Q Link Engineering Issues....

[ok3wire]

Seems Qlink are having a few troubles in QLD lately and it all seems to be very quiet.

Mustn't upset the punters.....

Dash 300 had a prop got into feather just after V1 at YBBN earlier this week (nice work by the crew to bring it home) and an informed source tells me that there was another incident at YBTL where a Q400 had an uncommanded spoiler deploy late on takeoff roll.

Sounds like they were lucky to have 3000 odd metres of bitumen in front of them, a shorter runway and they might have got the wheels muddy...

[VH-FTS]

That's aviation for you. Things break. What's your point?

[Citizen Blackhander]

when you take into account the thousands of flight hours that those bombardier aircraft are doing each week (combined) and the age of some of those airframes the engineers are doing a fantastic job.
word from a well informed and reliable source says that the engineers work tirelessly night and day to keep those aircraft in top nick and that they ground a plane for discrepancies that could affect passenger comfort levels! Now thats pretty rare especially for a regional airline but i guess when you have the numbers of aircraft like they do its no biggy for them, they could just pull another out of the shed i guess

Lucky break with the 300 and the 400 tho (no pun intended)! bet you the pilots ass cheeks puckered up:}

[Capt Basil Brush]

Sounds like they were lucky to have 3000 odd metres of bitumen in front of them, a shorter runway and they might have got the wheels muddy...

How long do you think the RWY in TL is?
Doesn't your Flight Sim PC game tell you that?
Is that the best 1st post you can come up?

[Capn Bloggs]

Sounds like they were lucky to have 3000 odd metres of bitumen in front of them, a shorter runway and they might have got the wheels muddy...
Who would have guessed it, an RPT that was able to stop within the length of the remaining runway after an Rejected Takeoff. Things are looking up. :D

[ok3wire]

Thanks for the replies even if some are a little on the acidic side.
I didn't mean for a minute to say that the engineers are doing a less-than-stellar job. These occurrences were random and probably have nothing to do with that side of things.

Also, this is, last time I looked, a rumour network so I certainly don't have all the facts, just wondering if there is any truth in the quiet words I've been hearing.

The YBBN thing was no big deal, I'm sure the crew would have practiced such situations a hundred times in the simulator. Still, for the prop to feather with the engine at full power must have put an unhealthy strain on the gearbox.
If that is what happened.

The YBTL takeoff sounded like the spoilers deployed as the weight came off the wheels, ie after V1, so not your average "rejected take-off". Some weird weight-on-wheels (squat switch?) malfunction. If that was the case then it must have been a rude shock to the crew. And yes, they probably only had 2400 odd metres of bitumen in front of them, minus what they had used.
If that is what happened.

[Capt Claret]

I experienced an uscheduled auto-feather years ago in a DH8-200 out of Broome. I recall seeing 125% torque, and a whole lot of confusion as to why an engine producing power feathers a prop.

However the rectification was, as best I recall, disconnecting & reconnecting the ECU, a perusal of the MM to conform that no other inspections were required and we were away.

[Flying Bear]

My Dash 8 tech is getting a little hazy now, but doesn't the Dash 8 AFx system look simply to the torque gauge output to determine if an engine has failed?

Therefore in the event of a torque gauge failure (ie loss of power) during take-off the AFx may interpret the nil output from the gauge as an engine power loss - and hence feather the prop...

This happened to a skytrans -100 in Darwin during my time there and I recall that the above was something like what caused it. Other aircraft types use oil pressure loss (from a dedicated transducer) for their AFx, which is probably a more reliable determinant of engine failure.

[Capn Bloggs]

The YBTL takeoff sounded like the spoilers deployed as the weight came off the wheels, ie after V1, so not your average "rejected take-off".
Apart from all the rumours, innuendo and pontifications, it would have been nice to put this in your first post! If the spoilers deployed after WOW switch went Air, then they have my congrats on a job well done.

So you did drive boats, eh Claret? :oh:

[PropDoc]

125% TQ in feather = prop change and engine inspections:{

[noclue]

The torque gauges have both anologe and digital information. Does anyone know which one the auto feather logic recieves? For instance, if the digital tq info was lost, but the anologe needle was fine, would the auto feather misinterpret that as an engine failure and feather the prop? Just curious.

[tmpffisch]

I can't find any data that the signal comes from the gauge, just the meter.
If it is the gauge, it would be the analogue component, the digital can be MEL'ed.

[noclue]

cheers tmpffisch

[Kiwiconehead]

Gauge is just a gauge - single 0-5VDC input from EEC(200/200) or TSCU(100) drives digital and analogue indications.

TSCU, ECU/EEC control the autofeather.

There is a time delay from loss of signal until feather - supposed to account for transient loss of torque signal. (during the test, drop the switch, uptrim light, 2 3 feather)

But autofeather with loss of sensed torque only (ie engine still operating) is almost always the TSCU getting upset.