Cold snap grounds AC flights to/from Yellowknife

[lucky37]

http://www.cbc.ca/canada/north/story/20 ... -jazz.html

Cold snap grounds Air Canada flights to and from Yellowknife
Last Updated: Tuesday, January 29, 2008 | 6:05 PM CT
CBC News

All Air Canada Jazz flights in and out of Yellowknife have been cancelled since Sunday, due to the current cold spell that has kept temperatures in the minus-forties.

A spokesperson for the airline told CBC News on Tuesday that the Bombardier regional jets used on Jazz flights to and from the Northwest Territories' capital are not certified to operate at or below –40 C.

Beginning late Saturday, a cold snap sent temperatures plunging below –30 and –40 throughout much of northern Canada, including all of the Northwest Territories.

Daytime temperatures in Yellowknife reached a high of –37 on Tuesday afternoon. Forecasters expected it to dip to –43 overnight. Environment Canada is forecasting much of the same for the rest of this week.

Details of the cancelled flights were not listed on Air Canada's website on Tuesday.

In the afternoon, passengers waited in line, hoping to rebook on Canadian North or First Air flights that are scheduled to travel south on Wednesday.

"When it was cancelled on Sunday, I phoned somebody instead of standing in line and they rescheduled me for the flight on Monday," Edmonton-based traveller Mike Hing said.

"When I saw online that it was cancelled on Monday, so they rescheduled me again for today and then I came here in line today and now they're putting me on Canadian North tomorrow."

All of Air Tindi's flights were also cancelled Tuesday because of cold weather.

[SkyWolfe]

Never mind,

[canpilot]

I'm suprised Tindi can't operate..

Does pre-heating not work at these temperatures? (I'm not slamming Tindi here) I'm just asking an informative question..

Can anyone shed some light? Sorry, flight training units don't really teach real-world flying..

[lucky37]

I did notice a few twin otters overhead today, but didn't notice if they were Tindi's or not.

[Carrier]

There were never such delays in the days of PWA and NWT Air. The B737s and Electras worked fine in such low temps. Those airlines obviously bought aircraft that were suitable for the operating conditions all year round. Did someone at AC forget to check the conditions at places they intended to operate in before they bought their aircraft? Doh!

[auto4]

With airplanes certified under the AMA 525, if limitations specifie no ops below a certain temperature, well you 're illegall to operate below those temperature. A King Air or a TO are under AMA 523, so the approuval are way different....

[rex sterling]

I don't think Tindi cancelled flights because of the cold. It was due to the weather in YZF. Take-off minima were hard to come by for most of the day.

[brokenwing]

some flight schools teach that kind of stuff, and their instructors are actual bush pilots. they're just hard to find. then again, you get the odd person on here that gets pissed off that their plane isn't ready and prepped for them when they show up to go flying. so what can one expect.

[skycoupe]

What about an RJ that blasts off at approved temps, then climbs up to sub arctic temps.
Are they altitude limited, due to temperature?
I have seen surface at 0 and cruise at -55, so just wondering?

[flightdude1]

Don't know for sure whether it matters or not, -40 on the ground is alot denser air than -40 at 20-30,000 feet...

[C-FABH]

That's slightly funny, considering it "warm" on top when it's like -30 up there! Better than -40 down here, I guess.

And yeah, that Tindi cancelling about cold weather doesn't seem entirely right either. The ice fog had a hard time lifting in a lot of places, it wasn't gone from here until 3pm really. Sure didn't have anything moving at YZF, though.

[CID]

There were never such delays in the days of PWA and NWT Air. The B737s and Electras worked fine in such low temps. Those airlines obviously bought aircraft that were suitable for the operating conditions all year round. Did someone at AC forget to check the conditions at places they intended to operate in before they bought their aircraft? Doh!

That's not completely accurate. The 737 or the Electra for that matter don't have Canadian type certificates. They were grandfathered under policy that allowed acceptance of the FAA TC for certain US state of design aircraft.

The FAA has no standard that corresponds to the Canadian "cold soak" requirements which state:

525.1301-1 Aeroplane Operations After Ground Cold Soak

Substantiation of satisfactory operation of the aeroplane as a total system, by cold weather testing or by documented evidence of satisfactory operation at low temperature, is required after the aeroplane has experienced a prolonged exposure to ground ambient temperatures equal to or less than -35°C unless an alternative minimum ground ambient temperature has been proposed by the applicant and accepted by the Minister.

That doesn't mean that the CRJ is any less capable of operating at the same ground temperatures as a 737. Bombardier may have just only tested it to -40. The Global Express was never tested to lower to -30 and has a corresponding limitation.

The 737 was never subject to complying with that standard. If it was, chances are it wouldn't have an unlimited ground operating temperature.

That's slightly funny, considering it "warm" on top when it's like -30 up there! Better than -40 down here, I guess.

Again, it has to do with ground temperature after cold soak. A much different scenario that a normal cycle.

With airplanes certified under the AMA 525, if limitations specifie no ops below a certain temperature, well you 're illegall to operate below those temperature. A King Air or a TO are under AMA 523, so the approuval are way different....

It's true that the cold soak standards doesn't apply to little airplanes (except commuter category), operators still need to publish limitations if applicable. I believe the Twin Otter is good to a ground temperature of -54 (or is that a Dash 8?). Many PT-6 equipped airplanes have a -20 to -40 oil temp limitation for starting.

Some "little" airplanes like the Piaggio P-180 had the FAR 25 cold soak standards forced on it because of novel design features and has a -30 take off limitation.

If anyone is interested, you can check the requirements for establishing the temperature limitations for large aircraft here:

http://www.tc.gc.ca/CivilAviation/certi ... 00-006.htm

[xsbank]

When the RJ went through the certification process, the coldest they could find anywhere was -40. Ergo bingo, low temperature limitation = -40.

That's it! It costs a fortune to certify or re-certify an aircraft and you can bet your *ss Bombardier ain't going to spend that dough for a few days of cold. How often does it get below -40? Not too often these days.

[Liquid Charlie]

It's simple -- the difference between "cold soaked" and being pulled out of a hanger. I'm surprised Joe isn't "soaking" jazz -- lmaooo -- for those who have never operated extremely cold soaked air planes -- -40 is the magic number -- putting rules and regulations aside -- things just simply break once it gets to "40" --
I remember trying to get a "hawker" going a -47C in YK -- we got it started after preheat but the oleos went flat -- the props leaked oil and the windscreen cracked (from preheating the cockpit) -- we went back to the hotel -- they put the airplane in the hanger and we left the next day with no issues even when it was colder than the day before. That was with a steam driven airplane -- apply that to the electronic PFM airplanes of today - electrons turn into homotrons -- they want to find a circuit to blow

[Bede]

It's not the engine temps that is the concern- they heat up, but everything else - flaps, landing gear etc.

[jspitfire]

I don't think Tindi cancelled flights because of the cold. It was due to the weather in YZF. Take-off minima were hard to come by for most of the day.

You are correct. All sched flights ended up being cancelled, but we did get a few charters out on the twotter and king air later in the afternoon.

[185/310]

xsbank wrote:

That's it! It costs a fortune to certify or re-certify an aircraft and you can bet your *ss Bombardier ain't going to spend that dough for a few days of cold. How often does it get below -40? Not too often these days.

I would hope a company like Bombardier would spend the money to cold weather test an airplane, and its gona take more then a few days. When a manufacture builds an aircraft they dont know who is planning on buying it. The company has to assume the aircraft is going to be operated in environments with cold temperatures which is alot of the world. Airbus brought there A380 to YFB, one of the new Falcon jets were cold weather tested in YFB and YRB. Im sure if you add up the amount of places in the world per year that see colder then -40C its a fair bit.

[ez4u2say]

Some info from AC

"Boeing 767s and Airbus are good to -54C on the ground. Embraers are certified for temps of -40C on the ground. In the sky they fly through much colder air. The average troposphere temperature is -56.5C.
In the air, planes can fly through lower temperatures, but there are limits, as fuel can freeze around -47C.
Flights into -65C must be limited to 90 minutes (if they encounter the limit, planes either descend or speed up, both of which increase fuel temperature)
It is even too cold for de-icing in some situations, because holdover periods (the time between deicing and takeoff) can be too short." Seems to me that the Airbus A320 was in the mid -40's on the ground based on my vague recollection...and it's getting more and more vague with time...

I can recall that the B747-200 required you to manually turn on the fuel heat (the toggle switch below the blue light on the S/O panel) for a period of time if the OAT went below a certain temp (can't recall what is was) however that is after we encountered an engine failure at altitude over the Greenland on a previous flight. This became a routine procedure after that pending the OAT.

[xsbank]

185/310, I can assure you that the certification team looked worldwide to find a place cold enough that winter. The Global was worse, something like -34 was the limit for a while - it was a mild winter. They had to spend the money to re-cert that model.

Why would you think there are max 'demonstrated' crosswind speeds that are sometimes quite low? No strong x-winds during the cert. process. The concept really isn't that difficult.

[DA900]

Hey people welcome to the north. I will tell you now it gets a lot colder then -40C. That is why First Air and Canadian North have been operating there for over 50 years. They know what they are getting into. If you want to come up to the north be prepared, and bring the right equipment.

[backon3]

It gets "alot" colder than -40 up there does it?? Whatever. I believe First Air had cold temp restrictions on the ATR's for awhile and couldn't fly sometimes. And no one should operate radials when it's colder than that either. Most people up north love going around in -40 and telling each other (especially visitors) that it's "only" minus thirty. Sooo tough.

[CID]

Im sure if you add up the amount of places in the world per year that see colder then -40C its a fair bit.

Not really actually. At least they don’t represent the majority of the market.

The Global was worse, something like -34 was the limit for a while - it was a mild winter. They had to spend the money to re-cert that model.

Nope. It was -30 and it’s still like that.

[Cat Driver]

Minus 40 is a good cut off point, but sometimes you do end up operating in colder temps due to the temp on the ground being way colder than at altitude.

Landed in Mayo one day when the temperature at 10,000 feet was around -30C and on the ground it was -64C.

And the airplane had radial engines on it.

[ragbagflyer]

Minus 40 is a good cut off point, but sometimes you do end up operating in colder temps due to the temp on the ground being way colder than at altitude.

Landed in Mayo one day when the temperature at 10,000 feet was around -30C and on the ground it was -64C.

And the airplane had radial engines on it.

Excuse my skepticism but the lowest recorded temperature ever in the Yukon, and I believe Canada for that matter was -63, in Snag on February 3rd 1947. Mayo that day was minus 62.2. This morning in Watson Lake it was -52.6. I'm glad I'm in balmy Calgary this week.

[Cat Driver]

The weather station was giving the temperature as -64 C that is what I am basing that on.

The year was 1971 as I recall.