My first flight in N509CT

[FlyingMonkey]

Got my first time in my new CTSW today. My instructor gave the airplane a thorough once-over before we went up, and pronounced "you STOLE this airplane". That made me feel good. He did notice, however that the spinner to cowling gap was slightly smaller at the bottom, which he thinks may indicate it has a hard landing at one time. He said this is common, and when his has this issue they shimmed the motor mount with washers at his last annual. Here's a pic that is at an odd angle to see what I'm talking about:

 

 

On preflight I noticed one of the exhaust springs was broken, but they were all safety wired as well and I already had some on order, so we didn't let that stop the flight.

 

We also think the prop may need some adjustment, as my CT with a three-blade Neuform does not seem to climb nearly as well as his with a two-blade Sensenich. Mine climbs in a much flatter attitude. It was getting about 550-600fpm at 1300lb-ish, and about 1000-1100fpm when he got out and dropped in to about 1100lb. Flat and level we saw about 5200rpm and 119kt. I know Roger says that should be 5600, but we were at 1900ft due to cloud cover and my usual cruise will probably be 3000-5000, so I'm not sure how that affects the calculus on that. I'm planning to go back up tomorrow and if the weather permits will climb higher.

 

The airplane handled great, no surprises, and took very little trimming to make it pretty much hands-off. Power off stalls broke straight ahead at 43-45 knots with zero flaps, pretty much right on book numbers.

 

My solo landings were a little disappointing. The first was total crap, a balloon and then dropped in in from a foot or two. The other two okay, but both left of the center line. I obviously need to be looking down the runway farther. In the end the instructor pronounced all three safe if not beautiful, and combined with our previous flights in his CT he pronounced me a CTSW pilot and released me into the wild.

 

If weather permits tomorrow will be more landing practice, and then next week some air work (stalls, cruise flight tests, etc) and some short hops to nearby airports.

[FlyingMonkey]

Here's the CloudAhoy telemetry of the flight:

 

http://cloudahoy.com/cgi-bin/fltShare.cgi?share=1870pDhgxNu4lcOymxFMn2

[Ed Cesnalis]

Before you adjust your prop, you need an objective. If I lived in GA I would flatten to 5,500RPM @ 7,500' DA. At this I would have my best performance at the plane's most efficient altitude.

 

I bet you can speed up about 7kts.

[FlyingMonkey]

Thanks CT, that makes a ton of sense. I'm not going to touch it until I fly a bit more.

 

I also needed a procedure for adjusting a Neuform...anybody have a link?

[Ed Cesnalis]

anybody have a link?

 

No we have a Roger.

 

Got Protractor?

[sandpiper]

You might want to call Roger but read your Neuform manual first. Might make it easier when he talks about the two different sized bolts and their function.

[WmInce]

. . . "...anybody have a link?" . . .

 

. . . "No we have a Roger." . . .

 

Roger is a great resource to this forum, eh?

As well as some other guys!

[FlyingMonkey]

Thanks Roger!

[Ed Cesnalis]

Roger,

 

I never had any doubt about the need to flatten my prop, for me the difference was more dramatic. All Andy needs to do is look at a Power/Torque chart and see how limited his power is at 5,200

 

IMHO Bounce is from rapid sink at contact, and is probably and indication of too much speed.

Balloon is from raising the nose before you are behind the power curve, it is surely a sign of too much speed.

[sandpiper]

Hi Andy,

 

p.s.

 

If you do the prop in less than 30 min. Sandpiper will buy you dinner. LOL LOL

 

Always someone in the group thinks they should have been a comedian!!

 

Of course, Roger had to have the cowl off first, all the tools lined up, etc. :blush:

 

But, it is easy.

[Ed Cesnalis]

You can bounce below stall speed. Just drop it in from a little too high especially with soft tires or yank the stick way back too fast and hard.

 

Rapid sink will do it, but pumping the stick like so many do will cause it too. An unsteady hand with too much back pressure at the wrong moment with a little extra speed will balloon you for sure. The speed doesn't cause the balloon, its too much sudden back movement on the stick. I have touched down way over flying speeds to show that doesn't cause ballooning or bouncing. Speed doesn't cause it, it is poor piloting, speed will just compound it. I can land at 80 knots and be very smooth and yes then you have speed to bleed on rollout, but so long as you don't do something dumb you just slow down.

 

Sure you can bounce below stall speed but there is a big difference and that is you are done flying. Most bounces result in more flying and another landing or two, those are a sign of too much speed at touch down.

 

Speed + pitch = performance, you can't say speed doesn't cause ballooning. 'too much sudden back movement on the stick' only works if you are in front of the power curve so you can't blame that.

 

I never said that speed is the cause, I said that ballooning and bouncing and flying some more are indicators of too much speed. You can't balloon if you you are behind the power curve and you can't flare if you are in front of it.

 

There are different ways to achieve rapid sink which is needed to bounce. If the control inputs include 'pumping the stick' and result in rapid sink that doesn't mean that pumping the stick not rapid sink caused the bounce.

[CT4ME]

Anyone for popcorn?

[FastEddieB]

Questions...

 

...is changing prop pitch something a pilot can do to his or her own S-LSA? I would think not.

 

...and does FD specify a pitch or acceptable pitch range?

 

Not nagging - just want to be sure everyone stays legal.

 

As far as the spinner/cowl clearance, when I noticed that on my Citabria it was worn engine mounts. Just adding spacers may not be the solution if that's the case.

[FlyingMonkey]

My understanding is that it's a user adjustment, no different really from a trim wheel. They advertise that it has a ground-adjustable prop, why do that if they don't want you to actually adjust it?

[Howardnmn]

I thought slight balloon was from getting a bit more lift from being in gound effect?

 

I also thought uneven spinner gap is to offset p-effect?

[CT4ME]

[FlyingMonkey]

Just to clarify, my first landing was not a bounce. It was a slight balloon caused by being overly aggressive on pulling the stick back in the initial round out. Plane had enough speed to rise a little, then with the nose high speed decayed very fast and the plane plopped to the runway when the lift was lost. The was no bounce.

 

I knew it was about to happen, but I thought in might settle instead of dropping. After the fist bit of balloon I should have just gone around or added a touch of throttle to cushion the descent. No harm done, nothing bent, and I learned to be Johnny-on-the-spot with throttle next time.

 

I will say the smaller tires on my airplane are less forgiving than the tundras on the trainer I was previously using. I wish I had the $3000 for the full upgrade sitting around. Does anybody have a suggestion on the best pressure to run in the smaller tires?

[Howardnmn]

let me try again...

 

i thought the bounce could be a result of plane coming into ground effect. ever see a pelican cruising low over water? it's because ground effect makes for flying with less effort. suggest google 'ground effect'. if you're low on fuel coming in from gulf of mexico for example, flying low over water will reduce fuel burn. i think half a wingspan of altitude will do it. [might also make your mayday call unreadable]

 

w.r.t spinner uneven offset, this is found on almost every rotax powered a/c i've seen. "p-effect" is not what i really meant (yeah, drinking too much coffee b/f flight, p-effect) i meant to say "p-factor" which comes from assymetric prop wash on airframe; mostly makes for yaw. with such a low time airplane i doubt you have engine-mount issues

 

i don't know if FD provides protractor for neuform but if your gonna say 'flatten pitch" by so-many degrees might want to also specify radial distance (from backing plate?) that pitch is measured; i.e., where on prop to measure. no free lunch...changing prop pitch will change short-field performance as well as cruise

 

 

 

 

[sandpiper]

You can measure angle on several places toward the prop tip. Anywhere that it's kinda flat. Maybe 8" from tip give or take. Pick the same spot on every blade. Place blade parallel to floor, measure blade angle. repeat for each blade.

 

There are protractors that clamp to the blade making this easy. You are not measuring to any manufacturers spec. You are measuring where each blade is in relation to level using the same spot on each blade when the blade is parallel to the ground.

 

If your RPM is too slow, take some of the pitch out. Otherwise add pitch. Then do a static run up. If you have 5100 or less, go fly. Carefully monitor RPM on climb and when level to make sure you don't overspeed. If your WOT level RPM is between 5500 and 5600 RPM at or near your favorite altitude, leave it alone. Otherwise it's back to the protractor.

[FastEddieB]

I never touched the pitch of my S-LSA Sky Arrow until I converted it to E-LSA.

 

Changing prop pitch is nowhere listed as maintenance or adjustment an owner can do. Since it requires tools, it's a far cry from a flight-adjustable trim*.

 

On top of that, my maintenance manual specified one and only one pitch setting for the prop: 13.5° at one specific prop station, IIRC.

 

It should not be a big deal, but any time you put a wrench on the airplane, that maintenance or adjustment should be specifically listed under 41.3 - otherwise it requires a certificated mechanic to at least sign it off.

 

Remember further that when you change the pitch on the prop, all your performance charts will be off from the factory setting: takeoff, cruise and climb performance, range, that sort of thing. As Roger has pointed out, even cooling may be affected.

 

Once converted to Experimental, virtually all these restrictions go away. Until then keep your eyes open to legalities to stay out of trouble.

 

*Even bending ground adjustable trim tabs is something a mechanic should technically do.

[FastEddieB]

All that said, I do have the protractor thingy that Warp Drive provided and would be happy to "consult" on a pitch change!

 

[FlyingMonkey]

That brings up another question...what tools or materials are needed to adjust a Neuform prop? I have an electronic level accurate to 0.1 degree, can use that strapped on the prop, or do I need Eddie's fancy protractor thingie?

[Ed Cesnalis]

I never touched the pitch of my S-LSA Sky Arrow until I converted it to E-LSA....

Once converted to Experimental, virtually all these restrictions go away. Until then keep your eyes open to legalities to stay out of trouble...

 

If your maintenance manual specifies a pitch, and if the reason for the pitch is to limit speed to remain LSA compliant than the adjustment would not be permissable even when converted to E-LSA.

[Runtoeat]

Andy, a suggestion - I built a simple wood fixture which spaces a electronic protractor a consistent distance from the root of the prop and sets consistently on the propellor surface and is a consistent 2/3rds of the way out from the root. I position the prop blade level to ground, position the protractor in this fixture, record the pitch angle and then increase or decrease the pitch "as needed". This provides a relative pitch angle from what was there prior to changing the pitch. If one wishes to do so, the distance out from the root could be set to the Neuform specs and then an absolute "angle-to-spec" could be achieved. The relative angle is all I am interested in for increasing or decreasing engine rpm.

 

A tip also is to keep slight tension on the clamping bolts so the prop can be turned but not loose enough to allow accidental movement if the blade is inadvertantly bumped during adjustment. I may have a picture of my fixture and will post this if I do. I have the clamp-on protractor like Eddie shows but the use of a fixture that positions an electronic protractor consistently on each blade provides better accuracy.

[Ed Cesnalis]

Speed is the SOLUTION to porpoising and bouncing the plane. Stalling the plane too high will make the bounce and multiple bouncing if you really lose control. If you have enough speed you will land much easier and smoother. Think of it as FLYING the plane on the runway instead of DROPPING it onto the runway.

 

We used to have a Mooney, a design with a short wheel base and a reputation for porpoising.

 

You cannot blame a series of bounces or a porpoising event on too little speed for the reason I stated to Roger above. If a stalled airplane bounces it cannot continue to fly because it no longer has flying speed. A plane that is bouncing ( doing multiple landings ) or porpoising has not stalled.

 

Porpoising is the worse case scenario for a bounced landing where the nose wheel contacts first resulting in the mains contacting next and a resulting increase in pitch causing the plane to climb. If the wheel base is short this can happen so fast that the pilots reaction will be too late or out of sync making the problem worse and the cycle continue until stall speed is reached or until the plane is so broken that it cannot continue.

 

This video is a great example, 5 unwanted liftoffs are not the result of too little speed but of too much speed and nosewheel 1st contacts.