Hot weather and flying

Rather than hijack Bob's thread, here's a second one for the alternative extreme.

What's the hottest temperature you'll fly in?

Last weekend I taunted some friends who fly shark patrol by waving an ice-cold bottle of water at them from the other side of the security fence as they stumbled out of a sweat-soaked Cessna 172 at 40 deg C (about 105 deg F)

I'm not a huge fan of flying when it's hot. I've observed the CHTs nudging 400F on climbout from sea level on a 36 deg C day (about 95 deg F). Easily fixed by dropping the nose a bit to increase the climb speed, or perhaps by levelling out and flying at full rich cruise power for a few minutes to let the temp come back down before resuming the climb. By the time I get above 5000' the combination of manifold pressure and adiabatic cooling basically solves the problem.

But I don't like having to solve it.

Besides that, being in a bubble canopy when it's that hot is pretty miserable at the best of times. Even when I'm up where it's cool and high, I know you'll have to get hot and low again eventually.

I'm not alone in feeling like this, right?

- mark

Mark, do you not have a Koger sunshade?

Here in Georgia it also pushes 100? and that shade is a real blessing.

Best,

I followed Rosie a couple of years ago from Carson City to Las Vegas. We were quite comfortable at 11.5 and when we tuned in the ASOS at Boulder City it reported 115F. I commented that I thought aluminum melted above 100F, I really did not want to go down. After a quick turn we departed Boulder City for southern California and climbed up to 12.5 for cooler air.

I don't remember having cooling problems during the climb. I climb full rich in the heat to help keep things cool.

From Rosie: Living in the desert, (full rich) takeoffs above 110F is normal, and I'm starting out at 2500' MSL (density altitude is >6K). My EI temp gauge alerts me at 430F to start leveling out, and I have NO problem letting the hottest cylinder see 450F for a moment in the level flight. When the highest cylinder temp is below 400F, I'll start an easy climb to altitude and also start leaning the mixture on the way up. My first-run cylinders went to 2500 hours with no complaints.

As for clothing, when it's REALLY hot, I like to wear the Lightweight, Polyester-Tricot Shirts that breath, much more comfortable than cotton

Too hot in climb

I am starting to fly the 7a higher and was surprised yesterday with CHT issues in Michigan in a climb from 5k to 11k. it was not that hot (80F on the ground) but I was only able to get 300fpm or so to keep the CHTs below 425 in the climb! I was leaning all the way up. I noticed this post, do others use full rich mixture in extended climbs? Its a Matituck O360 with CS hartzell, WOT and 2500rpm.

had no issues at all with oil temps.

zilik said:

I followed Rosie a couple of years ago from Carson City to Las Vegas. We were quite comfortable at 11.5 and when we tuned in the ASOS at Boulder City it reported 115F. I commented that I thought aluminum melted above 100F, I really did not want to go down. After a quick turn we departed Boulder City for southern California and climbed up to 12.5 for cooler air.

I don't remember having cooling problems during the climb. I climb full rich in the heat to help keep things cool.

Click to expand...

Left Parker AZ one afternoon last month and the OAT on taxi was 121F.

Not comfortable at all. It was still in the mid 80's at 9,500.

Temperature

Five summers of full time flying along the Colorado, mostly out of Lake Havasu City. Record high in Havasu is 128. The airplanes were parked outside and I figure the temp inside the airplane had to be 150 with outside temps in the mid 120's.

Flying in hot wx makes me think about this years Oshkosh. Cool wx and no flying incidents as far as I know of. Fly hot and stay hydrated. I always carry some h2o in the plane. I like those glass containers from the lemonade drink. There is always at least one full stashed along side the seat.

Bumps!

The worst part about flying in hot weather down here is the bumps. Pretty much guaranteed to take a beating down low. It really makes me think twice about taking passengers after 11 am or so.

David

Hi Mark,

Anne-Marie (my wife) and I had 57C in the cockpit flying towards Wilcannia (follow the link below to see where it is in Google maps), this was on the way to Broken Hill, I'm really not sure how accurate our cabin digital thermometer was, but OAT was 42C, and that was at 5500ft two years ago in early November.

Anne-Marie asked me to land at Wilcannia so that we could get some shade because she was starting to feel really heat stressed and that was with a sunshade fitted to the canopy.

Luckily there was a shelter at the airport and we had a couple of camel packs full of water with us that we poured over each other to cool down.

30 minutes later we where both feeling good enough to do the reminder of the flight into Broken Hill where we met some friends who collected us in an air-conditioned Holden Commodore, it never felt so good to get out of the heat before in all my life.

When we got to where we where staying we both jumped into the pool which believe it or not, felt freezing cold at 26C

My CHTs where 40F hotter than normal, but never exceeded 400F on climb out.

If you look at the map, zoom in, and you'll see the airport is 4km North of the town, we took shelter in the building south of the main runway.

https://maps.google.com.au/maps?oe=...gl=au&ei=bDcUUsrkA8O2kgXZm4DYAQ&ved=0CLcBELYD

Cheers

I used to fly my old Cherokee 140 in 110+ Texas summer heat all the time when I first bought it. Yes, it was uncomfortable, but I learned a lot about density altitude and flying an underpowered aircraft is such conditions too. I think the hottest I ever flew it in was 118 degrees at the surface. Arrived at my home airport at +6500AGL and circling down over the airport to pattern altitude was like descending into a blast furnace. Nobody else was dumb enough to be out flying that day

The hottest I've ever flown an RV was 114 at the surface, and that was the OAT here in W.Falls when coming home from Oshkosh a couple years ago. It was miserable, hot and bumpy, but still made a nice smooth wheel landing.

I don't like to intentionally go on a "pleasure flight" in an RV if the temps are over 100. Above that, it's just not fun anymore. On hot summer days, we gotta do our pleasure flying early just after sunrise and be back home on the ground by about 10:00am before the thermals get miserable.

Neal@F14 said:

I don't like to intentionally go on a "pleasure flight" in an RV if the temps are over 100. Above that, it's just not fun anymore. On hot summer days, we gotta do our pleasure flying early just after sunrise and be back home on the ground by about 10:00am before the thermals get miserable.

Click to expand...

And if traveling, just get as high as possible as quickly as possible

I used to fly 9 passengers at a time in a C-402 from Las Vegas to the Grand Canyon, shuttling tour groups back and forth and doing air tours in the very early 1990's. When the day time high said 115f it was closer to 125f on the tarmac. The poor passengers were already overheated before I could get the engines started (and we were all pretty fast at getting going, 5 to 8 planes at a time, all right after each other like a "Baa Baa Black Sheep" Squadron scramble). No air conditioning. The tires felt soft and slippery on the hot pavement during taxi and the climb out at 120kts was less than enthusiastic but at least we had ram air at 100 degrees shooting at us (that felt like a cold wind comparatively). Usually before setting takeoff power I could see the sweat soaking through my pant legs and there was just nothing you could do. I remember feeling like it was a good deal when the OAT showed 80 degrees at altitude. No way could I deal with those kinds of physioligical conditions today - no way. At 22 years old I was exhausted after a full day of flying upwards of 6 flights in heat and turbulence with no autopilot or yaw damper - 14 hour duty days, 110 hours of hard flying a month. I grew up playing competitive sports and training hard; double days in football, cross country running, track and field, soccer, working out hard in the gym between practice sessions... I knew heat and exhaustion BUT this was far more than simple fatigue.

Be careful out there on hot days. It's not just the density altitude that our engines and wings feel. It's the heat we endure and the physiology of being uncomfortable enough to subtly miss picking up on threats and not being able to actively manage hazards like we normally can. When we are hot and uncomfortable our minds are not even close to 100 percent!

no temp limitations only related heat/convective turbulence but I try to get high as quick as possible.
Hottest I flew was 112F from Llano TX. fully loaded, full fuel with 2pax, camping gear and waaay too much swag from Oshkosh. still climbed at 900fpm wot but I had to step to get altitude to keep CHT's down to acceptable temps.

Heat = thermals. More heat = better thermals. So, no limit.

Unhappy with your climb rate? Find a good thermal and enjoy a free 400+ FPM from mother nature

TODR

BillFear said:

I am starting to fly the 7a higher and was surprised yesterday with CHT issues in Michigan in a climb from 5k to 11k. it was not that hot (80F on the ground) but I was only able to get 300fpm or so to keep the CHTs below 425 in the climb! I was leaning all the way up. I noticed this post, do others use full rich mixture in extended climbs? Its a Matituck O360 with CS hartzell, WOT and 2500rpm.

had no issues at all with oil temps.

Click to expand...

Bill,
I have a box stock parallel IO-360.
Leaning is one of the last things I do on departure but I do continuously lean to the takeoff EGT temp while in the climb. I watch CHT too but it is unusual for me to have to do anything about them. I usually climb at 110 to 120 knots. I am surprised at your higher altitude story because I would have a hard time forcing my CHT out of bounds at that altitude. My only tickle with higher temps is on takeoff and initial climb (but that is only about 395F on hot summer days). My oil temps were too cold. Last winter I taped 1/2 the cooler shut. Could have gone more shut in the winter. Moved to 1/4 shut this summer (admitedly a cool season here but I think 1/4 is still right for me for any summer).


Sorry for the thread drift. In regards to hot weather, Diane and I have not really had to push the boundaries yet. I think high 90's may be the worst we have seen so far. Altitude has fixed that.

Flying back from Sun n Fun was a little rough this year, high 80's. Must say the Koger Sunshade was a big help. Seems as though no matter how cold it ets I still emerge from the cockpit quite sweaty. I'm considering purchasing a small battery operated fan and mounting it atop the fuel tank or the underside of the rollbar in our -12

117 !!!

The hottest I've ever taken off was 117 degrees. I used to fly to work often and required me to leave around 5:45 pm. (Phoenix area) Although 117 was the hottest, over 110 was quite regular.

That is why always laugh when many RV people say they won't let their CHT's get above 400. If we lived by that in AZ we would have to park our planes from May till October!!! Nice idea in theory but the reality of it is climbs will exceed 400. Transient temps and they stabilize after leveling off.

Landed at Needles CA a few weeks ago for fuel. I was bringing a Navion Rangemaster back to TX from Livermore Ca. It was 115F on the ground. The nice fellow at the FBO brought me out a bottle of water and an icecream sandwich, then fueled the plane for me. On the take off run the mirage was so bad one could barely make out the other end of the runway. Good Times!

I have an RV7A that I purchased with an Air-Flow air conditioning system installed.
The output temperature is a delta of 35 degrees. In Texas it is needed.

100 degree outside air , 75 degree from the vent

http://www.airflow-systems.com/rv-7/

BillFear said:

...I noticed this post, do others use full rich mixture in extended climbs?...

Click to expand...

I'm injected so I go LOP as a temperature control measure as soon as I get above 6500. CHT drops right away. Up to that point, I run best power EGT. If I can't get to 6500 before temps get out of hand, then I will throw more fuel at the engine, but this is rarely needed.

jgoehl said:

I have an RV7A that I purchased with an Air-Flow air conditioning system installed.
The output temperature is a delta of 35 degrees. In Texas it is needed.

100 degree outside air , 75 degree from the vent

http://www.airflow-systems.com/rv-7/

Click to expand...

How well does it work on the ground at idle speed? Is the performance noticeably better once flying?

PS: if your vent temp is 75 with 100 outside air, that's only a 25 deg delta...

Yes 25 Deg delta, Fat fingers .

That is on the ground at idle speed. (800)
In the air it gets colder ,

At 3500 with the ground temp at 98 the other day I remember that the output air was 64 deg,

Hi Eddie, let me know what you have under the cowler of your RV7 !!! I have 116ºC oil temperature with OAT of 18ºC and 53% power. If More power it will get red numbers in oil temperature. >118ºC
seems that there is two kind of RVs, the cool Rvs and the Hot RVs....

Antonio
RV7A
Portugal