Smyd (737 Ng)
 

Dear Engineers,

I post on the techlog forum but i did not get any answer.
(TE flaps disagree followed by indicator failure)

Could you please tell me if the situation where the TE flaps are in disagree and the indicator and the TE flaps transmitters are not working,(flaps at 15 for example,flaps lever moved to 30 ), if the SMYD will still give you a believable speed tape min maneuvering indication based on a higher AOA ,higher thrust).

Could you please also explain how does the SMYD calculate the highest BIAS(based on nrs?) and why the SMYD uses a basic VSF flaps up of 60 kts but a VSF flaps one of 105 kts.


Thank you so much!!!:8

I'm not sure I understood your question, but I'll try to answer anyway...

Did you mean disagree between indicator and flap position and both transmitters totally u/s?
Each flap position transmitter contains 3 internal resolvers for FSEU, SMYD, FCC etc. Lets say your position indication resolvers are u/s the SMYD's will still get information about flap position through their own resolvers.

The SMYD calculates all biases simultaneously and use the highest bias for L/E flap and slat assymetry bias, L/E UCM bias, TAI bias and High thrust bias.
If a bias is active the stall warning signal will come at a lower AOA.
The SMYDs subtract the highest bias from the normal trip point to reduce the trip point.

Regarding the speeds I have no idea...

Hejsan wmn,

tack so mycket:E
Could you please explain what is a resolver?
I understand the highest bias is used and will provide/result in a higher stall speed at same angle of attack.
So if i get u correctly,the SMYD has its own resolvers?in that case one can still not be sure that the TE flaps are down?
In other words,how do the SMYDs via their resolvers show to the pilots that the flaps are down(flaps disagree and indicator failure)?
Surely the low maneuvring speed band is not enough?
I need to ascertain myself that the maneuvring speed band is not a way to check te flaps are down.(as pitch vs thrust/aoa for a given weight would be).

Haha! You know some swedish?

A resolver in this case is like a little electrical motor with a stator and rotor. As the rotor turns, the electrical field will change and the output will be translated into "resolver angle". Maybe someonelse can explain it in a better way...

Yes, the SMYDs has its own resolvers but they are still inside the same flap position transmitter.
In what situation did this question appear? You don't fly around with the aircraft in this condition and if you do, you are in deep ****. Maybe you have a safe maneuvering speed band, but I guess that you as a pilot will have to go check if the flaps are moving or not...:eek: It's almost impossible to explain the flap system in a forum like this.