[Thad E Ginathom]

firewalled throttles

This phrase gets quite a lot of use here, but even having read it a few times I still don't know what you guys mean.

A firewall is something that separates two things. A literal firewall might keep animals out of an area. A computer firewall strictly regulates what gets into (and out of) a network. So what are you separating your throttles from? Automatic control?

[Akshay1234]

Originally Posted by Thad E Ginathom

This phrase gets quite a lot of use here, but even having read it a few times I still don't know what you guys mean.

A firewall is something that separates two things. A literal firewall might keep animals out of an area. A computer firewall strictly regulates what gets into (and out of) a network. So what are you separating your throttles from? Automatic control?

When they say firewalled I think they mean they stepped on it I believe it means pushing the throttles to the max position.

[searchingheaven]

Originally Posted by Thad E Ginathom

This phrase gets quite a lot of use here, but even having read it a few times I still don't know what you guys mean.

A firewall is something that separates two things. A literal firewall might keep animals out of an area. A computer firewall strictly regulates what gets into (and out of) a network. So what are you separating your throttles from? Automatic control?

Originally Posted by Akshay1234

When they say firewalled I think they mean they stepped on it I believe it means pushing the throttles to the max position.

Copy pasted from Wikipedia.

In automotive engineering, a firewall is the part of the bodywork that separates the engine from the driver and passengers. In aviation, a firewall on an aircraft serves a similar purpose to that of a motor vehicle. In single-engine aircraft it is the part of the fuselage that separates the engine compartment from the cockpit. "Put the throttle to the firewall" refers to setting the engine to run at maximum speed.

[Thad E Ginathom]

"Put the throttle to the firewall" refers to setting the engine to run at maximum speed.

Ahh... Putting the pedal to the metal!

Got you. It looked like sheer misuse of technical term, but now I see it makes perfect, if metaphorical, sense.

Thank you

[honeybee]

I guess the throttle stick, or thrust levers, have to be pushed ahead towards the firewall to increase the thrust or the power, so firewalling the engine means pushing the thrust levers all the way till the firewall, meaning maximum thrust.

I have gone through some of the ATC communication videos on YouTube and often find pilots referring to their aircraft as "heavy". What does that mean? Also I suspect it's usually the aircraft in the air which uses this term.

[searchingheaven]

Originally Posted by honeybee

I guess the throttle stick, or thrust levers, have to be pushed ahead towards the firewall to increase the thrust or the power, so firewalling the engine means pushing the thrust levers all the way till the firewall, meaning maximum thrust.

I have gone through some of the ATC communication videos on YouTube and often find pilots referring to their aircraft as "heavy". What does that mean? Also I suspect it's usually the aircraft in the air which uses this term.

The term you heard, 'heavy' refers to the wake turbulence category of the aircraft. Wake turbulence is turbulence that forms behind an aircraft as it passes through the air, causing wingtip vortices. This turbulence is dangerous and hence aircrafts are required to be separated from each other with respect to time & distance so that these effects can be avoided. So the ICAO has divided aircrafts into 4 wake turbulence category (WTC)on the basis of the maximum certificated take-off weight, as follows:

• H (Heavy): aircraft types of 136,000 kg or more (My 777 falls into heavy with MTOW 352,000)
• M (Medium): less than 136,000 kg and more than 7,000 kg
• L (Light) aircraft types of 7,000 kg or less.
• Super Heavy: for Airbus A380-800 with a maximum take-off weight of 560 000 kg.

The separation time is defined in the following table.

[Jeroen]

Originally Posted by Thad E Ginathom

Ahh... Putting the pedal to the metal!

Got you. It looked like sheer misuse of technical term, but now I see it makes perfect, if metaphorical, sense.

Thank you

Another term you might come across is "balls to the wall". Aircraft engine throttles typically have rounded / circular endings resembling balls. Hence balls to the wall means pushing the throttles toward the (fire) wall. I believe this phrase came up during the second world war in fighter aircraft such as the Spitfire where the pilot and his instrument panels sat right behind the firewall separating them from the engine mounted up front. On some planes the throttle is just a lever sticking out of the instrument panel. You push it into the instrument panel, ie towards the fire wall, for full power.


Jeroen

Originally Posted by searchingheaven

The term you heard, 'heavy' refers to the wake turbulence category of the aircraft. Wake turbulence is turbulence that forms behind an aircraft as it passes through the air, causing wingtip vortices. This turbulence is dangerous and hence aircrafts are required to be separated from each other with respect to time & distance so that these effects can be avoided. So the ICAO has divided aircrafts into 4 wake turbulence category (WTC)on the basis of the maximum certificated take-off weight, as follows:

H]

Just to add. Wake turbulence occurs as long as the wings are producing lift. Wake turbulence effects increase at relatively low speeds, heavy aircraft in so called dirty configurations, e.g. Flaps down.

An aircraft only starts producing wake turbulence when its wing develop positive. So on take off that is more or less on rotation. On landing its when the spoilers are deployed as this dumps all lift. For pilots in small and light aircraft, such as me, it is important to try and visually locate the point where the heavier aircraft in front of you rotates or deploys its spoilers. The tower should ensure adequate separation, timing wise. But it still makes good sense to ensure you rotate well prior to the rotation point of the Boeing/airbus in front of you. The same on landing. You try and touch down past the point where the spoilers popped up.

Wake turbulence is really dangerous and big and small aircraft have met with fatal accidents by inadvertently finding themselves in wake turbulence. Especially when you are close to the ground there is very little room for recovering from a big wake turbulence upset.

Have a look at this little video.

https://youtu.be/KXlv16ETueU

Jeroen

[honeybee]

Could you explain a bit more on the departure table? Does it mean that planes have to line up with a two minute gap while departing?

On the arrival table, I see there are no limits on a heavy following a medium or light plane. Also a heavy plane following another does not need any special consideration it seems.

From this analysis, it seems the ATC have more than their hands full of managing the air traffic. Any idea what kind of systems are used worldwide for managing ATCs?

[searchingheaven]

Very sad moment. Just watched the last 747 from KLM touch down in St. Maarten's Juliana International airport(TNCM). The beach was jam packed and the ATC asked the 747 to do a low flyover over the island one last time before landing

When the flight took off for the final time from TNCM, the controller said "You will be missed" in a teary voice. Very emotional moment.

[libranof1987]

Pretty eventful day in aviation today:

The right-side engine of an American Airlines Boeing 767 failed Friday during an attempted takeoff, sending debris as far as a half mile and passengers hurriedly down emergency slides onto a runway at Chicago's O'Hare International Airport.

http://edition.cnn.com/2016/10/28/us...ent/index.html

A FedEx cargo plane caught fire on the runway at Fort Lauderdale-Hollywood International Airport on Friday afternoon, causing the airport to shut down for several hours, the Federal Aviation Administration said.

http://edition.cnn.com/2016/10/28/us...ire/index.html

[Jeroen]

Originally Posted by searchingheaven

Very sad moment. Just watched the last 747 from KLM touch down in St. Maarten's Juliana International airport(TNCM). The beach was jam packed and the ATC asked the 747 to do a low flyover over the island one last time before landing

.

Inderdaad a sad moment. KLM like most carriers is phasing out the 747. Soon you will be hard pressed to see 747's. The 747-800 is still doing ok with some recent orders.

http://www.bloomberg.com/news/articl...47-767-decline

I have probably clocked the most of my Airmiles in 747's as a passenger and in the cockpit as observer or in the simulator.
End of an era.

Jeroen

[Jeroen]

Just came across this video:

https://www.youtube.com/watch?v=q0hE...ature=youtu.be

These folding wings are for the 777X. The new updated 777 Boeing is working on. The reason for the folding wings is so it can still use the same parking spaces at the airports as the current 777.

I don’t think I’ve ever seen folding wings on commercial jets.

Here some more on the 777X in typical (PR) Boeing style, but still pretty cool:

http://www.boeing.com/commercial/777x/

Jeroen

[Rehaan]

Originally Posted by searchingheaven

Slippery runways, we use Autobrake 4 setting, which is close to max braking.

How come you use the close-to-max braking on slippery runways?

I'd imagine it would be the other way around...

[audioholic]

Originally Posted by Rehaan

How come you use the close-to-max braking on slippery runways?

I'd imagine it would be the other way around...

Max braking is set in the autobrake system. However there is also the presence of anti skid braking system which will come to play in case of a slippery runway. Hence it's like slamming the brakes all the way in a car with ABS. Excuse me for the answer since I am not a pilot and just gave a logical explanation.

I recall reading somewhere that in Airbus aircraft the autobrake levels are set for required deceleration and depending upon the situation and external factors the brakes are used. Is it the same in Boeing? What is the meaning of the levels 1, 2, and so on?

[Jeroen]

Originally Posted by audioholic

Max braking is set in the autobrake system. However there is also the presence of anti skid braking system which will come to play in case of a slippery runway. Hence it's like slamming the brakes all the way in a car with ABS. Excuse me for the answer since I am not a pilot and just gave a logical explanation.

I recall reading somewhere that in Airbus aircraft the autobrake levels are set for required deceleration and depending upon the situation and external factors the brakes are used. Is it the same in Boeing? What is the meaning of the levels 1, 2, and so on?

I’m sure Searchingheaven can add more detail to it.

Boeing aircraft such as the 777 (and the 747) have an auto brake system. It comes with different settings (e.g. 1-5). The auto brake system ensures a specific level of deceleration. In essence depending on runway length, aircraft weight and some other factors the pilots will choose and appropriate setting that will give them sufficient stopping distance for the runway length and other factors, whereas it will also be still comfortable for the passengers.

Reverse thrust has very little effect on braking distance. It means the brakes are used less. On Boeing and I believe on Airbus in order to get max braking the pilot needs to step on the brake pedals him/herself. So manual braking is slightly more powerful than the highest setting on auto brakes.

At any point in time the pilots can override the auto brake system by stepping on the brake pedals themselves.

The brake pedals are the same pedals as controls the rudder (and to some extent the nose wheel steering). Pushing the top of the pedals actualise the brakes.

http://meriweather.com/flightdeck/777/deck/pedals.html#



Jeroen