Was reading a bit online about aircraft not being allowed to fly because the air temperature was too high.

Do any of the current simulators model this phenomena?

Too hot  to think...

Why not try for yourself.

pick an aircraft you can fly reasonably well. the c150 will be a good one if you do not have a preference.

Select an airport with an altitude of say 8000 ft

set the temperature to say 5 degrees c

test and see your take off distance

repeat several times increasing the temp by 5 degrees each time until you  need full runway length.  no need to  spill any blood.

You will find that all the sims will be affected.

once you have done this try again with temperature at say what gave you midfield take off above and change the pressure 

This is an important thing to understand when flying in high altitude and or high temperature conditions.

 

Edited July 14, 20223 yr by harrry

57 minutes ago, harrry said:

Why not try for yourself.

pick an aircraft you can fly reasonably well. the c150 will be a good one if you do not have a preference.

Select an airport with an altitude of say 8000 ft

set the temperature to say 5 degrees c

test and see your take off distance

repeat several times increasing the temp by 5 degrees each time until you  need full runway length.  no need to  spill any blood.

You will find that all the sims will be affected.

once you have done this try again with temperature at say what gave you midfield take off above and change the pressure 

This is an important thing to understand when flying in high altitude and or high temperature conditions.

 

This is also the reason historical weather is so important to some users as I have come to understand.  For example the Newark to Tel Aviv flight is actually delayed or weight limited on very hot days due to takeoff performance.  The daytime flight will be delayed in that instance the evening flight in cooler weather conditions will get out on time.  

So having that historical weather capability to fly at anytime in the sim but have the conditions match daytime is critical to it's impact on aircraft performance.  

And yes in P3D and other sims your takeoff roll will be significantly impacted by the two different weather conditions and your Takeoff Power settings will probably be different as well.  

For me personally I will just fly with Live Real Time weather but you can see above how having historical weather can also impact what happens in the sim. 

8 hours ago, B7X7-900 said:

Was reading a bit online about aircraft not being allowed to fly because the air temperature was too high.

Do any of the current simulators model this phenomena?

From 12 years in ops/crew sched/crewing, I can tell you the crew sickness and fatigue levels also go up when the weather is nice. Especially on Bank Holidays..... Who'd of thought.. 

Great question, I have been in some "too hot to fly" situations and I can give you some examples and how they are resolved. This issue is usually based on aircraft environmental limits or an aircraft system's technical limit. For environmental limits, properly coded flight dynamics would capture this, but most of these limits are caught during planning. The system limitations could be captured if coders code it in. In my examples, you will get an idea of what those limits would look like.

The first environmental limits I have experienced was in the KC10A/DC1030. The max environmental temp is 50C. During early operations in the Mid East, there were times jets departed and on return the temps would be just over 50C. Due to this situation, Micky D raised the max temp for go around to 55C. There have been numerous times where I would have to depart out of places at night because the temp is over 50C or the temp was high enough to limit my takeoff weight. During planning, you would make schedule changes based on the foretasted temps during your trip. Now in the real world, departing under these conditions means you may not achieve charted performance due to the thrust break of the engines. In flight sim, it depends on the coding of the FDE. But, you would not depart under those situations anyway since you adhere to limitations.

Here are some system limits that you may face on too hot to fly days. I had this one issue where one of my IRSs was over heating in South America. I had two, but needed them both operational for my extended over water flight back home. After about 10 to 15 minutes of it being aligned, the overheat light would illuminate and we would have to shut it down. In that situation, I elected to leave that IRS off until 5 minutes before departure. We aligned it near the runway and departed knowing once we started climbing, the system would continue to receive cooler air flow at a higher volume. We departed without issue. Now, in a G550 in Africa and in Arizona, I received amber and red avionics overheat CAS messages. I believe these messages meant that the airflow to these avionic components was exceeding 130 to 140F. With the jet sitting out there soaking in the sun along with the heat these systems generated, no wonder. The first step in this case is to do a hangar departure or depart at night. In this situation, you may not get into problems until the systems have been running for 30 minutes. Sometimes, you just don't have the option of departing at night. In that case, you want to delay operation of these systems or delay power up. You can bring the systems up, perform the pre-flight and then shut everything back down. If it isn't too bad, you can delay the power up and preflight to 30 minutes prior to departure. Ordering a ground AC cart, closing the shades, minimizing system use and opening/pulling all avionics panels will help as well. You might also consider departing with these CAS messages, but you have to know what the temps are. Are they steady near or at the limit or are they above and increasing. The closer you are to the runway, the better. Once you depart, at 1000 to 2000ft, all lights will be off. You are cramming a large volume of air to the packs with two engines at high power vs the low volume APU supplying air to the two packs on the ground. At the end of the day, its a judgment call and a risk. You only want essential items powered up for takeoff. SAT comm, phones, WiFi and entertainment systems off! You can get that stuff powered up passing 2000ft. Boss will have to wait a few on that conference call.

In all, this could be coded by developers where systems take in account of OAT and inside temps. It would be awesome to see a smoked IRS or avionics system because you left them on for too long during too hot to fly situations.

Rick     

I appreciate all the responses and the technical bits.

In my Air Force days, I participated in an exercise in Egypt In July. When it was time to leave, we boarded an old stretch 8. As we were getting on fuel was being pumped out. So I was told anyway. Our take off roll seemed to go on forever and the airplane seemed reluctant to lift.  I was told later by people who were still on the ground that they weren't sure we were going to lift off.

 

12 hours ago, B7X7-900 said:

Was reading a bit online about aircraft not being allowed to fly because the air temperature was too high.

Do any of the current simulators model this phenomena?

If you get one of the Helicopters in DCS, you will really notice this phenomenon is modelled in the sim and how hard it can make things, which of course is also the case in real life. In DCS there is a mission for the UH-1 Huey which involves doing a rescue mission up into the mountains, where of course the air density is reduced at altitude and the chopper has real problems ascending and hovering.

This was a real problem for the Huey in SE Asia during the Vietnam War, and indeed more recently in the Gulf War, where the high temperatures sometimes means they can't always carry a large number of fully equipped troops, even though they have the volume to physically fit them in, and so they have to resort to shuttling troops into the patrol area in smaller numbers, with several round trips. The Viet Cong and the North Vietnamese Army were well aware of this and would often attack the smaller first wave of troops with added fervour, and close to very near attack range, knowing it would be a while before they had some support from larger numbers and being aware that when in close contact, there would be little chance of additional artillery or airborne support strikes being able to be called upon to keep the enemy back.

Of course the other problem with this, was that the NVA and VC would also know that those choppers were coming back and they would almost certainly be landing in the exact-same LZ, at the exact same place, which meant they could get very well-prepared for shooting at the things whilst they were slow and vulnerable, knowing exactly where to set up the sight lines for their guns. More savvy chopper pilots would come in a different way to the LZ the second time around, but this wasn't always possible, so it was a risky aspect of airmobile operations to be landing where you knew the enemy knew exactly where you were going to touch down, and certainly made worse by high temperatures.

Edited July 14, 20223 yr by Chock

It happened to us in a Republic Seabee.

When I was learning to fly the Luscombe on floats they had two Republic Seabees there.  They used to fly charters to either Clear Lake or Lake Tahoe.

My flight instructor was going to take a customer on a flight to Lake Tahoe when I had just returned from a solo cross country.  He asked if I wanted to go along.  Of course I did.

It was an uneventful flight to Tahoe and we let the passenger off at Homewood.

But it was very hot that day and Tahoe sits at an altitude of over 7,000 feet.  The Seabee just wouldn't leave the water.

We had to stay at Tahoe overnight and fly back to Commodore early the next morning.  That adventure made density altitude stick in my mind forever.  I've always been very aware of it.

Noel

 

Yes, Density Altitude is modeled in XP, FSX , FG, MFS,  and in  some of the air combat sims too, although not in a "fully featured" form...

It's supposed to get fine tuned in X-Plane 12 and upcoming updates of the MFS 2020 weather modeling.

One of the lacking elements is water vapour, which is not taken into consideration at present in the above mentioned sims and does play a role IRL.

 

15 hours ago, birdguy said:

The Seabee just wouldn't leave the water.

 

You'd eaten too many pies. 

These last 10 days here in Florida it's been too hot to even walk. Never mind flying.

17 hours ago, jcomm said:

Yes, Density Altitude is modeled in XP, FSX , FG, MFS,  and in  some of the air combat sims too, although not in a "fully featured" form...

It's supposed to get fine tuned in X-Plane 12 and upcoming updates of the MFS 2020 weather modeling.

One of the lacking elements is water vapour, which is not taken into consideration at present in the above mentioned sims and does play a role IRL.

 

Atmospheric water is something I hope becomes the next leap forward in environment modeling.