Dash8-400 question

[Tu.114]

A lot could be improved. The avionics, and in fact the whole plane, has heaps of potential but has been artificially dumbed down to keep it operable under common type rating with the older series.

That vile altitude select system has been mentioned, as has the heading bug system, and I fully agree to what Artificial Horizon has said.

In addition - the speed bugs. There are two to five of them on screen (depending on situation), but only those for V1, Vr and V2 can be set from one point to be displayed on both sides. The remaining two bugs (their use is SOP dependent of course, but in my company they are used for minimum speeds and approach speeds) have to be set individually by each pilot. Now in case the autopilot is u/s or the PF is flying manually for any other reason, he will need to reach down to the control panel and reset the bugs whenever any flap setting is altered himself instead of having the PNF set the bugs as it should be. And on top of this, this is done by a much-loved single button with a million functions. You cycle through the different bugs using one button and then twist another knob to set the value.
Another little favourite of mine: when setting V1, Vr and V2, You set V1, then cycle to Vr and have to begin at 0 again. Is there ANY situation when Vr is lower than V1 or V2 lower than Vr? Why cannot Vr be initially equal to V1 and V2 equal to Vr - that would save much time inserting those speeds.

Staying with the ASI for a moment. That ADC can compute all those fluctuations of Vne and duly indicate it, but it can NOT set the Vne bar to the actual maximum speed when flaps or gear have been extended. So whatever the configuration, the indicated Vne is always at 246kIAS below 8000ft, while for example the actual Vmax is 200kIAS with Flaps 5 and 182kIAS with flaps 10 (both typical T/O settings). Now let ATC call You to level off early after T/O or better in a G/A with its systematically high workload in this A/C and remember that this aircraft is quite well powered - a flap overspeed in that situation happens much more often than it needs to, and just 5 or 6 simple lines in the code (such as IF FLAPS=5 THEN VMAXindicated=200) would provide a VERY obvious cue.

Now to the descent. A "banana" (indicating on the ND the point along the route where with the current G/S and V/S the armed altitude will be reached) would be a very valuable tool and again require only a line or two in the programming code, but obviously it is not needed.

Also the tradition of placing much-used levers in weird places has been well honoured in the -400. From the -300, I fondly remember the synchrophase switch that had to be operated by the PNF after departure and before landing - and of all the places to put it, some wise guy elected to stick it on the glareshield in front of the R/P. And on the -400, it is the flight/taxi switch that needs to be switched during lineup and after runway vacation by the RP but has been set in front of the L/P on the glareshield.

One might also look at the gear lever here - it is placed on the R/H center panel well in reach of the copilot, but not so from the captains side.
The already mentioned instrument control panel comes to mind as well - it is situated outside of the PFDs on the instrument panel and one has to bend well forward to reach it for any adjustment, be it to the speed bugs, the minima or the altimeter reference pressure.

All in all, the ideal DH8 pilot has the body features of a gibbon - short, stubby body (but not too rotund, lest he does not fit through the escape hatch!), shortish legs, but extremely long arms to reach all those weirdly located levers.

One little other thing comes to mind - the course selector on the glareshield. During the approach preparation, the course arrow will be briefly selected for display, then adjusted and then it will be deselected for the Nav display to come up again. Only when leaving FMS navigation for the final approach, the course arrow will be displayed again, this time in the HSI on the PFD. But keeping in mind the general system philosophy hinted at before - will the course selector be locked out, when the arrow is not displayed? Of course not - so if one inadvertently twists the course selector after having dialed the approach course, one might end up with a little surprise when resuming conventional navigation. Again, it would have taken one single line in the code to allow course selection only when the arrow is displayed somewhere.

I am sure I will come up with one or another thing later on when thinking about it a bit...