Dash 8 - 400 Reliability

[A380MSN0001]

Hi everyone,

I'd like to know what is the reliability of the Dash 8 - 400 (Ex Q400). According to some posts here some drivers are saying the aircraft is hangar queen and unreliable especially the APU & the landing gear. On the other hand some are saying the aircraft is reliable and not very different from other aircrafts. Somes are saying the Dash 8-400 is almost a "handmade" aircraft in terms of production and so, every single frame is different.

Thanks for your feedbacks.

[RVF750]

I flew them for 6 years.

First and foremost, they do need a bit of scheduled TLC. APU life is ok, but the generator brushes are crap frankly and need change schedules of 1,500hrs or so to keep them reliable. To be honest it was piss poor design not to give the APU a flight capable starter generator identical to the main engines. At least you'd have been carrying a spare along for the ride....
Secondly, prop balance is king. It's piss easy but requires line guys who care and have a laptop and small set of scales. If the props stay in balance, the NVH system can keep the cabin smooth and quiet and is also then reliable. Let the props get bad and it gets overworked and fails. Then the vibes slowly kill the rest of the airframes electronics. One follows the other like night follows day.
They can be landed smoothly. Honest. Slamming them in every time causes fatigue in the undercarriage on any aircraft, and Turboprops are all about compression damping to get the tyres to bite, so that's why they are smoother close to main gear overhaul.....
Overall, it's a very capable airframe, can be reliable if looked after and will let you down if you pay only lip service to maintenance and only fire fight.

Much like any other type.

Where dispatch reliability for any turboprop looks bad is they fly so many short sectors. My average over 6 years was about 45 mins. Rarely went tech and tried my best to fly smooth and take care of the beast.

[Uplinker]

Interesting info, RVF750. I flew Q400s a long time ago but don't remember any reliability issues, apart from the NVH system - but the fleet was new then.

The first one in the UK was G-JEDI, (I think we were the UK launch customer?), and I was one of the first pilots on it. For the first six months, it landed really gently, whatever you did. Then it and the others started giving harsh landings. Positioning as a pax on G-JEDI one day, I noticed that the main oleos were very low, and the poor thing was basically landing on its bump stops. I did flag this up at the time,but nobody took any notice.

After that, most of us learned to land one main at a time, whatever the wind, which softened the landings.

I also remember one day we had a brake hydraulic leak and the "engineer" fixed it by getting a large, agricultural, adjustable spanner and tightening the connection. Hmmmmm, I thought, not really a precision engineer; where's your proper flare nut spanner?

[A380MSN0001]

Thanks to both of you guys (RVF750 & Uplinker). This is really interesting. I assume Uplinker you were flying for Flybe. What was your opinion about the quality level of the maintenance done by the groundstaff?
It seems some aircrafts were in really great shape and workout with no issues, and some other got repeating issues that was grounding them?

[Uplinker]

I was then, yes - a long time ago now, and I moved airlines eventually. The engineers then were keen and helpful, but I honestly wouldn't know in detail the quality of their work. Apart from the main oleos, I don't remember any particular issues arising from (lack of) maintenance - something I did experience in one other airline.

The Q400 was new to the UK then, and perhaps some maintenance schedules got corrupted "in translation"? Maybe the main gear oleo nitrogen charge pressure should have been checked every week, but was only checked every year. I don't know, (I moved on from that fleet after a year).

[speedrestriction]

The de-icing boot system is prone to intermittent failure in flight. When I flew them the operating theory was that the DDVs were freezing in position. Of course by the time you landed and tested the bloody thing would work fine.

I seem to remember occasional de-ice mat failure on the props.

The thing would also constantly pop fasteners during the day which would require engineers to come out with steps.

The computer for the alpha vanes whatever it was called (ADC?) would occasionally throw a wobbly and ping up with a fault on touchdown.

TCAS used to also die every so often. Haven’t flown the thing now for a while so some of these failures may have been ironed out but if I remember the fleet technical pilot bemoaning the lack of support from Canada when it came to making any changes in spite of there being ample evidence of the need to.

[Uplinker]

I think the Q400 is a good machine - fast, powerful and efficient - but in my opinion it could have been more developed. Two things illustrate this; the wipers and the lack of an MDA bug for landing.

It seemed to me that the design team realised late on a Friday afternoon that they had forgotten about the wipers, and bodged something up from the local hardware store at the last minute.

The lack of an MDA bug on the altimeter instrumentation was extraordinary - you had to remember the figure ! Flybe fitted little plastic mechanical number counters on the glare-shield that you could set to display the MDA as a memory aid.

Maybe these things were sorted in later versions?

[8314]

Originally Posted by Uplinker

The lack of an MDA bug on the altimeter instrumentation was extraordinary - you had to remember the figure ! Flybe fitted little plastic mechanical number counters on the glare-shield that you could set to display the MDA as a memory aid.

Don't know, but we could set either MDA or DH and it showed on the lower part either left/ right of the PDF.
Was 10 years on it and totally agree with the wipers, usually after t/o on the first leg and enough airstream they came to the upright position, where they stayed for the rest of the day. Not approved, but helped my ears and for icing the lower inner corner of the windscreen was the first indicator anyway. And in rain they were useless!
Otherways I loved to fly her, never let me down.
Occasionally unhinged doors, just know the trick to readjust them and you're good to go.
The APU could have been better, gave us some interesting times especially with remote de-icing where you had to shut down and no GPU available at position. Well, what can I say, we could start it again after all that TypeIV drained out after some waiting time 😉.

[A380MSN0001]

Thanks guys, your experience feedbacks on the aircraft are really interesting. It seems this aircraft is a pretty good one but some minors issues on couple of systems.

Do you guys knows if those issues are sorted on the frames built recently ?

[8314]

Oh, just another fun fact: After she's been parked over night, the first leg's taxy out you got the nose wheel's parking spot vibrations at 12kts GS. So you could just vary your taxy speeds around it without even checking on the displays. 👍9pm