U/S Instruments - should an aircraft be flown with them?

[Contacttower]

the 172RG I mostly fly definitely has one.

Is there a difference between what most light aircraft have (outlined below) and a MEL like one would have in a larger aircraft? My understanding is that one is part of the POH but an MEL is something separate?

Just looking in the C182T's POH what it does have is a "Kinds of Operation Equipment List" which identifies the equipment required to be operational for airplane airworthiness in the listed kind of operations; Day VFR, Night IFR etc.

For example for day VFR the HSI does not need to be functional but for IFR it does...

[BillieBob]

So a defect in any piece of equipment whose proper functioning is not mentioned as a condition or limitation in the flight manual is not unairworthy, as a matter of law.

That is true so long as the aircraft continues to meet the relevant certification standards on which the Certificate of Airworthiness was issued. A failure to meet those certification standards voids the Certificate of Airworthiness and the aircraft no longer complies with Article 16(7).

To determine the minimum equipment requirements for any aircraft it is necessary to consult the relevant Certification Standard, the Flight Manual and Schedules 4 & 5 of the ANO. Further requirements above the minima may be set, in specific cases, by an Operations Manual, which may also include an approved MEL.

[dont overfil]

Coincidentally a CAA e newsletter has popped up this morning with links to an FAA site on the very subject. Sorry I can't offer a link.

D.O.

[englishal]

Where in the POH does it say which equipment may be unserviceable for flight?

Regarding instruments, we have a table in our POH/AFM for the Commander which lists type of flight (i.e. VFR day, VFR night, IFR) and which instruments are required to be operational. It is similar to the list in the FARs and actually you don't require an awful lot of instruments to fly.

Off the top of my head, to fly day VFR you must have:

Oil temp - in the case of an air cooled engine
A means of determining the fuel onboard
Oil pressure
Altimeter
ASI
Compass
CHT

and that is about it.

For IFR you need some additional stuff, like a clock, and navigation aids suitable for the flight.

[Grob Queen]

Thankyou again everyone. I think I am getting a clearer picture wrt instrumentation now.

Thank you for your post Prof Reed. So am I to understand then, in simple speak that one can legally fly without some instruments. But SENSIBLY it is up to the pilot to make up his/her mind when checking the aircraft/type of flight/wx conditions etc etc?

PB and GW-i'm pleased to see that cross checking the compass and DI is normal practice and not jsut down to my being thick . I am taught FREEDA cx when about to make a visual recovery and after the A and B of "ABC" cx. My cx during flight are "FEEL" about every 10minutes (when I remember or when my instructor prods me )

PB - Many thanks too for your detailed info on DIs, isogonals, prop pitch and Deviation. Thats really extremely helpful and explained in away that this "technical idiot" can understand!

We do indeed have a deviation card on the coaming, but we never use it!!!

GW - What are "UNOS?" Couldn't work that one out! I see what you mean about using the compass only.....my brains fried enough during a navex at the mo - but i'll get used to it...it is all part of the fun and challenge of flying after all! "CS" props, are they teh variable pitch type?

TVM GQ

We do not have the blue lever or MP in the Grob, but the Firefly dies indeed have such equipment

[thing]

Sounds an odd set up at your place GQ (I think I've said that before!). You ought to come up the road and see the stuff we fly. I reckon if we crushed them all together we'd get one serviceable a/c...There isn't an a/c on our fleet that doesn't have one fault (or several) at any one time.

[Grob Queen]

We may be odd thing, but its a damn good club to belong too We do have our problems...only today our engineer serviced one Grob, our other is having its bandy legs changed and has been u/s for a while, back on Monday, when the Firefly goes for its annual......

I really will come to you guys at some point (make that 5 minute flight when I'm qualified ) but probably before!

[peterh337]

This thread rapidly got confused between flying without the legally required equipment, and operating in accordance with some kind of "MEL". The former is relevant to all aircraft (though what exactly is legally required is to be found in multiple sources; not in one easy place) but a formal MEL is found in larger aircraft, and in AOC ops of any aircraft.

[Gertrude the Wombat]

So am I to understand then, in simple speak that one can legally fly without some instruments. But SENSIBLY it is up to the pilot to make up his/her mind when checking the aircraft/type of flight/wx conditions etc etc?

Correct.

cross checking the compass and DI is normal practice

Correct.

[Pilot DAR]

So am I to understand then, in simple speak that one can legally fly without some instruments. But SENSIBLY it is up to the pilot to make up his/her mind when checking the aircraft/type of flight/wx conditions etc etc?

Well Grob Queen, close, but overly simplified.

The regulations don't always give the pilot room to use sense. Sometimes you just gotta read and follow the regulations....

The Canadian regulation for this situation reads:

605.10 (1) Where a minimum equipment list has not been approved in respect of the operator of an aircraft, no person shall conduct a take-off in the aircraft with equipment that is not serviceable or that has been removed, where that equipment is required by
(a) the standards of airworthiness that apply to day or night VFR or IFR flight, as applicable;
(b) any equipment list published by the aircraft manufacturer respecting aircraft equipment that is required for the intended flight;
(c) an air operator certificate, a private operator certificate, a special flight operations certificate or a flight training unit operating certificate;
(d) an airworthiness directive; or
(e) these Regulations.
(2) Where a minimum equipment list has not been approved in respect of the operator of an aircraft and the aircraft has equipment, other than the equipment required by subsection (1), that is not serviceable or that has been removed, no person shall conduct a take-off in the aircraft unless
(a) where the unserviceable equipment is not removed from the aircraft, it is isolated or secured so as not to constitute a hazard to any other aircraft system or to any person on board the aircraft;
(b) the appropriate placards are installed as required by the Aircraft Equipment and Maintenance Standards; and
(c) an entry recording the actions referred to in paragraphs (a) and (b) is made in the journey log, as applicable.

Item 1(b) requires you to do some rather involved research, to be sure, and item 2 specifies some actions that must be taken if it is determined that flight is permitted without that equipment. The pilot is resonsible for not flying until these are done.

[BackPacker]

The other difference between the list in the POH of a light aircraft, and a full-blown MEL, is that the list in the POH is typically very simple and definitive: The equipment on the list needs to be there and function normally for the flight to be legal. Period.

A MEL, in contrast, is far more complex. For each of the items listed (and there are a LOT of items), it will specify the legality of the flight, and the mitigation measures to take if that item is U/S. And these mitigation measures may depend on the status of other items as well.

Here's a completely random example:

Flight Deck Fuel
Quantity Indicators
(Main Tanks)
Except for ER operations, one may be
inoperative provided:
a) All boost pumps in associated tank operate
normally,
b) Fuel flow meters operate normally,
c) Center tank indicator operates normally,
d) Flight crew periodically computes fuel
remaining, or checks fuel remaining against a
pre-computed fuel burn chart, and
e) Fuel quantity in associated main tank is
verified by an acceptable procedure.

Here's a list of master MELs from the FAA:

Flight Standards Information System (FSIMS)

[dont overfil]

Thanks BackPacker.
That's the one I wanted to post.

D.O.

[Sir Niall Dementia]

Try this one; it gets interesting from page 289!

http://www.easa.eu.int/rulemaking/do...ASA_Part-M.pdf

I've heard a rumour from the CAA that ALL privately owned aircraft with a Public Transport Cat CofA that are also used in a public transport role (training, aerial photography, chartered to a flying club etc) are going to be required to have an MEL, Ghengis may be able to squeeze more from his contacts, all I've heard so far is the rumour.

One of the G550's I fly for a living is operated managed by us (an AOC holder) and flown privately for the owner and no-one else, under the CAM it is required to have an MEL, and our insurers wanted an MEL in place as well (we just gave it the same one as the other two aircraft)

When the CAA brought in MELs for AOC ops it was a nightmare, with little or no guidance, and long delays in getting approvals. I'd give good money to watch them trying to sort out the applications from a hundred different flying clubs, all with different ideas.

Thankfully my aeroplane is on a permit

[peterh337]

So many flying school planes have INOP kit, and this includes FTO planes and also includes planes operated under charter AOCs, that somebody will have fun mandating MELs for all these.

Or perhaps the declared equipment will not include the stuff that is INOP There is no legal requirement for an autopilot, for example, and e.g. the Islander ops did not even have them (INOP or not) for many years.

[DeeCee]

How do you know that? I have been a member of a few different clubs and I cannot recall any aeroplane with an inop instrument. Please justify that statement.

[Genghis the Engineer]

Originally Posted by DeeCee

How do you know that? I have been a member of a few different clubs and I cannot recall any aeroplane with an inop instrument. Please justify that statement.

I think you've been very lucky, I've seen dozens.

I regularly fly two CofA aeroplanes one with a permanently U/S autopilot, and the other with a permanently U/S VOR. The first is within a flying school, the second a club based syndicate.


As a young Flight Test Gingerbeer circa 1996 I backseated (plenty to choose from!) an evaluation of a DC3 for a role in pollution dispersal spraying. In the way of these things, my test pilot was a US Navy F/A-18 driver (don't ask), as FTE, I sat in on the brief. Part of which was along these lines:

Company pilot: "And to put the gear up, we'll pump this, which is the standby pump - the main being u/s".

Test Pilot: "When the main system is serviceable, how do we do that?"

Company pilot: "You know, I've no idea. I've only been flying the aeroplane 4 years and haven't seen it serviceable yet."

G

[BillieBob]

I've heard a rumour from the CAA that ALL privately owned aircraft with a Public Transport Cat CofA that are also used in a public transport role (training, aerial photography, chartered to a flying club etc) are going to be required to have an MEL

Apart from the fact that none of the activities that you mention comprise public transport - they are all aerial work - the CAA clearly have not read the requirements.

So far as training is concerned, EASA have made it very clear that this will be subject to Part-NCO or Part-NCC depending on the type of aircraft used and irrespective of whether the activity is commercial or not. Part-NCO, which covers all non-complex aircraft (as defined in the Basic Regulation) makes an MEL optional. All operations under Part-NCC (i.e. in complex motor powered aircraft) will require an approved MEL.

Commercial operations, other than flight training, will fall under Part-CAT or (in the case of aerial survey, crop-spraying, etc.) Part-SPO and will require an approved MEL

[DeeCee]

Maybe I've just been lucky, although I wasn't thinking of DC3s. I've been flying for over twenty years from Stapleford, Top Farm, White Waltham, Thruxton, Oxford, Headcorn and Lydd, and I honestly cannot recall an instrument that didn't work. Maybe I didn't notice..........

[peterh337]

Actually a lot of duff avionics are not placarded INOP.... most VFR pilots don't know how to use an autopilot anyway so putting a sticker on it just makes the owner look like he is too tight to fix it

[Jim59]

I've come to this thread rather late.

I would like to suggest that AIRCOM 2010/12, The Management and Recording of Aircraft Defects, makes relavant reading. See link below.

"The purpose of this AIRCOM is to provide clarification and guidance to EASA Part M requirements relating to the management and recording of aircraft defects and deferred defects."

What is clear that aircraft with defects may fly either with, or without an MEL but only if the defect is recorded and has been deferred by an appropriate person. The appropriate person depends on several factors including the type of defect. If a defect has been identified and not deferred then the aircraft is U/S - even if the defective e.g. instrument is not a required instrument.

This applies only to EASA aircraft - not Annex II etc. For some defects, in some circumstances, a pilot may defer a defect - in other cases it must be an engineer.

http://www.caa.co.uk/docs/33/20101224_Draft7.pdf