Sgian Dubh

[Deskpilot]

Hi guys, I'm on a new journey. I've taken a shine to Hugh Lorimer's Sgian Dubh (Skian Doo) and have been adapting his plans into a larger, faster plane to suit my 6ft, 105kg frame. With his permission and help, I've increased the width by 2" and the headroom by 8 or there abouts. Some points are now a bit hazy. I've added a Jabiru engine despite all the negative stuff that's floating around at present, and added a manual retract system where the mains retract in a Cessna Cardinal fashion. Still working on the SketchyPhysics but hope to have a working model soon. Hugh aircraft was/is powered by a small Rotax 2 stroke, but has yet to leave the ground due to health problems, Hugh, not the plane.

 

I might have to add a bit of wing area after I do all the maths (putting it off as long as I can) but that should be easy enough. The construction is F/glass over foam with wooden spars and floor. The outer wing panels are removable by simply pulling one pin per wing.

 

Hugh's plans are available on the web but are, unfortunately, far from complete.

 

So, What do you think?

 

 

 

 

 

 

 

 

[rotax618]

I have been following Hugh's work for some time, I would wait until the prototype has been flight tested and the bugs worked out. Flying Plank tailless aircraft are VERY sensitive to the CG, retracting the undercarriage towards the rear may cause complications.

 

In my opinion the design has merit but because of its unconventional layout I would proceed with caution.

 

 

[Himat]

Interesting.

 

One major question, why retracts?

 

A more general comment, most pusher designs cries out for an inline engine with all ancillaries placed at the opposite end relative the propeller.

 

 

[Deskpilot]

Yes guys, retracts pose problem and possible dangers, and that's the challenge. Why retract, cause I like the look of a clean airframe. Excessive CG travel, I'm well aware of that and am working on it. I started with a Grumman design but it got way too complex and heavy, even though it didn't move the CG at all.

 

As for inline engines, mostly water cooled and heavier than a Jabbie.

 

Oh and FWIW, Hugh's plane will never fly, well, not in the UK at least due to some problem with the ruling authorities over there. Hugh prefers not to explain why. He flew a large scale r/c model to develop his design.

 

 

[rotax618]

I wish you well - please start a builders blog to keep us informed on your progress,I have no doubt that the concept is sound.

 

Cheers

 

 

[SGIAN DUBH]

Hi guys, I'm on a new journey. I've taken a shine to Hugh Lorimer's Sgian Dubh (Skian Doo) and have been adapting his plans into a larger, faster plane to suit my 6ft, 105kg frame. With his permission and help, I've increased the width by 2" and the headroom by 8 or there abouts. Some points are now a bit hazy. I've added a Jabiru engine despite all the negative stuff that's floating around at present, and added a manual retract system where the mains retract in a Cessna Cardinal fashion. Still working on the SketchyPhysics but hope to have a working model soon. Hugh aircraft was/is powered by a small Rotax 2 stroke, but has yet to leave the ground due to health problems, Hugh, not the plane.I might have to add a bit of wing area after I do all the maths (putting it off as long as I can) but that should be easy enough. The construction is F/glass over foam with wooden spars and floor. The outer wing panels are removable by simply pulling one pin per wing.

Hugh's plans are available on the web but are, unfortunately, far from complete.

 

So, What do you think?

 

[ATTACH]33790[/ATTACH] [ATTACH]33791[/ATTACH] [ATTACH]33792[/ATTACH] [ATTACH]33793[/ATTACH] [ATTACH]33794[/ATTACH] [ATTACH]33795[/ATTACH]

Deskpilot, The Sgian Dubh will be getting Air under it's wings very soon ;-)

 

http://publicapps.caa.co.uk/modalapplication.aspx?catid=1&pagetype=65&appid=1&mode=detail&dataindex=7&regmark=cjpk&pageindex=1

 

 

[SGIAN DUBH]

I have been following Hugh's work for some time, I would wait until the prototype has been flight tested and the bugs worked out. Flying Plank tailless aircraft are VERY sensitive to the CG, retracting the undercarriage towards the rear may cause complications.In my opinion the design has merit but because of its unconventional layout I would proceed with caution.

Rotax 618......The Sgian Dubh will be getting Flight Tested very SOON ;-) so I can confirm that any bugs will be worked out & reported on ;-)

 

We will certainly proceed with CAUTION ;-)

 

 

[SGIAN DUBH]

Yes guys, retracts pose problem and possible dangers, and that's the challenge. Why retract, cause I like the look of a clean airframe. Excessive CG travel, I'm well aware of that and am working on it. I started with a Grumman design but it got way too complex and heavy, even though it didn't move the CG at all.As for inline engines, mostly water cooled and heavier than a Jabbie.

Oh and FWIW, Hugh's plane will never fly, well, not in the UK at least due to some problem with the ruling authorities over there. Hugh prefers not to explain why. He flew a large scale r/c model to develop his design.

Deskpilot........ FWIW Hugh's Sgian Dubh will FLY, It will be flown in the UK as I have the complete backing of the ruling authorities over here in the UK.

 

In fact the UK CAA are now so enthusiastic about the Sgian Dubh being in our care that they actually want us to get it into the air, Hugh was in a different era where the officialdom was of such pragmatism that he was fighting against those who just couldn't understand the genius in Hugh's work ( Everything Hugh built was to BCAR-S standards )

 

I have such a great repertoire with our now very progressive CAA that I am prepared to take some credit for them accepting the Sgian Dubh, however the full credit belongs to Hugh Lorimer for having designed such an incredible set of Flying machines.

 

Watch this space.

 

 

[Deskpilot]

Oh Great. Keep us informed. Unfortunately, your publiapps link won't open for me.

 

 

[SGIAN DUBH]

Oh Great. Keep us informed. Unfortunately, your publiapps link won't open for me.

The Link will work as of Monday 25th April 2016.

 

Here is an excerpt from our Now Pro-Active CAA.

 

RE: Registering the Sgian Dubh G-CJPK SGIAN DUBH S/N PJK001

 

Inbox

 

x

 

 

RegAircraft

 

21 Apr (2 days ago)

 

 

to me

 

 

Dear Peter,

 

Thank you for your email and CA1 application form.

 

We would be grateful if you could confirm whether you are using your BHPA insurance cover for this aircraft. Also please could you clarify whether you are the owner of the aircraft following being gifted to you by Mr Lorimer as we are unable to register an aircraft to a keeper as this terminology is not used in the registration of aircraft. We can only register to an owner or charterer by demise. If the aircraft has been gifted to you please could you confirm the date on which this occurred.

 

Please could you also arrange for a signed and dated CA1 to be emailed or posted to us with the payment for £68. Alternatively, the payment can be made by telephone.

 

Thank you for your assistance.

 

Best regards

 

Sue Wood

 

Aircraft Registrar

 

Civil Aviation Authority

 

Aircraft Registration CAA House 45-59 Kingsway London WC2B 6TE

 

 

[SGIAN DUBH]

A couple of other bits of info on the Sgian Dubh

 

 

 

 

[Deskpilot]

What engine is in that now SD? Seems to have changed from the photos Hugh sent me.

 

I wish you luck with you endeavors. It will fly, but will it stall at less than 35knots, hmm, not sure about that.

 

 

[SGIAN DUBH]

What engine is in that now SD? Seems to have changed from the photos Hugh sent me.I wish you luck with you endeavors. It will fly, but will it stall at less than 35knots, hmm, not sure about that.

The Sgian Dubh will be having either a Rotax 447 0r Rotax 503 refitted, I am not sure what photos Hugh sent you? if you have them to hand, could you please either send me copies of them via email or copy them onto this site? I am interested to see ;-)

 

With the rotate speed at 38.4mph (33.6kias ) We have calculated the Stall speed as Vso 30.5kias ( it actually will stall at 28.7kias if our calcs were correct as we factored in a 6% buffer in our figures )

 

Academic anyway as the rotate speed is below the SSDR threshold.

 

My Aerodynamicist team are S#*T HOT on these types of calcs & to be honest between them & Hugh they baffle me ;-)

 

My forte is flying the things & putting these type of aircraft through SSDR. I see getting the Sgian Dubh through SSDR as an achievement, it even ranks higher than me getting an Inflatable RIB with a Flexwing attached through SSDR ( The BMAA & LAA wouldn't accept this under any circumstances prior to SSDR becoming available ).

 

Unfortunately for me, I will in all likelyhood only see the Sgian Dubh FLY from the ground, I exceed the seat limit somewhat ;-) so I have to relinquish the flights to a more svelte pilot within the team ;-)

 

 

[SGIAN DUBH]

Sgian Dubh is being prepped for transportation to the Rebuild Centre today, it will be roaded to Cornwall on 4th April 2016 & then Reassembly commences ;-)

 

Will post pictures on my return from this epic trip.

 

To confuse all Aircraft Spotters who will be gawping at it on the journey down we are leaving the G-MEXP registration on the side etc.

 

G-MEXP was a Ficticious registration placed on it for the Microlight Shows ( M for Microlight / EXP for Experimental. )

 

 

 

[kasper]

And to confuse us you are using a time machine to do the transport 1 month in the past???

 

And who is rebuilding? You are in Edinburgh and Corwall is pretty much as far away from you as it is possible to get while staying in the UK ...

 

 

[Deskpilot]

What engine is in that now SD? Seems to have changed from the photos Hugh sent me.I wish you luck with you endeavors. It will fly, but will it stall at less than 35knots, hmm, not sure about that.

My mistake, same engine. Same question a kasper, I'm confused as well.

 

 

[kasper]

On engines this airframe was 'given' an engine to fit into it for display purposes several years ago ... before SSDR was available to get it in the air.

 

The engine was NOT a flyer ... it was a bits-n-pieces engine to allow an enginesless airframe to be displayed 'complete'

 

The original engine per the drawings pack of plans I have of it was supposed to be a R447

 

 

[SGIAN DUBH]

And to confuse us you are using a time machine to do the transport 1 month in the past??? And who is rebuilding? You are in Edinburgh and Corwall is pretty much as far away from you as it is possible to get while staying in the UK ...

The timestamp of 4th April should have said 4th May ( my mistake)

 

Yes I am based in Edinburgh, I am also based in London, I am also based on the IOW.

 

The aircraft is fully built ( excluding the engine ) but for reasons of it actually having been built in 1999 we are going over everything to ensure it is all still good & airworthy still.

 

The Team overseeing all this work are a specialised team of Aviation Geeks from Cornwall who get uber excited about Flying Wings & have a wealth of knowledge on Flying Wings ( Me, I am just the numpty who wants for Hugh to see the Sgian Dubh take to the skies )

 

The Sgian Dubh briefly flew today on the transportation from Mauchline to Abington...... the winds were 50-60mph & it left the ground in a gust whilst we were enroute down the M74 so we had a 50mph forward speed & a 50mph crosswind briefly ( it made that sector of the trip very interesting. )

 

 

[SGIAN DUBH]

Pictures from the Transportation to Cornwall from Mauchline ( Pt1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[altair]

It is very good to see the stamped happy smile on you face hugh Lorimer ...

 

 

 

[SGIAN DUBH]

It is very good to see the stamped happy smile on you face hugh Lorimer ...

Hugh was certainly extremely HAPPY to see his Sgian Dubh going away to Cornwall for final checks & then commence Flight Testing ( when we locate a working 447 or 503 engine ). We have agreed that Hugh will be invited down to witness one of the Test Flights.

 

Hugh was impressed by the guy who will be doing the final checks & flight testing....... The Trailer has definitely seen better days, we flipped a coin as to whether to just go and buy a trailer or whether to repair the trailer ( The trailer had 'makeshift' repairs to enable it to get to Cornwall done by my Engineer ) I won't go into too much detail but it involved Welding & structural work to make it only mildly dangerous as opposed to suicidal to use.

 

Pictures of it at Cornwall :

 

 

 

 

[altair]

I wish you success in this endeavor and we are all very anxious and hopeful for a peaceful flight test.

 

perfect also was the decision to invite hugh to participate and witness all these events.

 

dream come true.

 

 

[SGIAN DUBH]

I wish you success in this endeavor and we are all very anxious and hopeful for a peaceful flight test.perfect also was the decision to invite hugh to participate and witness all these events.

dream come true.

Altair, It is only right that we invite Hugh to the Flight testing of the Sgian Dubh........ I think the Sgian Dubh is the most interesting of the LORIMER PROJECTS ( and probably the harder of the 2 I am interested in to fly )

The Quaich will be a very easy to fly aircraft, not that concerned by that at all........The Iolaire is the one that the verdict is out on !!! Some Aerodynamicists think it will be as stable as a dart & other Aerodynamicists think it will be a bucking bronco........time will tell on that one ;-)

 

 

Sgian Dubh ( PROJECT ONE ) likely to be a Handful.

 

 

Quaich ( PROJECT TWO ) Easy to Fly in my opinion

 

 

Iolaire ( PROJECT THREE ) This one is going to be a REAL CHALLENGE as it has already been subject to close scrutiny by the BMAA & I doubt will fit into the SSDR category without a lot of fuss.

 

 

[Deskpilot]

Iolaire has already flown hasn't it?

 

 

[altair]

yes, Iolaire flew.

 

there is a video which details hugh lorimer reports and shows the tests of all flights.