View Full Version : Dilemas of an airworthiness engineer

Genghis the Engineer
16th Jan 2004, 05:05
Interesting problem I hit today, hope you'll accept that I don't want to give specifics, but the generalities might be interesting.

I got asked today to go and spend a few hours with a man who has acquired an aeroplane. It's small, currently non-flying (although in excellent condition), and although obscure, nonetheless occupies an important slot in British aviation history - it's also probably the only example still in one piece. The aircraft hasn't flown for some years and has never held any documentation that would currently allow it to fly.

The gentleman who owns this fascinating antique wants to be able to fly it, he's also a fairly experienced pilot with a reasonable grasp of engineering - a good start. But, as I go through the aircraft and it's documentation it became very obvious that I couldn't possibly make it fly legally without some modification to the aircraft's basic design, and to meet current safety standards would mandate a huge redesign. It was also designed as a 2-seater, and there were potentially good reasons why it could only be allowed to fly solo.

Now, there's an excellent argument here that this beastie belongs in a museum. However, the owner is firmly of the view that aeroplanes should either be flown or scrapped, and he's no interest whatsoever in allowing it into a museum (not necessarily my own view, but I can see his point) - he is also fairly adamant that he wants to fly it (well, that's why he bought it!). Since he's the sole owner of it, if I'm to help preserve this piece of history, I have to find some way of allowing it to fly - and try and make sure he never crashes it !

An interesting dilema. The solution (or at least the general intent at present), which will no doubt take a fair while to achieve, is to reach a compromise of a fairly drachonian set of operating restrictions within which it can be safely operated, together with a minimum number of changes to the aircraft design - and trying to make those as visually identical to the original as we can manage.

Just thought I'd share that.


16th Jan 2004, 05:37
Hi Genghis,
Fascinating. D'you know, I think that just about defines the US 'Experimental' classification idea to a 'T'. Funny how that's not what it gets used for. Of course, I'm fascinated as to what it is... Granger Archeoptrix? (No, single (terified) seater)
NOT an engineer;)

I have control
16th Jan 2004, 07:47
JDK I'm confused by your comment. Did you mean "Experimental Exhibition"?

Feather #3
16th Jan 2004, 09:51
In Oz we've gone a bit beyond the US "Experimental" and have that plus a couple of other sub-categories below "Normal".

However, I thoroughly appreciate the dilemma. Dragging the UK authorities into the 20th Century in this arena may well be impossible, let alone the JAR's!!??:rolleyes:

What price a US experimental rego and fly it on a US licence in the UK?

Cheers ;)

Genghis the Engineer
16th Jan 2004, 15:29
On the technical point, without doubt if and when it flies (sorry, for various reasons I can't say here what it is) it'll be under the Permit-To-Fly route, which is the UK's sub-ICAO category.

There are actually a huge range of different sub-types of permit, and so far as I know that's what virtually all historic aircraft in the UK fly under. It varies from the very stiff operating rules of, say, a Gnat down to a very relaxed limited envelope, simple rules, flown on an NPPL of a single-seat homebuilt. What I have to do is find the right balance, then convince both the owner and the relevant authorities that it's an acceptable one.

The main difference between the UK system and the US system (apart from the name) is that in the US you have to convince yourself that you've done things sensibly, and tell the FAA that you've done so. In the UK, you have to convince either the CAA or their "delegated authority" (most usually the PFA) which means a bit more paperwork - but the systems are more similar apart from that than most people think.


16th Jan 2004, 16:30
Hi Genghis,

Do I know you??

Lots of speculation no doubt on the type - I reckon is the Granger ( I know Grangers son - wot a wag!).

Shuttleworth face similar challenges with their aircraft - my understanding is that the CAA are 'cautiously helpful'.

I'll draw Airbedanes attention to this thread - I am sure his contribution will be very helpful to you.

If it is something really exciting and 'fits' the Shuttleworth profile (whatever that might be??!!) maybe it could live there?

I know of no finer engineers ( I don't actually know you G!!) to look after it and no better place to operate our aviation heritage/ preserve same for our future generations.

Come on....wotisit??

All the best


16th Jan 2004, 16:37
I would have put money on HP having got something to get the bum twitching.

Edited to add that I mean an aircraft before you smutty ******s start. :E

Dr Illitout
16th Jan 2004, 16:48
You'r dammed if you do and dammed if you don't on this one G!
There are two options realy, throw so many modifications at him he will get board with it or run out of money. Or place so many resrictions on the beast that he will, again get board with it.
What are his chances of killing himself in it?.
I think that the C.A.A. have got the balence right with vintage aircraft, I know that's not everyone's view but having read B.C.A.R. A8-20 I feel "comfortable" with thier decisions. I would love to see a Vulcan, Victor, Lightning and Bucc fly again but only safely with the right engineering/operational organization behind them.
Do keep us informed,If you can
Rgds Dr I.

Feather #3
16th Jan 2004, 17:04
If indeed it is the Granger,

may I respectfully suggest you contact John Lewis via the OW connection [if he's not known to you already.] He gave a fascinating lecture at the inaugural HAA meeting at OW on the subject of flying Shuttleworth's Granger. Not for the faint hearted nor heavyweights!!

G'day ;)

Shaggy Sheep Driver
16th Jan 2004, 17:31
Please forgive my lack of knowledge in this area, but why does this aeroplane have to meet 'current safety standards'? If it used to fly in its 'as built' condition, why can't it simply be restored to that condition and fly again (albeit with operating restrictions)?

Does the Shuttleworth Boxkite meet current safety standards? Does a Spitfire? Would Concorde acheive certification under current airliner certification procedures?


Genghis the Engineer
16th Jan 2004, 17:41
Hairplane - not sure, I suspect that we may have met at some point - possibly at an Oxford RAeS branch meeting? It isn't the Granger. It's not appropriate since I'm talking about somebody else's attitude towards their aeroplane to give enough information to identify him and it.

SSD Simple answer I'm afraid, because the paperwork that allowed that aircraft to fly at the time no longer has any validity. Shuttleworth I'm certain have to prove an acceptable level of safety in their operations, albeit that they use a combination of operating procedures and engineering procedures - which is almost certainly where I'm headed. If you simply want an aircraft to fly (in the same was as your Yak might) then you must meet pretty much current standards however old it is.

I do know a lot of the chaps at Shuttleworth (and also deal with the same people at CAA as they do), although I've never been directly involved there myself.

In fact I turned up to see this chap hoping to persuade him that it belongs in a museum, preferably one like OW where it will be flown under what might be termed Bleriot-worthy conditions. But as I said, he made it very clear that he has no interest in that at-all, so my dilema is primary moral - if I don't find a way for him to fly it safely he's likely to take the engine for another aircraft he owns of similar vintage as a spare, and scrap the rest.

So far as the competence of engineers is concerned, I've as much respect for the chaps at Old Warden as anybody, but that's not my problem - I do have (either personally or access to) enough engineering and flight-test talent to make it happen (in fact I think one of my available Test Pilots may have flown one in his youth), and the owner has a suitable hangar and airfield to keep it safe, and enough skilled help to do the dirty work. The dilemas are primarily moral not technical in this case - or at-least it's moral issues that will ultimately guide my technical decisions.


Oscar Duece
16th Jan 2004, 18:21
G This aircraft wouldn't be located near me would it, on a certain tree lined farm strip used by a dh.:confused:

Genghis the Engineer
16th Jan 2004, 18:28
The chap had an interesting single seat British wooden biplane (of a type designed by the late Russ Light) in restoration there too, but a fairly common one and I saw no dH.


16th Jan 2004, 19:18
No disrespect to this chap, but if he can't fly it then it does seem remarkably odd to scrap it - surely donation to Shuttleworth is better than throwing it away. :{

Whilst I respect the fact that he owns it, the old adage that he is "merely the aeroplane's custodian" applies IMHO!

That said, I wish you well in your efforts to help him get it flying - what ever it is (I don't know which aircraft Russ Light designed - research tonight!)

Genghis the Engineer
16th Jan 2004, 22:09
Tend to agree, but I am a mere paid servant in these matters.

Russ Light designed several things, this example now resides in Newark Air Museum I think and is similar to the one I met in passing yesterday. The roundels are arguably a little pretentious but it's wooden, British, and a biplane - plus there are a fair number still around (23 listed on G-INFO of various marks).


16th Jan 2004, 22:20
Knock the wheels off, poke a couple of holes in the floor and stick his legs through em.

You can then class it as an FLPA (Foot Launched Powered Aircraft). No C of A required.


17th Jan 2004, 02:08
I think aircraft manufacturers (remember them) have some form of regristration/control sequence/system for their new types. Not that they've had any for many a year. Could not this a/c assume one of these non G- registrations say under bmaa or pfa design authority?

I am however curious as to how the type never managed to meet someones approval be it ARB or whatever.

Final solution is to move it to France and only bring it back occasionally until we join the EEC for real

Genghis the Engineer
17th Jan 2004, 02:18
I think aircraft manufacturers (remember them) have some form of regristration/control sequence/system for their new types. Not that they've had any for many a year. Could not this a/c assume one of these non G- registrations say under bmaa or pfa design authority?

Err, no. You can put a serial number and G-XXXX registration on a double bed or canal boat should you wish, but it gets you nowhere with regard to airworthiness documentation. An aircraft manufacturer has to certify that something confirms to an existing approved design before it can fly, which isn't the case here.

I am however curious as to how the type never managed to meet someones approval be it ARB or whatever.

Straightforward enough, the particular aircraft class, at the time, CAA/ARB didn't feel a particular need to impose significant safety regulations on. Later they changed their minds. (A bit like what is happening to gliders at the moment.) Same would apply to any type which had only ever flown under military authorisations.

Final solution is to move it to France and only bring it back occasionally until we join the EEC for real

Right at the moment we're worrying about whether it's safe to fly on the occasional calm sunday afternoon - you want to cross the channel?


17th Jan 2004, 02:38
You can put a serial number and G-XXXX registration on a double bed or canal boat should you wish

In the early 80s there was a craze amongst UK spotters for registering "bin-liners" which were basically model hot-air balloons - I'm not sure exactly how they were flown, if at all, though I believe one or two were radio-controlled. Tiring of this, the CAA gave them a special sequence (G-FYAA - FYZZ?). I'm not sure of the point of it and why the CAA allowed it. Odd thing is, some of those extraordinary R/C aeroplanes (did I see a pic of a quarter scale Beaufighter?) must almost qualify on size and weight alone!

One chap was so disgusted with the bin liner reggie practice that he registered a man-hole cover by way of a protest. Honestly, I'm sure I didn't dream this! I hope it wasn't in his back garden, or all the Reggie S Potters would have been breaking down the garden gate...

17th Jan 2004, 17:24

Apologies for the late input to this thread - it's been a busy week.

As far as the certification of old aircraft goes, there is only one route to take, with two possible branches - before you do anything, talk to the local CAA inspector, or to the PFA. Judging by the description of your project I'd choose the latter and get hold of the PFA's deputy Chief Engineer, John Tempest. With the right sort of approach, he should tell you what would be required to get the machine on the register. He's very good, very sympathetic to the preservation of old aircaft, but he's also very busy. If anyone can help you get the machine into the air certification wise, he will.

Remember that you'll have to get the authority involved at some stage, so best do it at the start and find out what they expect you to do. You'll save a lot of wasted time and more importantly, a lot of wasted engineering effort.

Good luck,


19th Jan 2004, 02:22
G the E, Er sorry I should have been more specific as I was talking about the B class registrations which I understand aircraft flew under whilst being tested etc prior to having CofA. They were G-then a number referring to the design authority - and then a number. Haven't seen or heard of one being used for a long time - perhaps because we have no (non micro) manufacturers.

PS Re the channel I hear that ships aka ferries and even trains now cross on a daily basis. :) (nbg at smilies)

Genghis the Engineer
19th Jan 2004, 05:55
You mean B-conditions. I have use of that (and we do have two non-microlight manufacturers left, Slingsby and B-N, both with F1 B-conditions), as do BMAA, all the microlight manufacturers and (sort of) PFA. (PFA operate under "exemption from A-conditions", which is something only they understand, but seems to work).

But, B-conditions is only for flight testing backed up by a design authority, it's not a license to keep flying something that doesn't meet any safety standard. In fact, normally you have to show that something *should* meet a defined standard before you can fly it under B-conditions.


Involved professionally with far too many of the above for my own sanity.

Rallye Driver
20th Jan 2004, 19:51
"Odd thing is, some of those extraordinary R/C aeroplanes (did I see a pic of a quarter scale Beaufighter?) must almost qualify on size and weight alone!"


The large models do qualify as UAVs and need a Permit to Fly. The CAA guy who is in charge of licensing them (and is a balloon pilot) explained about this at the Military Air Safety Day at Odiham last year.

I know Richard Rawle, who has built a third scale Grace Spitfire (ML407). He had to go through a test schedule with an inspector before he was signed off to display it.

Airbedane may remember seeing it fly at the Shuttleworth Garden Party last year.

RD :ok:

21st Jan 2004, 00:55
I used to fly them and still have several in the shed, 1/4 and 1/3 scale. My 1/3 Bowers FLyBaby is a honey, as is my 1/3 Tiger Moth.

I visited La Ferte Alais a few years back - how about a 29ft B29?


I also found nestling between a half Scale Staggerwing (yes honestly! - it had a Rotax microlight engine) and a half scale GeeBee Z (scary!) a one to one scale (!) Cri Cri. Built to full size but of course a lot lighter and with model plane engines.

The Beaufighter mentioned is alas no more - it got stuffed last year during a low pass (dropped the torpedo onto the ship - really!) but struck both props on the ground - the model then disappeared at a rate of knots and ended up in a tree. It seemed repairable until it fell out of the tree backwards and crunched the back end. Good night Vienna!

These are serious flying machines built and flown by serious modellers.

THe organisation to belong to is the Large Model Association - worth joining if only for the monthly journal to see amazing pictures of what people are creating in their garden sheds...

If you have never been to an LMA show - do it!

'The difference between men and boys is the size of their toys'. So true.


21st Jan 2004, 05:36
So it seems that with a few servos it could at least fly legally. - well at least with a dumy aboard :-)
:O :O

Genghis the Engineer
21st Jan 2004, 07:10
What I can't understand is, if somebody can build a 29ft model B29, why not stick a single-seat cockpit in and have the pleasure of flying it?


21st Jan 2004, 15:36
Certainly never knew that Rallye Driver... :ok:

Think I saw some pics of that half scale r/c Staggerwing in Jet Blast... staggering (forgive me!) detail, but sadly it got away from the pilot during takeoff and crashed - and burned...

Sorry Genghis, getting away from the topic, but then that's nostalgia!

21st Jan 2004, 17:28
Back on topic...

I bet an 'Ayrton Senner' that its the Blake Blue Tit.

At least a set of Avro 504 wings survives with this project, albeit cut down a bit....

Did the Blue Tit ever fly? I don't believe it was ever certified, which seems to fit your dilemna Genghis.

Nice to see a bit more info on this aircraft, especially if I have hit the bullseye. I seem to recall it at North Weald a few years back. It was looking well advanced then.


21st Jan 2004, 23:51

The phrase "The horns of a dilemma" comes to mind! Treadders makes a very valid point about an owner being only the custodian of a piece of aviation history. There is a very interesting parallel with listed buildings. An owner is, by law, responsible for maintaning it in its "original" state (in practise the standard at the time of the listing). If he wants to change it he must get local government (planning department) permission. However, it is generally acknowledged that a listed building is a home which must be lived in and so concessions to vary from the "original" standard must be granted, although they must be sympathetic to the existing structure. The problem is that there is no similar law to protect our aviation heritage.

Personally, I am a "get 'em flying/keep 'em flying" person, but I do concede that aircraft that are very significant to our aviation history and are unique should perhaps be preserved in a museum. Without knowing what the aircraft is, I would not comment on which category this aircraft might fit into.