I saw the video of that Wings Air flight from a crew seated on the observer seat. It was shown from an ATR flight safety event. The cockpit display turned on and off like Christmas lights! I can't imagine the challege the crew faced that day. They did handled it very well.
Some of acft in my company were already received the update for this TRU. So we don't need to engage it anymore. But since the procedure been used for so long and had become an habit, I sometimes reengage it after landing, gotta get used to it now
Hello Magnar, thank you for very interesting article. To my understanding this was dual failure. First 7PA (MAIN BAT switch) must fail - to incorrectly signal to BPCU to release BTR 58PA, 3PA, 95PA, 96PA into default non energized states. In such default contacts state if either DC BUS 1 or 2 are still energized (DC GENs are running), then based on BTR 1PA position DC ESS, EMER and STBY buses will be powered from DC BUS 1 or 2 (depending on the position of BTR 1PA). What was found and reported to EASA by manufacturer is, that contactor 1PA was stuck "in middle" position, not providing any connection to any DC bus. So therefor complete loss of DC ESS, EMER and STBY buses. But now I am getting really confused. 1. DC busses are powered from DC GENs through 11PU and 12PU contactors controlled by corresponding GCUs. If 7PA (MASTER BAT switch fails) IMHO all busses shall be de-energized, correct? So GCU shall be command (in simlar matter as BPCU) to release 11PU and 12PU to isolate DC BUS 1 and 2 from GENs, correct? Or 7PA controls only BPCU and when DC GENs are running feeding corresponding GCUs this is self reliant operation state? So in flight even if you switch MASTER BAT switch off, you will still have engines, DC GENs and DC BUS 1 and 2 running? 2. Even in the 7PA is not controlling DC BUS 1 and 2 states (as questioned in 1.), than if 7PA fails and signal to BPCU to release BTR 58PA, 3PA, 95PA, 96PA into default non energized state, than you will never get power from TRU to DC ESS, EMER and STBY busses, as you need 95PA and 96PA to provide contact continuity from TRU DC to DC ESS, EMER and STBY busses, correct? Than I am confused how in such case switching on TRU might help.
Thank you, Magnar, for another great and interesting video! This however, brings up another question: The parts will be replaced by 2024, and then the use on TRU on every flight will be a mamory, you say. This sounds like it implies there are drawbacks with using the TRU on every flight? Why wouldnt you continue to turn it on? Isnt the extra redundancy just a good thing? Are there any drawbacks with using the system, and if so, what are they? What is the reason for not always have it on? Thanks again, and excited for your next vid
The intention with the TRU was to provide backup power in case both DC generators were inoperative. This allowed the aircraft to be certified for ETOPS operations. The TRU has a cooling fan. Everything that moves will wear out sooner or later. Therefore, it is better to keep the TRU off when it is not needed.
Also the OEB says that engaging the TRU may produce some temporary shortage of electrical power during the transient phase of activation of the TRU, so this may, and it really does, produce some spurious alerts or fault indications, as for example, the AUDIO SEL CAPT FAULT, the CAPT MCDU or ADC2. I'm sure this is not a good thing to keep doing forever, cause you may damage the mentioned systems permanently.
No worries sir, it happens (also to me when creating course ware). Thx for the thorough explanations on systems in your video's, they really make a difference on ATR systems knowledge.
Congratulations, the videos are very detailed and well explained. I watched almost the whole series about ATR, keep going, you're doing this very well. I still have a question, where can I buy a t-shirt with ATR? :)
It is difficult to tell... Here is a link to a video showing how the aircraft is prepared for flight step by step: ua-cam.com/video/LcdOAeU-naI/v-deo.html
Good explanation! But I have a doubt: If during the after landing the TRU keep on, and you put CL1 in FTR, there will a lot of systems shut down. Well, If I Lost one engine in flight, this shutting down systems will occure?
Normal procedure is to select the TRU off after landing. It's in the checklist. Then, alter two minutes to allow the engine to cool down, we set CL1 to FTR. Thes causes ACW GEN 1 to go offline. However, the electrical systems (ACW and DC) have but tie connectors (BTC). When one generator is offline, the other generator supplies the entire systems via the BTC. The only systems that will go offline are those selected off by the crew after landing (ice protection). Therefore, when one engine fails in flights, all systems will still be operative (except for a few items in the cabin powered by the ACW Service Bus).
@@FlywithMagnar Ok, but If I forget to turn off the TRU PB, and feather de Eng1, there will occure a lot of systems shut down without Eng 2 supply. So my doubt is what happens in flight?
The TRU is powered by ACW BUS 2. The TRU is designed to be a backup for the batteries in case both DC Generators are inoperative. Without the TRU, the batteries will last for at least 30 minutes. When you shut down engine 1 after landing, nothing happens to the systems, because of the ACW BTC and DC BTC. After putting on the parking brake, you set CL2 to FTR. All ACW is lost, but we don't need it because the ACW system provides power to systems only needed for taxi and flight. If one engine fails in flight. Nothing happens to the systems. If both engines fail in flight, you have only battery power left. As i said, the batteries last for at least 30 minutes. Without engine power, you will land long time before that. Therefore, the TRU has no relevance when the engines are shut down.
@@FlywithMagnar Well, I'm ATR First officer, and I could see a lot of systems failures when i forgot to turn off the TRU after landing, beyond a Eng1 FTR, like X in panels and mcdu. Try "to forget" to see. Thank You for your attention and kindness.
Because most of the time you boarding an aircraft from left hand side so it would be more beneficial to installed it on RH side engine to prevent blowing those hot exhaust gas during boarding/loading
I noticed the AOM is dated 30-Nov-2022 covering the 42-500 all serials. Is this an OEB and if so what is the OEB identification number. My latest ORH is 8-Mar-2023 all serials. This is the first time I have heard of this procedure, so I am curious if the fix was implemented before our AT45's came online would it be omitted from our manuals?
When producing the video, I didn't have access to the latest issue of the AOM and OEM. The current AOM is issue 8, it I remember correctly. It is valid for ATR 42-600 (42-500 mod 5948) and 72-600 (72-212A mod 5948) with MSN listed in the AOM. The OEM is inserted in the manuals for the affected aircraft.
@@ExcessEngry That's because if you had an AT45 with mod 5948 it would be an AT46 :). Officially there is no such thing as an ATR 42/72-600; as far as the authority is concerned they are just ATR 42/72-500s with a specific modification installed. It just so happens that ATR install the mod in the factory when they build the aircraft and sell it with the designation -600.
Thank you amazing videos. In msfs 20 in ATR 72-600 there is a problem. While engines are running , the hydraulic pumps shut off, without throttle input. While taxiing at idle, you lose the hydraulic system and brakes, so you need to turn on the hydraulics crossfeed for it to work. Is this an issue? Thank you.
@@FlywithMagnar From what I understood, it's a bug introduced by the changes made in SU13, which affected how propellers are working. Asobo know about it (I was the one that actually confirmed to them that it was a regression caused by SU13), so it's probably just a matter of time before they update the ATR in the sim for it to work with SU13
Magnar, greetings! So it turns out that I have to turn on TRU by pressing a button - every flight and before taxiing before takeoff? And does it have to be on for the entire flight? And after landing at the destination airport, does TRU turn off? Or do we turn on TRU only when both generators fail?
@@FlywithMagnar It would probably be right if I also use TRU in the simulator before taxiing, before takeoff, and throughout the flight, and until I leave the runway after landing. Thanks a lot!
I saw the video of that Wings Air flight from a crew seated on the observer seat. It was shown from an ATR flight safety event. The cockpit display turned on and off like Christmas lights! I can't imagine the challege the crew faced that day. They did handled it very well.
Some of acft in my company were already received the update for this TRU. So we don't need to engage it anymore. But since the procedure been used for so long and had become an habit, I sometimes reengage it after landing, gotta get used to it now
Hello Magnar, thank you for very interesting article. To my understanding this was dual failure. First 7PA (MAIN BAT switch) must fail - to incorrectly signal to BPCU to release BTR 58PA, 3PA, 95PA, 96PA into default non energized states. In such default contacts state if either DC BUS 1 or 2 are still energized (DC GENs are running), then based on BTR 1PA position DC ESS, EMER and STBY buses will be powered from DC BUS 1 or 2 (depending on the position of BTR 1PA). What was found and reported to EASA by manufacturer is, that contactor 1PA was stuck "in middle" position, not providing any connection to any DC bus. So therefor complete loss of DC ESS, EMER and STBY buses. But now I am getting really confused.
1. DC busses are powered from DC GENs through 11PU and 12PU contactors controlled by corresponding GCUs. If 7PA (MASTER BAT switch fails) IMHO all busses shall be de-energized, correct? So GCU shall be command (in simlar matter as BPCU) to release 11PU and 12PU to isolate DC BUS 1 and 2 from GENs, correct? Or 7PA controls only BPCU and when DC GENs are running feeding corresponding GCUs this is self reliant operation state? So in flight even if you switch MASTER BAT switch off, you will still have engines, DC GENs and DC BUS 1 and 2 running?
2. Even in the 7PA is not controlling DC BUS 1 and 2 states (as questioned in 1.), than if 7PA fails and signal to BPCU to release BTR 58PA, 3PA, 95PA, 96PA into default non energized state, than you will never get power from TRU to DC ESS, EMER and STBY busses, as you need 95PA and 96PA to provide contact continuity from TRU DC to DC ESS, EMER and STBY busses, correct? Than I am confused how in such case switching on TRU might help.
Thank you, Magnar, for another great and interesting video!
This however, brings up another question: The parts will be replaced by 2024, and then the use on TRU on every flight will be a mamory, you say.
This sounds like it implies there are drawbacks with using the TRU on every flight? Why wouldnt you continue to turn it on? Isnt the extra redundancy just a good thing?
Are there any drawbacks with using the system, and if so, what are they?
What is the reason for not always have it on?
Thanks again, and excited for your next vid
The intention with the TRU was to provide backup power in case both DC generators were inoperative. This allowed the aircraft to be certified for ETOPS operations. The TRU has a cooling fan. Everything that moves will wear out sooner or later. Therefore, it is better to keep the TRU off when it is not needed.
Also the OEB says that engaging the TRU may produce some temporary shortage of electrical power during the transient phase of activation of the TRU, so this may, and it really does, produce some spurious alerts or fault indications, as for example, the AUDIO SEL CAPT FAULT, the CAPT MCDU or ADC2. I'm sure this is not a good thing to keep doing forever, cause you may damage the mentioned systems permanently.
Very nice video...perhaps ATR made good solution for every incident...❤
Always something interesting. Thank you Captain!!!
When DC Bus 1 is powered, the DC STBY Bus should be powered from the left (from the HOT EMER BAT Bus through the DC EMER Bus)
You are correct. My bad.
No worries sir, it happens (also to me when creating course ware).
Thx for the thorough explanations on systems in your video's, they really make a difference on ATR systems knowledge.
Very good video, very complete in providing information, happy landing always Captain Magnar Nordal
Did they lose the standby instrument too? I assumed that it has its own independent power supply.
We already have the modified battery switch in some of our aircra.
Great to hear!
Congratulations, the videos are very detailed and well explained. I watched almost the whole series about ATR, keep going, you're doing this very well.
I still have a question, where can I buy a t-shirt with ATR? :)
I bought my T-shirt from ATR Training Centre. Maybe I should start an online store?
@@FlywithMagnar Certainly, but I'm afraid that the cost of shipping will probably spoil the deal.
Thanks!
Kämpe gott Magnar, tack tack !
Thanks for this.
Excelent info, thanks so much.
Great thx , i've a bit issue with the trim, when i want to set it for take off,than to confirm it goes back to 0, i don't know why !!!???
It is difficult to tell... Here is a link to a video showing how the aircraft is prepared for flight step by step: ua-cam.com/video/LcdOAeU-naI/v-deo.html
So this is a -600 specific procedure? I know that it is not in use on 72-500s. Should it be?
Yes, this procedure is specific for the -600.
Good explanation! But I have a doubt: If during the after landing the TRU keep on, and you put CL1 in FTR, there will a lot of systems shut down. Well, If I Lost one engine in flight, this shutting down systems will occure?
Normal procedure is to select the TRU off after landing. It's in the checklist. Then, alter two minutes to allow the engine to cool down, we set CL1 to FTR. Thes causes ACW GEN 1 to go offline. However, the electrical systems (ACW and DC) have but tie connectors (BTC). When one generator is offline, the other generator supplies the entire systems via the BTC. The only systems that will go offline are those selected off by the crew after landing (ice protection). Therefore, when one engine fails in flights, all systems will still be operative (except for a few items in the cabin powered by the ACW Service Bus).
@@FlywithMagnar Ok, but If I forget to turn off the TRU PB, and feather de Eng1, there will occure a lot of systems shut down without Eng 2 supply. So my doubt is what happens in flight?
The TRU is powered by ACW BUS 2. The TRU is designed to be a backup for the batteries in case both DC Generators are inoperative. Without the TRU, the batteries will last for at least 30 minutes. When you shut down engine 1 after landing, nothing happens to the systems, because of the ACW BTC and DC BTC. After putting on the parking brake, you set CL2 to FTR. All ACW is lost, but we don't need it because the ACW system provides power to systems only needed for taxi and flight.
If one engine fails in flight. Nothing happens to the systems. If both engines fail in flight, you have only battery power left. As i said, the batteries last for at least 30 minutes. Without engine power, you will land long time before that.
Therefore, the TRU has no relevance when the engines are shut down.
@@FlywithMagnar Well, I'm ATR First officer, and I could see a lot of systems failures when i forgot to turn off the TRU after landing, beyond a Eng1 FTR, like X in panels and mcdu. Try "to forget" to see. Thank You for your attention and kindness.
Hm... I never tried that.
How is it that the instruments for both pilots can be affected by a single failed switch?
Because it's an ATR. Major oopsie.
Intressant som vanligt, precis som du sade...inte svaret jag hade väntat mig
Can you make a video with ATR 72-500 in flightsim, please?
Captain, why is the Hotel mode is placed on the right engine?
Because most of the time you boarding an aircraft from left hand side so it would be more beneficial to installed it on RH side engine to prevent blowing those hot exhaust gas during boarding/loading
I noticed the AOM is dated 30-Nov-2022 covering the 42-500 all serials. Is this an OEB and if so what is the OEB identification number. My latest ORH is 8-Mar-2023 all serials. This is the first time I have heard of this procedure, so I am curious if the fix was implemented before our AT45's came online would it be omitted from our manuals?
When producing the video, I didn't have access to the latest issue of the AOM and OEM. The current AOM is issue 8, it I remember correctly. It is valid for ATR 42-600 (42-500 mod 5948) and 72-600 (72-212A mod 5948) with MSN listed in the AOM. The OEM is inserted in the manuals for the affected aircraft.
@FlywithMagnar That makes sense why I haven't heard of it. No AT45's in our fleet have the 5948 mod. Good to know. Thank you Magnar
@@ExcessEngry That's because if you had an AT45 with mod 5948 it would be an AT46 :). Officially there is no such thing as an ATR 42/72-600; as far as the authority is concerned they are just ATR 42/72-500s with a specific modification installed. It just so happens that ATR install the mod in the factory when they build the aircraft and sell it with the designation -600.
Thank you amazing videos. In msfs 20 in ATR 72-600 there is a problem. While engines are running , the hydraulic pumps shut off, without throttle input. While taxiing at idle, you lose the hydraulic system and brakes, so you need to turn on the hydraulics crossfeed for it to work. Is this an issue? Thank you.
Yes, in MSFS, propeller RPM (NP) may drop below 70% if the power levers are not in GI or above. I hope this can be corrected soon.
@@FlywithMagnar From what I understood, it's a bug introduced by the changes made in SU13, which affected how propellers are working. Asobo know about it (I was the one that actually confirmed to them that it was a regression caused by SU13), so it's probably just a matter of time before they update the ATR in the sim for it to work with SU13
Magnar, greetings! So it turns out that I have to turn on TRU by pressing a button - every flight and before taxiing before takeoff? And does it have to be on for the entire flight? And after landing at the destination airport, does TRU turn off? Or do we turn on TRU only when both generators fail?
Both! Normally, we only use the TRU when both DC generators have failed. But until a new battery switch is installed, we use the TRU on every flight.
@@FlywithMagnar It would probably be right if I also use TRU in the simulator before taxiing, before takeoff, and throughout the flight, and until I leave the runway after landing. Thanks a lot!
once it happened on touchdown, all displays also went off. Was not funny...
Even the manufacture doesnt know what the cause 😅 tru just preventive measure from the manufacture.