737NG - Do you test the t/o config warning before flight?

[LeftHeadingNorth]

Hello fellow aviators,

Pretty straight forward question. Do you advance the thrust levers on your preflight checks to test the t/o config warning? According to the FCOM the wx radar starts sweeping (predictive WS warning) even though the engines are off when advancing the thrust levers (don't know how many degrees exactly). This is according to most ppl not so optimal for the people working on the ground. Perhaps a better question would be; is it dangerous for the ppl working on the ground (or perhaps the PNF doing a walk around passing below the nose) to get a short blast from the wx radar?

Cheers,
LHN (who prefer to test the t/o config warning)

[Sciolistes]

53 degrees. It is a terrible bit of design. If the PWS is activated on the ground by advancing the thrust levers, there is no annunciation!

[Golden Rivet]

The wxr is only dangerous if you put your tongue on it....

I wont be losing any sleep over it.

[IFixPlanes]

One sweep from the left to the right takes 3 seconds (WXR + PWS).
How long are you want to hear the sound until you know T/O warning is working? :E
WX set to 15° tilt up before testing is also a good idea. :ok:

[carb-heat]

well!! i have a additional question in the FCOM it says thust lever(s) does that mean both the thrust levers need to be advanced or even a single thrust lever will activate the radar sweep.. thnks

[IFixPlanes]

lever = 1
levers = both
lever(s) = 1 or both

:E

[LeftHeadingNorth]

ray-cosmic, thank you! I suspected it was something like that....

LHN

[EW73]

Another interpretation of that question gets a yes response from me.

Whilst taxiing, away from all and sundry, when the before takeoff list is done, quickly advance/retard one of the thrust levers past the vertical and back to idle, to test for any configuration warning, no noise is good, and saves getting any surprises on the active.

Did that for years following a false warning once during a heavyweight takeoff Anchorage - Seoul in a 742.

Cheers :ooh:

[LeftHeadingNorth]

EW73, that actually doesn't test the t/o config warning as such. If you get no sound when advancing the thrust levers after the before t/o checks are done, it can mean that u have the proper t/o config but it could also be that the system is simply not working.

LHN

[av8r76]

I do check during first application of power while taxiing out. No personnel in front at that point (hopefully).
If you really are keen on doing the check during preflight, put the radar on test mode and advance away to your hearts content. That'll prevent any inadvertent activation of the wx rdr.

Hope this helps.

[40KTSOFFOG]

I do not recommend this procedure on the 'Classics'.
Although it will test the T/O Config warning you tend to always subconsciously associate this sound with a take-off configuration condition only. Remember Helios!

[EW73]

Thanks LeftHeadingNorth...

I am aware of that, hence the "Another interpretation of that question gets a yes response from me." pre condition.... jeez...

[LeftHeadingNorth]

My bad.... misinterpreted your reply....:O

[de facto]

40KTSOFOG,

We all remember helios...
One of the changes following this tragedy is the Boeing REQUIREMENT for pilots to include in their t/o brief differences of meaning between an intermittent horn below or above 10 000ft UNLESS your aircraft is equipped with serviceable cab alt and t/o config lights.

[221340]

Good question. Seems there's always more to the story.
If you don't check it, who does?
In the mid 1980's a U.S. airliner crashed when the crew forgot to extend takeoff flaps. No t/o config warning was received.
In the NTSB review, it was discovered that the maintenance department thought flight ops did the config warning check, and vice versa.
Who checks it at your airline?

[Clandestino]

Why don't you just press the "TO config test" button to perform what's written on it? :confused:

Worked last ten years for me but then I've nefer flown Ceaddlewash built magnificent flying machines. Just French/Italian, French/Paneuropean and Canadian c**p. :E

[RTO]

Helios.....don't you just love that 2 douchebags in Greece makes your cockpit preparation longer. And what about the brits, I bet they have to show up the day before now to start their departure brief.

[framer]

221340
In the mid 1980's a U.S. airliner crashed when the crew forgot to extend takeoff flaps. No t/o config warning was received.
In the NTSB review, it was discovered that the maintenance department thought flight ops did the config warning check, and vice versa.

If you are talking about NorthWest AIrlines 255 then no amount of checking by engineers would have helped as the pilot group were in the habit of pulling the t/o warning config CB to prevent nuisance warnings while taxiing on one engine. Combine that with the failure to complete the checklist and Bob's your uncle. If you're talking about another flight, can you give the number as I am interested in reading about it, thanks.

[40KTSOFFOG]

Cheers De Facto,

Thanks for pointing that out. I didn't realise as it has been several years since I flew the Classic.

The key point that I was trying to make is that sometimes we come up with an unofficial procedure which we believe is enhancing our awareness of aircraft systems but subconsciously it is achieving the complete opposite. I have come across this several times over the years on several different aircraft types.

As the saying goes.... 'most QRH's and SOP's have a bit of blood on them!'.

[221340]

Framer

It was a Delta 727 at DFW in 1986 or 1987. There is a video about the investigation on utube.

[framer]

Thanks , I'l search for that :)

[profsx]

Source-Friend
In Jet airways, 737NG's (India), they've installed a T/O config warning 'switch' spring loaded to off, obviously, to check the T/O config, saves you the trouble.

-Know nothing of the 73