Flap Load Relief Limit Boeing 737

[supergimp]

I was recently informed, by the Flight Safety Officer that I had exceeded the flap 40 limit, and as a result the flaps had retracted to flaps 30. The Captain and I had no knowledge that this happened on the flight and we were both quite shocked, I would like to think that if I had exceeded a parameter I would at least know about it, and if I did not spot it the Captain would. Is it possible that the flaps could have blow back due to gusts? I know the limit is 163 knots on the NG, but we were no where near that speed. I am a little confused as I always consider myself to be a cautious Pilot. Is this exceedance considered to be serious?

[CaptainSandL]

It takes a moment for the flap load relief to activate, so I doubt a gust would trigger it, but it all depends how long you were above the trigger speed. Also the trigger speed is not always exactly as published I have seen them a few knots in either direction.

It can be a problem if you are heavy and have a high Vref and then start adding on 20kts for gusts. It may be prudent in these conditions to use flap 30 rather than 40.

S&L

[glhcarl]

While I know nothing about the B737 Flap Load Relief System it seems strange to me that you would not have know it was activated. Before it was removed on the majority of the L-1011 fleet if the Flap Load Relieving System was activated you would get a light (Flap LRS Limiting) and movement of the Flap Indicator. Which if they were awake should be enough to alert the Pilot (or Co-Pilot) to slow the thing down.

So the question, does the B737 have a Load Relief Light and a Flap Position Indicator? If yes how did you miss them?

[click]

No light but from those involved you'd know about it. In all cases it was in the flare. VERY positive landing as the rug is pulled out from you. Our SOP's changed to using 30 deg flaps due noise abatement. Paid too many fines.....:sad: I had a couple of WTF??? warnings go off in the cockpit with the DFDR clearly showing that we were well within limits so this might be the other case.....you guys had no indications but the tattletale was working overtime.

[CaptainSandL]

Only the early -300 & -400 series had the flap load relief light, but the function is there on all series.
http://www.b737.org.uk/flap_ind_panel.jpg