Vampire First flight findings.. Aileron issues..

[Ultralights]

Hello all, well, my firsts flight in my new vampire went, well, ok, 40 mins long, and the predominat issue was a strong tendancy to roll left, at all airspeeds and flap settings.. the force needed to keep her straight wasnt that much, but quite a bit of right stick was needed making flight uncomfortable.

 

thankfully it did turn right pretty well with a bit of encouragement from the rudders...

 

anyway, after doing a few repairs and upgrades today,(new 10,000ft altimeter and replaced a snapped nosewheel steering linkage) all the while thinking of how to resolve the issues, initial solution was to add trim tabs to both ailerons as both ailerons lined up, with the flap and wing tip, both travelled the through the same angles at full deflection, till after a few hrs, i sat in the cockpit with the stick where i felt it should be, and had soone take some pics of the aileron position... this is what i saw...

 

 

 

As you can see, the Right Aileron is down about an Inch, and the left is Up by the same amount, obviously this is causing the uncammanded roll to the left when the stick is centered..

 

my question is, being a new vampire owner, can the ailerons be re-rigged so that their deflection is the same when the stick is central, and how do you do this??

 

thanks in advance...

 

Rob.

 

 

[Student Pilot]

Arthurs the man to ask, looks a nice machine. 447? What's it get along at @5000 revs?

 

 

[Ultralights]

at 5300 rpm is indicating 90 kts, 5500 shows 95 kts. it has a 503 fitted. 114 hrs old.

 

 

[pylon500]

Two ways to adjust the aileron linkages, behind the seat or in the wings...

 

Remove the seat back/firewall and check that the 'T' arm on the end of the stick is still square with the stick, (not a problem that i know of?) then check the amount of pushrod thread showing under the eye-bolts on the 'T'.

 

Also check that the cable outers are clamped correctly on the cross bar behind the seat.

 

If all OK, you need to get into the wings....

 

Later production craft had small screws holding the wing trailing edge down to minimise the gap at the control surfaces, remove if there for access.

 

Now deflect each aileron (in turn) down to it's full travel and remove the 10/32 bolt (3/8 AF sockets) holding the pushrod to the aileron.

 

Take note of the amount of thread showing at this end of the pushrod to compare with the other side.

 

With both ailerons hanging down vertically, look inside the wing and check the position of the outer cable end clamps on the slots in the ribs.

 

From here it is pretty obvious how adjustments can be made to true up the stick and ailerons.

 

Usually the flaps were set to zero, then the ailerons set to match.

 

A point to note; Some of the early vampires had the flaps set up incorrectly (a faulty jig was used), all owners were notified and they shold have been adjusted accordingly.

 

To check this, sets the flaps to zero and place a straightedge under the flap running fore/aft under the wing, it should make contact with the wing under surface for at least 6", or even show about a 1/4" gap at the hinge to make up for 'float'

 

If the flap is higher than inline, you could be losing a bit of climb performance.

 

The flight loads on the ailerons should be equal and with both set to zero, you should not have had any tendancy to turn, just the stick sitting in the wrong place?

 

Did you check the 'ball' while in flight? you may actually require a rudder trim instead of an aileron trim?

 

Do the tips look like they are original?

 

Missalignment here can cause a turn.

 

Drop into 'The Oaks' any Saturday and I'll have a look at it.

 

Arthur

 

 

[Ultralights]

thanks for that info, during flight the ball and string were pretty much straight, not showing any significant slip.

 

All cable outers appear to be normal, and the adjustment was made behind the seat, even though there is a removable screw on the trailing edge above the flight controls, removing this still didnt give much room to get in there and rlease the control attach bolts to lower the aileron or flap.

 

Unfortunatly, after all the work is done, and verything should be well, the weather is not copoerating! every weekend i have been free to commi aviation it has been windy with localaised storm cells running about, and during this week this persistant annoying 15 kt easterly has seen me push her back in and out of the hangar numerous times, just to see the wind pick up again... This weekend im off down the south coast for a camping/ surfing trip, so i might drop in to the factory on the way through and have a chat about things, and get a new nosewheel assy if the price is right..

 

hopefully next week after work things will be calm enough to get a few hrs in after work to get the feel of things and se if my fiddling has worked..

 

 

[Guest Carl Booth]

Hi Arthur, I fly an SV-2 powered by a 447. Its presently in Germany but I expect to ship it back in a container soon from Hamburg. Can I ask you about the original propshaft assembly .. the old "live" shaft screwed directly onto the gearbox flange,

 

and literally "demolished" anything at both ends ( teeth in the gearbox, and prop bearing ) due to the horrific vibrations ! Some years back I got two German Dornier engineers to have a look at my "original" Vampire shaft, as I was worried by the vibrations and extremely high temperature in the gearbox) They looked at the assembly and stood back aghast in horror ! How can you fly with a nonfloating (supported ) drive shaft they asked me. That assembly is self destructing they said. So I got them to design and construct a beautiful fully (univeral joints and splined slides ) floating shaft, together with a stronger prop bearing. From that day on no cockpit vibrations and much cooler gearbox oil temp... And naturally better thrust and revs, . I've got some pics of the new assembly if you're curious. I was subsequently requested to forward specs drawings etc to Sadler and other pilots in the US. Look forward to talking to you one day at the Oaks cheers Carl

 

 

[Bernie]

Hi Carl. I'm also interested in your Vampire Pic's.

 

Bernie

 

 

[blueshed]

Hey Student Pilot

 

Thats a funny looking Pacer in Your Photo!

 

Cheers Guy

 

 

[Guest BaronVonEvil]

Aileron Issue...

 

Hi Rob,

 

Regarding your aileron issue, have you checked to see if both wings are set at the same angle or incidence relative to each other? It sound to me that one wing's incidence ( the light side) may have the leading edge slightly higher than the heavy wing.

 

I suggest using a level and check the incidence of both wings at the root and the tips to see if they match. Usually there is a slight amount of wash out or twist in the wings to aid in stability during a stall. Washout should be equal in both wings.

 

Not being a vampire driver I couldn't say where you would need to look to make any changes to correct a wing incidence issue. There may be a cam or shims at the wing attach points to make a trim adjustment to correct any minor aligment problems.

 

Another item that can cause the ailerons to be off is the weight of each wing. How does your weight and balance look? It should be very close to equal side to side.

 

I hope this helps out regarding your aileron trim. It sounds like Pylon500 has very good knowledge of the Vampire and can check the wings for you as well.

 

Best Regards

 

BaronVonEvil

 

P.S. Sorry, I didnt realize the original post of Rob's was from 2007 and my reply maybe somewhat late.