ISA +35 in DEN

[asayankee]

Isn't ISA +35 the max to fly with a deferred pack or inop APU?

Nope...For most operators >30C without APU or deferred pack is "not normally dispatched". ISA +35C is an actual aircraft limitation for T/O.

 

[Abernathy]

Isn't ISA +35 the max to fly with a deferred pack or inop APU?

That's what NOT to say when you blow that question on an oral

 

[goahead]

Isn't ISA +35 the max to fly with a deferred pack or inop APU?

Yea that's it man you got it!!!!

 

[trip]

Can anyone explain why it is ISA+35? it seems pretty standard among manufactures. If I recall in the EMB120 it was the EFIS tubes as the non-EFIS models had a higher max temp?

 

[AntiJedi]

If I recall in the EMB120 it was the EFIS tubes as the non-EFIS models had a higher max temp?

EFIS, ISA+35. Non-EFIS, +38. It has to do with the cooling of the tubes.

 

[CMRJetDriver]

EFIS tubes? ISA + 35 is a take off performance limitation. Higher altitudes and temperatures result in less wing efficiencies, longer take off rolls, etc. This limitation makes sure you can achieve the climb segments the aircraft was certified for.

 

[AntiJedi]

EFIS tubes? ISA + 35 is a take off performance limitation. Higher altitudes and temperatures result in less wing efficiencies, longer take off rolls, etc. This limitation makes sure you can achieve the climb segments the aircraft was certified for.

Thanks for the lesson, professor. I meant exactly what I said.

 

[dustrpilot]

Or maybe aircraft manufactures say ISA +35 is too frikking hot to test in, so no data above that temp?

 

[Mr. Johnson]

What is the high-end on Boeing equipment? Does Southwest ever shut down operations in PHX? How the rampers handle that kind of heat is beyond me...

 

[IBNAV8R]

Standard Dry adiabatic lapse rate is -1.98C per 1,000'. The ISA temp at KDEN is 4.23 degrees C. Therefore, the OAT limitation is closer to 39C. If you're operating at DEN at 40C, you're already outside the manufacturer's limitations.

 

[urflyingme?!]

-40C is not a hard number for the RJ. That's bulk fuel temp. I've flown -65C before. We lived. Dont ever trust a dispatcher.

 

[drinksonme]

What is the high-end on Boeing equipment? Does Southwest ever shut down operations in PHX? How the rampers handle that kind of heat is beyond me...

Not sure what Boeing or Airbus (remember US Airways is there too) is, but consider the lapse rate and ISA for PHX.....temp would have to be about 48*C in PHX for the RJ's not to be able to operate. 118*F. Elevation is a killer in DEN.

I do know that US Airways did stop operations during the day some years ago due to extreme temps. They actually had no data above 120*F to reference in their manuals for the Airbus.

 

[Flying Illini]

-40C is not a hard number for the RJ. That's bulk fuel temp. I've flown -65C before. We lived. Dont ever trust a dispatcher.

You should either clarify your statement or stop telling people your tale altogether. Keep in mind, this thread is discussing the TAKEOFF temp limits of the CRJ.

From the CRJ-200 PRM Vol 2: "Minimum ambient temperature approved for takeoff is -40*C (-40*F)."

The same temp limit applies to starting a cold-soaked APU on the ground.

Now let's visit the "bulk fuel temp" limits: "Takeoff with the bulk fuel temperature indications below the limits stated is prohibited.
Bulk Fuel Takeoff Limit-Minimum Temperature (ASTM D1655, Jet A): -30*C.
Bulk Fuel Freezing Point (ASTM D1655, Jet A): -40*C.

During flight, bulk fuel temperature must remain above the applicable bulk fuel freezing point."

So, in relation to what the OP posted, -40* actually IS a hard number for departures in the CRJ.


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[homerjdispatch]

you should either clarify your statement or stop telling people your tale altogether. Keep in mind, this thread is discussing the takeoff temp limits of the crj.

From the crj-200 prm vol 2: "minimum ambient temperature approved for takeoff is -40*c (-40*f)."

the same temp limit applies to starting a cold-soaked apu on the ground.

Now let's visit the "bulk fuel temp" limits: "takeoff with the bulk fuel temperature indications below the limits stated is prohibited.
Bulk fuel takeoff limit-minimum temperature (astm d1655, jet a): -30*c.
Bulk fuel freezing point (astm d1655, jet a): -40*c.

During flight, bulk fuel temperature must remain above the applicable bulk fuel freezing point."

so, in relation to what the op posted, -40* actually is a hard number for departures in the crj.


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pwned!!!!

 

[nerjdriver]

Dispatch says +40, so it must be OK.

+39C OAT corresponds to ISA +35 at a pressure altitude of 5500