Sparrowhawk Keel

[okikuma]

Can someone provide me with the dimensions of each part of the Sparrowhawk Keel including the side plates?



Thanks

Wayne

[Mark Sanders]

Hope this works for you. nice meeting you at the fly n.

[okikuma]

Hi Mark,

Thanks for the information and your help. It was a pleasure meeting you at El Mirage and answering all of my questions. Thanks for posting the picture of my wife and myself too. I think she'll get a kick out of it!

You're Sparrowhawk is the first one I have seen close up. It's a fine machine and your's does look professionally assembled. You did a great job. I now see where all the 900 lb. is at. I was quite surprised to see how thick the fiberglass was for the cabin, and the engine and associated hardware sure adds up the weight.

I like the Sparrowhawk but I just couldn't imagine where all that 900lb. of weight was at. I previously guessed from pictures that the engine, cooling system, belt drive, and pre rotator weigh in the 350 lb. range. I'm revising that guess to 400 lb. after seeing yours. The cabin and all the hardware inside then must weigh in close to 300 lb. that's 700 lb. The keel, rotor head, rotor, and landing gear then must be 200 lb. with all adding up to a total of 900 lb.

The keel dimensions will help me accurately figure it's weight.

Thanks again!

Wayne

[tadgyro]

Hi Wayne
I am wondering if you need any parts for your Sparrowhawk ?
Teddy

[Vance]

Hello Wayne,

Your shop looks a lot like Stan Foster’s shop.

Looks good, Vance

[okikuma]

Hi Teddy and Vance,

No, I do not own a Sparrowhawk kit. I just wanted the general dimensions of each part of the keel so I can figure out the approximate weight of the aluminum.

In my mind, the Sparrowhawk's empty weight is too heavy at 900 lb. The useful load of the Sparrowhawk is listed as 600 lb, with a gross weight of 1500 lb. I think the Sparrowhawk could be made lighter by 150 - 180 lb. without loss of structural integrity.

Bringing down the empty weight to 720 lb. and keeping the 600 lb useful load, then the gross weight can be honestly declared as 1320 lb., thus making the aircraft Sport Pilot eligible. Having a two place sport pilot eligible gyroplane makes the aircraft more resellable to a larger number of buyers.

The picture of the keel is Stan's picture. I included it only for visual reference to my request.

Wayne

[Xavier AVERSO]

Pour moi le sparrowhawk est certainement l'autogire que je desirerais posséder mais il est trop lourd pour la règlementation ultra légère en France.
Je pense qu'il est possible de le construire avec un moteur Rotax 912S et l'équiper d'un rotor de 854 cm ( 28 feet ) pour un poids a vide de 250 kg ( 550lb ) avec une masse maximum en vol de 500 kg (1100 lb )

Si possible je ferais un jour cette belle machine.

For me the sparrowhawk is certainly l' autogiro that I would wish to have but it is too heavy for the light ultra regulation in France. I think qu' it is possible to build it with an engine Rotax 912S and l' to equip d' a rotor of 854 cm (28 feet) for a tare weight of 250 kg (550lb) with a maximum mass in flight of 500 kg (1100 lb)

If possible I would make one day this beautiful machine.

[twistair]

Wayne,

The main structure is the last thing to try to save weight on a SH. I'm sure you'll find this confirmed after your calcs.
Things which may and must be lighter are: cabin itself, tail and propeller set. After assembling two SHs I estimated that one could save ca. 70-75 lbs on this. I made another prop set (with another prop) and metal tail for our first SH and save ca. (no exact numbers by hand right now) 14 lbs on tail and same on a prop set. Cabin composite structure should be twice lighter from it's original weight (ca. 66-68 lbs, may have 33-35 lbs with ease if fabricated correctly of structural fiberglass).
Next thing is landing gear where one can save 4-6 lbs.

[Xavier AVERSO]

Bonjour Alex,

Quel est le poids d'un mètre de tube aluminium du SH ?



Hello Alex,
Which is the weight d'one meter of the tube aluminium of the frame of the HS.?

[twistair]

Bonjour Xavier,

It's 2x4", 1/8" wall 6061-T6 aluminium, cross section is 960 sq.mm, weight of 1 meter is 2.7 kg.

[Xavier AVERSO]

Exemple:

Cabine =26 kg
rotor+tête de rotor =47 kg
empennage = 8 kg ( toile )
train principal essieu =16 kg
train avant (roue avant )= 6 kg
réservoir ( 50 litres)+tubes alimentation = 7 kg
moteur 912S complet huile eau hélice = 92 kg
chassis = 25 kg
commandes de vol = 4 kg
prélançeur = 6 kg
instruments = 5 kg
circuit electrique = 4 kg
batterie accumulateur = 4 kg
Total = 250 kg

Example:

Cabin =57 lb
rotor+ rotor head=103 lb
tail = 17 lb
landing gear =36 lb
nose gear = 13 lb
tank (50 liters) +tubes food = 16 lb
engine 912S complete oils water propeller = 202 lb
frame = 55 lb
orders of flight = 9 lb
prerotator = 13 lb
instruments = 11 lb
electrical circuit = 9 lb
battery accumulator = 9 lb
Total = 550 lb

[twistair]

That looks true, Xavier, though some things probably aren't included in this list, i.e. tail wheel, rotor controls, pedals, seat belts&harness, rotor brake lever and link, trim spring(s) and their controls. Anyway I see nothing impossible to reach 250 kg weight for such combination, especially if lighter rotor is used. Say. not extruded but bonded one, DW for example which weighs 38 kg complete with rotorhead.
Owen Dull in Oz do build gyros of such config. Don't know how good they are but from Ozzie gyroheads remarks these gyros aren't bad at all.
On the other hand 100 hp doesn't look enough for 500 kg take-off weight. Sure it will fly but it's rate of climb and accelerate performance will be not the best.

[Xavier AVERSO]

Merci pour ta réponse Alex, Quand j'ai donné 26 kg pour la cabine tout est compris avec sièges, portes, ceintures, palonniers dans le calcul les commandes de vol sont comprises aussi, c'est vrai que 100 cv pour 500 kg c'est trop juste mais en France la règlementation ultra légère est a 450 kg.
Quand au rotor plus lourd c'est mieux pour le CG et pour l'inertie, il se comporte mieux dans la turbulence.

Thank you for your answer Alex, When j' gave 57 lb for the cabin all is included/understood with seats, doors, belts, swing bars in calculation the orders of flight are also included/understood, c' is true that 100 hp per 1100 lb c' is too right but in France the light ultra regulation has 990 lb. When with the heavier rotor c' is better for the CG and l' inertia, it behaves better in turbulence.

http://img291.imageshack.us/img291/7418/dallagnol22hi6.th.png (http://img291.imageshack.us/my.php?image=dallagnol22hi6.png)http://img291.imageshack.us/images/thpix.gif (http://g.imageshack.us/thpix.php)

Autogire DALL-AGNOL = 240 kg / 528 lb Rotax 912S rotor AVERSO

http://img505.imageshack.us/img505/733/1002193dh5.th.jpg (http://img505.imageshack.us/my.php?image=1002193dh5.jpg)

Autogire SOLIGNAC = 262 kg /576 lb Subaru 1,8 turbo rotor AVERSO métal

[twistair]

Thank you too Xavier,

To be true the question about rotor inertia disturbs me for years since I still hadn't seen (probably missed) any information about what are quantitative methods and ideas of estimating sufficient inertia numbers for teetering rotors :( But this is the question for another thread.
These gyros on your photos look nice but I wonder why their authors didn't cover their engines - I suspect this should seriously improve performance.
Below are a couple of photos of Owen Dull gyro with Rotax-912ULS:

[Xavier AVERSO]

Vous avez raison Alex ces autogires seraient plus performant avec une finition a l'arriere de la cabine.

Je trouve très beau l'autogire de Owen Dull.

You are right Alex these autogiros would be more powerful with a completion has l' postponed cabin.

I find very beautiful l' autogiro of Owen Dull.

[okikuma]

Hi Alex,

Agreed, the structure such as the keel shouldn't be considered in the weight reduction. I do appreciate your input and help.

Thanks again,

Wayne