What an idiotic thing to say....

I'm not so sure of that.

It's not arbitrary. Bombardier have said that it would be calculated nearer 10kts but for the lack of ice-protection over the leading edge area where the landing/flare lights are housed.

what are flare lights? ( flying 34 years)

Can you list a few then? Aircraft that adjust stall warning speed for ice, that is.

I can think of one other, maybe.....

Flare lights are lights that are angled upwards, so that when you flare, they still light up the runway at night, and not point upwards. The landing and flare lights are both built into the leading edge, just outside of the engines.

Flare lights
 

Found on the Dash8 series of aircraft.

Essentially a second set of landing lights (set at a different angle to the landing lights).

Hope this helps.

DIVOSH!

does the dash 8 have a stall warning system predicated on an angle of attack vane?

flare lights...thanks for sharing that. how have I landed for this long without them?

I haven't flown any planes that adjust stall warning speeds for ice...aren't pilots supposed to know that if they are iced up that you might get a stall on the early side?

over and NOT impressed with modern planes.

Yes it does.

Embraer 170/190 do, I believe. In fact, it's latched, IIRC, so you carry a "ice" adder for the rest of the flight after a detected icing encounter. (The logic presumably being that you don't know if you've shed any accreted ice, even if you have since left icing condition)

Pilots are indeed supposed to know that ice affects aircraft, but aircraft certified for flight into known icing have to be able to meet the relevant FARs with ice on the unprotected parts of the airframe. if that ice affects the stall, you have two choices basically - penalise the aircraft on every flight by assuming the ice is always present, or have some kind of switch (whether automatic or pilot activated) which adjusts the stall warning etc only after/in an icing encounter.

Originally Posted by protectthehornet http://static.pprune.org/images/buttons/viewpost.gif
I haven't flown any planes that adjust stall warning speeds for ice...aren't pilots supposed to know that if they are iced up that you might get a stall on the early side?

Fairchild / Dornier 328 series
"elevator horn heating" - when switched ON by the pilots the stick shaker / stick pusher threshold is automatically increased by DAU1 & 2 and as such displayed on the speedtape.

ATR 42 has stickshaker activation threshold lowered when flight controls heating is turned on and green icing AoA pushbutton illuminates. When aeroplane is visually confirmed to be cler of ice, icing AoA has to be pressed to reset shaker to its normal activation AoA.

A320 has no adjustments on stall protections for icing.

I find Embraer's logic a bit funny - both ATR and Q400 have probes that have no other purpose than to catch the ice (IEP on ATR, wiper spigots on Dash)and they're designed to do so with maximum efficiency. When they're clear of ice, you can be pretty certain that the rest of the airframe is clear too. Also if one is landing with oat +30° C, there's no chance of ice still clinging to plane.

Clandestino,
at least on the DH8, I found the pins on the windscreen wipers not 100% reliable. Of course, if the icing reaches a certain level of severity, both the airfoils and the pin will show ice, but below that level, I have often seen the leading edge white with ice while the pin seemed clear. Must have something to do with the different radii of the wing leading edge and the ice detection pin and the size of the droplets encountered. Additionally, the black paint on the pin tends to wear off rather quickly on the forward side and leaves a whitish surface behind. It is not always easy to distinguish between actual ice and aluminium - even more so at night. A quick glance at the wing is imho still the most efficient way of detecting ice on the DH8.

The Dash 8 Spigot.. any views?
 

What is the wiper spigot on the Dash 8 supposed to be telling the pilot?
AOM:
An ice detector spigot is installed on each windshield wiper arm for determining the amount of ice accumulation. (there are no further references)

When assessing ice accumulation for the purposes of safe operation our flight manuals don't mention the spigot. They refer to monitoring the accumulation on the wing leading edge (inboard section) only. Severe icing is defined in the manual as ice accretion on parts of the airframe where icing is not usually observed. Not the spigot then. This has been interpreted as mainly the pilots' side windows as no other 'unusual' area is visible to the crew (some have mentioned that the amount on the spinner is worth noting too).

I have been told that the spigot is there to represent the amount of ice which may be building up on the 'unprotected parts of the tailplane'. Perhaps the T horn then? Is this part critical to flight? I have flown with pilots who despite the lack of ICE DETECTED on the ED and the lack of visible ice on the leading edges insist on flying with the INCREASED REF switch (stall increment 20kts) on if there is any ice remaining on that unprotected spigot..?

I know ice is a serious issue and I operate to the letter of the AOM but three pieces of information temper my view while flying the DH8 Q400 around ice and perhaps prevent distraction by the issue:

1. The type has been demonstrated to be 'not susceptible to tail stall'.
2. The Canadian certifying authorities are rigorous in testing a type for operation in icing conditions.
3. The ice protection systems are very efficient when operated IAW the AOM.

boils down to this
 

I haven't flown any planes that adjust stall warning for icing and I flown a bunch of planes.

I can only imagine that someone familiar with a plane that can ''tailplane stall'' and getting a warning/pusher would cause that person to pull instead of push...even if the airplane they were flying couldn't tailplane stall.

And if that is the case, someone in training department has really missed the boat.

I hope someone will start a thread about poor training in the modern world of flying. Training is money driven and pilots are being taught more about the gadgets than the wing.

YIKES.

Emb 190
 

Just to clear this up a bit (sorry it's slightly off topic).

You are correct that the stall threshold is increased in icing conditions. But the speeds we fly already include the increment for icing. Effectively we always fly around at icing speeds and the only difference we see is the low speed cue slightly closer to the bugged V speeds. This is different to the Dash where the actual speeds you fly are increased when in icing.

Edit to add that I heard that Embraer do this on all their types after a fatal crash involving, I think, a Bandit although I stand to be corrected.

protectthehornet

"over and NOT impressed with modern planes."

Agreed! That would never have happened in a B707!!

weido salt
 

why are they building planes that are crap? there are great planes still flying that should be continuing off the assembly line forever.

Hearings on Crash May Focus on Pilot Conduct
 

WashingtonPost
washingtonpost.com

What a ridiculous and pointless comment!
 

protectthehornet

All types have their issues, the DH8 series of course does too. But the aircraft is quite obviously NOT crap! This incident was almost certainly an issue with the pilots and their training.

NTSB Hearings on Buffalo Crash Expected to Focus on Pilots


By Sholnn Freeman
Washington Post Staff Writer
Wednesday, May 6, 2009; 8:18 PM

The professionalism of the pilots involved in the Feb. 12 crash of a commuter airplane outside Buffalo is expected to be a key area of scrutiny at public hearings into the accident next week, according to people who have been briefed by the National Transportation Safety Board.

The safety board is also expected to examine whether the pilots were properly trained to handle the plane's emergency features. Three days of hearings are scheduled to start Tuesday.

The Buffalo crash killed 49 people on board and one person on the ground. The Newark-to-Buffalo flight was operated by Manassas-based Colgan Air, a regional carrier with links to Continental Airlines. The safety board, which is conducting a federal probe into the crash, has called the accident the deadliest U.S. transportation disaster in seven years.

According to the sources, transcripts from the cockpit voice recorders are expected to show "extensive discussion" by the two pilots -- discussions not related to flying. Those discussions could violate "sterile cockpit" rules, which seek to limit pilot talk to flying matters, particularly during certain high-risk operations. The safety board is also expected to examine issues related to crew scheduling and pilot fatigue.

The sources spoke on condition of anonymity because the formal public hearing has not yet been held. A board spokesperson declined to comment.

The board will look at the effectiveness of pilot training on the use of emergency features on the plane, a Bombardier Q400 turboprop. According to a source familiar with the direction of the NTSB's investigation, neither pilot was fully trained to use the aircraft's stall warning and protection system, which includes a feature called the "stick pusher" that automatically presses the nose of the plane down to keep it from stalling.



washingtonpost.com