VOR Check question

I was told by an avionics guy that if a plane has VOR's they must be
accurate to file IFR, even if I file /G.

FAR 91.171 says "(a) No person may operate a civil aircraft under IFR using
the VOR system of radio navigation unless the VOR equipment of that
aircraft..."

I'm not debating the logic of having VOR's that are accurate, and I'm
getting mine adjusted - but it seems to me if my means of navigation is an
IFR certified GPS I do not have a legal responsibility to pass the VOR
check. Am I right?

Michael

On 7/22/2005 12:01, Michael 182 wrote:

I was told by an avionics guy that if a plane has VOR's they must be
accurate to file IFR, even if I file /G.

FAR 91.171 says "(a) No person may operate a civil aircraft under IFR using
the VOR system of radio navigation unless the VOR equipment of that
aircraft..."

I'm not debating the logic of having VOR's that are accurate, and I'm
getting mine adjusted - but it seems to me if my means of navigation is an
IFR certified GPS I do not have a legal responsibility to pass the VOR
check. Am I right?

Michael



You are also required to have available in the aircraft equipment necessary
for navigation along your route, in the event GPS goes out. That sounds like
VOR to me.

--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

if you go to the AIM: 1-19-1, d. 1.
(b) Aircraft using GPS navigation equipment under IFR must be equipped with
an approved and operational alternate means of navigation appropriate to the
flight.

So basically you MUST be able to complete the flight without GPS, so you'll
probably need a VOR (checked) to be able to comply with that.


"Michael 182" wrote in message
...
I was told by an avionics guy that if a plane has VOR's they must be
accurate to file IFR, even if I file /G.

FAR 91.171 says "(a) No person may operate a civil aircraft under IFR
using
the VOR system of radio navigation unless the VOR equipment of that
aircraft..."

I'm not debating the logic of having VOR's that are accurate, and I'm
getting mine adjusted - but it seems to me if my means of navigation is an
IFR certified GPS I do not have a legal responsibility to pass the VOR
check. Am I right?

Michael

Mark Hansen wrote:


You are also required to have available in the aircraft equipment necessary
for navigation along your route, in the event GPS goes out. That sounds
like
VOR to me.


Not if you have the right GPS. But an unchecked VOR is technically not
airworthy, so unless you're going to follow the procedures for inop
equipment, it would be easier just to do it.

Ron Natalie wrote:

Mark Hansen wrote:


You are also required to have available in the aircraft equipment necessary
for navigation along your route, in the event GPS goes out. That sounds
like
VOR to me.


Not if you have the right GPS. But an unchecked VOR is technically not
airworthy, so unless you're going to follow the procedures for inop
equipment, it would be easier just to do it.

Not so. VOR is still the primary means of navigation in the NAS. Even the
latest and greatest airline aircraft with dual GPS sensors, dual FMSes, triple
IRUs, etc, cannot be dispatched without operate VOR receivers (in their case
two).

The presumption is that the GPS system can fail at any time; at least in a given
area. WAAS doesn't mitigate that whatsoever.

If you use the VOR for IFR navigation, 91.205(d)(2) makes 91.171 apply
to you.

.... but (contrary to popular belief) there is no requirement under Part
91 (or Part 135) that says you have to have a VOR receiver to fly IFR.

So, assuming you don't use it, you're right.

"Brien K. Meehan" wrote:

If you use the VOR for IFR navigation, 91.205(d)(2) makes 91.171 apply
to you.

... but (contrary to popular belief) there is no requirement under Part
91 (or Part 135) that says you have to have a VOR receiver to fly IFR.


It's an indirect regulatory requirement because by FAA policy the primary
means of IFR navigation in the NAS is by VOR.

Whoever told you it's an indirect regulartory issue was making it up.

"Brien K. Meehan" wrote:

Whoever told you it's an indirect regulartory issue was making it up.

Well, okay, but I work with this stuff all the time.

Here is from the current FAA Order 8260.19C:

l. Dual Minimums. Enter dual minimums, when authorized. Do not publish
dual minimums unless a 60-foot operational advantage is obtained or a
reduction in visibility can be achieved. To avoid proliferation of dual
minimums, *all IFR aircraft are assumed to have at least one VOR
receiver*. Dual minimums based on a stepdown fix combined with local and
remote altimeter settings could result in four sets of minimums. When two
remote sources are used, treat the source resulting in lower minimums as
the "LOCAL" altimeter setting source in the following paragraphs.
Document only two sets of minimums. The combinations authorized are
minimums with and without a stepdown fix; or minimums with local and
remote altimeter settings.

The words between the asteriks are reflective of FAA Class I navigation
policy, which is a requirement to be a part of ICAO.

And, from the FAA's Instrument Procedures Hanbook (available in Summit's
Aviation Reference Library):

In the broad concept of air navigation, there are two major categories
of navigational operations consisting of Class I navigation and Class II
navigation. Class I navigation is any en route flight operation conducted
in controlled or uncontrolled airspace that is entirely within
operational service volumes of ICAO standard NAVAIDs (VOR, VOR/DME, NDB).
Class II navigation is any en route operation that is not categorized as
Class I navigation and includes any operation or portion of an operation
that takes place outside the operational service volumes of ICAO standard
NAVAIDs. For example, your aircraft equipped only with VORs conducts
Class II navigation when your flight operates in an area outside the
operational service volumes of federal VORs/DMEs. Class II navigation
does not automatically require the use of long-range, specialized
navigational systems if special navigational techniques are used to
supplement conventional NAVAIDs. Class II navigation includes
transoceanic operations and operations in desolate and remote land areas
such as the Arctic. The primary types of specialized navigational systems
approved for Class II operations include inertial navigation system
(INS), OMEGA, Doppler, and global positioning system (GPS). Figure 4-15
provides several examples of Class I and II navigation.

wrote in :

Not so. VOR is still the primary means of navigation in the NAS.
Even the latest and greatest airline aircraft with dual GPS sensors,
dual FMSes, triple IRUs, etc, cannot be dispatched without operate VOR
receivers (in their case two).

The presumption is that the GPS system can fail at any time; at least
in a given area. WAAS doesn't mitigate that whatsoever.

Not only airliners - I have to have 2 (not just one, but 2) operable VORs
to dispatch offshore, where there are precisely zero VOR transmitters,
and I'm almost always out of range of any VOR. But both VORs have to be
operable to dispatch IFR.

Ain't bureaucracy wonderful?

--
Regards,

Stan

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." B. Franklin