Max operating temperature for airplane

NoHeat

NoHeat

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NoHeat said:
In the news today, AA cancelled 40 flights from Phoenix because it was hotter than the 118 degree maximum operating temperature for the Bombardier CRJ.

The article in the newspaper said Boeings have a max 126 F, and Airbus 127 F.

http://www.azcentral.com/story/travel/airlines/2017/06/19/heat-cancels-phoenix-flights/409634001/

I'm wondering why temperature limits, and not just a limit on density altitude?
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Because the airline didn't pay for the extended operating temperature range chart.
 
My iphone locked up and overheated at 100 degrees at the lake last weekend. Maybe the plane locks up at 118?
 
NoHeat said:
In the news today, AA cancelled 40 flights from Phoenix because it was hotter than the 118 degree maximum operating temperature for the Bombardier CRJ.

The article in the newspaper said Boeings have a max 126 F, and Airbus 127 F.

http://www.azcentral.com/story/travel/airlines/2017/06/19/heat-cancels-phoenix-flights/409634001/

I'm wondering why temperature limits, and not just a limit on density altitude?
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Temp limits are density altitude limits. Temp limits are also weight limits.
Don't know about the airbuses but small composites such as the Jabiru have temp limits also, possible delamination of the composite.
 
pigpenracing said:
My iphone locked up and overheated at 100 degrees at the lake last weekend. Maybe the plane locks up at 118?
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Good point. For avionics, a temperature limit actually would make sense. Otherwise electronic components can fail from heat.

For takeoff, on the other hand, I don't see why temperature matters, by itself. Why a max operating temp that depends only on brand? Density altitude, in combination with runway length, seems more relevant.
 
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murphey said:
small composites such as the Jabiru have temp limits also, possible delamination of the composite.
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That would make sense, for an absolute limit on temperature.

It can't be what Bombardier had in mind, though, right?
 
If the OAT exceeds the top limit of the temp charts, then you're literally in uncharted territory. Part 121 operations do not operate without take off numbers, if the manufacture only provides numbers up to a certain limit and the OAT exceeds that temp, then you're stuck on the ground.
Temps, weights, runway lengths and altitudes are always calculated in every single TO.
 
AKBill said:
Bet Bombardier does not sell many CRJ jets to the middle east ... ;)
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I lived in Dubai for there years and most flights are at night. 2am is super busy there. I have only had one out of maybe 30 flights be during daylight.
 
54 C is the common temp limit for jets and is a number the manufacturer used as a limit. Yes, you can get the performance data above that but frankly it is too expensive for the relatively rare instances it is needed.

I fly in and out of Dubai regularly and have only had it factor in one time but it was due to wind patterns around the buildings and the aircraft impacting the temp sensors. 99.9% of my flights are in the daylight there as are several hundred others.
 
ircphoenix said:
Because the airline didn't pay for the extended operating temperature range chart.
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This.

It's. It the first time this has happened at PHX. Happened at least once or twice in the early 90s.

If the airline doesn't have the performance data for the temp, they can't fly. It's not like the part 91 world.
 
It happened on the day my wife and I happened to be passing through Phoenix when we were moving from California back to Texas, 1990 (June, I think); Phoeniz was at 122F, and the airlines had to have supplemental data faxed to them and added to their flight manuals (or so I understood it at the time).

My 1976 Eldorado was cool and comfortable - great AC.
 
AKBill said:
Bet Bombardier does not sell many CRJ jets to the middle east ... ;)
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Embraer sells more. The engines don't last long between shop visits in the hot and harsh environment of the middle east.

Of course, "not long" is relative. It's still several times the TBOs we deal with.

Sluggo63 said:
It's the performance data. They don't have the data to calculate takeoff speeds and weight above a certain temperature.
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Bingo! Performance data only goes so hot and so cold. When I was working turbine engines, we got requests at both ends of the spectrum. Actually we had a starting limit of something around -40C, which wasn't cold enough for some parts of Russia where some CRJs were operating.
 
All my planes have a max temperature limit for flying.
If touching the plane burns my hand, or the seat burns my butt, screw it. I go back in the FBO and get something cold to drink.
Now, if I could get a couple of "umbrella girls" to shade the plane and my esteemed person while I get in and get set, I might feel differently.

Nope.
According to my wife, who just walked past and saw this, even if I had a couple of "umbrella girls", I still wouldn't be able to fly due to my impending concussion.
 
Fearless Tower said:
If the airline doesn't have the performance data for the temp, they can't fly. It's not like the part 91 world.
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Well, even a 172 POH has a top limit on the performance charts. With a big not "no extrapolation allowed".
So I wonder, is a 91 pilot breaking the FARs if he takes off in conditions that exceed the charted data? I know we have to "familiarize myself with all takeoff and landing data" (or such) for the intended flight but cannot recall which reg (if any) prohibits us Joe Schmoes from flying in exceedance of charted performance numbers. (and yes, I am too lazy to google it right now)
 
Sluggo63 said:
It's the performance data. They don't have the data to calculate takeoff speeds and weight above a certain temperature.
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When I had the Citation, we were in Telluride one Summer, it was hot and of course high! I was fiddling with the charts and realized they didn't go to 9500 ft msl and 80 degrees. I was light on fuel, just enough plus reserves to get to my fuel stop. I had the wife and all three kids, they were 5, 7 and 12 at the time. As I was studying and trying to extrapolate the data to see if we had enough runway, a similar 550 loaded 6 people on it and blasted off. I figured they were about the same weight or higher, so we departed, it's an interesting departure down the valley until you climb above the mountains! :eek:
 
If I pass out walking from my house to my car, it is too hot to fly.

If it takes me more than 30 minutes to put on my clothes to go outside, it is tooo cold to fly.
 
has nothing to do with the airframe - all aircraft limitations are on paper. Violate them, and your azz belongs to the FAA or JAA or whomever.

The paperwork for the RJ's does not go above 118F.

The paperwork for the 737 700/800/900 series goes to 128.

And the Airbus A319/320/321 goes to 126.

It's all a dance of the balanced field length. Now you know why they have 11500' runways and are only 1100' elevation - its only 111 right now - so the DA is only 4900' . . .
 
Part 121 Rules: Performance charts cannot be extrapolated.

Therefore, if runway required @118F is 8,000 ft, and it's 119 degrees with a 12,000 runway, we all KNOW that the plane can meet performance requirements...

...but the regs say "no"....can't go.

Likewise, in meeting certification requirements, airframe manufacturers cannot extrapolate data, and must demonstrate performance at max temperature.

Bombardier didn't go through the trouble (ie: expense) of seeking out higher test temperatures (ie: flying a plane and test crew to the Mojave in August and waiting for a scorcher) because this is an isolated and rare extreme temperature, the limits of which -- in Bombardier's judgment -- would not significantly impact airplane sales or value to the customer. Boeing and Airbus sought out this certification because -- for their target customers -- this higher max operating temp matters.

The MSM is reporting this as "it's too hot for the planes to generate lift and fly". Utter nonsense.

/Max
 
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I bet the wx weenies at PHX do everything they can not to exceed the max temps in the official metar- but its ok now because AA has already canceled the RJ flights for the day -

It's like getting to -10F in Southern New England - if a flea farts the temp goes up 5 degrees. Geta slight breeze from a car going by and it shoots up to 0. It's HARD to get true extremes of temp in various climates -
 
Interesting thread....is there a min operating temp limit?

Sent from my SM-G935V using Tapatalk
 
Based on other threads over the years, I am under the impression that max temp varies by plane and airline.
Some extrapolation aspects were debated and allowed if the OpSpec gives a procedure for it. From what I recall, the margins are significantly enhanced to ensure performance.

Tim
 
Probably would have to leave too many passengers behind (due to DA) to be profitable.
 
The SR22 take off performance numbers go up to 40 C (104 F), and above that the POH says "use extreme caution as performance degrades rapidly at higher temperatures."

So not an absolute limit.
 
NoHeat said:
The SR22 take off performance numbers go up to 40 C (104 F), and above that the POH says "use extreme caution as performance degrades rapidly at higher temperatures."

So not an absolute limit.
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Does the chute have a temperature limit?
 
Clark1961 said:
Does the chute have a temperature limit?
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I don't think so.

But there might be a limit for the fiberglass. Here's what the POH says:

To ensure that the temperature of the composite structure does not
exceed 150° F (66° C), the outer surface of the airplane must be
painted in accordance with the paint colors and schemes as specified
in the Airplane Maintenance Manual.​
 
ircphoenix said:
No. But I do recall reading that performance charts for extreme temps are available for airlines that pony up extra cash for performance data.
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Well, it would only be fair, considering that the airlines try to charge passengers separately for every peanut, that their supplier should charge them separately for every datum.
 
DesertNomad said:
I lived in Dubai for there years and most flights are at night. 2am is super busy there. I have only had one out of maybe 30 flights be during daylight.
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Hehehe. One of my apartments was in Mirdiff, right under final approach to 30L (literally, if you were to spit, it would have hit me). An arrival every two minutes, all night long. Try sleeping through that.

A buddy of mine flies for Emirates. He tells me that the airport is a ghost town in the afternoon.
As an aside, he also said that Boeing tends to understate their aircraft. It will do what the manual says and more.
 
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