savannah accident

[Guest lyall]

does anyone know why the flinders island savannah lost power and crashed.i ask because i drive one

 

 

[markendee]

Mr Duigan

 

Lyall,

 

I have read all information available that I could find and it would seem that there were 50 kmh winds that day and the aircraft was caught in the down draft due to the wind coming over a hill forcing them down.

 

Do not take this as gospel as it is only information read on very sketchy media reports.

 

Have spoken to John Duigan by phone on Savannah related matters (before the incident) and he is a great bloke. (Not to mention very connected with Australian aviation)

 

I hope he and his son recover 100% and they are back flying soon.

 

Mark

 

 

[Guest brentc]

It was a matter of poor reporting. At first the press reported that the accident was due to a loss of power, however it was later found (as reported by Eugene Reid RA-Aus President) that the accident was attributed to wind conditions, an upwind runway and from what I'm lead to believe an aircraft at or around MTOW.

 

 

[obad]

Designer builder

 

I know John Duigan well and I actually carried out the initial test flight on his aircraft. it is the early model Savannah fitted with leading-edge slats. John flew this configuration for nearly 300 hours including a trip to Ayres rock with no problems. Two or three hours flying time before his accident he removed the slats and fitted vortex generators. As I understand it the flight of the accident was the first one with a passenger after the vortex generators were fitted. John's airstrip is on a fair slope and the day of the accident he was taking off uphill with the aircraft well laden.

 

Previously I have observed another savannah similarly configured but with only one person aboard drop a wing on take off and personally I believe removing the slats and fittings vortex generators without re-profiling the leading edge is not a good idea.

 

This may not have been the main cause of John's accident though as conditions were moderately turbulent that day with wind of up to 30 kn however I believe it may be a contributing factor. This is only my personal opinion.

 

I have also flown the VG late model Savannah with correctly shaped leading edge and find them a very well behaved machine.

 

Incidentally, John is 81 years old and built the Savannah in the last two to three years. He is already planning a new one for the future!!.

 

 

[Guest lyall]

savannah

 

thanks for the reply,it is useful to know what the problem was . We have 7 savannahs flying in nz now . information shared makes us all safer pilots

 

 

[Guest lyall]

savannah

 

i fly the vg model and have been a passenger in the slated model. they fly completely differently especially on landing ,the vg glides alot more. i would suggest that it would take a bit of flying time getting used to the vg glide if you were used to the slated model

 

 

[markendee]

Don't want to get right into the slats VG thing but our experiences consist of this.

 

Of all our friends flying Savannahs none are running slats.

 

Five of us have built VG kits.

 

One has converted from slats to VGs using the factory supplied kit. (leading edge mod)

 

Two have removed their slats and fitted VGs.

 

One has removed slats and not fitted VGs. (he is gamer than me)

 

All are flying and not posing a problem. We all fly out of private strips and as far as averages go we fly a lot and often.

 

Not going to get into an argument but this is a fact.

 

One of the aircraft with slats removed and VGs fitted was owned by a retired Aeronautical engineer with a ton of experience and knowledge of a/c design - no wing drop.

 

Very bold statement making accusations of wing drop - much better to talk of things you can prove or have had a lot of experience with.

 

Mark

 

 

[Guest lyall]

savannah vg

 

i had some spare vgs which i glued to the elevators leading edge (stolspeed website) which have really improved the control of the plane on landing. they are only open to the airflow when landing or steep climbs , during normal flight they are behind the horizontal stabiliser. they are a great addition . i dont understand why someone would remove the slats and not put on the wing vgs unless it is a brief experiment. the vgs only make our planes safer to fly particularly in tough flying conditions eg high wind

 

 

[Kenny]

Mark

 

I agree with your post 100% especially the last sentence, as you know I have removed the slats from my Savannah and fitted VGs I find the plane much more docile and safer to fly especially landing. I have practiced stalls repeatedly with both stages of flap and clean wing , landing with both stages of flap and clean wing and taking off with first stage of flap and clean wing and have never experienced any wing drop other than a very slight drop during a practice stall in quite turbulent air. The the plane just wants to mush. I have had the plane at very high angle of atack , hardly any forward speed and mushing at about 500 ft pm basicly the plane was still flying and controlable.

 

I will add here that I have purchased a VG kit having been told that they may be hard to get in the future and if ever I want to sell my Savannah I can sell it as a genuine VG , if it was'nt for that reason I would be more than happy to continue flying with slats removed and VGs fitted

 

Ken

 

 

[Guest ozzie]

Can i see some photos of these VGs and their location on the wing?

 

just curious as i fitted some of these kits to GA aircraft while back. Chieftan and Aerostar.

 

ozzie

 

 

[markendee]

Lyall, Stolspeed is the place to go for information on all things Savannah. John thoroughly and extensively tests all mods, configurations and ideas as no one else has in my reading of Savannah related matters. He is the authority. When John Gilpin talks we listen.

 

Kenny, interesting that you bought the kit and well done for thinking ahead. The retired aeronautical engineer I previously mentioned conducted a range of brilliant tests which included flying without slats or vortex generators. (as a short test flight) He taped lengths of black wool all over his wings and video'd the whole thing in flight. This man is no fool. His findings are comprehensive and worth taking on board.

 

Mark

 

 

[Kenny]

VGs

 

Mark. I am hangared next to John G and he is forever taping pieces of wool to the flying surfaces of his Savannah. His latest testing involves an inclinometer and static air speed indicator to measure exact angles of attack during stalls at differing air speeds and with the woolen tassels he can record just where and when the boundry layer starts to seperate.He is also measuring rates of climb best glide speeds etc. I have attached a photo of my plane during fitting of Vgs fo Ozzie to look at

 

 

 

[Guest Neilm1955]

VG,s

 

Kenny, exactly how did you establish where to glue the VGS,s

 

I have a Savannah with slats removed and no VGs fitted.

 

It will drop a wing in full power stall, but otherwise docile.

 

Neil

 

 

[Kenny]

VGs

 

Neil I have used the feathers VGs supplied by John Gilpin and was shown how to attach them by JG we used a cardboard template and a string line. There is a set measurement from the leading edge of the wing of which I can't remember. The template shows the angles that the VGs are set at and also the spacing, The VGs are self adhesive.

 

John has a web site StolSpeed Aerodynamics - Performance Enhancement for Light Aircraft which will show all of the reasearch etc. and his contact details you will find it a good read.

 

Cheers Ken

 

PS Neil I have just had another look at John's Web site and all of the instructions are there. How to measure and make up a template etc.

 

 

[Guest Neilm1955]

Thanks Ken,

 

I actually have a set of feathers vgs but have never installed them. Never quite got a handle on the measurements. I see the web page is quite updated now so I will have another read.

 

Regards

 

Neil