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Dan.Beadle(at)hq.inclines
Guest

Posted: Mon Jun 12, 2006 6:52 am Post subject: IFR Requirements

There has been a lot on TSO129.  I get that.  

   

What are the requirements for IFR flight in the EFIS age?  We are planning a Grand Rapids EFIS with an engine monitor.  So far, all eggs in one basket.  If not illegal, at least this is not safe enough for me.  

   

Certificated A/C use an AI, Altimeter, Tach, MP steam gage for redundancy.    

   

Would it be legal to put in a second EFIS with an independent AHRS on a separate essential buss and delete the steam gages?

Bruce(at)glasair.org
Guest

Posted: Mon Jun 12, 2006 7:19 am Post subject: IFR Requirements

I suggest you  read my posts on the GRT forum before they kicked me off. You need at least an  Artificial Horizon (preferably vacuum), Altimeter, and ASI. Even with another  separate EFIS you'll still need the steam gauges. If the EFIS's disagree, you'll  need a tie breaker.

  

  

 

Bruce

www.glasair.org

   [quote]   

   --

Tdawson(at)avidyne.com
Guest

Posted: Mon Jun 12, 2006 7:30 am Post subject: IFR Requirements

“Need” is an interesting word.  There are hundreds of IFR Cessnas with only one Attitude Indicator, with a turn coordinator for backup.  And they’ve got zero backup altimeters or ASIs.    

   

FAA requirements for “backups” or “tiebreakers” of any sort are on an individual aircraft model installation basis for TC or STC.  Since experimental aircraft don’t have TCs, it’s up to you how many or what kind of backups you have.    

   

TDT  

   

         

  

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bruce Gray

 Sent: Monday, June 12, 2006 11:16 AM

 To: aeroelectric-list(at)matronics.com

 Subject: RE: AeroElectric-List: IFR Requirements  

  

     

I suggest you read my posts on the GRT forum before they kicked me off. You need at least an Artificial Horizon (preferably vacuum), Altimeter, and ASI. Even with another separate EFIS you'll still need the steam gauges. If the EFIS's disagree, you'll need a tie breaker.  

    

   

    

   

  

Bruce

 www.glasair.org

     [quote]  

--

Bruce(at)glasair.org
Guest

Posted: Mon Jun 12, 2006 8:01 am Post subject: IFR Requirements

OK, I've been  in enough pissing contests on this subject that I don't want another one. Do  whatever floats your boat.

  

 Just  remember, the big iron guys have studied this issue for years and mega-bucks.  I've seen reports of 5 tube EFIS airliners going dark in IFR where the only  thing left was a flashlight and a vacuum ADI.

  

 I have a 75k  panel in my Glasair III and no EFIS. I wonder why?

  

 

Bruce

www.glasair.org

   [quote]   

   --

Tdawson(at)avidyne.com
Guest

Posted: Mon Jun 12, 2006 8:21 am Post subject: IFR Requirements

You won’t find a vacuum ADI on anything rolling off the Boeing or Airbus lines today.  As they say, “The only vacuum on this plane runs the toilet” . . .  

   

TDT

 

   

         

  

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bruce Gray

 Sent: Monday, June 12, 2006 11:56 AM

 To: aeroelectric-list(at)matronics.com

 Subject: RE: AeroElectric-List: IFR Requirements  

  

     

OK, I've been in enough pissing contests on this subject that I don't want another one. Do whatever floats your boat.  

    

   

    

Just remember, the big iron guys have studied this issue for years and mega-bucks. I've seen reports of 5 tube EFIS airliners going dark in IFR where the only thing left was a flashlight and a vacuum ADI.  

    

   

    

I have a 75k panel in my Glasair III and no EFIS. I wonder why?  

    

   

  

Bruce

 www.glasair.org

     [quote]  

--

john.erickson(at)cox.net
Guest

Posted: Mon Jun 12, 2006 8:21 am Post subject: IFR Requirements

Dan,

  

 A lot of people will respond with what they think or what  they heard. Here's what I have in writing. Note that while most Experimental  Operations Limits are fairly standardized, they may differ, so check the Ops  Limits issued for the aircraft you're putting the EFIS in for  specifics.

  

 Here's what my Ops Limits say under the Phase II  section.

  

 "4.  After completion of phase I flight testing, unless appropriately equipeed for night and/or instrument  flist as listed in FAR 91.205 (b through e), this aircraft is to  be operated under day only VFR."

  

 OK, pretty  straightforward. On to what FAR 91.205 b through e  says...

  

 FAR 91.205

  

  

(b) Visual-flight rules (day).  For VFR flight during the day, the following instruments and equipment are  required:  

(1) Airspeed indicator.  

(2) Altimeter.  

(3) Magnetic direction indicator.   

(4) Tachometer for each engine.   

(5) Oil pressure gauge for each engine  using pressure system.  

(6) Temperature gauge for each  liquid-cooled engine.  

(7) Oil temperature gauge for each  air-cooled engine.  

( Manifold pressure gauge for each  altitude engine.  

(9) Fuel gauge indicating the quantity  of fuel in each tank.  

(10) Landing gear position indicator,  if the aircraft has a retractable landing gear.  

(11) For small civil airplanes  certificated after March 11, 1996, in accordance with part 23 of this chapter,  an approved aviation red or aviation white anticollision light system. In the  event of failure of any light of the anticollision light system, operation of  the aircraft may continue to a location where repairs or replacement can be  made. 

(12) If the aircraft is operated for  hire over water and beyond power-off gliding distance from shore, approved  flotation gear readily available to each occupant and, unless the aircraft is  operating under part 121 of this subchapter, at least one pyrotechnic signaling  device. As used in this section, “shore” means that area of the land adjacent to  the water which is above the high water mark and excludes land areas which are  intermittently under water.  

(13) An approved safety belt with an  approved metal-to-metal latching device for each occupant 2 years of age or  older. 

(14) For small civil airplanes  manufactured after July 18, 1978, an approved shoulder harness for each front  seat. The shoulder harness must be designed to protect the occupant from serious  head injury when the occupant experiences the ultimate inertia forces specified  in §23.561(b)(2) of this chapter. Each shoulder harness installed at a flight  crewmember station must permit the crewmember, when seated and with the safety  belt and shoulder harness fastened, to perform all functions necessary for  flight operations. For purposes of this paragraph—  

(i) The date of manufacture of an  airplane is the date the inspection acceptance records reflect that the airplane  is complete and meets the FAA-approved type design data; and  

(ii) A front seat is a seat located at  a flight crewmember station or any seat located alongside such a seat.   

(15) An emergency locator transmitter,  if required by §91.207.  

(16) For normal, utility, and acrobatic  category airplanes with a seating configuration, excluding pilot seats, of 9 or  less, manufactured after December 12, 1986, a shoulder harness for—  

(i) Each front seat that meets the  requirements of §23.785 (g) and (h) of this chapter in effect on December 12,  1985;  

(ii) Each additional seat that meets  the requirements of §23.785(g) of this chapter in effect on December 12, 1985.   

(17) For rotorcraft manufactured after  September 16, 1992, a shoulder harness for each seat that meets the requirements  of §27.2 or §29.2 of this chapter in effect on September 16, 1991. 

(c) Visual flight rules (night).  For VFR flight at night, the following instruments and equipment are required:   

(1) Instruments and equipment specified  in paragraph (b) of this section.  

(2) Approved position lights.   

(3) An approved aviation red or  aviation white anticollision light system on all U.S.-registered civil aircraft.  Anticollision light systems initially installed after August 11, 1971, on  aircraft for which a type certificate was issued or applied for before August  11, 1971, must at least meet the anticollision light standards of part 23, 25,  27, or 29 of this chapter, as applicable, that were in effect on August 10,  1971, except that the color may be either aviation red or aviation white. In the  event of failure of any light of the anticollision light system, operations with  the aircraft may be continued to a stop where repairs or replacement can be  made.  

(4) If the aircraft is operated for  hire, one electric landing light.  

(5) An adequate source of electrical  energy for all installed electrical and radio equipment.  

(6) One spare set of fuses, or three  spare fuses of each kind required, that are accessible to the pilot in flight.   

(d) Instrument flight rules. For  IFR flight, the following instruments and equipment are required:  

(1) Instruments and equipment specified  in paragraph (b) of this section, and, for night flight, instruments and  equipment specified in paragraph (c) of this section.  

(2) Two-way radio communications system  and navigational equipment appropriate to the ground facilities to be used.   

(3) Gyroscopic rate-of-turn indicator,  except on the following aircraft:  

(i) Airplanes with a third attitude  instrument system usable through flight attitudes of 360 degrees of pitch and  roll and installed in accordance with the instrument requirements prescribed in  §121.305(j) of this chapter; and  

(ii) Rotorcraft with a third attitude  instrument system usable through flight attitudes of ±80 degrees of pitch and  ±120 degrees of roll and installed in accordance with §29.1303(g) of this  chapter.  

(4) Slip-skid indicator.  

(5) Sensitive altimeter adjustable for  barometric pressure.  

(6) A clock displaying hours, minutes,  and seconds with a sweep-second pointer or digital presentation.  

(7) Generator or alternator of adequate  capacity.  

( Gyroscopic pitch and bank indicator  (artificial horizon).  

(9) Gyroscopic direction indicator  (directional gyro or equivalent).  

(e) Flight at and above 24,000 ft.  MSL (FL 240). If VOR navigational equipment is required under paragraph  (d)(2) of this section, no person may operate a U.S.-registered civil aircraft  within the 50 states and the District of Columbia at or above FL 240 unless that  aircraft is equipped with approved distance measuring equipment (DME). When DME  required by this paragraph fails at and above FL 240, the pilot in command of  the aircraft shall notify ATC immediately, and then may continue operations at  and above FL 240 to the next airport of intended landing at which repairs or  replacement of the equipment can be made. 

  

Reading  this again makes things pretty clear. Basic Day/VFR equipment is listed  first.  Night VFR requires all the Day VFR equipment with some  additions.  IFR requires Night/VFR with some more equipment.  Here's  where another question typically arises when discussing EFIS use in IFR flight.  FAR 91.205 (d) specifies Gyroscopic rate of turn, pitch and bank, and direction  indicator. What is gyroscopic (especially since most (if not all) AHRS's do not  have any moving parts at all.  Here's what I copied off EAA's Homebuilt  page (link is http://members.eaa.org/home/homebuilders/faq/1Equipping%20a%20Homebuilt%20for%20IFR%20operations.html and  does require membership) 

"What is a gyro? 

The often-asked question is, what  constitutes a “gyroscopic” instrument. Is an instrument containing an actual  rotating mass gyro required, or are alternatives such as ring laser gyros or  accelerometer-based instruments acceptable? Unfortunately, there is no specific  definition of a gyroscopic instrument to be found in any FAA regulation or  guidance document. 

In order to try to answer  this question, the EAA contacted the FAA Small Airplane Directorate in Kansas  City, MO. The Small Airplane Directorate confirmed that there is no published  guidance on this subject, but indicated that the function of the instrument is  the main consideration. Any instrument that performs the function of the  required gyroscopic instrument and presents info to the pilot in the same manner  as the gyroscopic instrument will meet the requirement of 91.205, regardless of  what mechanical or electronic means are used to generate the information and  display." 

Bottomline, it seems pretty obvious from all this that  all of the popular EFIS systems out there meet the definition of gyroscopic  instruments given above, satisfy the equipment required by the FAR's, and the  requirements for instrument flight specified in the Ops Limits.  Note that  nowhere in any of this is there any requirement for any backup of any sort  (other than the requirement in the Night/VFR section for spare fuses).  I  like your statement of "If not illegal, at least this is not safe enough for  me." Remember the regs are a minimum.  Lots of stuff to consider including  electrical system design, quality of EFIS hardware AND software, installation,  etc. However, once the regs are met, everything else is really personal  preference. What one person feels is perfectly safe may seem to someone else  incredibly unsafe. To each his own. I'm going to have backups in my  RV-10. 

  

John Erickson 

RV-10 #40208 Wings 

(I think this is my longest post ever...   )

 



   From:  owner-aeroelectric-list-server(at)matronics.com  [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dan  Beadle

Sent: Monday, June 12, 2006 7:47 AM

To:  aeroelectric-list(at)matronics.com

Subject: IFR  Requirements

 

  

There has been a lot on TSO129.   I get that. 

  

What are the requirements for IFR  flight in the EFIS age?  We are planning a Grand Rapids EFIS with an engine  monitor.  So far, all eggs in one basket.  If not illegal, at least  this is not safe enough for me. 

  

Certificated A/C use an AI,  Altimeter, Tach, MP steam gage for redundancy.    

  

Would it be legal to put in a second  EFIS with an independent AHRS on a separate essential buss and delete the steam  gages?

Bruce(at)glasair.org
Guest

Posted: Mon Jun 12, 2006 8:52 am Post subject: IFR Requirements

Yes, they  have that cute little battery operated Jet 2.25 ADI that costs  15k.

  

  

 

Bruce

www.glasair.org

   [quote]   

   --

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Mon Jun 12, 2006 8:59 am Post subject: IFR Requirements

Note however, that every TC aircraft with glass panel, whether G-1000,  

Avidyne or other, all had to put in the basic steam gages for their TC.

I suspect that the FAA is more concerned with electrical/panel failure  

than they are with a mechanical gage that needs no power or vac source  

to operate.



Quoting Tim Dawson-Townsend <Tdawson(at)avidyne.com>:



[quote] "Need" is an interesting word.  There are hundreds of IFR Cessnas with

 only one Attitude Indicator, with a turn coordinator for backup.  And

 they've got zero backup altimeters or ASIs.



 FAA requirements for "backups" or "tiebreakers" of any sort are on an

 individual aircraft model installation basis for TC or STC.  Since

 experimental aircraft don't have TCs, it's up to you how many or what

 kind of backups you have.



 TDT



 ________________________________



 From: owner-aeroelectric-list-server(at)matronics.com

 [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bruce

 Gray

 Sent: Monday, June 12, 2006 11:16 AM

 To: aeroelectric-list(at)matronics.com

 Subject: RE: IFR Requirements



 I suggest you read my posts on the GRT forum before they kicked me off.

 You need at least an Artificial Horizon (preferably vacuum), Altimeter,

 and ASI. Even with another separate EFIS you'll still need the steam

 gauges. If the EFIS's disagree, you'll need a tie breaker.



 Bruce

 www.glasair.org

 	--

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

bferrell(at)123mail.net
Guest

Posted: Mon Jun 12, 2006 9:56 am Post subject: IFR Requirements

Dan -



And to add another datapoint, my FAA (Cincinnati) regional inspector who will do

my op limits stated that he had no concerns with my self-certifying that my dual

BMA EFIS system met these requirements (no vacuum system at all, no round

gauges).  Folks need to do what they're comfortable with, and do so from a

position of knowledge, but I agree that it's pretty clearly established what is

"required".



Brett



Quoting John Erickson <john.erickson(at)cox.net>:



 	  Quote: 	
		   Dan,



 Bottomline, it seems pretty obvious from all this that all of the popular

 EFIS systems out there meet the definition of gyroscopic instruments given

 above, satisfy the equipment required by the FAR's, and the requirements for

 instrument flight specified in the Ops Limits.  Note that nowhere in any of

 this is there any requirement for any backup of any sort (other than the

 requirement in the Night/VFR section for spare fuses).  I like your

 statement of "If not illegal, at least this is not safe enough for me."

 Remember the regs are a minimum.  Lots of stuff to consider including

 electrical system design, quality of EFIS hardware AND software,

 installation, etc. However, once the regs are met, everything else is really

 personal preference. What one person feels is perfectly safe may seem to

 someone else incredibly unsafe. To each his own. I'm going to have backups

 in my RV-10.



 John Erickson



 RV-10 #40208 Wings



 (I think this is my longest post ever...  )

Tdawson(at)avidyne.com
Guest

Posted: Mon Jun 12, 2006 9:56 am Post subject: IFR Requirements

Note that Garmin or Avidyne probably could have satisfied the FAA if

they installed two EFIS systems (with 2 ADAHRS) on separate buses, as

long as the aircraft had an appropriate electrical architecture.  (note

Cirrus' backup ADI is electric)  Then one could eliminate the "steam

gauges."  



Of course, two EFISs starts to add up to $$ . . . 



TDT

--

brinker(at)cox-internet.c
Guest

Posted: Mon Jun 12, 2006 10:04 am Post subject: IFR Requirements

        I would  like to read the reports. Not trying to be a smart alex just out of  curiosity.

  

 Randy

 [quote]   ---

brinker(at)cox-internet.c
Guest

Posted: Mon Jun 12, 2006 10:32 am Post subject: IFR Requirements

Accually GRT is now offering a dual ahrs system for $1500 extra. From 

my understaning both ahrs's are in the same enclosure, but funtion 

indipendently. for experimental use only of course.



Randy



---

Bruce(at)glasair.org
Guest

Posted: Mon Jun 12, 2006 10:42 am Post subject: IFR Requirements

Here's  one.

  

 http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/ComAndRep/MartinAir/martinair-summary.html

  

  

 

Bruce

www.glasair.org

   [quote]   

   --

brinker(at)cox-internet.c
Guest

Posted: Mon Jun 12, 2006 11:24 am Post subject: IFR Requirements

               I found this PROBABLE CAUSE: "Numerous  electrical anomalies as a result of a loose main battery shunt connection and  undetermined electrical system causes."  at  http://aviation-safety.net/database/record.php?id=19960528-0

              It  would seem they had no control over their dc bus. I would say this is a good  reason for anyone building an airplane to go with a pilot operated e-bus. 

  

 Randy

 [quote]   ---

rv8ch

Joined: 10 Jan 2006
Posts: 250
Location: Switzerland

Posted: Mon Jun 12, 2006 11:27 am Post subject: IFR Requirements

 	  Quote: 	
		    

 http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/ComAndRep/MartinAir/martinair-summary.html

  

  


	


Although they didn't lose radios in the above incident, if I were

flying transatlantic today, I'd bring a handheld.  You sure

don't want to try to come into the US NORDO.  Divert to Canada.



-- 

Mickey Coggins

http://www.rv8.ch/

#82007 finishing

do not archive

_________________
Mickey Coggins
http://www.rv8.ch/

Dan.Beadle(at)hq.inclines
Guest

Posted: Mon Jun 12, 2006 12:09 pm Post subject: IFR Requirements

John,   

Thank you for the thoughtful reply.   

   

I had read the regs several times and had visited the EAA site.  I just didn’t quite put it together as you have.  I am comfortable with dual, independent systems on separate battery busses.  In the unlikely event of a lightning strike, I might lose both, but I can live with that.    

   

I probably will go with the dual battery, dual EFIS, dual AHRS system and no gyros.  I may have to educate the DAR for sign-off, but it should be doable.  

   

Thanks.  

Dan  

   

         

  

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John Erickson

 Sent: Monday, June 12, 2006 9:19 AM

 To: aeroelectric-list(at)matronics.com

 Subject: RE: AeroElectric-List: IFR Requirements  

  

   

Dan,  

   

A lot of people will respond with what they think or what they heard. Here's what I have in writing. Note that while most Experimental Operations Limits are fairly standardized, they may differ, so check the Ops Limits issued for the aircraft you're putting the EFIS in for specifics.  

   

Here's what my Ops Limits say under the Phase II section.  

   

"4.  After completion of phase I flight testing, [b]unless appropriately equipeed for night and/or instrument flist as listed in FAR 91.205 (b through e[/b]), this aircraft is to be operated under day only VFR."    

   

    

OK, pretty straightforward. On to what FAR 91.205 b through e says...  

    

   

    

FAR 91.205  

    

   

    

(b) Visual-flight rules (day). For VFR flight during the day, the following instruments and equipment are required:   

(1) Airspeed indicator.   

(2) Altimeter.   

(3) Magnetic direction indicator.   

(4) Tachometer for each engine.   

(5) Oil pressure gauge for each engine using pressure system.   

(6) Temperature gauge for each liquid-cooled engine.   

(7) Oil temperature gauge for each air-cooled engine.   

( Manifold pressure gauge for each altitude engine.   

(9) Fuel gauge indicating the quantity of fuel in each tank.   

(10) Landing gear position indicator, if the aircraft has a retractable landing gear.   

(11) For small civil airplanes certificated after March 11, 1996, in accordance with part 23 of this chapter, an approved aviation red or aviation white anticollision light system. In the event of failure of any light of the anticollision light system, operation of the aircraft may continue to a location where repairs or replacement can be made.  

(12) If the aircraft is operated for hire over water and beyond power-off gliding distance from shore, approved flotation gear readily available to each occupant and, unless the aircraft is operating under part 121 of this subchapter, at least one pyrotechnic signaling device. As used in this section, “shore” means that area of the land adjacent to the water which is above the high water mark and excludes land areas which are intermittently under water.   

(13) An approved safety belt with an approved metal-to-metal latching device for each occupant 2 years of age or older.  

(14) For small civil airplanes manufactured after July 18, 1978, an approved shoulder harness for each front seat. The shoulder harness must be designed to protect the occupant from serious head injury when the occupant experiences the ultimate inertia forces specified in §23.561(b)(2) of this chapter. Each shoulder harness installed at a flight crewmember station must permit the crewmember, when seated and with the safety belt and shoulder harness fastened, to perform all functions necessary for flight operations. For purposes of this paragraph—   

(i) The date of manufacture of an airplane is the date the inspection acceptance records reflect that the airplane is complete and meets the FAA-approved type design data; and   

(ii) A front seat is a seat located at a flight crewmember station or any seat located alongside such a seat.   

(15) An emergency locator transmitter, if required by §91.207.   

(16) For normal, utility, and acrobatic category airplanes with a seating configuration, excluding pilot seats, of 9 or less, manufactured after December 12, 1986, a shoulder harness for—   

(i) Each front seat that meets the requirements of §23.785 (g) and (h) of this chapter in effect on December 12, 1985;   

(ii) Each additional seat that meets the requirements of §23.785(g) of this chapter in effect on December 12, 1985.   

(17) For rotorcraft manufactured after September 16, 1992, a shoulder harness for each seat that meets the requirements of §27.2 or §29.2 of this chapter in effect on September 16, 1991.  

(c) Visual flight rules (night). For VFR flight at night, the following instruments and equipment are required:   

(1) Instruments and equipment specified in paragraph (b) of this section.   

(2) Approved position lights.   

(3) An approved aviation red or aviation white anticollision light system on all U.S.-registered civil aircraft. Anticollision light systems initially installed after August 11, 1971, on aircraft for which a type certificate was issued or applied for before August 11, 1971, must at least meet the anticollision light standards of part 23, 25, 27, or 29 of this chapter, as applicable, that were in effect on August 10, 1971, except that the color may be either aviation red or aviation white. In the event of failure of any light of the anticollision light system, operations with the aircraft may be continued to a stop where repairs or replacement can be made.   

(4) If the aircraft is operated for hire, one electric landing light.   

(5) An adequate source of electrical energy for all installed electrical and radio equipment.   

(6) One spare set of fuses, or three spare fuses of each kind required, that are accessible to the pilot in flight.   

(d) Instrument flight rules. For IFR flight, the following instruments and equipment are required:   

(1) Instruments and equipment specified in paragraph (b) of this section, and, for night flight, instruments and equipment specified in paragraph (c) of this section.   

(2) Two-way radio communications system and navigational equipment appropriate to the ground facilities to be used.   

(3) Gyroscopic rate-of-turn indicator, except on the following aircraft:   

(i) Airplanes with a third attitude instrument system usable through flight attitudes of 360 degrees of pitch and roll and installed in accordance with the instrument requirements prescribed in §121.305(j) of this chapter; and   

(ii) Rotorcraft with a third attitude instrument system usable through flight attitudes of ±80 degrees of pitch and ±120 degrees of roll and installed in accordance with §29.1303(g) of this chapter.   

(4) Slip-skid indicator.   

(5) Sensitive altimeter adjustable for barometric pressure.   

(6) A clock displaying hours, minutes, and seconds with a sweep-second pointer or digital presentation.   

(7) Generator or alternator of adequate capacity.   

( Gyroscopic pitch and bank indicator (artificial horizon).   

(9) Gyroscopic direction indicator (directional gyro or equivalent).   

(e) Flight at and above 24,000 ft. MSL (FL 240). If VOR navigational equipment is required under paragraph (d)(2) of this section, no person may operate a U.S.-registered civil aircraft within the 50 states and the District of Columbia at or above FL 240 unless that aircraft is equipped with approved distance measuring equipment (DME). When DME required by this paragraph fails at and above FL 240, the pilot in command of the aircraft shall notify ATC immediately, and then may continue operations at and above FL 240 to the next airport of intended landing at which repairs or replacement of the equipment can be made.  

   

Reading this again makes things pretty clear. Basic Day/VFR equipment is listed first.  Night VFR requires all the Day VFR equipment with some additions.  IFR requires Night/VFR with some more equipment.  Here's where another question typically arises when discussing EFIS use in IFR flight. FAR 91.205 (d) specifies Gyroscopic rate of turn, pitch and bank, and direction indicator. What is gyroscopic (especially since most (if not all) AHRS's do not have any moving parts at all.  Here's what I copied off EAA's Homebuilt page (link is http://members.eaa.org/home/homebuilders/faq/1Equipping%20a%20Homebuilt%20for%20IFR%20operations.html and does require membership)  

"What is a gyro?  

The often-asked question is, what constitutes a “gyroscopic” instrument. Is an instrument containing an actual rotating mass gyro required, or are alternatives such as ring laser gyros or accelerometer-based instruments acceptable? Unfortunately, there is no specific definition of a gyroscopic instrument to be found in any FAA regulation or guidance document.  

In order to try to answer this question, the EAA contacted the FAA Small Airplane Directorate in Kansas   City, MO. The Small Airplane Directorate confirmed that there is no published guidance on this subject, but indicated that the function of the instrument is the main consideration. Any instrument that performs the function of the required gyroscopic instrument and presents info to the pilot in the same manner as the gyroscopic instrument will meet the requirement of 91.205, regardless of what mechanical or electronic means are used to generate the information and display."  

Bottomline, it seems pretty obvious from all this that all of the popular EFIS systems out there meet the definition of gyroscopic instruments given above, satisfy the equipment required by the FAR's, and the requirements for instrument flight specified in the Ops Limits.  Note that nowhere in any of this is there any requirement for any backup of any sort (other than the requirement in the Night/VFR section for spare fuses).  I like your statement of "If not illegal, at least this is not safe enough for me." Remember the regs are a minimum.  Lots of stuff to consider including electrical system design, quality of EFIS hardware AND software, installation, etc. However, once the regs are met, everything else is really personal preference. What one person feels is perfectly safe may seem to someone else incredibly unsafe. To each his own. I'm going to have backups in my RV-10.  

   

John Erickson  

RV-10 #40208 Wings  

(I think this is my longest post ever...  )  

    

   

      

  

From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dan Beadle

 Sent: Monday, June 12, 2006 7:47 AM

 To: aeroelectric-list(at)matronics.com

 Subject: IFR Requirements  

There has been a lot on TSO129.  I get that.  

   

What are the requirements for IFR flight in the EFIS age?  We are planning a Grand Rapids EFIS with an engine monitor.  So far, all eggs in one basket.  If not illegal, at least this is not safe enough for me.  

   

Certificated A/C use an AI, Altimeter, Tach, MP steam gage for redundancy.    

   

Would it be legal to put in a second EFIS with an independent AHRS on a separate essential buss and delete the steam gages?

Bruce(at)glasair.org
Guest

Posted: Mon Jun 12, 2006 1:14 pm Post subject: IFR Requirements

Tim,



Just to throw another data point on the fire, it's my understanding that the

G1000 and Avidyne systems in certified aircraft are certified as secondary

flight instruments. The round steam gauges are considered the primary flight

instruments by the FAA.



Bruce

www.glasair.org

 



--

BobsV35B(at)aol.com
Guest

Posted: Mon Jun 12, 2006 3:34 pm Post subject: IFR Requirements

In a message dated 6/12/2006 12:57:56 P.M. Central Standard Time,  bferrell(at)123mail.net writes:

  	  Quote: 	
		  Dan    -



And to add another datapoint, my FAA (Cincinnati) regional inspector    who will do

my op limits stated that he had no concerns with my    self-certifying that my dual

BMA EFIS system met these requirements (no    vacuum system at all, no round

gauges).  Folks need to do what they're    comfortable with, and do so from a

position of knowledge, but I agree that    it's pretty clearly established what  is

"required".



Brett

	


 

Good Evening All,

  

 May I add another small comment?

  

 The FAA has only recently started to interject a need for redundancy in IFR  aircraft.  Anything approved before the FAA got on this kick is not  required to have ANY redundancy. 

  

 Personally, I don't think they should be able to make such a requirement.  

  

 It is my opinion that it is up to the operator to decide what level he/she  is comfortable with. 

  

 If you talked to ALPA they would tell you that no airplane should be  allowed in the sky unless it had a minimum of two engines and two pilots.

  

 I think one engine, one pilot, one generator, one battery, one radio and  one gyro instrument is all the regulations should require. If I want more, I  will add it.

  

 Happy  Skies,



Old Bob

AKA

Bob Siegfried

Ancient Aviator

Stearman  N3977A

Brookeridge Air Park LL22

Downers Grove, IL 60516

630  985-8503

Tdawson(at)avidyne.com
Guest

Posted: Mon Jun 12, 2006 4:44 pm Post subject: IFR Requirements

Not true.



TDT

RV-10 40025



--

flyboy494

Joined: 09 Jan 2006
Posts: 10

Posted: Mon Jun 12, 2006 6:47 pm Post subject: IFR Requirements

To take this thread in a little different direction, what is everyone's thoughts on Sporty's electric backup attitude indicator?



Kent



---- Tim Dawson-Townsend <Tdawson(at)avidyne.com> wrote: 

[quote] 

 Not true.

 

 TDT

 RV-10 40025

 

 

 

 --

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