Penalty because of missing seals
 

Guys,

thanks so much, appreciate your answers.

My question: missing one seal(just an example!!) and in the MEL you got the note:

Takeoff and landing : no penalty
Climb: -635kg

How do you handle this? Any formulas in your head? which tables do you use and is in my example the climb limit weight reduced??

Talking about the 737

Cheers and

Bye

OD

If you are climb limited during your TO calculation, you have to subtract 635Kg to the climb limited weight.

MEL ?

more likely to be found in the CDL i would think...if i understand you correctly!

I believe this came about after some tests from Boeing which proved that the lift/stall features of the wing changed significantly with various seals missing/damaged on the slats. I think there was an in flight occurance which triggered this investigation.

Jap sorry, meant the CDL

This is a weight penalty. It means that you must calculate the performance as though the airplane weighed that much more. It doesn't perform as well, and will perform as though the airpalne were heavier. This is simply a way of applying a performance penalty in a manner that allows an easy calculation.

If it a standard Boeing-type CDL, it would normally mean that no performance decrements need to be applied for TO and landing but enroute climb performance would suffer. The operating ceiling at a particular instant needs to be calculated using the actual aircraft mass + 635Kg. As I understand it...

Sounds unlikely for something where you're only applying a clean config penalty. Perhaps the WUSS-to-slat seal, maybe. I'm more tempted to guess that it's being applied only to the clean config because the basic drag is much lower, so the delta due to the missing seal is proportionally greater. With all the mess of gear and high lift devices dangling in the wind, it may not be as significant.

Also, if you were suffering stall characteristics changes, and yet not adjusting speeds to account for stall speed changes ... again, sounds a bit odd.

Penalty because of missing seals
I have a Lockheed TriStar Service Digest from the 1976 with all 32 pages decated to Fuel Conservation. Here are some of the fuel penalties from the artical, for missing/damaged seals:

Slats - Missing chord wise interslat seal 5,040 to 5,970 gal per year.
Cargo Door - five square inch effective leak 11,750 gal per year.
Passenger Door - five square inch effective leak 11,750 gals per year.

That's referencing the economic penalty...or in other words what it cost extra to have the seal missing.

What's in discussion here is the performance penalty associated with the missing seal.

If I remember correctly the RJ calls for an increase of 1 or 2% trip fuel if seals are missing. No performance penalty. Could be wrong.

rcl

If there is a performance penalty it will be spelled out in the CDL.

Regardless of the place where to fing the figure (CDL of course, I guess MEL was a mistake) or the historical remembering, the question was : "How do you handle this? Any formulas in your head? which tables do you use and is in my example the climb limit weight reduced??"