Max Take off Weight for QF Q300 ?

[Kelvin R]

Hi,

Coming out of Canberra yesterday we had a delay of around 30 minutes as the aircraft was declared overweight for the conditions shortly after boarding was finalised. Eventually I noticed that they pulled about 20 bags out of the rear hold and we departed towards the north from the full length of the runway getting airborn well past the cross runway. This was after a full powerup with breaks on take off roll, followed by a very slow rate of climb.

Obviously the conditions changed (perhaps the breeze dropped off?) as this was only my third time experiencing an aircraft which was overweight (the first was on a flight out of Lizard Island, the second was being evac'ed off Wilson Island in a heli) but considering the length of the runway at Canberra now it seemed strange the Dash was too heavy.

Normally the Q300 is airborn in next to no time, even when I have been on a full flight. So this got me wondering what would have been to Max take off weight yesterday afternoon out of Canberra?

Also, anyone know what happened to the Q400 that was meant to operate the service?

[Adam P.]

Possibly fuel requirements due weather at the destination?

[Paul Spira]

Hi Kelvin,

I think I may have flown yesterday afternoon with the cabin crew who were operating your service back to Sydney. They seemed to think that there may have been a tailwind component that the crew were waiting on to abate.

In addition it was also fairly warm yesterday afternoon in Canberra (25 degrees ish at 7 when we arrived so perhaps a couple of degrees warmer for your departure). This in combnation with the relatively high elevation can quickily limit the 300, especially from runway 35. It's sometimes possible to request rnwy 17 in light wind conditions to allow a higher BRW (traffic permitting of course).

I agree it seems odd that the dash would be limited from such a long runway, but I believe that the limiting factor is in fact the climb performance required departing CB due to the obstacles that exist in the takeoff splay (as opposed to an ASDA, TODA or TORA restriciton).

I can't say I'm all that familiar with the 300 fgures any more but it's quite likely that the ambient termperature, elevation and possibly tailwind all together reduced the Max BRW from the structural limit of 19.5 tonnes down to the 17.5 - 18 tonne range, which with a full load of pax could have required the offloading of a few bags as you describe.

The Q400 that was scheduled to operate your service had a minor technical issue that apparently procluded the use of the autopilot (hence it was in Sydney being repaired). Was fixed by mid afternoon and continued to operate 1493 in the evening.

[Hugh Jarse]

Kelvin, I'd be interested to know how you, as a passenger can objectively assess that the aircraft had a "very slow rate of climb". All take-offs (no matter what airport) must achieve the minimum climb gradients required (no disrespect intended).

As Paul S. wrote, the conditions at CB (usually temperature) can impose a limitation on your BRW in the Dash-300 (which is 19.5t max), particularly on RWY 35 due to second segment climb performance (CAO 20.7.1B). However, when the temp is above about 24 deg in CB, you actually can depart RWY 17 at a significantly higher BRW with 10kt tailwind (due to less terrain to the south, hence less effect on 2nd segment performance). I did this many times when I flew the Dash.

Adam P. the Dash-300 is always LDG wt limited with a fuel burn of less than 450kg at max BRW, though, with a typical burn CB-SY is around 550kg, it's not much of an issue.