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View Full Version : Prop (engine/thrust) reverse use on FlyBE Dash 8-400


ZBB757
25th Nov 2007, 17:27
Sorry may have used wrong term but not sure what its called on a turbo prop.

Last week i flew LBA - BHD with FlyBE. During taxi at both airports and on both flights i noticed that it seemed that the pilots were using reverse thrust to slow the plane down when taxiing. Is that normal?? I have flown the Dash 8 previously and not noticed this occurance.

Thanks

Paul

406pilot
26th Nov 2007, 13:44
hi

sorry dont mean to be rude to you but ive just completed a ground school course on the q300 so may be i can answer ur question correctly, wht i think u reffering to is called discing and not reverse thrust,u can slow down the dash like tht without use of brakes which as u know is always a good thing...i know u must have heard a noise tht sounded like reverse thrust when landing but discing sounds the same as in both cases the pilot changes the blade angle...

keep it up there fellows,

no more 406pilot

Pontius's Copilot
26th Nov 2007, 17:52
Correct 406, reverse thrust is not routinely used on the Q400 by flybe - nor is it required. The significant retardation effect you experienced is 'Discing', caused by selecting what on other types may be referred to as Ground Fine / Ground Idle, where the flat surface of all blades is presented to the direction of travel. Discing is used before braking to control speed on the ground.

stellair
26th Nov 2007, 18:03
AKA Beta range (beta blade angle) :ok:

barit1
26th Nov 2007, 19:16
Turboprops using short airfields often use reverse for (very effective) braking.

With a propeller it's done by actually moving the variable-pitch blades to a negative blade angle.

Turbofan blades are fixed-pitched, so for reverse thrust, the exhaust is redirected forward either by clamshell buckets, or by blocker doors and an array of vanes.

ZBB757
26th Nov 2007, 21:10
Thanks for your replies. I didnt think it was reverse thrust but I was unsure to the correct term.

It was only the 3rd and 4th flights on a turbo prop and, being more used to Jets, just wondered what it was. I love the noise made by a turbo prop, although I did notice that sat behind the engines is quite a lot noiser than in-front even with the Q400's anti noise/vibration system.

Paul

SlowAndSilly
27th Nov 2007, 09:25
The reverse on the Dash8 may also be used for "backing" on the ground if your operator allows you. This is for sure valid on the 100-300 series. Donīt know for sure on the 400?

excrab
27th Nov 2007, 15:26
S&S

Its the same but subject to a 10kt side wind limitation (can't remember what the limits were on the 200/300)

406pilot
28th Nov 2007, 13:10
hi, same limit on the 100/200/300 but use of nose wheel steering is prohibited purely because of nose wheel castoring effects after 60 degrees of travel

does anyone know where to download the best q300 cockpit photos ? wife is wondering why i gave up the 732 right seat for the dash8 left seat,wanna show her off...didnt see anything nice on airliners.net


keep it up there fellows.

no more 406pilot