All posts tagged 'weather'

Why Aircraft Engines Thrive in Colder Temperatures

Since day one of flight training, we have all heard pilots say that aircraft perform better when it's colder outside. 

You may have heard the term density that has to do with this factor but may have not have seen it actually broken down and explained before. So here's why:

Temperature and Density

When air is entering an aircraft engine to be mixed with fuel, it goes through the 4 phase process of "intake, compress, combust and exhaust" in order to generate power. This is the same for both jet and piston engines. 

But how much air can actually enter the air inlet in order to enter the 4 step process?

Well, the slightly better question is how many air molecules

jet engine design

As explained by BoldMethod.com, "cold air molecules move slower and collide with less energy than hot molecules, causing cold air to become denser. As temperature drops, more air molecules enter an engine, and as temperature rises, fewer air molecules enter an engine."

The more air molecules that can enter an engine, the more power/performance that can be generated, therefore cooler temperatures are more preferred. 

Density Altitude & Performance 

Since we're discussing the density of air in relation to temperature, density altitude goes hand in hand with the topic. Density altitude is altitude relative to standard atmospheric conditions at which the air density would be equal to the indicated air density at the place of observation.

Or for better terms, simply put it is the density of the air given as a height above mean sea level (MSL). 

The higher you are above sea level, the less dense the air becomes, posing the same problem: fewer air molecules entering the engine, therefore, less fuel is mixed with it and lesser power is generated. 

So if you're flying somewhere with a high field elevation such as Jackson Hole, Wyoming for example, and you're taking off in the afternoon where temperatures are at their hottest, you may want to double-check performance numbers. High altitude and high temperature is the worst combination for your aircraft. 

This can even potentially stop you from being able to take off, where your only option is to wait out the temperature until the sun goes down and air cools off again. 

So, if you've been flying and curious why your plane seems more sluggish than a few months ago, now you know! Airplanes like the cold!

questions or comments? Write us below. 

5 More Things ATC Wants You to Know

2 weeks ago we discussed the topic of tips from ATC. After surveying some air traffic controllers, they provided advice for talking on the radios and things they really dislike that pilots do.

Well, the feedback on this was so good I mentioned doing part two. So here it is! 

cockpit

1) Emergency

If you're ever in distress for any reason, tell your controller. They can't help if they don't know what's going on. Maybe you have an electrical issue and are having to pop some circuit breakers before you get to the next assigned task or it's as drastic as losing an engine. But whatever the reason, even if it's not yet a full-blown emergency and you need some assistance from ATC, don't be afraid to just let them know.

Sky

2) Pop Up IFR

If you need a pop-up IFR, also sometimes referred to as a local IFR request, just ask for it. Some pilots will advise never to do that because it adds extra workload to controllers having to take that information from you, put it in the system then give you clearance. Sure, it does take a little extra time to do that work, but if you think it'll jeopardize safety, then do it. ATC would rather take the time to give you that clearance than you try and stay VFR and get into trouble. It truly only takes a few extra steps and if they aren't busy it isn't that big of a deal. Just have required information ready to read off such as name, phone number, the color of your aircraft, souls on board, fuel remaining, etc.

3) Request on Check In

When you're en-route and have a switch off between frequencies, most pilots' first instinct is to check in and advise of any requests they want then and there. "Center N224JW flight level 320 requesting direct destination."

Believe it or not, in most cases on that first initial check in with the new frequency, you're likely still in the last sector's airspace. This means for your new controller, most requests have to be called in and coordinated before authorizing it. So if you check in, it's busy, and you want to help ATC out, wait a minute or two before calling back if the request isn't urgent and you're more likely to get it off the bat.

4) Approach Check In

Another check in tip! When you're checking in with approach, try and give them all the required information you know they'll ask for so they don't have to play 20 questions. "Approach, N10JM 17,000 descending via the GESSNER4 arrival, information foxtrot for ILS 13R." 

Here they don't need to ask if you've gotten the ATIS and they know what approach you're wanting so they can be ready for it. 

5) Expedite

If a controller asks you to expedite through an altitude and report your current level, they actually needed that like 5 seconds ago. Don't delay on the expedite or reading it back to them. Seems simple but the issue occurs pretty commonly and this is where both teams need to work together.

This concludes just about all of the main talking points that were sent in. If you have any questions for ATC, things you as a controller would like to add, or questions/comments in general, comment below or send it in to us! 

 

Understanding Thunderstorms & How to Fly Around Them

There's no doubt about it, thunderstorms are a big threat to aviators. Next to hurricanes and tornadoes, they can seem as if they're the lesser issue to worry about of these. Pictured below is a photo of one of the planes out of KLCH after Hurricane Laura hit last month. Flying into or near a thunderstorm can actually be just as devastating. 

-A side note, Lake Charles has faced a lot of devastation in the aftermath of the storm. Not pictured was a PC 12 that was upside down and absolutely destroyed. Almost all of the hangars were taken out and the airport had a lot of wreckage left behind. If there is any way you can help the locals there by donating supplies or evening bringing hot meals it is much appreciated. We flew supplies over as a relief effort and some lost everything, even now people there are looking at weeks without power.

However, we face thunderstorms more commonly than other types of dangerous weather phenomena, so let's talk about them.