light aircraft maintenance

[DoItForTheThrill]

Hi all,

I'm very new here so apologies if this is a silly question...:O

I understand that the for the most part, maintenance on aircraft requires a licence, but as a PPL arent you qualified to do, for example, 50hr checks/basic maintenance? If so, is anyone willing for me to tag along so I can gain a bit more knowledge/show me the ropes?

I'm recently qualified PPL based in the south east (trained at Redhill) and a flight simulator maintenance engineer at CAE. I'm a typical 'ive had a passion for aviation since i was a kid' guy and want to understand a bit more about the aircraft i'm flying... I thought here would be a good place to get some advice/pointers from you lovely aviators!

Any replies are very much appreciated,

Tom

[Jan Olieslagers]

(after deciphering)

The one thing I can assure you is that your PPL will not change anything here: it is a license for a pilot, i.e. it allows you to steer an aircraft. It says nothing about maintenance or repair work.

There are certain jobs anybody may do, example wiping the windscreen. Perhaps you may even replace the fuse that was blown when your ladyship wanted to power her hairdryer from the cigar plug.

The exact limit of what you may do depends on the class of craft (much much more is possible on Permit to Fly craft) and on law and tradition in your country.

[Prop swinger]

The rules concerning pilot maintenance for EASA aircraft are laid out in Part M: details here (https://drive.google.com/file/d/0B8HBzUxq6Dqwa2p5VWhTdjZUSTg/edit?usp=sharing)

[Crash one]

I would recommend that you join the LAA then join your local "Strut/club". Find out who the resident LAA inspector/engineer is and ask him, I am quite sure you will be welcome. Depending on your relationship with your engineer, if you own a Permit aircraft you could well be allowed/encouraged to carry out virtually all of the maintenance under his supervision/guidance/sign-off.The average spam can or Permit aircraft is no more complex to maintain than a 1960s classic car.


If you rent club aircraft, maintained through CofA, Part M etc, you will not be allowed near it and you will learn nothing .


An example: a friend of mine in a syndicate of 8, a Cessna 152. Faulty oil temp gauge. Gauge replaced, (eventually) by local CofA maintenance outfit cost: ~£800, shared between them.


My own (sole owner) Permit aircraft, vacuum gyro compass, (DI) not working.
Venturi tubes removed, all pipe work replaced, Venturi tubes stripped of paint, oil, muck, and repainted. Instrument removed from panel, air inlet filter found blocked, removed, cleaned, replaced. All reassembled. Test flown, all perfect.
Total cost: £16 including purchase of a mini pipe bender. All work done by me, checked & approved/signed off by my inspector.

[DoItForTheThrill]

Thanks for the replies, looks like it isnt going to be as easy as I thought :S

To be honest im at the stage where im trying to involve myself in the general aviation community and I thought with my avioncs and maintenace skills ive learnt through CAE I could try through the maintenance side of GA...

Crash One, thank you for the LAA explination, quite a cost and leniancy difference! I'll have a look into it :)

Tom

[Crash one]

Tom.

You are welcome. Please also be advised that "leniency" may be but integrity is not in any way compromised by the different system. LAA inspectors work for their love of the job, they ask little more than their direct expenses, their reputation is important to them. If you speak to a CofA maintenance organisation you may hear all sorts of opinions regarding "non approved parts" fitted etc. our system works on the principle of "Fit for purpose" as well as "approved" depending on the function of the part. The system is a delegation to the LAA who then regulate with the approval of CAA. Engineers are all qualified CAA certified engineers. All work carried out has to be approved, checked & signed for, both by the person who actually did the work and the engineer.


So if I were to mention that the door handles on my a/c came from B&Q DIY store, the stainless steel exhaust was welded/repaired by an agricultural engineer/welder. Please don't be alarmed!!! The tyres came from a CAA approved source at ~£1000 with paperwork.


Good luck.

[magpienja]

Get into microlights and you have lots of freedom for your own maintenance...some things just need a check over by an inspector when your done..very often at no cost.

[Maoraigh1]

but as a PPL arent you qualified to do, for example, 50hr checks/basic maintenance?

The EASA document refer to Pilot-Owner - not just any PPL. You can only do it on your own plane. (or part-owned). You can't do it on someone else's plane.

[Monocock]

I felt I should step in here when I saw the word 'leniency' with regard LAA maintenance.

Leniency is far from what LAA maintenance is about. The standards are as high (if not higher) than C of A stuff, but just without the stupid overhead costs and rip-off prices.

I used to pay a company to keep my Cessnas flying and I paid them a fortune for routine stuff. Since then I've seen the light and have taken the LAA route. My maintenance standards are higher (really they are), I am involved in my maintenance and my costs are 85% less than what they were.

No brainer IMHO.

[Russell Gulch]

Get into microlights and you have lots of freedom for your own maintenance...some things just need a check over by an inspector when your done..very often at no cost.

Not just microlights, the same applies to Group A aircraft on an LAA permit too.

[robin]

Just be clear.

Whether you are LAA or CofA, you can work on your own aircraft as much as you feel comfortable. You only need to convince your LAA inspector or your engineer as to the quality of your work.

They have to sign it off (except for the pilot/owner bit) so they will want assurance you know what you are doing

[Crash one]

I would love to know the practical reality of that. It may be CAA legal practice but what about the practicality of asking your local Part M engineer to believe your capabilities and sign for them, thereby not getting the job himself?

[A and C]

It's strange that if you read the comments above when I am certifying an EASA aircraft with a license that took a lot of time and effort to get I am one of the ripoff scum using the EASA system to take advantage of the poor innocent aircraft owner.

Then I go and do the same job on an LAA aircraft I a wonderful person supporting light aircraft owners.

It would seem that first a lot of the comments above seem to think that I can live for free and do not deserve to make a living and also fail to understand that a large proportion of the maintenance costs are directly or indirectly a result of regulatory issues imposed by the authority's.

The fact of the matter is that a lot of the LAA flying is living on the back of EASA certified aviation by using an engineering and supply chain that simply would not otherwise be in place.

As for Quality control of LAA aircraft I think that some of you should have another think about this, I have been presented with more than a few appalling death traps that I am expected to certify ( for little more than expenses ) and then a bunch of abuse when I won't renew the permit on the said death trap .

It is only the experience training that most LAA inspectors have gained within the industry that keeps these death traps on the ground and protects the owners and general public from those who think that aircraft can be held together with sealing wax and string and even try to beg borrow and steal this because they won't part with a penny even on critical safety issues unless forced to do so.

The LAA system has my utter respect as do the inspectors who are in the front line when it comes to quality and flight safety issues.

[Monocock]

I wouldn't disagree with many of your comments.

However, my point was more along the lines of being able to buy identical (but not 'ticketed') parts under the LAA system is where there is a huge industry-wide rip-off going on. Two identical parts, from the same factory, and a C of A person has a to pay up to ten times more for theirs. For what?

I think there are also as many (using your terms) death traps on the C of A fleet as there are LAA fleet. I know of at least two maintenance firms who are happy to shut their hangar doors on an aircraft for 9 days, change the oil, clean the windscreen and then sign it off for anther year, all for the sum of £2,500.

Another one, not far from here who actively advertises as 'the cheapest place you'll get an annual'. That's hardly the kind of ethos the industry needs is it?! It's also doing nothing for the integrity of that side of the industry.

To be clear, I don't think maintenance firms are charging too much for their time. It's the cost of parts and paperwork that's got silly. I pay £90 per hour for a man to service my farm machinery, and he has only a fraction of the training that an aircraft engineer has. Sadly though, with aviation being mostly a hobby for SEP owners, it's highly cost sensitive. Tractors earn me money and I'm therefore prepared to pay the costs that are required to keep them working. SEP owners want everything for as little cost as possible, as there is no financial return from their investment.

My post last night was not berating maintenance firms; I just wouldn't want to be in your shoes and put up with the typical private GA SEP owner wanting something for nothing.

[A and C]

The reason that parts without certification cost less is that you are waving your right to take the manufacturer to court in the event of failure as they are selling you the part on the grounds that it is to be used in an experimental aircraft and so you take full responsability for its use.

This vastly reduces the manufactures liability insurance bill.

[Monocock]

Thanks, I'm aware of that. All I was suggesting is that I think most non-commercial C of A type operators (ie private Cessna/Piper owners), given the choice, would be more than happy to save 75% of the cost of a new part by having one (identical) that didn't have a certificate of conformity.

I'm not suggesting that inferior or alternative manufacturer parts are used as substitutes, but there is a raft of identical hardware (made in the same factory) out there that can be sourced, albeit without the all-important 'yellow ticket'.

On the subject of alternative manufacturers, there are also lots of cases where it seems ludicrous that alternatives are not permitted too. Take interior plastics for example in a C172. It costs thousands to replace a whole set in an aircraft if one buys genuine Cessna ones, and one is obliged to do just that. However, other manufacturers churn them out for 20% of the cost and because they're not 'approved' on a C of A type, they can't be used. I'm not convinced that the aircraft in question is going to enter 'plummet mode' just because the panel and door trim plastic isn't genuine Cessna stock.

And the above example is a single one of hundreds that can be made.

[A and C]

You are now getting into the realms of PMA parts, there is no doubt that some manufactures are taking advantage of a dominant position to overprice parts, Cessna are becoming the worst at this. At one time Cessna parts were quite reasonable in price but of late the price has gone through the roof.

At the same time because of the economy's of scale company's are now producing PMA parts at half the Cessna cost and in some cases better quality.

The trouble with PMA parts is that some manufactures like McFarlane produce high quality parts and others like a well known cylinder manufacture produce junk.

As Monocock says some would be happy to fit parts with no paperwork, this is OK until some Far East sweat shop owner finds out he can make more money manufacturing aircraft control cables than he can making Breitling ripoffs....... Then the surviving family members of the unfortunate cheapscate who dies following a control failure will be asking why the CAA was not protecting them from poor quality parts.

[Big Pistons Forever]

It seems to me the fundamental problem is the rules that are in place to ensure the safety and traceability for the exotic and special parts on large commercial aircraft are being mindlessly applied to small aircraft parts.

A perfect example is the electric aux fuel pump. The last one I saw replaced came with a big stack of paperwork and a hefty bill. But when you opened the box the instruction package thoughtfully provided details on how to install the pump in your boat, car, or home generator.:rolleyes:

You could go on the web and order the exact same unit direct from the manufacturer for 1/5 the cost. The box still had its original manufacturers shrink wrap around it so nobody in the aviation supply chain that sourced and handled it ever looked at the pump, did any QA, etc etc , what you were paying for was only the paper to make it legal.

What makes me scared as the owner of a certified aircraft is that the, mostly USA based, light aircraft supply chain is going away fast. Decreasing demand coupled with an ever increasing regulatory burden is causing many of the companies that supply parts to get out of the business. Some popular types like the Piper Commanche, have parts that are now officially made of "unobtainium". Some of these aircraft are going to get grounded for extended periods of time or even for ever. because of the inability to obtain one crucial part.

[cockney steve]

Then the surviving family members of the unfortunate cheapscate who dies following a control failure will be asking why the CAA was not protecting them from poor quality parts.

Fortunately, the thousands of LAA permit plane parts that continue to lack traceability,do not lack the ability to continue operating as part of said aircraft!:)
I have the greatest respect for your posts, A&C, but on this issue, I think you are somewhat misguided.
It would seem the LAA do a terrific "halfway house" job , between a totally unregulated market and the ludicrously over-regulated Cof A market.

(didn't help on the boeing battery fires, did it?:} )

How many crashes have been put down to parts-failure?....now, how many regulated Vs. unregulated parts.

I'd suggest the benifits are minute when set against the cost of compliance..Big Pistons' post is affirmation of this.


Some years back, i had a customer with a porsche...An electrical problem indicated a possible fuel-pump fault.....Owner appears some days later with a boxed "genuine Porche" fuel -pump at an eye-watering price..."but the waiting-area was lovely and free tea and coffee"

NO!- squire, you paid for it.....that is a Bosch fuel pump for your Bosch injection system...Had you gone t a Bosch agent, the same pump is 20% cheaper, retail....Had I ordered it, I'd have got it less 25%, so I could have charged you less labour to fit it!

Said guy was a qualified solicitor and I had to carefullyexplain that, the "specially sourced" Bosch pumps, could have been , for example, those that had no scratches on the paint. Performance parameters were laid down, so it could alsohave been those that showed the smallest deviation-level in the tolerances.

He realised that vanity and bits of paper had clouded his judgement.
No different from BP's scenario....A lit of money is made on this paper-trail and "insurance against liability" racket.

It will be interesting to see how UK GA develops , if ever the hurdles against night flight, instrument/ imc flight, instruction etc. are removed from the Permit fleet......Iguess there's a huge vested interest in keeping them, in order to artificially incentivise the continuance of the C ertified stuff.

But what would I know, just a cynical old sod who's seen a bit!

[A and C]

As an LAA inspector where do I draw the line when it comes to fitting a safety critical part to a permit aircraft ?

Do I fit an bolt for an unknown sorce ? Do I get that bolt magnafluxed to Check it ? Do I fit an aviation bolt with a release note ?.

Should the bolt fail and someone die which of these actions would a court see as not exercising the duty of care that as an LAA inspector ?

It seems to me that some on this forum don't spend money on quality assurance, and expect LAA inspectors to take the responsability for parts fitted for next to no financal reward.

I don't give a damm about the nif-naf & trivia bits of LAA aircraft but when it comes to the Quality control of critical parts there is only one standard for aircraft and that is the same for a Piper cub and a B747, it is just how we achive that quality assurance that may differ.

[Silvaire1]

Most of the worlds privately operated certified light aircraft operate without traceability paperwork required for replacement parts. FAA regs require that the installing mechanic verify that the part is legal by whatever means he has at his disposal, no manufacturer paperwork required.

The FAA certificated mechanic doing light aircraft repairs operates outside of a maintenance organization, doesn't pay government or quasi-governmental fees to any organization, and is free to supervise others in doing certified aircraft maintenance. His authority includes supervising aircraft owners maintaining their own aircraft and also supervising, inspecting and signing-off work such as weld repairs and machine work performed by uncertificated personnel. By my observation most privately owned N-registered aircraft are maintained by team work between owner and FAA mechanic, in either the owner or mechanics hangar. There is no recognition or necessity for a documented maintenance program except for following FAA requirements that cover all aircraft, for instance A.D. compliance and generic annual inspection requirements. The over regulated maintenance paperwork and licensing/fee structure that one reads here as being inextricably associated with 'C of A' aircraft does not apply.

[robin]

Since I've been in aviation, both in Permit and CofA types, the most frustrating thing I've found is in maintenance.

CofA types are more expensive (my prop was 20% more than the identical Permit equivalent) because of Form 1.

I've been ripped off by maintenance organisations over the years whether the aircraft was Permit or CofA - the worst was an LAA inspector, surprisingly.

I'm pleased to say my current CofA arrangements have been great. Delays do happen, but so do they with certain inspectors.

I've also seen some seriously dangerous Permit aircraft - one had to be transported to its new owner by road as it was in such a poor condition and another, after its delivery flight was grounded on the spot. I have little doubt it occurs with CofA aircraft as well.

But these days I would be very wary about buying a homebuilt or kit aircraft.

[Big Pistons Forever]

I once was hired to deliver a Cessna 421C from Toronto to the West Coast for its new owner. It had a fresh 100 hr/ annual inspection. By the time I made it back home the snag list was 59 items long. :ugh:

[Genghis the Engineer]

As an LAA inspector where do I draw the line when it comes to fitting a safety critical part to a permit aircraft ?

Do I fit an bolt for an unknown sorce ? Do I get that bolt magnafluxed to Check it ? Do I fit an aviation bolt with a release note ?.

Should the bolt fail and someone die which of these actions would a court see as not exercising the duty of care that as an LAA inspector ?

It seems to me that some on this forum don't spend money on quality assurance, and expect LAA inspectors to take the responsability for parts fitted for next to no financal reward.

I don't give a damm about the nif-naf & trivia bits of LAA aircraft but when it comes to the Quality control of critical parts there is only one standard for aircraft and that is the same for a Piper cub and a B747, it is just how we achive that quality assurance that may differ.

Whilst I agree with the basic principles, surely as an LAA inspector you aren't fitting anything. You're overseeing, inspecting, and certifying the work carried out by the owner or the person they've hired to do the job.

A CofA aeroplane has work done by a qualified person; a PtF aeroplane has work checked by an independent qualified person. As a BMAA inspector I'm prohibited from signing for my own work, and I thought that the same applied to LAA?

G

[A and C]

Perhaps I should have said inspecting rather than fitting but the principle stands, in these day when accidents never happen because the lawers are driving society to always think that someone is to blame an inspector has to be very careful.

A few years back an recreational aircraft inspector was involved implicated in events that resulted in a fatal accident, the law did not difereciate between the duty of care that the recreational inspector and a professional inspector must give. The results for the inspector were tragic as the full weight of the law and prison loomed, and this all because he was acting with the best of intentions and made a mistake.

In my view this puts the inspector in a very dangerous position, if something goes wrong he can loose his home, his savings and his liberty if he fails to take reasonable steps to assure the quality of the work he is certifying..........and all this for travel expences !

The bottom line is that there has to be some sort of quality control on safety critical parts, and this sort of audit trail costs money and if you want to fly you have to understand you must pay for this quality control.

[cockney steve]

The bottom line is that there has to be some sort of quality control on safety critical parts, and this sort of audit trail costs money and if you want to fly you have to understand you must pay for this quality control.

And there is!

Any reputable manufacturer will have a QC system in place, as evidenced by the fact that steel-framed buildings, bridges, cranes, schools, hospitals.......aren't falling about around our ears!
All metric fasteners have a strength-code embossed on them (not sure about Unified, it's been a long time:O )
Even cheap "knockoff" Chinese Quad "bikes" are NOT notorious for falling apart......granted, they usually rust pretty quickly and screws and bolts often shear off if they don't get pre-treatment....so, I;d say the threat of in-service failure is a red-herring....
The threat is real, of course, Statistically, it's vanishingly small, as is the chance of a piece of alloy tube or sheet in a Microlight failing......If you think I'm spouting crap, please explain why the CAA have decided that lightweight single -seaters are perfectly OK being unregulated...
AIUI, not evena basic fabric-strength-test (Betts test? ) Joe soap, the pilot of said machine , is quite within his remit to pick up nuts and bolts from his local hardware-store...Fortunately, the nature of the undertaking/hobby, and the mandatory pilot-training, make it probable that he is well-aware of the safety-implications of using sub-standard components.....He'll also know that the "off the shelf" High-tensile fastener-stock from a reputable engineer's supplier has probably sold in it's billions , against the aircraft-approved equivalent in it'sthousands or millions....and probably with a lower failure rate,despite Fred the steel-erector not having a torque-wrench or an understanding of elastic deformation, etc.

There are areas where items are stressed to the limit....IMHO, they are undersized...in these instances, I can see the point in NDT -ing every itembefore release from the manufacturer.

The Rotorway helicopter comes to mind as an example of engineering down to the margin....I believe it has now become reasonably safe and reliable.

I remember looking at a Rans aeleron pivot -bolt and bracket,thinking how flimsy it was, then realising that it was probably about 10 times bigger than it actually needed to be, for the loads developed in service.

Certified aircraft, carrying thousands of Pax, in the air ~ 20 hours a day, 7 days a week......yes, I can see the value of an extra layer of quality-assurance.

I struggle to see any benifit to GA and the statistics and evolving legislation would appear to back up my view.:)


Was very impressed with the Vans AD's re-cracks ...what a well-built machine, for an "amateur" product.

[A and C]

Your choice to flag up the Vans aircraft as amateur built is a bad one the only thing "amature" about the Vans is that no one is paid to build them, it is for all intents and perposes a factory built aircraft assembled in shed & garages all over the world and made out of standard aviation parts.

On the other issues I think we are in violent agreement, when I say quality control I mean just that, it is not nessesaraly reams of paper it is just the assurance that the part is fit for service, as you say motorcycles don't fall apart but we must be sure that the HTS bolt is fit to hold the motorcycle together and is NOT the bolt that held together the packing case the motorcycle that the motorcycle was delivered in !

In a lot of cases for American size standard parts buying from normal aviation sorces is the cheapest way of quality assurance, for metric the best way to go would be a reputable sorce who can provide a certificate of conformity.

As for the CAA's attitude to single seat microlights, I think they are relying on the fact that these don't have much energy and the only person likely to be killed by the machine is the pilot........... Added to the fact that the CAA scale of charges is regulated by the MTOW resulting in there being very little money in regulation of microlights.

[cockney steve]

@A&C said single seat microlights, I think they are relying on the fact that these don't have much energy and the only person likely to be killed by the machine is the pilot.

But what about the patients, puppies and schoolchildren the intrepid Aviator may fall on?:}

resulting in there being very little money in regulation of microlights.

Now we get to the reality......CAA is a self-serving beaurocracy, Admittedly,the Government's insistence on using it, uniquely in a Public Service, as a milch-cow, doesn't help it to serve the interests of the customer. there is a clear conflict of interest in serving the customer's needs , whilst ensuring a very firm grip on the nuts, which can be squeezed readily,until the pips squeak!

it is for all intents and perposes a factory built aircraft assembled in shed & garages all over the world

Disagree, It's an aircraft built from factory-quality parts, assembled by totally unqualified amateurs in highly variable -quality surroundings.

Here we are, arguing the toss on another thread, as to wether a formerly-licensed engineer is capable of changing and cleaning spark-plugs, yet we agree that Joe Soap can build a superb aircraft,albeit progress-checked by an experienced supervisor at regular intervals.

Totally agree, re- the difference between packing-case bolts and good-quality ones...the point stands, the ones with the "bit of paper" carry a ridiculous premium which is little more than monopoly abuse and extortion. Statistically, I would suggest the differencein risk is ,realistically, unmeasurable....therefore, either the insurance industry is abusing it's position, or the supply-chain is.

[A and C]

If you are looking for abuse of a monopoly it is the Leagal (so called) profession, these are the people who charge huge fees in search of huge compensation payouts from the industry.

It follows that the insurance company's have to charge large premiums to provide liability insurance to manufactures and maintenance company's. In addition to this the industry has to maintain a large paperwork trail to prove that the work has been done properly beond reasonable doubt to stand a chance in court as the leagal profession only has to prove a civil case on the balance of probability.

On the subject of Vans aircraft the reason that fleet quality is high is the ease of inspection, what you don't see is the bits of rejected structure as the homebuilder learns is craft............... It is almost imposable to inspect a composite aircraft to this depth without being present during almost all of the composite lay up and so the quality control of these aircraft in a problem.

The last thing I have to ask you is that if you were an LAA inspector fitting a safety critical bolt to an aircraft ( remembering that your family home and liberty are at risk if you get it wrong) what quality assurance would you be happy with ?

[cockney steve]

The last thing I have to ask you is that if you were an LAA inspector fitting a safety critical bolt to an aircraft ( remembering that your family home and liberty are at risk if you get it wrong) what quality assurance would you be happy with ?
As Mr Genghis pointed out. I wouldn't be fitting anything
I would be saying to the constructor....."This bolt with the impressive tag, is fifteen quid,- if it fails, the CAA can issue an alert and maybe , just maybe, recall the rest of the batch....IIRC it happened with Robinson helicopter main-blade bolts cracking....So, it's not an absolute guarantee of quality.......Your alternative is to go to "bloggs engineer's merchants" and buy a box of 100 for six pounds...you should know the BS Spec. for ht fasteners, you shouldknow the strength-coding on the head.....If not, google and learn.....then check the rest o fyour aircraft Your call, you need a dozen, 6p each, no paper trail or 15 quid each" " your life your decision".

But I'm not a LAA inspector, anyway :p
Were I to bw building, I'd hope the inspector would lead me to make informed choices....As I said before, the certificate is no guarantee of quality, neither is "GKN bs xyz" on the box....but they both have product-liability and therefore , one assumes, insurance for same.
I believe that even the main hang-bolt on a flexwing , has a backup safety strop? The "Jesus bolt" on a heli, doesn't....it goes, you're dead traceability will not help you!


Interesting discussion....I'd love to see a similar stimulus to UK GA, as the American "Experimental" scene, but don't think I'll live to see it happen :hmm:

[Genghis the Engineer]

Depends upon model.

Ravens for example have no backup to the hangbolt, whilst all the Mainair types do. I don't think that the Pegasus aircraft range have a backup.

In practice, it's probably not the most critical "Jesus" bolt anyhow, that is the much smaller bolts in the bottom corners of the A-frame.

Doesn't stop me checking the hangbolt bloody carefully every time I rig, and given it costs about £10 or so, changing it at half the recommended interval :8

G

[Jodelman]

but they both have product-liability and therefore , one assumes, insurance for same.

The standad products liability insurance wording excludes parts for aircraft. The specialist supplier will have made special arrangements not so the general dealer.


a. any products relating to aircraft, including missiles or spacecraft, and any ground support or control equipment used in connection with such products

b. any products installed in aircraft, including missiles or spacecraft, or used in connection with such craft, or for tooling used in their manufacture including ground-handling tools and equipment, training aids, instruction manuals, blueprints, engineering or other data, advice and services and labour relating to such craft or products

[ChickenHouse]

Let's get back to the original question.

Yes, the PPL is a pilot license and has nothing to do with maintenance, at first glance. But, from tradition it has been assumed that a pilot has basic knowledge of all relevant mechanics of his plane to repair it on even remote places of the world. By this, a privately operated even licensed light aircraft can have a certified maintenance manual on basis of so-called pilot-owner maintenance. For the certified part the manual has to state which maintenance can be done by the screwing hobby mechanics - i.e. 50h/100h/200h maintenance can usually be done by pilot-owners, annual has to be done by a part.145 organization, so at least once a year somebody does have an eye on it. There is a very large variety of things allowed to be done by this pilot-owner and yes, it is coupled to the license by the above mentioned reason.

[cockney steve]

Thanks, Jodelman1 Seems like the insurance industry share a lot with the bankers ( Bank manager- guy who lends youan umbrella but snatches it back at the first sign of rain!)
Those exclusions are the ultimate in arse-covering!
Ultimately, it would need a test-case to establish if a sub-standard part had product-liability attached, irrespective of application. A bolt stressed to 50% of it's designated loading/stress parameters , doesn't know if it's holding an undercarriage leg or a car suspension-leg!

@ Genghis,.... I can see your point, but apart from throwinfg away ~£5 of "unused-life" what about the A-frame bolts?

Those fitted have proven safe so far.

changing introduces the risk of...
incorrect fitting...faulty bolt....faulty nut....wear in fixing-points.....
OTOH, the one removed, may have been about to give way :eek:

(crossing with the thread on scheduled maintenance and "if it aint broke, why fix it" schools of thought. ):)

[Genghis the Engineer]

It's my aeroplane (well shared with two other likeminded hedgehoppers), we do pretty much all the maintenance between us, and slightly worn or corroded fasteners just get replaced as a matter of course, because we can, the cost is trivial, and it creates this warm fuzzy feeling of a slightly "better and safer" aeroplane.

Flexwings are rigged/derigged and bits disassembled for inspection as a matter of routine anyhow. They're designed for it. I know it's unnecessary, but it's still my aeroplane and I can. I wouldn't, as an inspector, insist that somebody else did unless the part was genuinely approaching end of life or unsafe.

Same with some other things like cleanliness, neatness of wire locking, tidiness of wiring - there's acceptable safe standards I'd insist on if overseeing somebody else's aeroplane, then there's the higher standard I want on my own.

G

[Jan Olieslagers]

@chickenhouse: thanks for patiently explaining. Is the regulation you mention fixed in law? If so, is it limited to certain countries? What does EASA say on the matter?

[A and C]

What troubles me is that you seem to have a very strange idea of the price differential between high quality bolts from a commercial source and those standard parts from an aviation source, the fact is given the extra effort to check the suitability of the commercial bolt and the liability ( or lack of ) issues the price differential is very small for the extra quality assurance.

As for the so called freedom of the American experimental scene, it is all very well for those who know what they are doing but it gives the idiots a chance of killing them selfs and any innocent who is unfortunate to fly in the aircraft built by an idiot. I have only once been unfortunate to get involved with an experimental type Imported from the USA, my lasting memory from a string of safety critical defects was the high voltage strobe light wires that passed through the fuel tanks inside a bit of normal garden hose !

This aircraft can't have been typical of most American home built aircraft and may be it got to the UK because all the locals in the USA had the inside information on the builder, but it shows that the LAA quality system is in place for a reason, and works well to keep a check on those who don't have the skill or knowledge to do the job properly.

[cockney steve]

@ A&C I just use the example of bolts, as a common product with no publicised safety-issues or recalls in the vast numbers sold commercially.

It could just as easily be pop-rivets....back in the early 60's I was fabricating aluminium yacht -spars (aluminium spars for yachts, before the Grammar nazis strike :} ) We used an aircraft rivetting system for affixing tracks that had a rivet about every 4 inches down each side. I have no idea if these rivets were certified, time expired, or what. certainly, the pop-rivets were aircraft-spec, but carried no "papers"
The real issue, is , as cited by a previous poster, an "off the shelf" standard product having the price ramped by several hundred percent, merely because a supplier has insured themselves against "a claim"

In spite of all this bull, the fact remains, parts still fail in service, are no better quality because of the paperwork and the whole industry of certification is largely selling an illusion.

Rotorway helicopters were notorious for transmission failures and main driveshaft -failures....The parts were redesigned...Rotorway didn't go under in a sea of litigation...Why? Because buyers knew they were buying a product at a fraction of the "proven" mainstream Heli's price.

IF we choose the cheaper route in this country (LAA Permit)-there is a massive cost-saving, allowing many more people to fly, who would be priced out of the "Certified" market.

The statistics conclusively PROVE that permit-aircraft are just as safe (if not safer) as those where there is a huge paper-trail.

I am certainly NOT knocking the Permit regime....on the contrary, I'm suggesting that it's far more cost-effective than the Cof A regime and , were the artificial obstacles removed (night, IFR, hire/reward/training for example) there would be little incentive for GA to pay the huge premium over Permit,that C of A demands, with no demonstrable benefits.

(I'd also suggest that GtE's microlight bits are far cheaper than if they were CAA components.)
Therefore, more affordable and easier to justify changing.

[robin]

When we had a prop strike a few years back, we ordered a new prop. The particular model was a fairly common one and it arrived quickly, but we were asked if we were fitting it to a CofA or Permit type

The price differential was £400+ even though the prop is identical in every way to that fitted on hundreds of Permit aircraft.

Does the additional effort really amount to that level of cost?

[A and C]

By guess is that 80% of the extra cost would have been to pay for the manufactures liability insurance and the rest for the extra paperwork.

However I don't discount the fact that the prop supplier was pulling a fast one.

cockney Steve

I still don't understand your claim that the basic American nuts and bolts are supplied at a price ramped up by "several hundred percent" 20 % would be nearer the mark.

[cockney steve]

I still don't understand your claim that the basic American nuts and bolts are supplied at a price ramped up by "several hundred percent" 20 % would be nearer the mark.


Sorry, I didn't mean to claim , categorically, that all American (Unified) bolts were marked -up by an obscene amount....I wastrying to suggest that there's an enormous amount of mass-production stuff, which , as many will know, already have full traceability....but, as soon as a copy of that traceability is supplied in a format that denotes "aircraft" the price is ramped totally disproportionately.

You obviously have a huge personal investment in time, qualifications and cash, to secure your industry -position.... I, too, would mount a stout defence of the status-quo, under those circumstances. I repeat.... Where are the statistics that show any individual component producer being held liable and needing insurance several hundred percent more than standard insurance....
Re-quality assurance....even a cheap, nasty Taiwanese consumer nick-nack can, and does, get a public recall in case of serious fault being detected....so, a five- quid set of hair-curling tongs, can have documented, accurate batch-control and monitoring.......now we have the "but aircraft parts are made in very small quantities"...Some, yes, over a certain level, small-batch production does not see a huge saving, if ramped-up to mass-production..

The fuel-pump quoted by another poster, is a prime example of profiteering from the captive Aviation-market.
Ultimately, over-regulation will kill the Certified GA market.

How the hell can Cessna justify~ £400 for a flat-spring U-bolt, and then intimate that it's such piss-poor quality, you have to change it every 3 years.....this, despite the fact that many have been in active service in excess of 10 times that life, in a hard training-environment.......is the private, 50-hours a year owner (say 100 landings) really going to be happy paying aover £1 a flight, just for u-bolts???.....the worms will turn, I tell ya!:}

[A and C]

I don't think that it is the traceability that is the prime cost issue, it is the product liability insurance.

The failure of a critical aircraft part is likely to result in death, by the very nature of aircraft they are generally flown by the more affluent members of society and so if there is a liability case the numbers are likely to be large.

The chances of a domestic product attracting the same level of liability and the vastly larger number of units sold brings the insurance liability rate per item down to a very low level............. It's all a numbers game.

Just as the aircraft manufactures can't justify loading all the product liability onto the few critical parts the numbers game says they have to spread it over all the parts they sell.

From my point of view as an LAA inspector who has a duty of care to the aircraft owner I have to take the veiw that an aircraft bolt is better than an equally specification commercial bolt, they may be equally fit for perpose but when some smart lawyer finds out that the commercial item is also used in a domestic appliance and the Daily Mail prints the story that the aircraft was held together with washing machine parts how do you think this will play with a jury ?

You only have to see how the Lack of aviation understanding played out in the case of the BA 747 that made a poor approach at LHR a few years back played out to know what happeneds when those with little understanding of a subject are called to find fault.