And probably many parts on liners (A350, B787)
Peter wrote:
A Cirrus is bonded – as is the DA40/42 etc.
Seriously? Bonding is not exactly rocket science. Anyone capable of building a Lancair is equally capable of bonding it. Or do you mean incorporating nitted metal mesh? I think Lancairs have that also. If I don’t remember totally wrong here, it was Glasair (or Lancair?) who first developed bonding/meshing of composite aircraft. I think they even got NASA involved doing tests. Old Rutan canards is probably another matter maybe?
Peter wrote:
17-Jul-16 is this year.
I didn’t actually read it I only remembered we have had this discussion before, a loong time ago, and then I read some old German AIPs and the ECAC sheet. Reading it again, I don’t see the exact relevance, no references to German AIPs there.
Anyway, all UK LAA pilots with IFR capable homebuilts are welcome to fly IFR all they want in Scandinavia and Finland No questions asked (well, no more than with any other plane). Lots of airspace, lots of long distances and lots of ILS/GNSS airports all over the place (lots of VFR only airports also).
Is lightning susceptibility not a consideration for IFR certified aircraft? Does the LAA proposal address this?
Can a previous EASA aircraft be moved to LAA class?
Could say a PA-28 be moved to LAA register? If so can the owner then start fitting equipment himself that, although not being used for IFR could certainly increase the resale value and increase, possibly by a very big margin, the safety ( navigation, collision avoidance, situational awareness ) of their flying?
The reduction in paperwork and labour costs alone would be an enticement to go and fit a moving map GPS and ADS/B, Flarm, Engine monitor etc.
The LAA proposal “addresses” lightning protection by including a restriction on the permit. They are cleared for IFR but not in thunderstorms (and not in known or forecast icing conditions).
From the unpublished 2012 docs:
In essence, and unless something has changed, no bonding, no antistatic measures, no lightning protection.
The most obvious issue is that a static buildup will cause a partial or total loss of comms.
They mention something about US homebuilts being OK with this, but there may well be a very different mission profile involved.
Lightning is just one issue for bonding. I haven’t seen any mention about approval for operation in HIRF environments (High intensity radiated fields) which all essential EFIS attitude displays and other critical systems have to comply with for IFR in certified types.
Raiz wrote:
The LAA proposal “addresses” lightning protection by including a restriction on the permit. They are cleared for IFR but not in thunderstorms (and not in known or forecast icing conditions).
Well I don’t know of any certified aircraft cleared for thunderstorms or indeed known icing unless FIKI certified.
Agreed, I wouldn’t plan on flying in T storms, even if it were permitted.
Bonding is the interconnection of conductive surfaces, with bits of wire. But the surfaces need to be conductive to start with. On certified planes, you have a metal mesh embedded in the skin, which comes out on connection points which are then bonded together. A search here on “bonding” digs out many posts – example
That will give you lightning protection and static protection and RF protection.
If you don’t need lightning protection then you could achieve a good enough result by spraying the inside of the “plastic” (usually glass fibre, etc) with a conductive coating. There are many options, used in industrial electronics, and zinc is quite cheap and effective.
The business of flying into a TS is misunderstood. Nobody will knowingly fly into a TS or into a CB, in any aircraft. But IFR → IMC and IMC → you can’t see where you are going So unless you have a means of avoiding these things (radar, stormscope, a careful assessment of the wx situation and doing only short periods in IMC) you cannot be assured of not getting hit.
The bottom line is that if you have a “plastic” plane without the full measures (and that is just about all “plastic” homebuilts AFAIK) then you could have major issues flying in IMC.
Even in VMC, some types have comms issues due to a static buildup. You don’t need a high density of water droplets for this (i.e. you can have it in VMC). A few years ago, after a good service with plenty of grease in the elevator bearings, I almost lost COM2 whose antenna is further back (near the elevator). It was completely cured with a couple of lengths (2 for redundancy) of copper braid, running from the airframe to the elevator.
RVs shouldn’t have problems because they are all-metal. But for the others, an IFR approval is likely to just mean that they can usefully fly IFR in VMC, and in this case mostly within UK airspace.