Flaps?

[N96337]

Re: Flaps?

That's an interesting setup! I'd thrown around this idea for quite a while, but was more pulled to head to an attach bracket more like the Husky uses.
John

[AeroCapture]

Re: Flaps?

Hello Tim,

Just responded to your PM.

- Lyle

[astjp2]

Re: Flaps?

I am interested in the flap hardware...Tim

[AeroCapture]

Re: Flaps?

Well, they were included in a good sized parts cache that I recently purchased and in all honestly, I have no plans to use them or the hardware. Might see if converting the flaps in ailerons is a viable option...

Thank you Lyle for taking the time to reply and post some great pictures. I too am a layman but am always interested in new and different. I suspected the flap<>aileron assemblage link but only because the aileron design seems to have survived the test of time. Adding a complex slotted or other design would have required engineering and new parts, whereas using existing hardware simplified the process. The local experimental with flaps looks like an aileron adaptation, but his extendable leading edge slats are another matter.

How did you come by these parts and information?

Gary

[PA1195]

Re: Flaps?

Well Gary,

I am only a layman here but it does appear that the flaps were basically a reworking of the ailerons and were attached with modified versions on the same aileron hardware and aileron cove material.

-Lyle

Thank you Lyle for taking the time to reply and post some great pictures. I too am a layman but am always interested in new and different. I suspected the flap<>aileron assemblage link but only because the aileron design seems to have survived the test of time. Adding a complex slotted or other design would have required engineering and new parts, whereas using existing hardware simplified the process. The local experimental with flaps looks like an aileron adaptation, but his extendable leading edge slats are another matter.

How did you come by these parts and information?

Did Taylorcraft install a gap seal on the upper slot between the wing and flap like Piper did on their Cubs with flaps? I flew my Pipers and Citabria with and without that seal and found it beneficial when installed. I then installed a similar gap seal between the aileron and wing for better roll control. That and installing a spill-plate on the outboard ends of the flaps plus VG's resulted in a GPS stall/mush of 29 mph in level flight.

Gary

[AeroCapture]

Re: Flaps?

Well Gary,

I am only a layman here but it does appear that the flaps were basically a reworking of the ailerons and were attached with modified versions on the same aileron hardware and aileron cove material.

-Lyle

Hi Lyle. How did taylorcraft support the flap's loads forward into the wing structure? Did they use compression bracing between the spars or any visible structural improvements? There is an experimental retro-fit here (Greg Clayton the skylight STC owner) but externally it looks similar to the aileron installation...internally ??? I've not asked him. It would take a major wing and airframe change to install but might be a fun project nonetheless.

I installed flaps on my C-90 PA-11 after flying it for a few without. Cost was $5000+ and the benefit on takeoff questionable. Unless deployed no more than 12* the additional drag hindered takeoff (there were three notches at 12/25/50*). I could land on a $0.10 but not takeoff in the same distance...unbalanced performance. They were nice for slow flight and on floats or in deep snow at times.

It's interesting to discuss flaps with Supercub owners. When asked if they ever leave them up for takeoff or landing I've been met with a deer-in-the headlights stare. I owned two PA-18's and rarely deployed them for takeoff unless the conditions required...maybe 4 mph difference in performance which is blown through with their power very quickly. They can increase rate of descent through increased drag nicely over obstacles or minimize ground roll on rough terrain.

Gary

[PA1195]

Re: Flaps?

Does this help?

Looks like it gets flakey at more than 30 degrees of flaps (ie 50 and 60 degrees).

Abbott and Von Doenhoff, Fig. 119. I re-read Section 8 this afternoon after 40 some years which is where I found the link #664. They don't really exclude the slotted flap design and limiting flap travel could control the pitching effect within the range of elevator control.

What Taylorcraft did when implementing flaps, how well they function, and whether or not they're desirable to retrofit is open to question. I'd not do it mainly for certification reasons. It would take an extensive airframe change as well. Better to buy a plane with them installed.

Gary

[M Towsley]

Re: Flaps?

We had an Auster owner/attempted restorer at one time here on the forum if I remember correctly. I think he went crazy because he owned it. Personally, I wouldn't waste my time reading about them.

Oh if you could have only spoken to my now departed uncle who was an aircraft engineer/designer for Convair/General Dynamics. B-36, B-58, F-111 and F-16 among others. Great stories...

Re: Flaps?

Does this help?

Looks like it gets flakey at more than 30 degrees of flaps (ie 50 and 60 degrees).

[PA1195]

Re: Flaps?

We seem to be forgetting that NACA did tests with flaps on this airfoil, maybe someday I will look them up again, but its not so much a structural problem as it is with the massive changes in flight dynamics when you don't have the right combination. I remember from the report that the airfoil was having a sever pitching forward moment when flaps were introduced, causing the airplane to tip on its nose...more than other air foils. Tim

More flap about flaps: http://naca.central.cranfield.ac.uk/...report-664.pdf Note the analogy for the plain flap to the effect of an aileron. However the Fowler flap did exhibit relative large pitching-moment coefficients relative to the others. Employing that design (similar to Cessna's) would require a flap track system and it's design and load complexities. They authors appear to favor a slotted flap over the other designs tested.

Gary

[PA1195]

Re: Flaps?

Thanks Marty I've read about them for years starting with my first Taylorcraft in 1974. Mainly looking for ideas on performance and modifications at that time. With any tool form follows function and I suspect that they were designed to fulfill a wartime role as an observation and ? aircraft. Whether or not and how well they fit the mission profile better than a plain Taylorcraft, I'd like to hear more. The sanity of their current owners remains a question.

There appears to be two main themes on this Forum...those that are here to restore and maintain, and those that enjoy flying in atypical circumstances and modifying accordingly. I'll not argue the merits of either just note them.

Gary

[M Towsley]

Re: Flaps?

The English designed and produced, (and named), some of the most beautiful aircraft around......except for the Auster. That is a pathetically ugly aircraft no matter how you look at it.

For your reading pleasure, until Rob responds: https://en.wikipedia.org/wiki/Taylorcraft_Auster

[astjp2]

Re: Flaps?

We seem to be forgetting that NACA did tests with flaps on this airfoil, maybe someday I will look them up again, but its not so much a structural problem as it is with the massive changes in flight dynamics when you don't have the right combination. I remember from the report that the airfoil was having a sever pitching forward moment when flaps were introduced, causing the airplane to tip on its nose...more than other air foils. Tim

[PA1195]

Re: Flaps?

I just installed VGs on my Tcraft today, it sure did change the stall. The air is rougher than heck so I didn't want to play around too much, but so far I'm impressed. The break seems softer? and it's somewhere down below 40 now. It's definitely going to chop some distance off the ground roll.

Hi Dave. Yes they appear to soften the stall and help with slow flight roll control. I can link a reference to perhaps why there's a softening. It has to do with a leading edge discontinuity (airflow separation) for the airfoil with a 12% thickness ratio that forms above a certain AOA. If reduced there's the potential for a less abrupt loss of lift when the trailing edge discontinuity moves forward. Some theory supported by some fact.

I use them (had them on four planes before and after) as money on the bank...not to spend unless needed especially in gusty conditions.

Gary

[PA1195]

Re: Flaps?

You assume incorrectly, Gary, so go home and wash your mouth with soap, young man! Austers did well with nothing, apart from taking a good design and persuading the idiot British authorities to turn it into a military machine. For some reason that I cannot appreciate, there are some here in the UK loving of Austers. All the owners of them that I have met are all barking mad, so perhaps that's the attraction.

Well Robert at age 70 I'm beyond an oral rinse of soap, especially in a Forum I presume is still open to opinion and discussion based upon experience and knowledge. Your attitude initially makes you appear to be one that might do well with the same, but having never flown an Auster or met an owner I can't confirm or deny your claim. There must have been a reason for them to augment that model with flaps, and perhaps their love of type has reason. Maybe you can elaborate on the basis for the modifications so we can all learn.

Gary