For the aviation fans

[SwissVan]

On 12/14/2022 at 1:10 PM, SwissVan said:

End of the line (production line) for a legend
 

https://youtu.be/3XjcUI-hY84

 

Tragically this same aircraft crashed into the sea near Herlikon Greece shortly after take-off early today.

One of the pilots a 62 yr old Indonesian died (RIP) and the other a 32 yr old South African survived.

Reasons for the crash are unknown, other than the pilot declared an emergency shortly after take-off.

 

[Spokey]

Flew from Kuwait to UK yesterday for the aeries first 24 month check. Had to drop the RAT on the way in to Biggin as an Operational check was required. Was good to see that it does all it needs to in the event of it being required in flight. Over Western Europe the temperature was -73 at FL430. We did pay attention to the fuel temp in the tanks but it never got below -13 so all good there!

The pic with the aerie in flight is us passing an Emirates A380 cruising down at FL360 over Turkey. Normally I cannot get pics from inside the cabin, but no pax yesterday.

[SwissVan]

3 hours ago, Spokey said:

Flew from Kuwait to UK yesterday for the aeries first 24 month check. Had to drop the RAT on the way in to Biggin as an Operational check was required. Was good to see that it does all it needs to in the event of it being required in flight. Over Western Europe the temperature was -73 at FL430. We did pay attention to the fuel temp in the tanks but it never got below -13 so all good there!

The pic with the aerie in flight is us passing an Emirates A380 cruising down at FL360 over Turkey. Normally I cannot get pics from inside the cabin, but no pax yesterday.

Hi Spokey, does the RAT have any noticeable affect on the aircrafts trim during flight?

[Long Wheel Base]

4 hours ago, Spokey said:

Flew from Kuwait to UK yesterday for the aeries first 24 month check. Had to drop the RAT on the way in to Biggin as an Operational check was required. Was good to see that it does all it needs to in the event of it being required in flight. Over Western Europe the temperature was -73 at FL430. We did pay attention to the fuel temp in the tanks but it never got below -13 so all good there!

The pic with the aerie in flight is us passing an Emirates A380 cruising down at FL360 over Turkey. Normally I cannot get pics from inside the cabin, but no pax yesterday.

Can you hear the RAT running during flight?

I have done ground tests on them and my word they are loud. They also spin seriously fast, it is actually pretty scary being close to it.

[Long Wheel Base]

1 hour ago, SwissVan said:

Hi Spokey, does the RAT have any noticeable affect on the aircrafts trim during flight?

It almost looks like that door doesn't close while running, I am sure that has some affect.

[The Ouzo]

anyone want to explain RAT to us non aviation peeps ?

[Spokey]

54 minutes ago, Long Wheel Base said:

It almost looks like that door doesn't close while running, I am sure that has some affect.

Hi there. It is noisy but not unbearable. There is no noticeable increase in drag although of course it will have increased.  I did not notice any increase in thrust to maintain speed.  It was very windy into Biggin, 28kts gusting 38, so the auto throttles were working a bit anyway! The whole test is conducted from 180 kts down to touch down. We had clearance from London Area to slow to 180 around 50 nm out as there is a fairly involved sequence of checks to carry out. We ran the APU as well to ensure back up power was available. 
The test is performed with slats out and 1st  stage flap. 
The Hydraulic pumps are isolated to ensure the RAT can drop the gear off the System 3B (which is powered by the RAT)

At 147 kts the AC power is largely shed from the RAT and it powers only hydraulics to ensure hydraulic power is available for landing. The aircraft will then only be on Battery power for electrics apart from the Air Data probes which still have power from the RAT in case of icing conditions.

[Spokey]

1 hour ago, The Ouzo said:

anyone want to explain RAT to us non aviation peeps ?

Ram Air Turbine…it is amble to provide emergency AC power at 9Kva which in turn powers the Essential DC. It also powers the System 3 hydraulics . This on our aeroplane anyway. It drops automatically if there is a total loss of AC power. The airliners have larger ones normally stored in the fuselage forward of the wing leading edge, as far as I know!!

[Spokey]

2 hours ago, SwissVan said:

Hi Spokey, does the RAT have any noticeable affect on the aircrafts trim during flight?

Hi Swiss, we were so busy running checklist and bumping around that I did not notice! In all honesty, I believe it would be very little. Just my opinion. 

[The Ouzo]

19 minutes ago, Spokey said:

Ram Air Turbine…it is amble to provide emergency AC power at 9Kva which in turn powers the Essential DC. It also powers the System 3 hydraulics . This on our aeroplane anyway. It drops automatically if there is a total loss of AC power. The airliners have larger ones normally stored in the fuselage forward of the wing leading edge, as far as I know!!

Thanks, did not know planes had these. 

so its for backup power during load shedding

Edited December 20, 2022 by The Ouzo

[Long Wheel Base]

On 12/20/2022 at 2:02 PM, The Ouzo said:

Thanks, did not know planes had these. 

so its for backup power during load shedding

And tbh, you don’t want to be on a plane where it is needing to use it. Testing aside, when the RAT is deployed, people who know, are sweating and possibly praying. It’s worse than load shedding. Think complete blackout as in no power. Contrary to some people’s belief, it can NOT propel the plane forward, you are gliding a passenger aircraft!!!!

[The Ouzo]

2 minutes ago, Long Wheel Base said:

And tbh, you don’t want to be on a plane where it is needing to use it. Testing aside, when the RAT is deployed, people who know, are sweating and possibly praying. It’s worse than load shedding. Think complete blackout as in no power. Contrary to some people’s belief, it can NOT propel the plane forward, you are gliding a passenger aircraft!!!!

how are the controls on a plane operated ? hydraulics or electric ? would the RAT allow for the operation of the controls if they are electric ? or is it purely for comms and some emergency stuff ?

[Long Wheel Base]

On 12/20/2022 at 1:42 PM, Spokey said:

Ram Air Turbine…it is amble to provide emergency AC power at 9Kva which in turn powers the Essential DC. It also powers the System 3 hydraulics . This on our aeroplane anyway. It drops automatically if there is a total loss of AC power. The airliners have larger ones normally stored in the fuselage forward of the wing leading edge, as far as I know!!

On the Boeing and airbus’s I used to work on, they were never in a common spot. Was all dependent on the best spot with smooth airflow depending on the angle of attack used when the RAT is used for real. I’d need a refresh but I think the 787 it actually sits in the wing to body fairing just aft of the wing and landing gear. The 330 I think it’s under the wing in one of the flap fairings. But the 319 is pretty much where you mentioned. Funny thing now that I think, the aircraft I have the most hours on in my logbook, the 737, I have never tested a rat or can’t remember where it sits!!! And I have done the full course🤦🏼‍♂️

[Long Wheel Base]

6 minutes ago, The Ouzo said:

how are the controls on a plane operated ? hydraulics or electric ? would the RAT allow for the operation of the controls if they are electric ? or is it purely for comms and some emergency stuff ?

Some hydraulic, and some electric. It allows you to control the plane. So in spokeys case, system 3 hydraulics I think he said. Pretty much all the bigger jets have 2 or 3 hydraulic systems. Each system operates different things. Some are primary for one control and then secondary for another. Airbus call them yellow, green and blue systems. Small Boeing A and B systems. Big Boeing, hmm damn I can’t remember the newer ones like 777 and 787 but 747 was A,B,C and D. Those main landing gears required lots of hydraulics and 2 of them would rotate a little bit like the nose wheels when turning. 

[Spokey]

2 hours ago, The Ouzo said:

how are the controls on a plane operated ? hydraulics or electric ? would the RAT allow for the operation of the controls if they are electric ? or is it purely for comms and some emergency stuff ?

As per LWB….

Our aerie is fly by wire. The control input via the side stick is all electric to three Primary Flight Control (PFC’s) computers. The flight controls themselves are powered by hydraulic Power Control Units. (PCU’s)  The  PFC’s operate with flight envelope protection. If the Primary mode fails the aerie reverts to a form of direct mode where you lose the flight envelope protection. In other words you can over bank, stall or steep dive the aerie and it will not self recover. The worst direct mode is when the flight controls directly power the hydraulic Power Control Units (PCU’s). The auto pilot does not engage and the controls feel quite sloppy. Flyable but would be a handful in gusty conditions to a landing with minimum viz!

RAT allows sufficient electrics and hydraulics to fly safely to a landing at your nearest suitable en route alternate airport. It operates at normal cruise altitude and speeds…….however the speed and altitude  would change depending on the reason for RAT deployment. Eg losing all AC power.   
It is more complicated but I hope that gives an idea….

[Bateleur1]

Spokey, in my mind, most causes of losing all AC power would most propably be complete engine failure.  Should one or more of the engines still be running the plane should still be flyable and not gliding.  Or could there be many other scenarios where you could have all AC power loss but still have running engines?