Current hot condition

adam88

Can anyone tell me how this hot weather affects landings takeoffs and getenersl route planning. ?

BZ

adam88 wrote: »

Can anyone tell me how this hot weather affects landings takeoffs and getenersl route planning. ?

Heard on Shannon ATC before 2pm today that water had been sprayed on the runway and the surface temperature was 47 degrees celsius.

bkehoe

In general very little, these are normal temperatures operated in by European airlines and pilots daily. Engines such as those on the 737 can deliver full rated thrust up to 30 degrees but its extremely rare to actually need full thrust for takeoff anyway. An aircrafts true airspeed (and therefore groundspeed) would be slightly higher due to the hot air but that wouldn't make a significant impact on operations in most airports. If you're talking very hot weather such as over 40 degrees and high elevation (such as Madrid at 2000ft or Johannesburg at 5500ft) then things can become more interesting.

In practice the only consideration if its 30 degrees vs 15 degrees outside is ensuring passenger comfort with air conditioning on the turnaround.

kub

BZ wrote: »

Heard on Shannon ATC before 2pm today that water had been sprayed on the runway and the surface temperature was 47 degrees celsius.

I now know why runways are usually concrete rather than tarmac, considering the state of some of the roads from the heat.

kub

kub wrote: »

I now know why runways are usually concrete rather than tarmac, considering the state of some of the roads from the heat.

The roads are having issues due to the cheap method the councils used to lay them. They spray on a thin layer of bitumin and then top that with aggregate and roll it. This is far cheaper and quicker than laying a new tarmac road surface.

The side effect though is it tends to react poorly to hot weather and the Bitumin will soften and when vehicles drive over it it obviously ripples. This is very common and doesn’t necessarily need these high temps to happen.

Runways will be made out of far higher spec material that will have a higher “melting” point for want of a better word.

The vast majority of runways that I am aware of are made from asphalt not concrete.

adam88

adam88 wrote: »

Can anyone tell me how this hot weather affects landings takeoffs and getenersl route planning. ?

Zero affect on routes, it’s just a bit sunny that’s all. This isn’t unusual weather.

Slightly faster approach speeds, slightly longer landing distance.

Aircraft climb performance is poorer as air gets less dense when hotter so more runway required and climb rate is reduced.

Every pilot will see this regularly across Europe, this is just slightly unusual to have an actual summer season in Ireland.

Pat Dunne

Deleted User wrote: »

This isn’t unusual weather.

Would you get out of it! :eek: I don't remember anything like this in Ireland, since the mid 1970's

Gaoth Laidir

The density altitude at Shannon (8 ft amsl) when it was 32 degrees and dewpoint 10 yesterday was 1750 ft. Air density was 5% less than what it would have been if the temperature was only 15 degrees. 5% less density means 5% higher takeoff groundspeed, 5% more runway, 5% less climbe-rate.

Pat Dunne

Pat Dunne wrote: »

Would you get out of it! :eek: I don't remember anything like this in Ireland, since the mid 1970's

Tut tut selective quoting Pat “Every pilot will see this regularly across Europe, this is just slightly unusual to have an actual summer season in Ireland.”

The one you quoted is a general quote about the weather where as I specifically state it is slightly unusual to get it here later on in that post.

I still think it’s great that this year we’ve had proper snow and a proper summer aka seasons. I guess we are too used to cold rain and then warm rain seasons.

smurfjed

This is hot weather



The interesting figure here is the ISA Deviation, we are certified to ISA+35, so 2 more degrees and we are grounded, same value applies to Bombardier CRJS, most other manufacturers certified their aircraft to ISA+39 or 39.4. However the majority of engines are certified to ISA+15 for Flat Rating Thrust (Maximum) with the exception of the Rolls Trent which is certified to ISA+22. This means that in Dublin the engine will deliver maximum thrust up until 30C, after that the thrust output will diminish and the aircraft performance will suffer. You might see the super long flights from Dublin start to suffer if the temperatures get significantly above 30C.

Pat Dunne

Deleted User wrote: »

Tut tut selective quoting Pat “Every pilot will see this regularly across Europe, this is just slightly unusual to have an actual summer season in Ireland.”

The one you quoted is a general quote about the weather where as I specifically state it is slightly unusual to get it here later on in that post.

I still think it’s great that this year we’ve had proper snow and a proper summer aka seasons. I guess we are too used to cold rain and then warm rain seasons.

Memo to GVHOT
Please note that the emojies used in my post, denoted "humour and mirth". If you have any difficulties understanding these words, please consult with your nearest dictionary to obtain their meaning.
Or as we would say in my part of Dublin, "t was a joke Pal, a bleedin joke"! :P

Pat Dunne

Pat Dunne wrote: »

Memo to GVHOT
Please note that the emojies used in my post, denoted "humour and mirth". If you have any difficulties understanding these words, please consult with your nearest dictionary to obtain their meaning.
Or as we would say in my part of Dublin, "t was a joke Pal, a bleedin joke"! :P

Memo to Pat, that was exactly the way I took it pal.

andy_g

Pat Dunne wrote: »

Memo to GVHOT
Please note that the emojies used in my post, denoted "humour and mirth". If you have any difficulties understanding these words, please consult with your nearest dictionary to obtain their meaning.
Or as we would say in my part of Dublin, "t was a joke Pal, a bleedin joke"! :P

Deleted User wrote: »

Memo to Pat, that was exactly the way I took it pal.

Ah here buds leave it out.

Ok where did my mod hammer go :P may i have it back please

newcavanman

Deleted User wrote: »

The roads are having issues due to the cheap method the councils used to lay them. They spray on a thin layer of bitumin and then top that with aggregate and roll it. This is far cheaper and quicker than laying a new tarmac road surface.

The side effect though is it tends to react poorly to hot weather and the Bitumin will soften and when vehicles drive over it it obviously ripples. This is very common and doesn’t necessarily need these high temps to happen.

Runways will be made out of far higher spec material that will have a higher “melting” point for want of a better word.

The vast majority of runways that I am aware of are made from asphalt not concrete.

There were surface dressing trucks out in Cavan yesterday. Im guessing, they reckon with the tar so soft, if they spead some dressing, then normal traffic will roll it in and they can save the cost of bitumen