Pitch Limit Indicator 737

[frumpy]

Hi guys,

I'm having a slightly offtopic question. Perhaps anyone
knows about it.
In a video I saw a 737 during takeoff run. At about 80kts
the yellow eyebrows (the pitch limit indicator, which
depends on AOA and speed) drops from about 20° to 0°,
just to rise again to reach final pitch limit again shortly
before v1.
I checked on a 747-400 video and did not see this drop -
the eyebrows stay where they are.

Anyone having an idea, why this difference is?

Here is the video, check @0.58:
https://www.youtube.com/watch?v=P1luqXNqC1c&index=1&list=LLkWNNoBRpGjaVkadXC3wyig

Thanks,

Olli

[Hardy Heinlin]

Hi,

perhaps a pre-NG 737 specific feature to indicate V1?

Or it's a side effect, or intentional effect, of the start of the computation of TAS and IRS track?


Cheers,

|-|ardy

[Lasse]

Hi,

Hmm I havent flown CL in years, but I cannot recall this to happen looks more to be related to a temporary snag..

The PLI is fixed to 15 deg until the stall warning computer commands a greater value after around 100 kts that could happen. Above 100 kts its a function of various inputs.

/L

[Vnav]

This would not be a normal PLI behaviour for the 737.

Vnav

[frumpy]

Thanks, guys.

I talked to a former 737 captain, he wasn't aware of that
either and supposed it to be a transient effect. However, I saw
this happen in a 737CL sim youtube video too.
I'll stick to it, maybe I can find out more.