Pilot Maintenance - Avionics

[2close]

Could one of you learned gents point me at the piece of legislation, preferably an Approved Code of Practice as opposed to mere Guidance, that says that a Pilot Owner/Operator CANNOT undo a retaining screw on an aircraft radio, send an item off for a very simple repair then reverse the process upon return.

Many thanks for your assistance.

2close

[Fargoo]

2 Pilot Maintenance
A licensed pilot who is the owner or operator of the aeroplane may carry out the following:
• 50 hour check if the aeroplane is operated for private purposes;
• Certain maintenance tasks prescribed in Regulation 16 of the Air Navigation (General) Regulations 1993 (as amended), if the aeroplane
is operated for private purposes.
The issue of a Certificate of Release to Service is not required. The pilot must include his/her pilot's licence number with his/her signature
in the appropriate log book(s)..

From page 19 of CAP 411 - LAMS. Presuming it's a light aircraft for non-commercial use.

The Air Nav Reg 1993 says

Pilots maintenance—prescribed repairs or replacements

16. For the purposes of article 11(3), the following repairs or replacements are hereby prescribed—

(1) Replacement of landing gear tyres, landing skids or skid shoes;

(2) Replacement of elastic shock absorber cord units on landing gear where special tools are not required;

(3) Replacement of defective safety wiring or split pins excluding those in engine, transmission, flight control and rotor systems;

(4) Patch-repairs to fabric not requiring rib stitching or the removal of structural parts or control surfaces, if the repairs do not cover up structural damage and do not include repairs to rotor blades;

(5) Repairs to upholstery and decorative furnishing of the cabin or cockpit interior when repair does not require dismantling of any structure or operating system or interfere with an operating system or affect the structure of the aircraft;

(6) Repairs, not requiring welding, to fairings, non-structural cover plates and cowlings;

(7) Replacement of side windows where that work does not interfere with the structure or with any operating system;

(8) Replacement of safety belts or safety harness;

(9) Replacement of seats or seat parts not involving dismantling of any structure or of any operating system;

(10) Replacement of bulbs, reflectors, glasses, lenses or lights;

(11) Replacement of any cowling not requiring removal of the propeller, rotors or disconnection of engine or flight controls;

(12) Replacement of unserviceable sparking plugs;

(13) Replacement of batteries;

(14) Replacement of wings and tail surfaces and controls, the attachments of which are designed to provide for assembly immediately before each flight and dismantling after each flight;

(15) Replacement of main rotor blades that are designed for removal where special tools are not required;

(16) Replacement of generator and fan belts designed for removal where special tools are not required;

(17) Replacement of VHF communication equipment, being equipment which is not combined with navigation equipment.

If its VHF, it looks like you're covered by item 17.

The Air Navigation (General) Regulations 1993 (http://www.legislation.gov.uk/uksi/1993/1622/regulation/16/made)

Hope this helps. I assume by your initial post that you intend to remove an LRU, have it repaired and refit it?

[2close]

Thank you for the speedy reply.

It's actually an integrated VHF NAV/COM (with no external CDI), which I see is not covered by Item 17.

So the undoing of the retaining screw must be carried out by a fully qualified, experienced and competent avionics engineer, which means that the aircraft must be flown to such, transport back provided, then a full reversal of process once repair completed........for one screw.

I appreciate that testing, calibration and/or certification must be undertaken by a B2 engineer but undoing a screw....do be serious.

I can take a wing off and put it back on but not undo a screw to slide out a 'plug n play' unit.

Amazing....this can only have been written by an aviation authority 'specialist'.

:ugh:

[Fargoo]

You keep going on about this one little screw - what about the connections, the installation checks etc...?

Most of these rules are in place to protect people on the ground as well as the lump of meat behind the control wheel, past experience tends to shape the rules - unfortunately many people have over inflated opinions of their own abilities and tend to find themselves in all sorts of trouble.

Not saying this is the case with your good self just the reason the rules are there :ok:

[Kuchan]

You keep going on about this one little screw - what about the connections, the installation checks etc...?

Most of these rules are in place to protect people on the ground as well as the lump of meat behind the control wheel, past experience tends to shape the rules - unfortunately many people have over inflated opinions of their own abilities and tend to find themselves in all sorts of trouble.

Not saying this is the case with your good self just the reason the rules are there .

Well said, Fargoo.

[NutLoose]

It says replacement, you are not replacing it, simply removing it, I cannot see why you cannot take it out, send it off and arrange it to go to your avionics engineer, then he can fit it on one visit as opposed to two, just check with him if he is happy for you to remove it.

As for connections, as said most light stuff just fits into a tray, the plugs etc are all part of the said tray and as such are simply racked.

[wigglyamp]

The quoted regulation is not relevant to a certified aircraft. See EASA MA803(b) for the tasks an owner can do. The specifics are covered in part M appendix viii. In the case of avionics, tasks are limited to changing units that don't require the use of specialist test equipment to prove serviceability. For the posted example, how do you certify the VOR function if you can't check receiver sensitivity, bearing accuracy, single-tone failure on LOC etc without a NAV signal generator?

[Kuchan]

................send an item off for a very simple repair then reverse the process upon return .


.............send an item off for a very simple repair then reverse the process upon return .

Take it out, repaired and replacing it = replacement in my engineering understanding.

AS common sense prevails, it can be taken out by a crew send away but must be fitted (replacement) by qualifying person who can sigh the CRS unless as mentioned by Fargoo that the aircraft is for private purpose.

[jxk]

As a follow from this question. Can the aircraft be flown whilst the radio is away for repair?

[Kuchan]

Look in MEL

[SimWes]

Take it out, repaired and replacing it = replacement in my engineering understanding.

In my understanding of "replacing it", it means to replace it with an item that is not the original one (exchange repair or so)

If it is the original it would be: removal, repair and finally refitting

[Kuchan]

Any item fitted with a new GRN, batch number, green label or Form1 etc is a replacement which warrants a CRS signature.

[2close]

I welcome the comments gents and please rest assured no over-inflated opinion of own abilities (no offence taken whatsoever).....but have come across plenty that have such.

My enquiry simply relates to the need for a licenced engineer to remove a simple 'plug n play' (I use the term loosely) Nav/Comm unit, the majority of which that I have personally come across and presently refer to are held in their tray by one securing screw. No fiddling about with any wiring, etc. on the other side of the tray, just that one infernal screw! ;)

If the repair was a straightforward replacement of a worn item, say a frequency selector switch, and the repaired item is returned with EASA Form 1 saying it has been fully tested and is all OK, then surely the action of sliding it back into place and tightening the securing screw back up doesn't need expert intervention. The EASA Form 1 tells me it's all OK and if it's the same unit going back into the same rack, with absolutely no modifications whatsoever being made, I fail to see why I need to part with several hundred pounds for something so straightforward.

[grounded27]

As silly as it may sound you are hung up on the nav part as I read. If it flies, F%^ks, or floats... rent it is the saying. Many AME's with several thousand hours playing MSFS could fly your aircraft with a decent rate of reliability. We do not because we are not liscenced to do so. You need to understand the difference between what should be and what is!

[717tech]

If the unit is a COM/NAV, then I would have thought it would require testing before the aircraft is considered "serviceable".

If a test of some sort is required, you would need a licenced engineer to certify the installation?

[ukv1145]

The FORM1 does not prove that the unit is operating correctly when installed in the particular aircraft. For example the antenna system could be operating well below spec and the signals are not actually reaching the unit, this can only be tested reliably using a calibrated test set. There can also be many problems with distorted and worn mounting trays - the single screw is often connected to a locking pawl which can fail to engage with its receptacle and even though the screw is tight, the unit is not actually secured. Connector pins can be worn/broken/pushed back and particular functions may also not work reliably even though the box appears to be powered up.
I would say that removing the unit and sending it away would not be a problem but the fitting and testing by an LAE is a must.
The aircraft should not be flown with the unit removed even if MEL authorised - the MEL only allows for the system to be unserviceable - not removed from the aircraft.

[Fargoo]

If the repair was a straightforward replacement of a worn item, say a frequency selector switch, and the repaired item is returned with EASA Form 1 saying it has been fully tested and is all OK, then surely the action of sliding it back into place and tightening the securing screw back up doesn't need expert intervention.

The EASA Form 1 tells me it's all OK and if it's the same unit going back into the same rack, with absolutely no modifications whatsoever being made, I fail to see why I need to part with several hundred pounds for something so straightforward.

Have you had a quote for the job, I can't see anyone charging several hundred pounds for this job. You need to ask around at your local flying club and see who they use for small ad-hoc jobs.

What's wrong with your unit anyway? Have you had the fault diagnosed as a definite unit fault and not a wiring or interconnected system fault?

I'm glad you at least investigated the possibilities. Many people would just have gone ahead and changed the unit without looking into the pitfalls. :ok:

[Kuchan]

My enquiry simply relates to the need for a licenced engineer to remove a simple 'plug n play' (I use the term loosely) Nav/Comm unit, .....................to are held in their tray by one securing screw. No fiddling about with any wiring, etc. on the other side of the tray, just that one infernal screw .


As ukv1145 & 717tech and others have rightly point out, it is not simply one screw.
See the link for testing and the cost of the test kit.

Aircraftmech (http://www.aircraftmech.com/index-2.html)
Avionic tool . THE VOR/ILS/MB TESTSET