PMDG Dash 8

[boeingace1618 0]

^{Is the project still in production? or has it been droppped with the upcoming 777? just curious}

 

 

cheers!

[ZKOKQ 984]

Yes it is. It will be fitted in at some stage.

[duchman 1]

it shuld be based on dash 8 001 and not the later 100 ceries or 200

[Houghton11 12]

I'm not sure what you mean by the "001" Dash and "not the 100 or 200"

 

The initial visualization of the Dash 8 was a bit different, lacking a T-tail and retaining a relatively low aspect ration wing, but it never went beyond a couple drawings.

 

The -100 is the initial variant of the aircraft, followed by some mods, uprated engines in the 103, 106..etc etc.

 

-200 is basically a -100 with 123's and some new interior options (depending on S/N) and is a beauty.

 

-300 is probably the variant most of familiar with. 50 seat stretch.

 

The -400 is a whole different ball-game.

 

I think you may be confusing aircraft with electro/mechanical insturments vs. Glass equipped aircraft. Really there is not much different in the operation of these two cockpits. Maintenance a little different in the pointy end but not much else.

[duchman 1]

dash 8 production serial number 1 or dash 8 cn 001 not shore what the tail number was but that's what i meant by dash 8 001 witch is a dash 8 100 was never sold and leader scraped but it is the oldest dash 8 they might have to talk to a historian about that aircraft because it does not exist today. an just a question does any one know if any airlines fly the dash 8 100/200 with 39 or 40 seats

[Houghton11 12]

Well I'm sure a repaint can be made for that classic Dehavilland paint job.

 

As for the aircraft specific prototype instrumentation and such...who knows.

 

Dehavilland had a habit of destroying the majority of it's early S/N aircraft as part of the destructive testing programme. Even the early production-S/N Dash's are a bit wonky. I think (not sure) that the first production S/N DHC-8 is actually S/N 7. Early S/N Twin Otters also have really specific life-cycle limitations for lots of the structural components.

 

I've just been browsing and i've come across some interesting info...apparently the prototype -300 was actually the -100 prototype lengthened and converted...interesting.

 

May have to bring out the de Havilland books out.

[duchman 1]

why is there not an airline that flyes the dash 8 200 with 39 pasengers in a 2 class configuration of 9 first and 30Y class

[deeknow 10]

Oh dear, another PMDG Dash8 thread .. jeeze .. after all this anticipation I hope they dont pull the project

[Houghton11 12]

why is there not an airline that flyes the dash 8 200 with 39 pasengers in a 2 class configuration of 9 first and 30Y class

 

There's some regulatory issues with 2-class configurations and only 1 flight attendant. You could operate the flight with 2 FA's but that costs $$$.

 

Having said that, unless it's a limited STC, the -200 series is only approved for 2 configurations, 39 and 37 seat configurations. Many operators do have specific ops-specs and LSTC's though. Below is the 39 seat config. For the standard 37 seat config, remove the rear-facing front seats and install a galley.

 

 

You would have a very hard time getting 39 people in a two class configuration in the Dash-8 100/200. First of all, any 'first-class' seats wouldn't fit in the aircraft, and I'm not aware of any first class seat ever made for the Dash-8 series. The seat track and aisle width restrictions make things very restrictive. Emergency exit access would also prevent the addition of a dividing bulkhead between the 'classes'.

 

The -100 series is much more flexible in it's configurations, allowing the bulkhead to be placed in a bunch of positions, and even features this slick config...no STC required!

 

[duchman 1]

Houghton11

 

where do you find all your info

 

whats the diffidence between the standard dash8 202 and the Q202 or the dash 8-202Q and how does the noise and verberation superposition system work and what exactly is it.

 

chadhittenberger

[N520AT 3]

why is there not an airline that flyes the dash 8 200 with 39 pasengers in a 2 class configuration of 9 first and 30Y class

 

There's just no room. Our airline really crams em in with 37 in the back, all Economy.

 

My knowledge of the NVS is limited, however I do know that it breaks a lot, at least on our airplanes. About a quarter to half of our flights are flown with it INOP.

[Ishigami 0]

whats the diffidence between the standard dash8 202 and the Q202 or the dash 8-202Q and how does the noise and verberation superposition system work and what exactly is it.

 

chadhittenberger

 

Q = Quiet

 

It simply means that ANVS is present and that the noise levels inside the cabin are lower. The Q was introduced to market this. Every Dash 8 since sometime around 1996 is a Q.

 

The ANVS is series of microphones and actuators (ATVA: Active Tuned Vibration Attenuator) placed on several location of the fuselage. It also includes an accelerometer mounted underfloor, vibration transducer mounted on the reduction gearbox of each engine and a box to control it all the ANCU: Active Noise Control Unit which is also mounted under floor.

The microphones pick up the noise inside the aircraft while the ANCU outputs certain vibration levels via the ATVAs depending on propeller RPM, cabin noise and their own location.

The vibrations of the actuators and propeller are out of phase cancelling each other out thus leading to a quieter cabin.

Nice “side” effect is that the structure is also stressed less since it oscillates less.

I think there is really cool animation inside the CBT but I'm unable to find it on the web atm.

 

The reason this system often operates in degraded mode or is even goes inop is that the system only works perfect if every part is operating and that means mostly every microphone, actuator and amplifier. (I've never seen a failed accelerometer or vibration transducer thus far)

Once a certain amount of microphones, actuators or amplifiers fails the systems goes into degraded mode and when there are enough failures it goes inop.

The reason your maintenance will not act immediately is that it is quite a lot of work. After all the actuators are mounted directly onto the fuselage via a small bracket. If you have to change one you have to disassembly the cabin in this area.

The same goes for the microphones. They are placed all over the cabin and the most annoying ones are the ones behind side wall panels.

Since there are so many ATVAs and mics chances are high that a few are U/S.

There is only a inop indication for the crew. I imagine they never know when the system operates in degraded mode. For that to check you would need to access the maintenance panel above the wardrobe.

[duchman 1]

does any body knoweney thing about whats going on with the Q400x program

this is the 90 seat dash 8 project.

[Jax_Chief 0]

Houghton11

 

where do you find all your info

 

whats the diffidence between the standard dash8 202 and the Q202 or the dash 8-202Q and how does the noise and verberation superposition system work and what exactly is it.

 

chadhittenberger

 

He works for the same company that I do. We are a MRO that "specializes" in regional jets. Currently at our location in FL we have 3 DHC8-202's in the hangar. 2 of them our going through 40K inspections (just about the heaviest check you can do on a dash 8. Every inspection that DHC8 gets in maint. is done on a 40k +/- a few.), the 3rd just went through a C check and we will be doing a B check on it. Long live the DHC8 Maint Manuals............ nuff said. haha

 

As far as the difference between a Q series and a "non-Q series;"

 

The Q series for is equipped with a ANVS system.

 

Brief Description of the system:

 

"A. The Active Noise And Vibration System (ANVS) is installed in the passenger compartment to decrease the noise and vibration caused by the aircraft propellers.

B. The ANVS supplies secondary noise and vibration fields in the passenger compartment that cancel the original noise and vibration fields.

C. The ANVS goes into the active control mode when the Aircraft (A/C) pressure and tachometers are in range.

D. The ANVS resets when the Weight−On−Wheels (WOW) input shows that the A/C has landed."

 

In laymens terms, there are a few dozen small microphones installed throughout the cabin the pickup noise levels in the cabin while in flight. These levels are computed in the NVS computer and then the NVS controller sends signals to several thumpers (Mini subwoofers) installed in the cabin the emit low freq sound. The sound emitted by the thumpers is at the same frequency, if you will, as the vibrations throughout the cabin caused by the props "pushing" air against the cabin. This therefor cancels out the vibrations caused by the props and less noise is heard and felt within the cabin.

 

To put it even more simple, haha, Noise & vibration from the props is being canceled out by noise being emitted from the thumpers.

 

Its pretty cool when we have to calibrate the ANVS during maint. You have to keep the hangar quite for a few hours while these thumpers rumble away and the system calibrates its self.

 

There are a few other differences in the Q series as compared to a "traditional" DHC8 but there isn't anything major.

 

Thanks

JR

[duchman 1]

is the 90 seat dash going to happen or no can anyone answer that please