Colgan 3407 Down in Buffalo

[UndauntedFlyer]

As far as the yaw damper is concerned, is someone here saying that the yaw damper played a role in the Colgan crash somehow?

Yes, I brought this up in an earlier post. The question concerns the use of right rudder to offset the torque reaction/p-factor that would be required to correct for the addition of the full power used by the captain during his attempted recovery. Since I suppose the yaw damper (dampener) is the only automatic servo assist, my question asks if the amount of additional rudder correction required by the pilot is significant (in the Q-400) under a full power recovery at a slow speed; and, could this have been a factor.

If someone has any experience in this airplane (or similar) your comments would be greatly appreciated.

 

[WSurf]

Suggest we close this one down, Mods.

What'a Suck up!

 

[GSXR600]

Yes, I brought this up in an earlier post. The question concerns the use of right rudder to offset the torque reaction/p-factor that would be required to correct for the addition of the full power used by the captain during his attempted recovery. Since I suppose the yaw damper (dampener) is the only automatic servo assist, my question asks if the amount of additional rudder correction required by the pilot is significant (in the Q-400) under a full power recovery at a slow speed; and, could this have been a factor.

If someone has any experience in this airplane (or similar) your comments would be greatly appreciated.

Could be a contributing factor as well on top of everything else been discussed.
I have a couple friends at colgan and this sadly included CA Renslow as well, and they say that the adding power and trimming the ruder is one operation at the same time.

 

[Singlecoil]

Could be a contributing factor as well on top of everything else been discussed.
I have a couple friends at colgan and this sadly included CA Renslow as well, and they say that the adding power and trimming the ruder is one operation at the same time.

Which is not correct, but that is how most pilots fly the airplane.
Add power and using your right foot is one operation. Trimming out the rudder pressure is the second operation. You don't level off with the elevator trim, you don't roll into a turn with the aileron trim, you shouldn't use the rudder trim for primary yaw inputs.
It seems a lot of pilots are introduced to multi-engine aircraft via the Seminole or Duchess which have counter-rotating props and little torque. In this regard, the 182 has more in common with a large turboprop than a Duchess or Seminole.

 

[UndauntedFlyer]

Lack of the use of the rudder and an understanding of the need to use rudder anytime there's yaw is at an epidemic level in the training of new pilots at the primary level. Unfortunately, because of the law of primacy, this deficiency carries though to more advanced and larger aircraft that might later be flown. This could have been a factor in this accident.

 

[ReverseSensing]

Yes, I brought this up in an earlier post. The question concerns the use of right rudder to offset the torque reaction/p-factor that would be required to correct for the addition of the full power used by the captain during his attempted recovery. Since I suppose the yaw damper (dampener) is the only automatic servo assist, my question asks if the amount of additional rudder correction required by the pilot is significant (in the Q-400) under a full power recovery at a slow speed; and, could this have been a factor.

If someone has any experience in this airplane (or similar) your comments would be greatly appreciated.

I'm sorry; I thought I addressed this. Yes, the Q400 requires a significant amount of rudder input to counteract the torque effects. I would fully expect, though I haven't tried it in a sim, that if you add full power (10,000 shp to 13' conventional rotating props) at slow speed, it will roll hard left if no rudder inputs are added. I'm not suggesting this is what happened; I don't know. It's possible it contributed to the upset.

The yaw damper uses an electric actuator to supply inputs to a summing mechanism, and only amounts to approx. 4.5 degrees max rudder deflection. This same summing mechanism receives the input from the manual rudder trim system (and the rudder pedals, for that matter).

I understand Singlecoil's point about how rudder inputs are made from a technique standpoint, but from a systems standpoint, any inputs (YD/rudder trim/rudder pedals) are all going through the same summing device. But it is true that the only way to simultaneously add power and keep the rudder trimmed is using your feet.

 

[belchfire]

J31's did in fact have a yaw damper, it was just turned off for to's & lndgs making you think it had no yaw damper...

I rode on Corp express years ago into RDU and talked to a j31 capt about the yaw squirreliness (thinking it was mel'd) and found out they selected it off for to's & landings. (which was a norm for many a/c I learned.)

http://www.google.com/search?hl=en&rlz=1C1CHMI_enUS311US312&q=jetstream+31+yaw+damper+?&btnG=Search

Later on the yaw dampeners in corpexe's jballs were all deactivated. Seems replacements were made from "unobtainium".

On a good day they only helped a little...on most days they were better know as "yaw enhancers"!

Just because there is a yaw dampener installed doesn't mean the autopilot is connected to the rudder. In fact many older autopilots that have autoland capability don't have control of the rudder yet to be sure there were yaw dampeners.

 

[Timebuilder]

I understand Singlecoil's point about how rudder inputs are made from a technique standpoint, but from a systems standpoint, any inputs (YD/rudder trim/rudder pedals) are all going through the same summing device. But it is true that the only way to simultaneously add power and keep the rudder trimmed is using your feet.

That's what I was thinking.

 

[Captzaahlie]

Later on the yaw dampeners in corpexe's jballs were all deactivated. Seems replacements were made from "unobtainium".

On a good day they only helped a little...on most days they were better know as "yaw enhancers"!

Just because there is a yaw dampener installed doesn't mean the autopilot is connected to the rudder. In fact many older autopilots that have autoland capability don't have control of the rudder yet to be sure there were yaw dampeners.

Thanks for educating me on that..... it was in fact a very yawie (sp? word even?) or slip sliding flight. Flying on that thing gave commuters bad name, at least that particular flight.

Well i better stop going on about the yaw damper or Walter will have this thread shut down!

 

[Captzaahlie]

I'm sorry; I thought I addressed this. Yes, the Q400 requires a significant amount of rudder input to counteract the torque effects. I would fully expect, though I haven't tried it in a sim, that if you add full power (10,000 shp to 13' conventional rotating props) at slow speed, it will roll hard left if no rudder inputs are added. I'm not suggesting this is what happened; I don't know. It's possible it contributed to the upset.

The yaw damper uses an electric actuator to supply inputs to a summing mechanism, and only amounts to approx. 4.5 degrees max rudder deflection. This same summing mechanism receives the input from the manual rudder trim system (and the rudder pedals, for that matter).

I understand Singlecoil's point about how rudder inputs are made from a technique standpoint, but from a systems standpoint, any inputs (YD/rudder trim/rudder pedals) are all going through the same summing device. But it is true that the only way to simultaneously add power and keep the rudder trimmed is using your feet.

That's pretty interesting about the 400. I can see how it might have that tendency because thats a lot of hp (10k). I never noticed any tendencies like that in the DHC8-200 but then I never really goosed it that often either from slow flight. The 300 on the other hand has just enough power to get out of it's own shadow when it's loaded with 50 pax and bags. (not horrible performance but then again nothing that'll will make you smile like the 200 did....(you could barber pole it in level flight at lower altitudes).

Has any information come out yet (publicly released by the NTSB) about actual rudder/elevator/aileron positions yet? I'm thinking that the FDR was modern enough to record these parameters.


(Walter I made an honest attempt to not use the word YAW DAMPER or J31 in this post!)