RFguy

I read there is a crossover point with faster aircraft , and that prop stopped is more drag than prop idle for airplanes with 70-90 kts (for example) best glide. Your best glide would be , what , 50 kts clean ?

JG3, any idea how different is your sink rate with prop stopped versus idle ? . I do a glide whenever there is no one else in circuit. Not too polite a manoeuver, otherwise.

Skip you are going to have to put some numbers on the requirement. Force - I cannot beleive much unless it is acting as a bucket scoop ,But it WILL have some of the pressure of the cowl insides... You would be able to make a reasonable estimate of the upper limit of the pressure on the cowl flap. Travel ? . Many Model RC-servos will do the job you want , since I gather you are fine if it doesnt work.

at least from where they are, that should be an easy for any pilot. But ya do need to do them regularly to be regularly successful. I find that doing them with some wind around is useful - IE adding the requirement to think about the wind . When I practice and end up short, its usually because I forgot to take into account the 10 kts at 500', which can make a difference.... Some are hesitant when a bit high on final, to point the nose at the ground and / or use a slip near the ground in order to increase the rate of descent- still thinking about a 500fpm descent rate....

Oh , not the flap ? Doh I thought it was the FLAP actuator. OK. "disregard last and all previous " It seems I cannot read.

can we get back to the topic ?

those cheap chinese actuators are for things like kitchen robots, not airplanes....

Sean, as you are aware, anything you buy on ebay from China- you got to plan for a failure in flight, but you know that. Check if they live up to their specs etc. if it says 20kg, try 20kg, then try 30kg. and try pulling as well as pushing...they will be different.... and see how much there is in hand, and be sure to do it at 12V, not 13.8V etc on the bench , as wire volt drops are not insignificant near stall. You want about 2:1 at least on whatever it needs. Can you monitor the DC current during deployment at Vfe with the wing loaded ??? In the datasheet - notice the "Duty Cycle: 10%" - you should treat that as a red flag- that tells me the motor is very underdone for the job- avoid or substantially lower the load. -" Full load current: 0.2~0.3A at 12V" . you need to measure this at Vfe in flight (with the wing loaded) and see what current you are pulling. SUggest at Vfe, no more than 50% of full load current for whatever size you choose. - Note the very important spec "and the pulling force is less than pushing force." - the spec is pushing force (19kg). the pulling force might be 1/2 or 1/4 etc ......

the sealed beams, like the classic GE4509 are pretty bright (landing lights). they are a narrow beam, draw alot of current, and get hot, and have a MTBF of perhaps 15 hours in an aircraft something like 110,000 Cd. My Whelen Parmethius G3 PN# 01-0772102-10 says 100,000 Cd for the first 5 minutes, then as it warms up, 80,000, and at 1 hour and max ambient is at 60,000 Cd has 10deg beam spread.

How much thrust is required when airborne at Vfe ? - you need to know this. Sonex aircraft will know. how much room do you have ? did you get a ball screw, rack or lead screw type ?

You can see a good flashtube strobe at least 1nm in broad daylight...

Lyndon, also consider my viewpoint with my answers- I'm involved in GA maintenance...... but I also have a RA plane also, so I see both ends of arguments. what are you building? EDMO isnt expensive. you are not putting in 100km of wire.... doesnt really matter if you buy 20 different wires in 10 foot lengths of 100 foot lengths - all same price. Some coloured stuff is 50' minimum. I'd recommend using coloured stuff where you can for avionics, it will be much easier on your brain. Or, invest in a effective cable labelling tool (or labeller with those laminated print roll up wire sleeves.....) -glen.

good point Nev Most people i know in GA are installing the LED replacements for their sealed beams - I have a PARMETHEUS G3 SERIES LED LANDING LIGHT 01-0772102-10. which draws about one third of the current of the incandescent light with more light and far far less heat... Got from CJ Aerospace. skippy you dont take off from a real airport. LOL. a landing light on the glideslope at noon with the sun out is chalk and cheese.

I think a bright headlight is very effective for seeing an aircraft coming down the glideslope , when when waiting at the holding point or turning at the runway end I run my headlight whenever the plane is on the runway or airborne. and its bl00dy bright. The headlight I have is excellent. I think they should be compulsory and an airworthy requirement. As for strobes on the tail and wings- I'd suggest the flashtube type........ LEDs are half arsed at best IMO, for wide throw strobes. The Blondel-Rey equation is not a good fit , despite this is what the LED people will have you beleive- as it was primarily for very short durations. looking around the net for something so I dont have to write all about it I find : https://airbornelights.wordpress.com/lighting-technology/at-what-cost-will-leds-replace-flashtube-lights/ certainly the LED beacons and anti-collision lights meet the FAA requirements but they're pissweak IMO compated to a flashtube. The manufacturers for the LED beacons are also cagey about their tech details ..... go figure https://rosap.ntl.bts.gov/view/dot/9071/dot_9071_DS1.pdf

and no guarentee it is even what it is claimed......and I am guessing that it didnt come with release paperwork either... suggest EDMO. they're good to deal with.

between- as in forward, aft of mainspar of person CoM on the spar? What's the CoG location look like with no fuel in the fuel tanks (assuming forward of mainspar) and max people and baggage ? I see a few low wing aircraft that with nothing in the tanks(which are often forward of the mainspar) and full peeople and baggage, marginal CofG condition.

have you got pilots sitting over the wing spar, in front, or behind ? I'd also like to see +6g for these planes, so the Va doesnt get too low. IMO, that's a potential hazard in these land-slow but fly-fast slippery airplanes. 120 kts (IAS) is not that much use if Va (clean , at half fuel and 1 POB) ) is 75 kts etc.

How many sqft of wing do you have at the moment ? Lancair of course is not in the same race / category at what you are proposing , a different beast. The Lanceair foil, type NLF-0215 is worth studying. it is a new foil from the 1980s. Have a look at NASA technical report 1865 . (June 1981 ).. it is in there.... it isn't all plain sailing though, the super-duper airfoil is quite sensitivie to flow disruption (bumps turbulence etc etc) https://www.n91cz.net/Interesting_Technical_Reports/NASA-81-tp1865.pdf Retract : Cirrus does pretty well with non retract, I'd suggest same. Many small GA planes are retract just so they can be commercial trainers. Hanging around a maintenance facility, I can tell you that retractable gear systems - is probably problem child #1 and in general, never quick to solve due to the sheer numbers of joints, switches, pressure sensors, pumps, motors, relays O.M.G !!!!!

well, this is a Lanceair 320/360, for reference. 76 sq ft of wing.... there were a couple of different wings.

I love my Stabilator (PA28) but I love complexity.... Stuart is right about the anti servo tab linkage.... there is a bit to it.... Stabilator is more efficient, for sure, and more effective.... but at considerable complexity... Like I love my multi-link Oleos on my PA28, great on the rough, and like I love the stabilator- so much range. But the Oleos are a maintenance PITA . As I also have aJabiru - I appreciate the simplicity of the jabiru control surfaces and cable system, and I appreciate aircraft using spring steel or 'glass etc sprung main gear (Cessnas, Jabirus) . I only really appreciate the simplicity after running maintenance on the Piper for a couple of years. Sure they're really nice to use, makes the airplane super nice....(Oleos, Stabilator ) makes for a royal aircraft..... but at maintenance PITA which I would not recommend for an RA-aus level of maintenance and $$$ spent.

My 2c: *** Ideally the aircraft should have PLENTY of elevator authority in hand at stall / low speeds, this will enable better flare control in the landing, to keep the pressure off the nosewheel during run out and taxi. I've flown a couple of aircraft that had nothing left in the tail when they got slow in the landing phase, seems not ideal. tailwheel has quite a bit of rough strip advantage. although, I dont see many (any?) damaged Cherokee nose gear due to rough strips as it is built like a brick sh1thouse ( PIO / porpoising excluded) There is alot you can do to look after a nose wheel on rough terriain. Good landing technique will go a long way, (slow , keeping nosewheel away from the ground as long as possible) cherokee has heaps of H-stab authority before it even flys. As Yenn said in 2010: "Posted November 17, 2010 The reason the taildraggers have safer landings than nose wheel types, may be more to do with pilot inputs than aircraft configuration." I'd like to see the RV6A have a bit more authority in the rear to keep that fragile nosewheel away from the ground for longer. But that probably depends on how nose heavy that particular RV is. Stuart, on paper, your's is a bit heavy in the nose I thought from the W&B with the CS compared to some POH I have looked at (online) with fixed pitch O320s engined machines which are likely to be 'just right'.

My 2c worth is 1) that common areas that might need repairs try and keep as fibreglass, or at least replaceable whole regions--- as structural carbon fibre repairs are not a beginner's pasttime.... 2) consider what metal or wood ablative charing layer or fire retard on the fibreglass etc / resin you want up front such that an engine fire is survivable...... glen.

The SP I know is a very different beast from a 230C or 230D. Ask the factory for specifics for your SN aircraft What year built ? What is the MTOW that it is placarded for ? sure it is a "230SP" not a "SP" or "SP470 "? oh its a USA airplane. ask Nick, the local factory rep. There were a few different naming differences in different regions. between legs throttle or panel throttle ? header tank under seat or beyond rear bulkhead ? what wingspan ? how deep chord ? 1m ? what tail width? winglets ? what max flap angle setting (measure) ? what width between the mains? what empty weight ?

evening summer flying. Oh the enjoyable long days and twilight. plenty of time for flying after 6pm or even 8pm this time of year. A mix of cut and uncut paddocks. Had a look at Thruster's farm. no longer underwater. I really am paying attention. although- it does fly hands-off better now than it ever did before. (post re rigging the ailerons) Hmmm time to find an airport. I can see the reflection of my tail strobe on my instrument panel.

It's an interesting engineering problem, to put in in tech terms, in most applications, the internal state is much larger (has more degrees of freedom) than the few observable parameters which are measured (by the accelerometer).