Instrument Requirements for IFR

TopperHarley · Post by **TopperHarley** » Sat Jan 15, 2005 9:19 am

Hey guys,

From the Aerocourse ATP Workbook:

"Which of the following meets the min radio nav equipment required for an a/c operated by an air taxi operation, in IFR flight on an air route:

a. 1 RNAV and 1 GPS.
b. 1 VOR/ILS and 1 ADF.
c. 1 ADF.
d. 1 ADF and 1 GPS.

The correct answer is d. I know that a and c cannot be correct; however, I do not understand why b is incorrect.

If instead of saying "1 VOR/ILS and 1 ADF" it read "1 VOR/DME and 1 ADF," then would it also be acceptable? I believe that you need to have a VOR/DME combo in order to operate IFR (i.e. it can't just be VOR), but I have not been able to find a source for this.

The other thing that kind of threw me off on this question is the "air route" part. I understand that an air route is uncontrolled airspace (as opposed to an airway).

Thanks for all comments,

Chris.

jackrabbit · Post by **jackrabbit** » Sat Jan 15, 2005 10:20 am

I remember seeing that question and answering wrong as well. Sitting there thinking about it, the only explanation I can come up with is this.
I have never seen an airport that has IFR approaches without a beacon on or by the field, but there are tons of them without a VOR. The VOR in your airplane is useless at the airport with the NDB A approach. However, many of theses airports now have GPS or some type of RNAV approach.
I know that's kind of stretching it but....... maybe someone else has a better explanantion.

Tango01 · Post by **Tango01** » Sat Jan 15, 2005 11:18 am

It's weird how the VOR is not there, since you must determine your MEA and MOCA.

If it was VFR, you would need a GPS. CAR 723.28

T01

chipmunk · Post by **chipmunk** » Sat Jan 15, 2005 11:33 am

You do not need DME to fly IFR legally.

Benwa · Post by **Benwa** » Sat Jan 15, 2005 11:45 am

Tango01 wrote: If it was VFR, you would need a GPS. CAR 723.28

CAR 723.28 wrote:723.28 VFR Flight Minima - Uncontrolled Airspace

The standard for reduced VFR limits of one mile in uncontrolled airspace is as follows...

Here's what I think of this: if you fly IFR, you need to be able to navigate even if you lose one of your navigation equipment.

With the VOR/ILS - ADF combo, you would need an air route covered by both VOR and NDB stations. Which is not all that common in uncontrolled airspace. On a NDB - NDB air route, if you lose the ADF, you can't continue with your VOR...

Or they just made the common mistake that an air route is a ndb-ndb route...

Benwa

Cat Driver · Post by **Cat Driver** » Sat Jan 15, 2005 11:57 am

Hmmmmmmmm..

Answer is D...

How many airplanes being operated IFR in 2005 would have an IFR certified GPS and the only other working nav aid was an ADF???

Or am I just getting senile and can't see the picture?

Cat

Tango01 · Post by **Tango01** » Sat Jan 15, 2005 11:58 am

Jack, your post makes sense, but the questions isn't based just on an approach. How about the enroute?

Benwa you're right, I quoted the wrong reg. Can't find the appropriate one for Chris.

T01

Airtids · Post by **Airtids** » Sat Jan 15, 2005 12:09 pm

What would've been the answer 8-10 years ago? What has changed? You're not using a study guide produced by a guy whose name rhymes with 'No Shame" are you?

Benwa · Post by **Benwa** » Sat Jan 15, 2005 12:10 pm

Before the GPS era, a good answer would've been flying with 2 ADFs.

---

You will not find anything specific in the CARs, they wrote the regulation without reference to specific navigation equipment on purpose.

As mentioned in this Policy Letter.
http://www.tc.gc.ca/CivilAviation/comme ... /PL142.htm

Inthesoup · Post by **Inthesoup** » Sat Jan 15, 2005 3:53 pm

RTFQ2. It's for an A/C operating on an Air Route (uncontrolled airspace). Your minimum Altitude would be the ASA (area safe Altitude).

Benwa · Post by **Benwa** » Sat Jan 15, 2005 4:45 pm

Well, inthesoup... if you fly an air route, I'm quite positive you can fly the published MEA for that route...

If you fly outside an air route in uncontrolled airspace, you need the route approved by TC.

Spiraldive · Post by **Spiraldive** » Sat Jan 15, 2005 5:26 pm

C-hris:

The rule is actually fairly simple: The rule is based on where you are flying and what you need to get there. The last of a whole heap of regs about it says:

605.11 to 605.13 Reserved

(j) sufficient radio navigation equipment to permit the pilot, in the event of the failure at any stage of the flight of any item of that equipment, including any associated flight instrument display,

(i) to proceed to the destination aerodrome or proceed to another aerodrome that is suitable for landing, and

(ii) where the aircraft is operated in IMC, to complete an instrument approach and, if necessary, conduct a missed approach procedure.

So (b) is wrong because if you lose the only adf you have on an air route, and the only backup equipment you have only reads vors, you're fucked. The VOR/ILS do nothing for you in that case, so its up to you to figure out if you've got enough ifr stuff for any given flight.

(d) is correct, because the GPS qualifies (if it and you are certified) as the "second" piece of equipment. You can still get there with the gps-only if the adf fails, or the adf-only if the gps fails. The vor is just useless weight for that particular flight. They are trying to see if you know the difference between the mx regs (ie. the equipment required to get a plane certified in the first place, v.s indicator, oat gauge and all that shit), and the interpretive part of the regs.

Dual adfs would qualify too, on an air route.

It's that easy.

Benwa · Post by **Benwa** » Sat Jan 15, 2005 5:35 pm

Spiraldive, an air route can be an Uncontrolled VOR to VOR route... so you'd be fucked with an ADF + GPS ...

There's not enough information in the question to give a definite answer.

Often you have a NDB to VOR Air Route, so then again what equipment do you need ?

Spiraldive · Post by **Spiraldive** » Sat Jan 15, 2005 6:55 pm

Benwa:

You're right. Forgot that airoutes come in the vor/vor format too. Frankly, never flown on one in that format either. Most of them are adf somewhere along the line. Aerocourse was probably assuming the adf thing in the original question, hence the gps/adf answer. They do need to specify the radio aids available on the route to ask that question and expect an answer.

And in answer to your other question, same rule applies. An ndb to vor airoute: Then you'd need either gps/adf/vor (gps lets you fly vor or adf), or dual adf/vor's. Alternate equipment not included.

Benwa · Post by **Benwa** » Sat Jan 15, 2005 7:32 pm

Spiraldive wrote:Benwa:
You're right.

I love being right.

Cat Driver · Post by **Cat Driver** » Sat Jan 15, 2005 7:55 pm

What about only having two IFR approved GPS's ?

Cat

Benwa · Post by **Benwa** » Sat Jan 15, 2005 8:31 pm

Our good friends at TC wrote:GPS is approved as a supplemental navigation system for enroute and terminal operations, and as the “primary” means of navigation during a stand-alone non-precision approach. As well, Canada Air Pilot General (CAP GEN) and Aeronautical Information Publication (AIP), Rules of the Air (RAC) Section 3.14.1 do not permit the use of GPS approach minima to determine the suitability of an alternate aerodrome for flight planning purposes. This limitation restricts the flexibility to use GPS receiver, as compared to a traditional navigation aid such as VOR or ADF.

Sorry Cat, you can't. Unless they changed that.

Benwa

Cap'n P8 · Post by **Cap'n P8** » Sat Jan 15, 2005 9:04 pm

Of course, probably the most serious problem with a GPS is likely to be loss of RAIM, which would hoop all the GPS units on board anyways!

Benwa · Post by **Benwa** » Sat Jan 15, 2005 9:06 pm

Yeah the GPS in my C172 once showed me flying at 170kts @ 42 000' 60nm off track.

But it's a portable GPS... an approved one would have at least warned me...

as a side note: I was flying VFR that day.

Cat Driver · Post by **Cat Driver** » Sat Jan 15, 2005 9:31 pm

Funny thing is I have been using GPS all over the world for years and can only recall two very short interrupted receptions, and they were both caused by poor placement of the antenna on a handheld.

Once turning final at Bourdeaux France, it was off for about ten seconds and the other time was just approaching Bamaco, Mali in Africa...that time the antenna fell on the floor.

I prefeer the Anywheremap because I can mount the thing right in front of me on the glareshield, sort of like a quasi HUD.

By the way we run three or four GPS units all the time and seldom see any difference in the info being displayed beyond a knot or so difference in GS due to repeatability set to set.

Cat

Benwa · Post by **Benwa** » Sat Jan 15, 2005 9:40 pm

Yeah this was the first and only time anything bad happened with the GPS.

There was a lot of solar activity causing electromagnetic irregularities.

I use PocketFMS on my PocketPC, it's really good... and it's free !!!

Try it out, if you find any bugs, you just write to Rob and he's quite fast at fixing it. Being on the software subject, I also recommend AirPlan, I've been using it for over 4 years now. It's awesome.

Spiraldive · Post by **Spiraldive** » Sun Jan 16, 2005 1:02 am

Benwa:

You're not right.

At least about the gps-alternate.

They have changed the rules. You can file a gps-only airport as an alternate (as in no adf onsite, gps approach only) under a bunch of conditions. If the airport has a traditional approach aid, you have to use those minima for alternate requirements.

Your destination must be served by a conventional navaid. You must establish raim at the alternate before you leave the ground (by asking fss for the satellite notams and checking them against the office copy of the world gps satellite almanac, yeah, like that'll happen, or turning the avionics on). Then you have to check the raim again for the alternate before you reach halfway to your destination.

And I believe two ifr-gps units would qualify. TC no longer requires the monitoring of conventional underlying approach aids if you are shooting a conventional non-precision approach using gps information.

TopperHarley · Post by **TopperHarley** » Sun Jan 16, 2005 8:08 am

SpiralDive,

There is one thing that I have not been able to find the answer to regarding GPS-use at alternate airports. You mentionned that if there is a traditional instrument approach at the alternate as well (NDB, ILS, VOR), you use those mins; however, what if the airport only has GPS approaches available? Will the mins be based on whether you have VNAV capability or not? (i.e. if you only have LNAV, then the mins are 800-2; if you have VNAV, the mins are 600-2, etc)?

Thanks in advance,

Chris.

Spiraldive · Post by **Spiraldive** » Sun Jan 16, 2005 10:22 am

C-hris:

V-nav is as yet not authorized for use shooting gps approaches. I suspect it's coming with WAAS and the placement of ground-based gps trancievers at airports, but as of yet you can't use it at all. They just have a place for it on the plates in anticipation.

When it does come in, I guess they'll have to decide whether v-nav qualifies as a precision approach. Knowing TC, they'll probably come up with a new standard like 742' and 2 5/16miles.

But for now, the mins are the standard non-precision 800-2 for filing gps-only alternates.

Also, I see from the July aip amendment, they now allow you to use the gps minimums at your alternate regardless of whether there is a traditional approach aid there. But if you do, you're not allowed to plan to shoot a GPS approach at your destination, you must use the traditional aid.

Benwa · Post by **Benwa** » Sun Jan 16, 2005 10:32 am

Spiraldive wrote:And I believe two ifr-gps units would qualify.

Transport Canada wrote:GPS is approved as a supplemental navigation system for enroute and terminal operations

Is that still true ? If so, you can't fly the EnRoute part with only 2 GPS units. You'd need the traditional equipment.