Avionics installer working on my aircraft asked me for W&B sheet. I send him one, singed off and rubber stamped in March 2017. The aircraft was delivered to avionics installer in August 2017. There were no changes to aircraft equipment since weighting. There are no changes in aircraft records and the installer has received a complete photo documentation back in 2016. It looked just the same in August 2018. Here is replay of the installer:
“I previously asked you on the equipment list. The equipment list should be part of the paperwork with your aircraft. Without it it is impossible to tell what was included in the weighing and what was not included. It also shows which equipment was installed standard from the manufacturer, which equipment is optional from manufacturer, and equipment that was installed later. Then it also mentiones the approval. Typically it also mentions the weight and arm of each product. Basically now it is impossible to tell wheter the rotating beacon for example was installed by the manufacturer, or that added later, and if how it was. Therefor this was also unable to be used, and the DOA needed to make additional calculations based on my measurements. Please ask the previouse owner for the equipment list, if you don’t have it, and add it. It will also be helpfull to prevent you for loosing your ARC when and ARC inspector notices this.”
“Please supply me with a complete and correct W&B, including equipment list. If you can not reproduce this, we can generate on, but this will be relative expensive, especially if you have the paperwork available. If the paperwork is lost, you don’t have a choice. During the last W&B, likely after recovering your W&B and equipment list should have been actual for that time, and thus still quite relevant.”
I check aircraft documentation starting from 1972 and didn’t find a trace of equipment list the installer is asking for. There is a document called “registre de controle” showing which options were factory installed, but this is rather manufacturing registry then maintenance related document It doesn’t show weigh and arm of installed components. It was never updated. Aircraft maintenance records do not contain an “equipment list” which would be equivalent to factory “registre do controle”. There is radio equipment list and avionics list plus a lot showing engine, prop, magnetos etc etc etc.
Q 1: Can an installer undermine credibility of documents he received, especially when they were generated just 5 months before I delivered the aircraft to the installer and there is no reasonable doubt that the aircraft wasn’t altered.
Q 2: Even if the rotating beacon would have been installed illegally does it invalidate the W&B sheet? (for the record, the beacon was factory installed and the installer had the “registre de controle” on his mail since September 2017)
Q 3: Is there any regulation which would require aircraft owner to maintain equipment list with weight and arm?
In many cases, the original factory list would be in the W&B chapter of the POH.
Can an installer undermine credibility of documents he received
No; he should accept the documentation at face value. That is how the certification system works, otherwise every Release to Service would have to involve a total “back to birth” inspection (which, in turn, would involve the replacement of every life-limited part which does not have a serial number).
The above is… unless the installer has clear evidence of document forgery, smells a rat, etc.
Regarding the beacon… obviously if you have evidence the beacon was installed before the date of the w&b schedule which you have, then that w&b schedule must too be accepted at face value as including the beacon. The obvious observation is that the beacon is irrelevant to the overall w&b so one has to wonder why this is being raised at all. It is likely to be below the “triviality” threshold.
On Q3 I have no idea.
Peter wrote:
No; he should accept the documentation at face value.
Why? If an installer suspects that an existing W&B is incorrect, then he’s perfectly justified in querying it. Not just because he suspects it may be fraudulent, but because people make mistakes and a competent installer has a duty to release the aircraft to service with an accurate W&B report.
If for example, an aircraft has undergone several modifications since it was last weighed, then it’s possible that any calculated changes won’t reflect the current condition. From your own aircraft Peter, the W&B change you recently provided for your TAS605 failed to include the approx. 60 feet of antenna cables.
In the EASA SDMP for an ELA 1 aircraft, there is a requirement for a review of the W&B – see AMC M.A.302 (i):
Review weighing record to establish accuracy against installed equipment. Weigh the aircraft as required by the Part-NCO rules.
It’s also a requirement of the ARC renewal to check the status of the W&B AMC M.A.901 (d) (b)
Also from EASA OPs:
NCO.POL.105 Weighing
(a) The operator shall ensure that the mass and, except for balloons, the CG of the aircraft have
been established by actual weighing prior to initial entry into service. The accumulated effects
of modifications and repairs on the mass and balance shall be accounted for and properly
documented. Such information shall be made available to the pilot-in-command. The aircraft
shall be reweighed if the effect of modifications on the mass and balance is not accurately
known.
If an installer suspects that an existing W&B is incorrect
My comment was a general one, especially on the questioning of the legality of the beacon installation. That is just so totally ridiculous.
Weigh the aircraft as required by the Part-NCO rules.
the CG of the aircraft have been established by actual weighing prior to initial entry into service
That appears to contradict this post of yours which doesn’t mention a mandatory weighing requirement.
Practically, it is not that hard to weigh an aircraft (if you have the equipment or can rent it reasonably) so this should not be a major obstacle. It is doubly curious since the installer already has the aircraft!
One also wonders why an avionics installer is concerned with a factory installed rotating beacon?
The question from the mechanic, and his tone, is ridiculous. I’m not sure about what kind of silliness may exist on this aircraft’s (European?) register but very clearly many or most light GA aircraft do not have current equipment lists. Older aircraft did not even have them from the factory. What’s required is a valid and current W&B.
Here is what FAA says on the subject. Note their careful use the word ‘must’ to indicate a requirement to update (i.e to update the W&B record), and its omission elsewhere (in relation to the equipment list supplied by the aircraft manufacturer when the plane was built).
An equipment list is furnished with the aircraft, which specifies all the required equipment, and all equipment approved for installation in the aircraft. The weight and arm of each item is included on the list, and all equipment installed when the aircraft left the factory is checked. When an aircraft mechanic or repairman adds or removes any item on the equipment list, he or she must change the weight and balance record to indicate the new empty weight and EWCG, and the equipment list is revised to show which equipment is actually installed. Figure 2-22 is an excerpt from a comprehensive equipment list that includes all of the items of equipment approved for this particular model of aircraft. The POH for each individual aircraft includes an aircraft specific equipment list of the items from this master list. When any item is added to or removed from the aircraft, its weight and arm are determined in the equipment list and used to update the weight and balance record.
The guy works for you, on your property, in a way no different than the plumber who came to my house last week. His apparent obsession with a rotating beacon that is not within the instructed scope is not what you are giving him money to address. If he won’t follow your instructions, asks for data that he doesn’t need to do the job for which you’re paying him, while making threats about your next annual and adopting a ridiculous insolent tone, fire him.
wigglyamp wrote:
If an installer suspects that an existing W&B is incorrect, then he’s perfectly justified in querying it.
Sure, but what is suspicious in my situation? W&B was 5 months old where the aircraft was delivered. And the equipment list as requested by the installer was never created for my aircraft which was flying since 1972.
wigglyamp wrote:
Not just because he suspects it may be fraudulent, but because people make mistakes and a competent installer has a duty to release the aircraft to service with an accurate W&B report.
What happens then? The installer says “I suspect that your W&B is incorrect. I can make a new one but this would be expensive and cost you XXX”. What should I do? The aircraft is over 600 NM away from where I am at the moment and it’s been rendered unairworthy. There is no easy way to get there by airline and unfortunately it’s 13 hours drive. What would you do?
Silvaire wrote:
The guy works for you, on your property, in a way no different than the plumber who came to my house last week. If he won’t follow your instructions, asks for data that he doesn’t need to do the job for which you’re paying him, while making threats about your next annual and adopting a ridiculous insolent tone, fire him.
Call me an idiot, but I already transferred to the installer’s bank account 35k Euros.
I typically have any work done on my plane in my (locked) hangar and pay the bill at the end of the job. No progress payments. That will surely be my plan for installing ADB-B Out within the next year.
Doing a physical W&B measurement and report has nothing to do with creating an equipment list, and is a fairly quick and straightforward procedure. That’s one reason why equipment lists are very often not updated – why bother when you can instead reweigh the plane easily when and if required. I think your mechanic is attempting to crudely coerce you into giving him more money 
As Silvaire has suggested, the easiest solution is to re-weigh the aircraft. Any significant avionics upgrade will result in lots of deleted wiring and old equipment being removed, plus the new parts going in. A calculation in this case isn’t likely to be very accurate (determining the moment for a wiring harness?).
A reweigh typically costs less than 1% of the amount you’ve spent and you can have confidence that your empty weight and C of G will be correct.
If the aircraft is F-reg, the equipment list is mandatory alongside WB per national requirement.
Otherwise I’m not aware of any other european rule mandating an equipment list.
