In the latest SERA and AMC&GM to Annex VII (Part-NCO) publications, the list of instruments being required for IFR flight is surprisingly limited. The conclusion seems to be that the equipment needs to match the requirements of the flight, i.e. if you're only going to perform GPS approaches you only need an IFR GPS. As a result, ADF, DME and even a second VOR or barometric altimeter (mentioned nowhere) would no longer be required to have a Part-NCO plane IFR certified. Am I missing something?
Seems very pragmatic and in line with what happens in the USA. Seems valid for GPS approaches. But if a missed approach mentions DME or ADF, then the equipment becomes mandatory.
Yes i think you are right, the equipment list is minimal. On the other hand, the AMC requires an alternate static air pressure system. Something that is often not available nor on the STC list on general aviation airplanes.
That's actually in a Guidance Material, not an AMC. So it isn't required. Even if it was an AMC, you could use an alternative means of compliance, as per NCO.GEN.101, by cracking the window of the altimeter or VSI (as long as a functioning one remains).
[~93] cracking the instrument window taps into the static pressure of the cockpit, which does not meet accuracy requirements. In my aircraft the inside pressure is 300ft off.
[~2058] that's correct, the pressure inside the cabin will cause an error of a couple hundred feet, which must be taken into account (even with an installed alternate static source that is usually inside the cockpit on our small airplanes). A Guidance Material probably had to be used for this, because older certification requirements did not require one and some installs are not even available (like the shoulder harness requirement that was corrected in the last minute before Part-NCO came into force, which thankfully prevented a large portion of European aircraft from being grounded).
Tom, your reading seems correct to me, the mandatory equipment level is very low, and there is no such thing as a "certified IFR" plane,
BUT remember two points:
- First, you need to review the list of mandatory devices in order to operate your flight in the given airspace you will use : the device list is much longer then...
- Second, you have to consider also your own safety, do you feel OK to fly in the clouds with only the minimum required, even if it is legal ?? You may want to add a few goodies for your own "comfort", and I will not blame you..
Keywords are : operational needs, and safety. Seems OK to me!
Hope this helps
Hi Christian, thank you for your comments. The reason I asked the original question is that in my country (Belgium), at least until superseded by EASA, aircraft were indeed certified for IFR operations and it was not allowed to fly IFR in non-certified planes. Certification required al lot of equipment, including second altimeter, second comms, two VORs, ILS, a DME and an ADF. I'm not advocating flying IFR with only a GPS but I think it is a good evolution that that list can be reduced. A G1000 equiped C172 of my club was not certifyable because an ADF was missing, so this showstopper has now gone.
[~1472] your MEL probably mentions under ADF May be inoperative only under DAY VFR or if VOR is operational. Hence no requirement to have an ADF anymore for IFR.
Tom, please read
NCO.OP.140 Destination alternate aerodromes – aeroplanes
NCO.OP.142 Destination aerodromes – instrument approach operations
My understanding is that if you fly with IFR GPS, you need to have non GPS navigation means to perform your route to the destination aerodrome or alternate aerodrome. These means depend on the requested means as seen on the IAC charts of the intended destination or alternate. According to the aerodromes, you'll need either VOR, DME, ADF…
The additional requirement of NCO.IDE.A.195 confirms that alternate means of navigation is mandatory in case of failure of one equipment to continue you route.
I also understand that if you're in full VMC conditions, the contingency action can be to switch to VFR for a safe landing. Therefore IFR flight seems possible in full VMC with only one IFR approved GPS. Has anyone the same understanding?
I also haven't found any request for a second altimeter.
Denis, thank you for pointing that out, particularly NCO.OP.142: "Destination aerodromes — instrument approach operations
PBN OPERATIONS
The pilot-in-command may only select an aerodrome as a destination alternate aerodrome if an instrument approach procedure that does not rely on GNSS is available either at that aerodrome or at the destination aerodrome."
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