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Compass

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expglider

I'm New Here
Is it required to install a compass in an experimental aircraft? If so can you tell me were I will find that in the regs?

JG
 
And...

...in the newest Van's "THE RVATOR" (fourth issue 2010), Sott McDaniels has an article on Magnetic Heading Indicator calibration. He also mentions that a magnetic compass is not required, only a MHI device.
 
expglider said:
Good stuff, thanks. Would an experimental be legal to fly with no magnetic indicator of any kind?

JG
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Well, I think that one may be able to legally fly a plane without a MHI provided:

that the plane was kept at 10,000' MSL, or less,
that the plane was operated in day light,
that the plane was not being used for any sort of commercial applications,
that the plane was flying in VFR conditions, and
that the plane was kept out of controlled airspace.

However, I seriously doubt that any DAR would approve of an experimental without some sort of magnetic heading indicator regardless of where the plane was going to be used.
 
Agree with Crossbow--91.205 does not apply unless you want to fly at night or IFR, IOW no instruments of any kind are "legally" required for day-VFR ops. However, if you desire to fly at night or IFR, then not only does the 91.205 night and/or IFR requirements apply, but all of the daytime VFR requirements apply as well.
 
Not right.
91.205 (b) lists required equipment for VFR, DAY. Item #3 is... Magnetic Direction Indicator. Can't get much more specific than that.
 
aerhed said:
Not right.
91.205 (b) lists required equipment for VFR, DAY. Item #3 is... Magnetic Direction Indicator. Can't get much more specific than that.
Click to expand...

Common mistake. You gotta read part (a) too. Experimentals do not have standard airworthiness certificates.

(a) General. Except as provided in paragraphs (c)(3) and (e) of this section, no person may operate a powered civil aircraft with a standard category U.S. airworthiness certificate in any operation described in paragraphs (b) through (f) of this section unless that aircraft contains the instruments and equipment specified in those paragraphs (or FAA-approved equivalents) for that type of operation, and those instruments and items of equipment are in operable condition.
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Day-VFR requirements apply only to aircraft with standard Airworthiness Certificates:

91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.

We're talking E-AB AWCs so there's no requirement to adhere to 91.205. IAW with the OP Lims, 91.205 does apply for night and IFR:

(8) After completion of phase I flight testing, unless appropriately equipped for night and/or instrument flight in accordance with ? 91.205, this aircraft is to be operated under VFR, day only.

In those cases, the VFR parts do apply because of the way the para is worded:

91.205
(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.......

NOTE: Para b is the day VFR section.

91.205
(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......
 
aerhed said:
Not right.
91.205 (b) lists required equipment for VFR, DAY. Item #3 is... Magnetic Direction Indicator. Can't get much more specific than that.
Click to expand...

Well, you are correct, of course. Because the regulation that you refer to aplplies to "Powered Civil Aircraft with a Standard Airworthiness Certificate" (see below), and if one wants to get an airworthiness certificate for their experimental plane, then one had better follow this regulation.

http://rgl.faa.gov/Regulatory_and_G...D97FA35A1232A3988625768F005C12DE?OpenDocument

However, I was answering the question that was asked about flying an aircraft without a Magnetic Direction Indicator and that is why I said that such a plane can be leaglly flown provided that one keeps out of controlled airspace, flys in the daytime, flys in VFR conditions, and so on.
 
Yeah, I know but the "authorities" usually won't buy off on the distinction. Same wording for anti-collision lights, fuel gages, etc. I bet you won't find a DAR that will give an A/W cert for an instrument-free airplane.
 
Agreed. Legal is not always synonymous with safe and/or practical. In this case I'm with you that most likely receiving an AWC would be problematic without any instrumentation. It's probably been done, but that would definently be the exception to the norm and I certainly don't condone this extreme course of action, legalities aside.
 
On the practical side, if you don't have some means of indicating the plane's magnetic heading, you won't be able to use a manual or electronic E6B to determine the wind's direction and speed in flight with a GPS.
 
E6B? Is that an app on the iPhone? :D

A question from the practical side (read, what will get me into, or keep me out of, trouble...then again, that's assuming consistency of interpretation of Standard vs Experimental AWCs and consistent enforcement...hmmmm...oh what the heck, I'll ask anyway):

I've seen the discussion of wet compasses, and what will get you through a DAR inspection, versus a ramp check. I've seen reputable posters say they used a stick-on compass for the DAR inspection, and then tossed it. My plane had a vertical card compass dangling from the center post, and I've replaced it with a velcro-on compass. Both were/are worthless, as least in my case (IMHO).

If I toss the velcro add-on, and run with nothing, am I legal (I have two Dynons, and I feel yes in Day/VFR, not sure for Night/VFR). I meet all the other 91.205 requirements for Night/VFR, and the plane is not equipped for IFR (Day or Night), so not worried about that.

Whaddya think? It really is another way of asking the original question...I think! ;)
 
elippse said:
On the practical side, if you don't have some means of indicating the plane's magnetic heading, you won't be able to use a manual or electronic E6B to determine the wind's direction and speed in flight with a GPS.
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Why would you need that info if you had a gps with you?
 
Thanks again.

Here is the situation that sparked the question. I am an A&P and was working on a sailplane that is experimental. I noticed it had no compass in it. I informed the owner that it needed one to be legal and he argued that it did not, as it made no mention of a compass in the manufacturers manuals or the operating limitations page. I have found nothing that says differently, even though the ship had a compass at one time. There is no electrical system and no other direction indicator installed.
Either way - when he needs one, he will be going somewhere else for a conditioanal inspection.
JG
 
expglider said:
Either way - when he needs one, he will be going somewhere else for a conditioanal inspection.
JG
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Huh??? Why is that? Everything in this thread shows that he was right and that he did not need one. So why are you now not interested in doing a conditional inspection for him? If you just did not get along personally, then I understand your statement but if your decision is based upon the question posed in this thread I am confused as to why you feel this way.
 
Also note that even if 91.205 did apply to an experimental, note that it says POWERED...
So I guess even standard certificated sailplanes don't need compasses.

The stuff you learn here, amazing.

But I would like to know why someone that has built a fine flying machine worth many thousands of dollars would not want to have a $100 dirt simple, ultra reliable magnetic compass in their airplane. Especially in something that is travelling at least over 2 miles a minute. Even my J-3 needs a compass and you can just barely get lost in that; heck it takes half a day just to get out of sight of your departure point!
 
My decision to do a conditional and soon to be annual, on an aircraft takes into consideration the owner/operators attitude toward mainteance and safety as well as the condition of the AC. The repair I just did was taking care of a previous repair that was illegal and done without documentation.

JG
 
expglider said:
My decision to do a conditional and soon to be annual, on an aircraft takes into consideration the owner/operators attitude toward mainteance and safety as well as the condition of the AC. The repair I just did was taking care of a previous repair that was illegal and done without documentation.

JG
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I don't blame you in the least for not wanting a client that may give you grief in the future.

Having said that, you have now tickled my curiosity concerning the repair. What kind of repair would be illegal on an experimental aircraft? Also, there is precious little legal obligation to document repairs on an experimental aircraft.

Did it involve a "major modification" that changed the configuration of the airframe from what it was when the aircraft was originally given an experimental airworthiness certificate? The need to place the aircraft back into Phase One is the only scenario I can think of that would trigger concerns of legality.

Thanks in advance for any clarification.
 
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This experimental situation is a bit different than yours as most of you RV'rs are the builder. This ship was manufactured overseas and certificated as experimental when shipped to the US. Many repairs need approval by the provided manual, manufacturers authority, 43-13 or DER since the ship is manufactured. The repair that was illegal was a broken cable, spliced back together with U bolt clamps, probably purchased from Tractor Supply co.

JG
 
gasman said:
Why would you need that info if you had a gps with you?
Click to expand...

My Garmin 196's E6B function (yes, it has one), asks for heading and uses that with IAS and total temperature (that's OAT plus stagnation rise) to calculate TAS and wind speed and direction. When you make a pirep to FlightWatch that's the info they would appreciate having. But even those guys don't know what total temperature is 'cause I asked them. They don't seem to realize that these planes that fly close to 200 mph or more might be giving then the wrong poop about OAT. When I use this function, I must first set IAS to zero and put in my OAT which has no rise, note the density altitude, then put in my IAS and increase the temp until I get the same dalt; usually I have to add 5F to OAT to get total.
 
expglider said:
This experimental situation is a bit different than yours as most of you RV'rs are the builder. This ship was manufactured overseas and certificated as experimental when shipped to the US. Many repairs need approval by the provided manual, manufacturers authority, 43-13 or DER since the ship is manufactured.
Click to expand...

Ok, that mades sense. I'm not familiar with the "imported assembled experimental" regs and how they differ from our domestic experimental environment (in our case, not being the builder doesn't impact legality of repairs).

The repair that was illegal was a broken cable, spliced back together with U bolt clamps, probably purchased from Tractor Supply co.

JG
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That is not good...legal or otherwise.............
 
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I wish I could put winglets on my glider and put myself back in a box but the co that made my glider is out of business. I need to get a DER - to much hassle.
I appreciate all the input on my question and your putting up with a guy with no engine. My brother has a RV6. I am looking fwd to installing a autopilot this winter.

JG ;)
 
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