg
http://s14.postimg.org/urrkap56p/IMG_1596.jpg
http://s24.postimg.org/wspeoe69x/IMG_1595.jpg

HuskyMan · #2 08-23-2013, 07:37 PM

I'm not a pilot but I do not trust McDonnell Douglas airplanes. Plus, there is usually very little leg room........

kerry · #3 08-23-2013, 08:03 PM

Pilot must think people are really stupid to come up with a line like that. He should have said it was water leaking from the swamp cooler. Looks like hydraulic fluid to me.

Dudesky · #4 08-23-2013, 08:48 PM

Quote:

Originally Posted by spdrun

I was on an MD-80 flight today and noticed a fluid leaking from a fuel pump cover (marked "boost pump") on the wing. Mentioned this to the flight attendant, she had the co-pilot come back and check. They announced that a passenger had noticed a fluid leaking from the wing area, and that "fuel sometimes collects" around the pump cover on the wing, it's normal, and we were continuing on to the destination airport.

After we landed, out of the pilots said thanks, that it was "just de-icing fluid" and that they couldn't have legally flown the aircraft with even a minor fuel leak. TSOR shows that MD-80s do not carry de-icing fluid internally, and it's summer in both NYC and the destination.

Pictures attached, not very clear, but you can see that the anti-slip tape is wet and there's a streak of fluid to the rear of the cover. Was this actually de-icing fluid, or was this a convenient lie? Granted, the leak didn't look very severe, but was this a dangerous situation, or merely one out of the ordinary?

http://s23.postimg.org/sdyv8gq63/IMG_1597.jpg
http://s14.postimg.org/urrkap56p/IMG_1596.jpg
http://s24.postimg.org/wspeoe69x/IMG_1595.jpg

Leaks are rated in drops per period of time and how much of a puddle they make under the plane.

Notice in picture three, all of the bolt heads and the gap between the access plate and the recess have been filled with black sealant most likely to clear a log book entry at an overnite station. Also notice the fuel is dissolving the black sealant.
I found an explanation elsewhere:

Quote:

Fuel Suction-seepage from screw-holes on Boost Pump Access Panel
Fair QUESTION posed in top slot, re' MD80 WING upper surface:

"... 'liquid' flowing from the wing surface ... wet on the ground ... flight progressed this liquid ... continued to flow. ... appeared to 'run' from an "access port" on the surface of the wing...."

This MD8 Fuel “suction-seepage” sometimes frightens passengers seated over the wing.

Outside the aircraft, while in-flight, there is a lower-pressure atop the upper exterior surface of the wing (that also provides the LIFT force). Meanwhile, inside the inboard portion of that Main Wing Tank, with more than about 4500 pounds of fuel, the interior upper wing-skin is still “wetted” by the liquid fuel. The liquid can seep-out (sucked-out) by the lower pressure area that results DURING FLIGHT.

That suction-seepage is no big deal; but if any pax informs the pilot about that suction-seepage, then the pilot is obligated to enter that into the aircraft maintenance logbook as a “discrepancy” [see case in which one AA pilot failed to make the required logbook entry].

On the MD80 such “suction seepage” will stop once the quantity of fuel inside that Main Tank decreases to less than 4500 pounds (due to dihedral angle); there are illustrations of the wing section (dihedral), and the relation (contact) of the liquid and upper wing skin, in SHK’s AAR “C-1993:57” [pg 22 of Appendix 5], on the 27Dec91 mishap near Gottrora.

Here’s an example of an FAA report on one case of suction-seepage, with the post-flight corrective action:

ASIAS BRIEF REPORT

GENERAL INFORMATION

Data Source: ACCIDENT AND INCIDENT DATABASE
Report Number: 20000804035779C
Local Date: 04-AUG-00
Local Time:
City: KANSAS CITY
State: MO
Airport Name: KANSAS CITY INTL
Event Type: INCIDENT - AIR CARRIER
Mid Air Collision: NOT A MIDAIR

AIRCRAFT INFORMATION

Aircraft Damage: NONE
Aircraft Make: MCDONNELL-DOUGLAS-BOEING
Aircraft Model: MD-80
Aircraft Series: 82
Airframe Hrs: 48605
Operator: AMERICAN AIRLINES
NARRATIVE

(-23) ON AUGUST 4, 2000, AT APPROXIMATELY 1921 CDT, AMERICAN AIRLINES FLIGHT 2006, A DC-9-80, N274AA, LANDED AT KANSAS CITY INTERNATIONAL AIRPORT, KANSAS CITY, MISSOURI (MCI), AFTER DECLARING AN EMERGENCY DUE TO FUEL VENTING FROM THE LEFT WING.

THE AIRCRAFT LANDED WITHOUT INCIDENT.

AMERICAN AIRLINES MAINTENANCE RETOURQUED THE LEFT HAND AFT FUEL BOOST PUMP ACCESS PLATE MOUNT SCREW, LEAK CHECKED OK AND RETURNED AIRCRAFT TO SERVICE. WITH THIS REPORT, INCIDENT #CE2000LAC073 IS CONSIDERED CLOSED....

= = = = = = / / = = = =
Edit: Various videos were on the web, example videos showed the shearing-flow of liquid streaming aft from the Boost Pump Access Panel. Here's the link to litigation against AA in Sep'05, regarding a case in Nov'03 (FAA-ASI aboard notified pilot of "fuel leak", but Mx unable to find any leakage while aircraft was on ground:
AAL sued for safety violations

davidmash · #5 08-23-2013, 09:25 PM

Quote:

Originally Posted by HuskyMan

I'm not a pilot but I do not trust McDonnell Douglas airplanes. Plus, there is usually very little leg room........

Leg room is decided by the airline not the manufacture.

MTI · #6 08-23-2013, 10:12 PM

Quote:

Originally Posted by davidmash

Leg room is decided by the airline not the manufacture.

Consider the source, a member who in many threads discussing air travel and the TSA says he doesn't fly . . .

ptoro01 · #7 08-23-2013, 10:26 PM

Inside the cabin is nice and calm but the outside is sorta windy .

Fuel / deicing fluid would evaporate so quick . . .

davidmash · #8 08-23-2013, 11:00 PM

Quote:

Originally Posted by MTI

Consider the source, a member who in many threads discussing air travel and the TSA says he doesn't fly . . .

I know. There was a descriptive adjective at the end but I thought better of it before I hit the submit button.

I was also going to mention the fact that a over whelming majority of the accidents are due to human error not design flaws but I thought smashing my hand with a hammer would be a better use of my time.

Brian Carlton · #9 08-24-2013, 12:02 AM

Quote:

Originally Posted by davidmash

I was also going to mention the fact that a over whelming majority of the accidents are due to human error not design flaws but I thought smashing my hand with a hammer would be a better use of my time.

...........the one glaring exception being the DC-10's cargo door and the criminal behavior that allowed the problem to continue for years until 346 people died in 1974 outside Paris.

spdrun · #10 08-24-2013, 05:04 AM

Quote:

Originally Posted by Dudesky

Leaks are rated in drops per period of time and how much of a puddle they make under the plane.

Notice in picture three, all of the bolt heads and the gap between the access plate and the recess have been filled with black sealant most likely to clear a log book entry at an overnite station. Also notice the fuel is dissolving the black sealant.
I found an explanation elsewhere:

Thanks, Dudesky, that looks about right, especially since the leak stopped by the time we landed. I don't know, the sealant didn't looks like it was dissolving, it looked like fuel was seeping past the sealant and partly evaporating (boiling) away, partly streaking down the wing.

Don't know why they bothered to lie about it once we were on the ground, though -- I'd rather hear "harmless fuel leak" (assuming the quantity couldn't increase, it was really harmless) than be told an obvious BS story.

Skippy · #11 08-24-2013, 06:42 AM

According to a military pilot friend of mine, a "leak" is cause to ground an aircraft. However "seepage" is okay. He used to fly CH-47's, which along with CH-46's are notorious for seeping hydraulic fluid, to the extent that they say if it isn't seeping you have a problem, since it's out. One time in Iraq I flew on a CH-53D that seeped so badly people were covering themselves with trash bags to keep it off them. We still arrived at our destination in one piece.

davidmash · #12 08-24-2013, 10:02 AM

Quote:

Originally Posted by Brian Carlton

...........the one glaring exception being the DC-10's cargo door and the criminal behavior that allowed the problem to continue for years until 346 people died in 1974 outside Paris.

I believe the DC10 also had the 3 hydraulic back ups all located in the tail section. When the tail engine on the UA flight went FUBAR it took out all the hydraulic systems and it crash landed in Sioux Falls.

There are always going to be a few exceptions to the rule but human error is always a good place to start when something goes sideways.

Brian Carlton · #13 08-24-2013, 10:07 AM

Quote:

Originally Posted by davidmash

I believe the DC10 also had the 3 hydraulic back ups all located in the tail section. When the tail engine on the UA flight went FUBAR it took out all the hydraulic systems and it crash landed in Sioux Falls.

There are always going to be a few exceptions to the rule but human error is always a good place to start when something goes sideways.

The design problem was the fact that none of the hydraulic systems had any safety check valves to prevent dumping all fluid in the event of a large leak. It could be argued that three independent systems precluded the need for such valves............but, there you go.

Dudesky · #14 08-24-2013, 10:47 AM

Quote:

Originally Posted by davidmash

I believe the DC10 also had the 3 hydraulic back ups all located in the tail section. When the tail engine on the UA flight went FUBAR it took out all the hydraulic systems and it crash landed in Sioux Falls.

There are always going to be a few exceptions to the rule but human error is always a good place to start when something goes sideways.

Hydro was the main system with no cable back ups, when the disc went it took out the main system.

Quote:

Wikipedia:
The DC-10 included no cable backup for the hydraulic powered flight controls because it was considered nearly impossible for three hydraulic systems to fail during one flight, and furthermore the control surfaces are too large to be moved without hydraulic assistance. However, all three hydraulic systems were in close proximity, directly beneath the tail engine. The #2 engine explosion hurled shrapnel that ruptured all three lines, resulting in total loss of control to the elevators, ailerons, spoilers, horizontal stabilizer, rudder, flaps and slats

Human error was the main factor as a NDE inspector missed small cracks in the disc. Later inspection found liquid penetrent in the places where the disc separated.