Pilot Training

Re: Turboprop Arrival Times...help?

WWA1965 — Sun, 21 Feb 2010 18:51:55 GMT

That's fantastic -thank you Ken!

I really need to get a whiteboard for my bedroom so I can do these calculations without using half a tree.

Re: Turboprop Arrival Times...help?

Ken G — Sun, 21 Feb 2010 16:18:41 GMT

A13NM -200

Airspeed Limits VMO(Maximum operating) 0 to 14000 ft 242
(IAS) 15000 ft 239
20000 ft 223
25000 ft 207

A13NM -400

VMO (Maximum Operating) 0 to 8,000 ft 245
10,000 ft 282
18,000 ft 286
20,000 ft 275
25,000 ft 248

So for the -200 it looks like you maximum speed is going to be around 15,000' while for the -400 18,000'.

Realize that the numbers above are for IAS and the maximum airspeed is measured in TAS. True Airspeed is IAS corrected for Density Altitude. For a down an dirty conversion for an IAS day the following works out OK for lower altitudes: TAS = IAS + (IAS/60 x Ht (in thousands of feet)) Another quickie is IAS + 2% x the altitude / 1000.

For 18000' at 286 is 2% x 18 or 36% + 286 KIAS or 388 KTAS. So at 18,000' I suspect that I can push maximum power and run out of torque before I overspeed the airplane.

Re: Turboprop Arrival Times...help?

WWA1965 — Sun, 21 Feb 2010 12:11:14 GMT

This is what I'm guessing are the speeds -

at 6’000 ft 365 KIAS
at 9’000 ft 360 KIAS

----> More likely 250 knots due to the speed restriction <10,000 ft

at 12’000 ft 355 KIAS
at 18’000 ft 340 KIAS
at 24’000 ft 325 KIAS

Probably not the realistic way of doing it but at least it's better than pushing the engines to 100% and finding out the approximate speeds. Most of the time though I'm using the Dash 8-Q200, the -Q400 I only need for the routes out of Toronto City Centre Airport - imitating Porter routes.

Re: Turboprop Arrival Times...help?

Ken G — Sun, 21 Feb 2010 05:11:03 GMT

According to Bombardier the Q200 has a maximum cruise speed of 290 KTAS while the Q400 comes in at 360 KTAS. This are maximum cruise figures and could very well represent the much larger engines on the Q400 (almost twice as much shp on the Q400 as the Q200). Looking at other websites including a few airline sites it seems that the Q400 is faster than the Q200. How this translates to full load speed at typical Dash 8 altitudes of around FL180 is unknown without performance charts to actually look at.

Re: Turboprop Arrival Times...help?

WWA1965 — Sat, 20 Feb 2010 17:57:38 GMT

I find looking at the real-world times makes me feel a little more positive about arriving 30 mins later than the WWA schedules - most of the time I match the real world quite close. I also use the exact flightplan from those flights so I'm double assured that I should be taking the correct amount of time.

Just one question though - how do the speeds IAS wise differ between the Dash 8-Q200 and Dash 8-Q400. The max stated is 240 knots for the -Q200 and 360 knots for the -Q400. Does this really mean ground speed rather than fully IAS - because it changes the higher you go of course.

Here's a copy from a checklist I use for the -Q200 -

at 6’000 ft 245 KIAS 78%
at 9’000 ft 240 KIAS 76%
at 12’000 ft 235 KIAS 73%
at 18’000 ft 220 KIAS 68%
at 24’000 ft 205 KIAS 63%

Re: Turboprop Arrival Times...help?

Ken G — Sat, 20 Feb 2010 15:05:52 GMT

If the route tables were based on a jet (i.e. RJ) then there is nothing that you can do in the Dash 8 to arrive on time. You are running 100 to 150 KTAS slower than the jet and there is no way to make it up. Turboprops should have their own time tables based on their slower cruise speeds.

Turboprop Arrival Times...help?

Peter Arnold — Sat, 20 Feb 2010 11:10:41 GMT

Hi Gang,

I've become so used to flying the narrow-body routes in a 737-800 and arriving mostly on time as per the WW boards, and now that I am playing with the Turbprop routes in a Dash 8-300, I find that I'm constantly late. I know that we don't have to follow the times strictly, but I like to, just for the realism. Can anyone give some advice on how to arrive on time in a Dash 8-300 please?

Cheers,