Touch and Go!...Not Go!

[skidmark]

Would like to hear what you guys think out there. When I'm doing circuts ,on finals I'm in idle for approach, touch down , full throttle after landing for a touch and go and then!!!spltter splutter!. Bit of choke alls okay. Close choke and you on your way again. I know this is not cool so I approach with a bit of power and cut throttle just before touch down and I don't have any problem. 503 dual ignition. Carb sockets are good so its not sucking air. Any other points to check?

[Tailspin]

Hi Skidmark

When i was doing myTraining, my Instructor told me never to slam open the Throttle on a 503. Rather apply the throttle gradually. The reason for this would be the sudden surge of air and not enough fuel this causes the motor to splutter and it could also die on you.

Rather apply the throttle evenly and don't slam it open.

Just my 2 Zim Dollars.
Definately not gospel. Use it don't use it.

[Biggles]

Skidmark

Is this a continous thing or just a bit of a splutter as you apply throttle?

I am with Tailspin on slamming open the throttle on a 503 and always come in with abit more than idle incase I need lots of noise quickly to get out of the dwang. But that usually manifests itself in a gurgle and when you come off the throttle she recovers and you then slowly apply throttle. Don't think you could get it to splutter long enough to apply choke/ enricher.

A longer splutter splutter... could be to do with the engine cooling while on idle with high airspeed.

[skidmark]

Thanks guys I also learnt not to slam the throttle full but come on gradually. I think it has happened when I've been on idle for too long on approach. But when I fly next time I'll see and make mental notes of exactly when and how. Going to check plugs and carb set up just to double check anyway.

[Morph]

Skidmark,

I would definately take to carbs off and service them. Using the choke slightly to enrich the mixture tells me that your idle jets are dirty or blocked or the carb is not set up correctly. I'll come to MS on Saturday morning and help you if you like

[skidmark]

Morph,
That would be cool then if its ok weather we can go fly. See you at Conti's tonight.

[skidmark]

This has only happened on the touch and go thing. Other than that she starts great and idles just like a 503 does rough so you lift her to1800 to 2000 rpm and she smooth's out. Don't want to put too much pressure on the crank.I'm flying a Challenger just to let you guys know.

[Dre'man]

I'm flying a Challenger just to let you guys know.

We'll try our best not to hold that against you

[skidmark]

cool

[skidmark]

Kept a low profile for awhile!.... Just to let you know....
Changed and replaced all fuel pipes to rubber 300 psi fuel injection ...da da da! New fuel filter...merc diesel... clear ones so that you can see all the juice flowing thru. New needles and needle seats (for the coast). Stripped and cleaned all the throttle cables. Replace the plugs BR8ES. Checked the floats. Checked and made sure that the the carbs are in sinc with each other! Got idle really mooi. Drained all the fuel out in this process too so all is clean. Starts and idles like a dream. On the ground warm it up then let it idle lowest about 1540rpm smack the throttle response immediate! Wack full power no problem. Kill power on finals put it down...... power slowly for touch and go guess WHAT!!!!"????? SPLUTTER SPLUTTER!! Keep it at 2000 rpm no problem. Running a 54 inch GSC wooden Prop with 37 Deg pitch. Engine mounts look good too. Carb sockects lekker. Got a lekker up draught on finals last week couldn't get power on and had a very interesting landing! Still here and plane is still mooi.....but very scarey big wake up call!

[CHARLIE WHISKEY]

I agree with tailspin as wel, don't slam the 503. I've got a new 10.7 hour 503 dcdi. Since day one "touch and goes" same problem with a 1 second lag. Setted and resetted all twice, same. Problem with engine I thought.

An old bold pilot told me that you must remember where your torque curve runs - low revs little torque , thus you force your aircraft nose dawn (power on idle) for landing to maintain a landing speed, creating more force (wind flow) on you prop.Remember your prop especialy wood 2 braders acts then like a brake and now you are forcing it to brake even more. Slamming on power will pull open your carbs , creating a sort of a over fueling or "floting". The engine on the other hand must now overcome the exstra force(or drag on prop) with no torque and with a "keel vol petrol". once thats over it goes like a bullet.
Thats why you'l not likely to get on static reving.
Why diveing towards the runway like a F16bomber, you've got power use it and it's much more relaxing on your engine.
I learned something wich resulted in changeing my way of landings.

I approach now with a smaller angle towards the runway,little power and ease towards full power on "go".Works every time.

Thanks old bold pilots and thanks instuctors for teaching me F16 flying.

Cheers

[Tailspin]

This is how my landings go :-

Turn finals - setup and line up for Landing - Radio Call - get my spot on the runway - start pulling the bar to maintain speed - keep my spot - pull more bar - maintain speed - pull bar now through my poepol and hold her there - start to flare - touch throttle to get engine to slowly start to spool up touchdown - keep applying throttle now on the ground throttle now wide open motor is running at full tilt - rotate and start to climb away.

As long as you are aware that when you stop flying and when you start flying you quickly learn to adjust your tactics. Basically like dive bombing as CHARLIE WISKEY said.

[Morph]

Skidmark my mate

There at Saldanha, come in on power, nice and smooth, shallow approach

When you get back to Morning Star, cut the power to idle on finals, as you drop below the trees, smoothly bring your power back to 1800 to 2000 rpm to smooth the touchdown and to prep the motor for a go-around if neccessary. If you do need to go around, go to full throttle smoothly again, while holding back on the stick (the Challenger will nose down when you apply throttle and you don't want to bend a nose wheel)

Every motor is different, my old Challies 503 used to drop to 1400 , run rough for a short while and recover itself back up to 1800rpm idle.

[skidmark]

Morphie my sweet pal....that is my exact problem! Everybody is under the illusion that I smack the power on...I don't! I try to bring it back slowly and a couple of times its even cut out on the runway and I have had to restart. Going to adjust my idle to 1800rpm and see what transpires! You can't have no power available on finals. A dead stick is something totally different. I don't want to treat every landing as a dead stick.....got my groove? I've done a few now while doing my conversion and I think I can handle it but I don't want to be that tense every landing..... Am I being naive? :D

[skidmark]

Tailspin.. I got you. That's not my problem I do everything as we have been taught and actually after 5 years of flying by.. instinct.This is the first time I have ever exrerienced this type of situation that you motor doesn't responsed when you put power.. when you need it .... you abort landing and go round ...you with me now? I'm a technical person so I'm trying to work out why my plane doesn't respond to the the application on power should I need it of finals from an idle situation. If I test the plane on the ground it works perfectly...not when I'm on finals!