Van's Air Force
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Dual Landing Lights
- Thread starter Bob Ross
- Start date
Hi Bob, I have finished my tailcone and have ordered the wing kit. I have also ordered the lighting kit. Like you I dont want a one eyed RV12. I was going to see what came in the lighting kit and then order what I needed for the other wing.
Now I have discovered the RV12 Maintenance Manual. If you refer to page 8-1 there is a drawing of the electrcal system. What I wondered is do we need a second right wing cable combination, to install on the left wing. Or do we only need a right wing landing light cable to add to the left wing?
I emailed Ken at Vans. I dont really have an answer. It is not somthing they are concerned about. They are happy to provide what we order. One thing Ken mentioned which they dont have information on, is whether the alternator has enough power for two landing lights?
I have talked to the aircraft engineer who is advising me.(He has built an RV 6) His answer was as follows. "The rotax generator puts out 20A max.You can install another alternator but with the new LED light , 20A should be enough."
I wonder if some one who has installed the lighting kit can help us. Sorry I sat on Kens information for so long.
Now I have discovered the RV12 Maintenance Manual. If you refer to page 8-1 there is a drawing of the electrcal system. What I wondered is do we need a second right wing cable combination, to install on the left wing. Or do we only need a right wing landing light cable to add to the left wing?
I emailed Ken at Vans. I dont really have an answer. It is not somthing they are concerned about. They are happy to provide what we order. One thing Ken mentioned which they dont have information on, is whether the alternator has enough power for two landing lights?
I have talked to the aircraft engineer who is advising me.(He has built an RV 6) His answer was as follows. "The rotax generator puts out 20A max.You can install another alternator but with the new LED light , 20A should be enough."
I wonder if some one who has installed the lighting kit can help us. Sorry I sat on Kens information for so long.
vernhendershott
Well Known Member
Yes a second landing light would be nice to have in the left wing, but "should be OK" is not a safe way to go.
Van's for its own reasons is refusing to give its customers any information on the electrical system, we have ask individually and as groups and they are not going to provided it at this point, so there is no safe way to make changes to the electrical system.
The second landing light would still be a high draw unit (compared to the other electronic items installed) and we do not know the capacity of or the load on the current landing light circuits in the switch and fuse box. With two landing lights drawing from one Sub D pin you may exceed its capacity. You may (as Van's will not supply data) also overload internal PC board wiring that was not planed for the greater electrical load.
Then there is the issue of the wiring in the left wing, the landing light requires two wires, one for constantly on and one for flashing on. As the wing to fuselage electrical connection device is only set up for four wires and three are already in use you would come up one connection point short. Yes this could be fixed but it will require an engineered solution.
This is just the tip of the iceberg, as time goes by and changes to the electrical system become required by regulation (new equipment required by FAA regulation such as ADS-B) or the need to replace failed equipment (like the Garmin 496 which should be out of production some time this year and will only be supported by the factory for a few years after that) with new production equipment that is cheaper to purchase than the cost to have the older unit repaired. With out the wiring information and limitations of the system provided by Van's we will have very few choices and the most likely will be to have to remove much of the current system and each of us at significant cost, will have re-engineered the electrical system so that we can be sure of what we have and its limitations.
Please do not just add new electrical items to the system with out proper calculation and respect for the physical limitation of the system installed. I do not want to read about a RV-12 burned up by a wiring fire do to something one of us has done to just add some nice new equipment.
Best regards,
Vern
Van's for its own reasons is refusing to give its customers any information on the electrical system, we have ask individually and as groups and they are not going to provided it at this point, so there is no safe way to make changes to the electrical system.
The second landing light would still be a high draw unit (compared to the other electronic items installed) and we do not know the capacity of or the load on the current landing light circuits in the switch and fuse box. With two landing lights drawing from one Sub D pin you may exceed its capacity. You may (as Van's will not supply data) also overload internal PC board wiring that was not planed for the greater electrical load.
Then there is the issue of the wiring in the left wing, the landing light requires two wires, one for constantly on and one for flashing on. As the wing to fuselage electrical connection device is only set up for four wires and three are already in use you would come up one connection point short. Yes this could be fixed but it will require an engineered solution.
This is just the tip of the iceberg, as time goes by and changes to the electrical system become required by regulation (new equipment required by FAA regulation such as ADS-B) or the need to replace failed equipment (like the Garmin 496 which should be out of production some time this year and will only be supported by the factory for a few years after that) with new production equipment that is cheaper to purchase than the cost to have the older unit repaired. With out the wiring information and limitations of the system provided by Van's we will have very few choices and the most likely will be to have to remove much of the current system and each of us at significant cost, will have re-engineered the electrical system so that we can be sure of what we have and its limitations.
Please do not just add new electrical items to the system with out proper calculation and respect for the physical limitation of the system installed. I do not want to read about a RV-12 burned up by a wiring fire do to something one of us has done to just add some nice new equipment.
Best regards,
Vern
Beyond the alternator (or generator) capacity.
One other potential area of concern with an added load could be the voltage regulator. As those who have installed the lighting kit know, the addition of the lights also requires installation of a cooling blast tube and cooling shroud over the voltage regulator. I don't know what the detailed specs are but this suggests to me that the regulator might not be capable of handling much additional load either. Hence, I agree with Vern that there would need to be a full assessment of the capability of all aspects of the electrical system. I will be happy with one landing light!
Jeff
One other potential area of concern with an added load could be the voltage regulator. As those who have installed the lighting kit know, the addition of the lights also requires installation of a cooling blast tube and cooling shroud over the voltage regulator. I don't know what the detailed specs are but this suggests to me that the regulator might not be capable of handling much additional load either. Hence, I agree with Vern that there would need to be a full assessment of the capability of all aspects of the electrical system. I will be happy with one landing light!
Jeff
Van's made it very clear to all RV-12 customers at the time they ordered their very first kit, that they were marketing the RV-12 as an E-LSA kit with the intent that it be built that way (and built exactly as designed).
With that being the case, it is no surprise that they do not wish to spend company engineering resources helping people redesign and modify their RV-12. Also, I don't think it is fair to be negative of Van's for not designing the RV-12 so that it was simple to modify. The airplane was designed to be what it is. That design philosophy is a good part of what makes it the great airplane that it is. If customers want an airplane that is easy to modify in what ever way they wish, then they should buy a kit for an airplane that requires them to figure out for themselves how to design and install all of the airplanes systems.
Be that E-LSA is experimental category, it is well within an RV-12 owners right to experiment, but Van's is under no obligation to help. If you want to experiment, then do the research that is required (AC 43.13 section 11). It is not too difficult to find power consumption data for all of the electrical devices installed in an RV-12. A builder could simply resort to measuring the individual loads by making an amp meter adapter that would plug into each fuse location.
Personally I would not consider the practical output of the 912 internal alternator to be much above 18 Amps considering the engine RPM that most RV-12 owners will likely operate at. The standard for load allowance is 80% continuos load, of the max. output capability of the alternator (meaning you do not have to consider the radio power consumption when in transmit mode, etc). This should be used when considering upgrades.
As time goes by, it should not be difficult to change/upgrade equipment in an RV-12. All Com. radios have pretty much the same wires to connect regardless who manufactured it. The new Aera GPS pretty much has the same wire connections as the 39X/49X. Van's plans to sell RV-12 kits for a long time. Avionics will undoubtedly change over time and the RV-12 will undoubtedly get changes that will accommodate that.
E. D. Eliot
Well Known Member
Appreciate
Scott - I appreciate your forthright and quick input to this and other RV-12 questions. Your last paragraph is especially welcome as I hope that I will be able to purchase a Skyview from Van's when the time comes for me to install avionics. Would also like to have the option of an SL-40 R/NAV. Thanks again for your knowledgeable input.
Scott - I appreciate your forthright and quick input to this and other RV-12 questions. Your last paragraph is especially welcome as I hope that I will be able to purchase a Skyview from Van's when the time comes for me to install avionics. Would also like to have the option of an SL-40 R/NAV. Thanks again for your knowledgeable input.
