kontiuka Posted August 15, 2017 Share Posted August 15, 2017 I was reading the "Wall Panel" section of the manual and was doing some testing and found some discrepancies. First, it says the radios and datalink can't work without AC power. I tried switching off the DC to AC inverter but the radio still seemed to work. Engines were off so the AC generators weren't operating. Second, the manual says the APU is fed by the rear fuel tank. I turned off the rear tank boost pump but the APU was still able to start (cross-feed switch off). As an aside, the engine fuel feed logic seemed to work as expected. Link to comment Share on other sites More sharing options...
Ranma13 Posted August 16, 2017 Share Posted August 16, 2017 I can verify the first issue with the radio. Either it's implemented incorrectly, or the manual is incorrect and it's supposed to be DC power instead of AC power. I'm leaning towards the latter, as it wouldn't be too useful for a helicopter to not be able to communicate if the inverter goes out. As for the APU, I can't reproduce it. Are you starting the APU, and then turning off the boost pump? If so, the suction from the APU will keep fuel flowing into it. If you're turning off the aft fuel pump prior to starting the APU, then the APU sound should play, but the temperature won't increase, and the APU will die after a short while. 1 Link to comment Share on other sites More sharing options...
kontiuka Posted August 16, 2017 Author Share Posted August 16, 2017 I can verify the first issue with the radio. Either it's implemented incorrectly, or the manual is incorrect and it's supposed to be DC power instead of AC power. I'm leaning towards the latter, as it wouldn't be too useful for a helicopter to not be able to communicate if the inverter goes out.Not sure. I think in the A-10C, the inverter has to be on to work the radios so maybe the same thing. As for the APU, I can't reproduce it. Are you starting the APU, and then turning off the boost pump? If so, the suction from the APU will keep fuel flowing into it. If you're turning off the aft fuel pump prior to starting the APU, then the APU sound should play, but the temperature won't increase, and the APU will die after a short while.Ya, retried and works as expected. I must of shut off the booster pump after start. Thanks for the reply. Link to comment Share on other sites More sharing options...
Kappi Posted August 17, 2017 Share Posted August 17, 2017 (edited) Not sure. I think in the A-10C, the inverter has to be on to work the radios so maybe the same thing. . Do you really think it's a good idea to compare an American plane to a Russian helicopter?! Try to compare it with the Mi-8, but not even this comparison can be guarantied. Edit: Now at home and checked it: The Radios are DC power supplied via the DC emergency bus (directly fed from the batteries) The following power consumers are supplied by the DC emergency buses (in case both generators and rectifiers fail): POS-500B inverter to supply the AC consumers Communication equipment: VHF radios, intercom Radar altimeter IFF responder Black Shark manual page 471, chapter 13-21 Edited August 17, 2017 by Kappi ___________________________________________ [sIGPIC][/sIGPIC] Looking forward to it, Belsimtek!:thumbup: Link to comment Share on other sites More sharing options...
AlphaOneSix Posted August 19, 2017 Share Posted August 19, 2017 Electricity doesn't care what country it's in or who designed the thing it flows through. ;) Kidding aside, every radio I've ever seen in an aircraft has been powered by DC. From any country. Link to comment Share on other sites More sharing options...
Paradox Posted August 19, 2017 Share Posted August 19, 2017 I've never even heard of an AC radio, is that even possible? Link to comment Share on other sites More sharing options...
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