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a330pilotcanada
27th Sep 2012, 17:04
Good Afternoon All:

A question for the Q-400 crowd.

Does the Q-400 have a more lively rotation rate at aft c of g low weights with quartering cross wind?

Does any one have more information to expand on this incident?

There was no date given on the TSB daily summary for this incident

Aircraft Information:

Registration: C-GLQG Operator: PORTER AIRLINES INC.
Manufacturer: DE HAVILLAND Operator Type: COMMERCIAL
Model: DHC-8-400 CARs Info: 705 - AIRLINER
Injuries: Fatal: 0 Serious: 0 Minor: 0 None: 32 Unknown: 0

Occurrence Summary:
A12O0156: The Porter Airlines DHC-8-400 (registration C-GLQG, flight number 574) was departing from Windsor, Ontario when a tail strike occurred during takeoff. Because the flight crew was unaware, the flight continued to its destination where it landed without further incident. As the flight crew suspected a bird strike, a post flight inspection was completed when the damage was located. The underside of the aircraft, aft of the pressure bulkhead and tail strike sensor was damaged. The operator is currently assessing the damage. The TSB deployed two investigators.

pcm
29th Sep 2012, 00:56
I've sat in the back of several Porter flights. This is no slight on the company or the service but someone needs to teach them normal rotation rates. You don't need to instantly go from the ground to being airborne.

+TSRA
30th Sep 2012, 00:25
So pcm - you've flown the Q400 from the front and know how much pitch it takes to maintain the V2 speed to the engine out altitude, and how much of a rotation rate it requires to ensure that you do not blow through this speed?

To give you a relative idea, the 100 series Dash 8, which is underpowered compared to her younger sisters, requires (with 5 degree of flap and 90% torque) a pitch from rotation to approximately 13 to 15 degrees in 3 to 5 seconds to maintain the V2 speed - any slower and you'll easily be 15 to 20 knots faster. It is an AFM requirement to maintain V2 or V2+10, operators choice, to 400 feet. I personally prefer V2 - a little more uncomfortable for the passengers, but a whole lot more comfortable for the pilots if an engine quits because of the extra altitude you have.

The Porter guys and gals know what they're doing. I've had a chance to sit in on one of their sim sessions while I was down for my own recurrent training - I've never seen a more anal bunch of pilots in my life, so don't think for a second that what they are doing is in anyway "abnormal." Quite the opposite from what I saw.

tbaylx
30th Sep 2012, 14:52
3-5 seconds is a long time...i've seen many guys at several airlines that are fine pilots but have never been taught correct rotation rates.

If they had taken 3-5 seconds to reach desired pitch attitude then they wouldn't have had a tail strike no?

J.O.
1st Oct 2012, 10:42
Admittedly I am not a Q400 expert but why would you need to maintain V2 speed to the EO altitude in a normal 2 engine condition?

Single engine climb performance is predicated on the engine failing after V1 when the aircraft is still on the ground (or just lifting off). During a normal takeoff with 2 engines, there is extra energy available for the climb. This energy typically turns into extra airspeed - i.e. energy - that will help the airplane to climb if an engine fails after liftoff. I've watched and conducted thousands of normal takeoffs in my career, all of them on 2 engines, and I have never seen an intentional effort to maintain V2 all the way to the EO altitude. Even more disconcerting, I have never seen an SOP that requires pilots to conduct the takeoff with a rotation rate that raises the risk of a tail strike in an effort to maintain a speed that you don't need to maintain in a 2 engine condition.

tbaylx
1st Oct 2012, 16:25
It's normal ops to maintain v2 -v2+15 until on many transport category aircraft until end of second segment climb at the very least, often to S/E flap retraction altitude.

The point is you don't have to over rotate an aircraft to do it, regardless of the type. 3 degrees/sec is more than enough assuming you don't pause the rotation and continue to pitch to your climb attitude. In a jet that can be almost 30 degrees nose up.

If you tail strike an aircraft you have either rotated at an incorrect Vr speed that is too low, or you are rotating at too quickly a pitch rate. It should be a nice smooth slow pull right into the climb attitude.

Jetgate
4th Oct 2012, 00:10
You don't fly this aircraft at V2 or anywhere near it if both engines are operating!

I will now on be referring to NORMAL 2 engine operations of the Q400 -

It is operated in pitch until the Acceleration Altitude (AA).

If you went V2 or near V2 up to the AA on two engines with moderate loads in busy Terminal areas in the Northern Hemisphere you will scare everybody including your self.........

(The AA can be varied, manufacturer recommends 400'' but up to 1200'' is approved if memory serves me?. I know of one company that uses 800'' but majority fly pitch to 1000'' as it keeps everything in manageble proportions. Also if we do have to deviate and talk about single engine then neither is it operated on the prescribed Turboprop climb profile of 5 (FIVE) segments. It is flown like a Jet on a 4 segment profile.)

Now, these are my employers SOP's devised after many years of operating this machine. Close to the manufacturers AOM on most but refined to suit our needs. This perticular manufacturers advice sometimes beggars belief.....so we try and put some common sense in to it.

From what I've heard this perticular incident was influenced by a bunch of our featherd friends.....

Latte tester
8th Oct 2012, 12:17
+TSRA...remind me not to fly on anything that you are in command of...

So what you're trying to say that if you rotate rapidly to V2 you personally feel comfortable with no concern for the people in the back who are basically paying you...
Explain to me just how much airspeed you lose if you experience an engine failure at V2 before you are under control, better still, how aggressive would your push be to get the nose down to maintain that V2 that you seem to love to fly?

altiplano
9th Oct 2012, 01:15
A manager at Porter wants the guys to go from runway to 10 degrees now on rotation. Some guys in the training dept with their heads up their asses go right along with it. They even put out a bulletin on it.

It is not normal.

A lot of guy on the line know better and fly a typical rotation rate but a lot are right into the idea that this should be done and go out there throwing 10+ degree per second rotation... and this is what Porter management wants. Tail strike was a matter of time...

FlexibleResponse
12th Oct 2012, 13:50
With an engine failure just after V1, the correct rotation rate will achieve the engine inop target pitch attitude at a speed of V2.

Therefore that correct rotation rate with all engines operating will achieve a speed of greater than V2 passing the engine inop target attitude, due to the greater acceleration of having all engines operating.

QED...

Even a Manager could understand that logic..?

FWs and aviation don't mix...but unfortunately, they persist.