gmcjetpilot
Well Known Member
This video link was well done. FAR's are not totally clear on back up instruments for EAB kit planes. In Certified planes the requirement is in the TSO for the certified EFIS. Large jets with 4 displays and redundancy have small backup standby instruments, but then again it is a transport category.
My other post about 3.125" backup EFI PDF got me thinking. What if the main EFIS with all the info went blank (not related to electrical power). As we integrate all control of radios, transponder, engine instrument that display is critical. Not withstanding back up electrical power, what if a lighting strike took out your display?
For VFR not as critical on IFR flight in IMC. You need Attitude Instruments and NAV. The REGS for EAB Kit planes really does not specify any back up, electrical or otherwise. Of course common sense and survival instincts would say have backups.
Before EFIS in GA, many people did not do well when their Vac pump failed and went "partial panel". The EFI reliability is very good and back up standby battery power is not hard to do well. The question is how much redundancy do you need?
For me I need a back up flight instrument AI, AS, ALT. After that wet compass for heading. Nav, IFR GPS with small map and can provide at minimum lateral guidance. People point to their iPad or Tablet with built in GPS (and even rudimentary AHAR) and the EFB (Elect Flight Bag) software. That is for Ref only. As far as radio control, my EFIS can tune the radio but have separate tuning head. The transponder is remote and has no independent control. However is should keep doing it's thing and say on last squawk. I could add a discreet IDENT button in panel. Engine Inst in EFIS is back up by a EIS (Engine Information System). It is a small dedicated LCD screen with 3 buttons. This allows me to tune radio and have engine instruments. But what about Attitude Instrument flight, Attitude, Airspeed, Altitude, Slip/Skid, Rate of Turn... There are many electronic choices. It makes no sense to add a vacuum pump. However Vaccum pump has some charm, in that a lighting strike will not take it out. f
I fly and do instructing in a flight club C182 with a GTN750 and G5. The primary attitude is still Vacuum. The AI rolled over and died. It was the AI, suction was good. I switched the G5 to PDF mode for attitude. However the STEC autopilot uses the G5 in HSI mode only for commands. G5 in PFD mode I had no autopilot, no heading, no NAV track. No big deal, even on an IFR flight plan, I was in mostly VFR conditions. Could I have flown without bring up the G5 in PDF mode, leave it in HSI so Autopilot worked? Yes because I had pitot static instruments: Airspeed, VSI, Turn Coordinator, and the DG is is a Bendix/King kcs-55a all electric HSI, which gets Nav info from King KX155, #2 Nav/Com. It is nice having a mix of old school and wiz-bang.
The GTN750 is a touch screen display, with IFR WAAS GPS , COM, NAV (VOR/LOC/GS), ADS-B IN/OUT S-Transponder, Audio Panel. All in one unit.
Engine instruments are 1967's Cessna.
Makes me think, if GTN750 dies (with audio panel) will I be able to use the KX155 #2 COM? Nav to HSI should be OK. Sounds like I would lose COM (pun intended). With all eggs in on basket, be it an do it all GPS or EFIS, you should have redundancy for an IFR plane. The question for experimental how much redundancy. It really is up to you.
You can spend a lot of energy on this. I'm all GPS. no panel/aircraft mounted VOR/LOC/GS.... I do have a iPad EFB. I suppose a handheld Transceiver with VOR/LOC/GS (Yaesu FTA750A), for emergency may be a good idea. I am adding a backup PFD/EFIS, and subject of my other post.
Youtube Video
My other post about 3.125" backup EFI PDF got me thinking. What if the main EFIS with all the info went blank (not related to electrical power). As we integrate all control of radios, transponder, engine instrument that display is critical. Not withstanding back up electrical power, what if a lighting strike took out your display?
For VFR not as critical on IFR flight in IMC. You need Attitude Instruments and NAV. The REGS for EAB Kit planes really does not specify any back up, electrical or otherwise. Of course common sense and survival instincts would say have backups.
Before EFIS in GA, many people did not do well when their Vac pump failed and went "partial panel". The EFI reliability is very good and back up standby battery power is not hard to do well. The question is how much redundancy do you need?
For me I need a back up flight instrument AI, AS, ALT. After that wet compass for heading. Nav, IFR GPS with small map and can provide at minimum lateral guidance. People point to their iPad or Tablet with built in GPS (and even rudimentary AHAR) and the EFB (Elect Flight Bag) software. That is for Ref only. As far as radio control, my EFIS can tune the radio but have separate tuning head. The transponder is remote and has no independent control. However is should keep doing it's thing and say on last squawk. I could add a discreet IDENT button in panel. Engine Inst in EFIS is back up by a EIS (Engine Information System). It is a small dedicated LCD screen with 3 buttons. This allows me to tune radio and have engine instruments. But what about Attitude Instrument flight, Attitude, Airspeed, Altitude, Slip/Skid, Rate of Turn... There are many electronic choices. It makes no sense to add a vacuum pump. However Vaccum pump has some charm, in that a lighting strike will not take it out. f
I fly and do instructing in a flight club C182 with a GTN750 and G5. The primary attitude is still Vacuum. The AI rolled over and died. It was the AI, suction was good. I switched the G5 to PDF mode for attitude. However the STEC autopilot uses the G5 in HSI mode only for commands. G5 in PFD mode I had no autopilot, no heading, no NAV track. No big deal, even on an IFR flight plan, I was in mostly VFR conditions. Could I have flown without bring up the G5 in PDF mode, leave it in HSI so Autopilot worked? Yes because I had pitot static instruments: Airspeed, VSI, Turn Coordinator, and the DG is is a Bendix/King kcs-55a all electric HSI, which gets Nav info from King KX155, #2 Nav/Com. It is nice having a mix of old school and wiz-bang.
The GTN750 is a touch screen display, with IFR WAAS GPS , COM, NAV (VOR/LOC/GS), ADS-B IN/OUT S-Transponder, Audio Panel. All in one unit.
Engine instruments are 1967's Cessna.
Makes me think, if GTN750 dies (with audio panel) will I be able to use the KX155 #2 COM? Nav to HSI should be OK. Sounds like I would lose COM (pun intended). With all eggs in on basket, be it an do it all GPS or EFIS, you should have redundancy for an IFR plane. The question for experimental how much redundancy. It really is up to you.
You can spend a lot of energy on this. I'm all GPS. no panel/aircraft mounted VOR/LOC/GS.... I do have a iPad EFB. I suppose a handheld Transceiver with VOR/LOC/GS (Yaesu FTA750A), for emergency may be a good idea. I am adding a backup PFD/EFIS, and subject of my other post.
Youtube Video