Airline Pilot Central Forums

Airline Pilot Central Forums (https://www.airlinepilotforums.com/)
-   Regional (https://www.airlinepilotforums.com/regional/)
-   -   Q400 question (https://www.airlinepilotforums.com/regional/31093-q400-question.html)

skybolt 02-17-2009 12:37 PM


Originally Posted by Avroman (Post 461139)
Until you bag an engine of course then you are getting the dance workout.
And at least on the 900 the autopilot is garbage too. The only turbine I have flown with a worse autopilot was the Citation. Yes even the Jetstream (well the one that had an autopilot installed) I flew had a better autopilot.....

Say it ain't so, the Jetstream had an AUTO pilot? ? ?

Those were the days!

DashGirl 02-17-2009 01:21 PM


Originally Posted by flynwmn (Post 560202)
On the 300 I dont know if it's me or not but I can't land it unless I use flaps 35. Also at Piedmont we have a capt who has tail struck the 100 twice.

It's you dude..:p The 300 lands real nice with flaps 15 about 10 over ref with a pretty flat attitude..maybe 4 degrees pitch up or so..With the 300 it's all about speed control and approach stability. Big pitch changes in the 300 will hose you..you want to get it settled into a real nice constant pitch drift down all the way to the pavement then hold it off with a slightly high nose up pitch and it rolls on every time. Now if your fighting strong gusty winds the 300 lands like doo doo cuz ya have to just drive on the centerline throwing out any desire for a soft landing.The 100 is a bit more forgiving but lands like crap unless you have everything perfect.

trent890 02-18-2009 02:26 PM

Another question about the Q400. Is there any aural or tactile feedback to the Q400 pilot when the elevator trim is in motion while the autopilot is engaged?

Obviously, there is the pitch trim indicator next to the parking brake handle on all DH8 series aircraft. But you wouldn't notice the indicator line slightly moving with the autopilot on unless you specifically redirected your line of sight to monitor it for movement.

The DH8 -100/200/300 series aircraft have the irregularly shaped manual pitch trim wheel on both sides of the center pedestal. Not only can your hand feel the bumps in this wheel moving as the autopilot trims the pitch, but with alternating light and dark segments painted on the wheel, you could also see that the pitch trim wheel is in motion. The A320 pitch trim has the same type of alternating color segments on the wheel, and the B737 uses the off-balance weights to produce the "clacker" effect when the pitch trim wheel is in motion.

Other than knowing the expected speed vs. pitch vs. power setting that comes with experience in type, how does the Q400 pilot know when the autopilot is slowly using the pitch trim to mask dangerous flight conditions approaching the limits of the flight envelope?

Diver Driver 02-18-2009 02:45 PM


Originally Posted by trent890 (Post 562109)
Another question about the Q400. Is there any aural or tactile feedback to the Q400 pilot when the elevator trim is in motion while the autopilot is engaged?

Obviously, there is the pitch trim indicator next to the parking brake handle on all DH8 series aircraft. But you wouldn't notice the indicator line slightly moving with the autopilot on unless you specifically redirected your line of sight to monitor it for movement.

The DH8 -100/200/300 series aircraft have the irregularly shaped manual pitch trim wheel on both sides of the center pedestal. Not only can your hand feel the bumps in this wheel moving as the autopilot trims the pitch, but with alternating light and dark segments painted on the wheel, you could also see that the pitch trim wheel is in motion. The A320 pitch trim has the same type of alternating color segments on the wheel, and the B737 uses the off-balance weights to produce the "clacker" effect when the pitch trim wheel is in motion.

Other than knowing the expected speed vs. pitch vs. power setting that comes with experience in type, how does the Q400 pilot know when the autopilot is slowly using the pitch trim to mask dangerous flight conditions approaching the limits of the flight envelope?

I would imagine that it does, the CRJ has an aural warning when the trim is in motion after like 3 seconds or so... and you can get an "AP TRIM NU" or "AP TRIM ND" caution message if it runs away with the AP on. Being a fellow Bombardier product, I'm sure it has something along those lines.

usmc-sgt 02-18-2009 04:32 PM

The 400 does not have a trim wheel like the other models. The same window that shows the trim setting is all that we have. If the trim moves for more than 3 seconds it "clicks" or beeps continuously until it stops trimming.

Most guys with a few hundred hours in it like any other plane know settings. I use base power settings to get me in the balpark and then fine tune.

trent890 05-14-2009 07:23 PM

What Prop RPM range do the condition levers regulate on the Q400? I know from the -100/-200/-300 series, MIN is 900 RPM and MAX is 1200 RPM. I thought I remember reading that MIN in a Q400 will come back to 850 RPM or so.

I thought the Q400 has a FADEC type system, rather than the ECU/HMU on the earlier Dash models. So what Prop RPM can you get out of Q400 and the P&W 150 with the condition levers at MAX? Can you get MAX Prop RPM even when the power levers are at an approach setting? Or does it take a torque setting near TOGA to really get the rubber bands wound up and send those blades cutting thru the air?

I just find it unusual in the NTSB animation of the Colgan crash, that the CA calls for "gear down", and the next thing you know the gear is coming down and the condition levers have gone to MAX. The CA never called for the condition levers to MAX, the airspeed has bled off by a good 40 kts, and yet the power levers haven't moved much at all. Is it possible that the CA himself (as PF) moved the condition levers to MAX?

On all the other Dash 8 models, when the condition levers go to MAX, the PF better be ready to match it with the application of some torque. Otherwise, you've got two 13 foot diameter discs of drag out there, as the prop blades drive towards fine pitch because the prop governor is trying to achieve 1200 RPM. Or on the Q400, is it as I suggested above, where the prop RPM will not accelerate with the condition levers moved to MAX, unless there is a corresponding amount of torque applied?

JungleBus 05-14-2009 08:48 PM


What Prop RPM range do the condition levers regulate on the Q400? I know from the -100/-200/-300 series, MIN is 900 RPM and MAX is 1200 RPM. I thought I remember reading that MIN in a Q400 will come back to 850 RPM or so.
Only 3 settings on Q400: 1020, 900, & 850.


I thought the Q400 has a FADEC type system, rather than the ECU/HMU on the earlier Dash models. So what Prop RPM can you get out of Q400 and the P&W 150 with the condition levers at MAX? Can you get MAX Prop RPM even when the power levers are at an approach setting? Or does it take a torque setting near TOGA to really get the rubber bands wound up and send those blades cutting thru the air?
They'll do 1020 at flight idle, just need oil pressure to drive them flat.


I just find it unusual in the NTSB animation of the Colgan crash, that the CA calls for "gear down", and the next thing you know the gear is coming down and the condition levers have gone to MAX. The CA never called for the condition levers to MAX, the airspeed has bled off by a good 40 kts, and yet the power levers haven't moved much at all. Is it possible that the CA himself (as PF) moved the condition levers to MAX?
That's the landing flow for the PNF/PM. Gear down, fuel & hyd pumps on, condition levers max. At Horizon you'd also press a Reduced NP button so that when you put the condition levers to max, the props would stay at 850 and only advance to 1020 if you brought the power levers way up for go-around. Colgan Q400s don't have that option.


On all the other Dash 8 models, when the condition levers go to MAX, the PF better be ready to match it with the application of some torque. Otherwise, you've got two 13 foot diameter discs of drag out there, as the prop blades drive towards fine pitch because the prop governor is trying to achieve 1200 RPM. Or on the Q400, is it as I suggested above, where the prop RPM will not accelerate with the condition levers moved to MAX, unless there is a corresponding amount of torque applied?
Yeah, there's a lot of drag when they go to 1020. Very helpful when ATC dumps you in. Not so helpful when you're level, already slowing, and not watching airspeed. :(


All times are GMT -8. The time now is 02:30 PM.


Website Copyright © 2026 MH Sub I, LLC dba Internet Brands