Dash 8 Q400
Thread Starter
Join Date: Nov 2006
Location: Fairfield
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
Dash 8 Q400
A qestion for Q400 pilots: Having flow around the UK and it's shores in turbo props for almost 50 years I grown fond of them. However, the Q400 is like no other and I cannot appreciate why that should be. Turbo props have a progressive fight performance but the Q400 is entirely different. All changes in pitch and roll are abrupt and mechanical. Approaches tend to be far from smooth and controlled with the aircraft continually moving in a seemingly uncontrolled fashon particularly on short finals. Full flap approaches seem to exasipate matters and I get the feeling that the two guys/ gals up front will be glad to reach the ground safely. Certainly the aircraft has an impressive performance and could it be this factor which which leads to a bumpy ride as those props must move a vast amount of air. The 200 series is a delight to fly in and the 300 similar but not the 400. Flybe seem to have minimised full flap approaches with engines roaring and that inevitable 'hanging' feeling. Please let me have your views on my experiences. Thank you.
Hm... I cannot entirely subscribe to Your view on the -400s ride qualities, as I am under the impression that it can be flown equally smoothly as any other airliner. Were the flights You described affected by adverse weather maybe, and did You sit at the rear end of the cabin? The fuselage tube is a bit prone to flexing in turbulence, and the flight attendants seated on the rear jumpseats occasionally complain about this. But let me look at the points You brought up:
There are indeed some little peculiarities to this aircraft that tend to make life less easy for its pilots. In no particular order:
Many colleagues including me find the aircraft a challenge to land. As You say, the engines move a bit of air and much of the wing is in the props slipstream, so any power change in flare will have a direct effect on sink rate. Additionally, the landing gear is very unforgiving of crabbed touchdowns; if the aircraft is only a tiny bit misaligned with the runway, it will easily result in a major impact. On top of that, an approach with Flaps 15 will normally see a pitch slightly above 0°, and to avoid the rear fuselage scraping the runway, flaring is limited to 5° nose up. This together results in a not too wide window of pitch, power setting and airspeed that has to be hit for a reasonable landing. QAR readouts in my company on the other hand show that while a normal landing may feel bumpy inside the aircraft, the G load experienced is noticeably less than on other fleets.
Just to make sure though - what I just wrote should in no way be construed as alarming or unsafe; while a normal DH8-400 landing might bruise the pilots ego a bit occasionally, it is nowhere even near to a close call and I am not aware of any -400 that was damaged due to a badly executed landing.
Another thing is the flap setting You mentioned. Flap 35° approaches come both with a remarkable nose-down pitch and a rather unpleasant airframe buffet caused by some degree of flow separation ahead of the flaps trailing edge - in rain, You will see flowing some water forward from the upper trailing edge on that flap setting. So unless performance requires such a configuration, it is generally not preferred.
Coming back to the engines. As they are way more powerful than those on the -300, they have some potential to cause an uncomfortable ride if they are handled by some ham-fisted guy. Just like in a Cessna, the prop comes with all the associated effects like P-factor, torque, gyroscopic effects etc, so any power change will require trim changes about all 3 axes; WAY more so than on the -300. If a large power change is required, it is thoroughly recommended to do it in steps (if practical, of course): move the power levers a bit, then readjust trim, then move the power levers another bit and so on; otherwise this will cause an immense yawing moment in the aircraft. While pitch trim and aileron trim changes are noticeable in the flight deck, the passenger comfort is mostly influenced by those yaws.
But just to be sure again: While this type has its weak sides (just like any other aircraft I have gotten to know until today), I find the -400 a rather agreeable aircraft to fly, with as You say remarkable performance rather comparable to a jet than a turboprop.
There are indeed some little peculiarities to this aircraft that tend to make life less easy for its pilots. In no particular order:
Many colleagues including me find the aircraft a challenge to land. As You say, the engines move a bit of air and much of the wing is in the props slipstream, so any power change in flare will have a direct effect on sink rate. Additionally, the landing gear is very unforgiving of crabbed touchdowns; if the aircraft is only a tiny bit misaligned with the runway, it will easily result in a major impact. On top of that, an approach with Flaps 15 will normally see a pitch slightly above 0°, and to avoid the rear fuselage scraping the runway, flaring is limited to 5° nose up. This together results in a not too wide window of pitch, power setting and airspeed that has to be hit for a reasonable landing. QAR readouts in my company on the other hand show that while a normal landing may feel bumpy inside the aircraft, the G load experienced is noticeably less than on other fleets.
Just to make sure though - what I just wrote should in no way be construed as alarming or unsafe; while a normal DH8-400 landing might bruise the pilots ego a bit occasionally, it is nowhere even near to a close call and I am not aware of any -400 that was damaged due to a badly executed landing.
Another thing is the flap setting You mentioned. Flap 35° approaches come both with a remarkable nose-down pitch and a rather unpleasant airframe buffet caused by some degree of flow separation ahead of the flaps trailing edge - in rain, You will see flowing some water forward from the upper trailing edge on that flap setting. So unless performance requires such a configuration, it is generally not preferred.
Coming back to the engines. As they are way more powerful than those on the -300, they have some potential to cause an uncomfortable ride if they are handled by some ham-fisted guy. Just like in a Cessna, the prop comes with all the associated effects like P-factor, torque, gyroscopic effects etc, so any power change will require trim changes about all 3 axes; WAY more so than on the -300. If a large power change is required, it is thoroughly recommended to do it in steps (if practical, of course): move the power levers a bit, then readjust trim, then move the power levers another bit and so on; otherwise this will cause an immense yawing moment in the aircraft. While pitch trim and aileron trim changes are noticeable in the flight deck, the passenger comfort is mostly influenced by those yaws.
But just to be sure again: While this type has its weak sides (just like any other aircraft I have gotten to know until today), I find the -400 a rather agreeable aircraft to fly, with as You say remarkable performance rather comparable to a jet than a turboprop.
Join Date: Feb 2009
Location: Australia
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
I've flown as SLF a lot on QantasLink's Dash 8 fleet. In my experience, the 400 rides more smoothly in the air and through turbulence than the 300 and 200, which seem to get tossed around a bit more, being so much lighter.
On my flights with QF, the approaches seem pretty stable, but the landings always seem harder than on the smaller series (save YLHI where they slam it onto the deck!), I've had a few fairly exciting ones.
On my flights with QF, the approaches seem pretty stable, but the landings always seem harder than on the smaller series (save YLHI where they slam it onto the deck!), I've had a few fairly exciting ones.
