Waiters 2nd First Flight

[Waiter]

Independence Day was a good Day. N961EZ won her independence from the Hangar and took to the air again. Total Time for Today 1.0 hr, and three full stop landings.

 

I didn't retract the gear the first time, just around the pattern, controllability check, and landed. A quick walk around to see if any parts fell off, then out again.

 

Second time I did a full retract, WOW, When the gear hits the wells, its like somebody hit the Rocket Switch :-)

 

SURPRISES - The only surprise I had, I can't hear the Hydraulic pump running (Sure is loud on the ground, but can't hear it running when airborne.

 

I've got a couple issues to deal with, some may be related:

 

 

1)Rough engine, high Oil temp, and High CHT on #1. I'll bet money that the injector on #1 is plugged, or the intake tube gasket is cracked. #1 is very lean ant the other 3 cylinders are sooty (looking at the exhaust)

 

2) Left UP indicator shows "In Transit" even though the gear is UP. Most likely a switch adjustment.

 

NOTE - I can't see the mains to see if they are UP or DOWN, BUT, I can see the upper door that rides out under the wing. I'll paint a couple stripes on the wing leading edge, that line up with the door. One when the gear is down, and the other when the gear is up. This is a good visual indication of the gears position, based oon the position of the upper door.

 

3) Gear warning horn did not sound when I retarded the throttle to Idle. I need to check into this.

 

4) Fuel Qualtity, Need to look at the sensors and see whats going on. I can see the fuel in the windows, but the guage isn't working.

 

Speaking of Fuel:

 

My original EZ would hold 43 - 44 gallons total. The New configuration holds 34 in the strakes, and five in the sump. So, I lost ten gallons in the strakes, but got back 5 by installing a thigh support sump tank.

 

I'll keep you posted when I start speed test.

 

Waiter

[TMann]

It sounds great Waiter.

I was hoping you would get airborne again today. I'm anxious to hear some numbers!

[Edge 513]

Waiters declared his independence.....from terra-firma.

[longezdave]

I hope that working out the bugs doesn't take too long and you get back to having fun with your creation! That's what it's all about. I look forward to meeting you at future EZ events.

[JLKnolla]

Congratulations Waiter, this has been a long time in coming and I know you will approach this 're'test phase with your usual professionalism and attention to detail. Hope the rough running clears up with an injector cleaning and that the performance blows you away (then you can blow all of us away).

 

I have said it before but think it bears repeating, thank you so much for putting in the additional time beyond this serious upgrade and modification effort to catalog it on your website for all the flyers and dreamers out here in happy data land - it is a tremendous resource and a great legacy.

 

Blue Skies!

[RGlos]

After all this what is your new empty weight.

 

Congratulations by the way. You sure kept a lot of us informed and entertained. Thanks

 

Rick

[Waiter]

New Empty weight is 1170 lbs (from 950lbs in 1995)

New Fuel Quantity is 39 gal (was 44)

 

Had a small piece of debris in the #1 injector. Also had a cracked intake gasket. This solved the High CHT on #1

 

Calibrated the fuel Quantity guages.

 

Fixed the Gear Alrm horn (Throttle position switch adjustment.)

 

Fixed the left gear UP indicator (switch adjustment)

 

Still have a high Oil Temp (260 - 290 at the input to the oil cooler). I found a missings bolt in the oil cooler, may have been allowing air to bypass the cooler. Also, I'm going to clean up the intake ramp , Hopefully this should take care of the Oil Temp.

 

Waiter

[ZUCZZ]

Congratulations ...!!!

[JLKnolla]

Jonesin' for an update....how goes it Waiter?

 

Do you have a qualitative before and after handling feel yet?

 

Hope all is going according to plan.

[Waiter]

Been trying to get to the airport.

 

EGT / CHT under control. Still a little high.

 

My cowling is close to the prop (2 inches, ???) I seem to recall from my original Phase I, that the bow wave from the prop was pushing air back into the cowl. I cut 2 inches off the back of the cowl and made a significant improvement in cooling.

 

I'll try this tonight and see what happens (maybe 1 inch at a time)

 

ALSO. I place the wing shims in the wrong place. I need to reshim the left wing. The plane requires a lot of left trim (wants to turn right). I need to remove one shim from the left top outboard, and place it at the left bottom outboard. This will lower the angle of attack of the left wing and should reduce the left trim.

 

ALSO - left gear still doesn't indicate UP when I know its UP.

 

ALSO - UP switch doesn't work, I have to use the UP BYPASS. I probably have a safety switch thats not making.

 

ALSO - I can barly hear trhe gear warning horn (loud buzzer). I purchased a car horn and will be replacing the buzzer with the horn.

 

Waiter

[Cozy Girrrl]

 

ALSO - I can barly hear trhe gear warning horn (loud buzzer). I purchased a car horn and will be replacing the buzzer with the horn.

 

Waiter

NTSB-"Pilot stopped flying the plane when diesel train horn evacuated his bowels..."

[Waiter]

Or; " I swear, I heard a Chevy on short final..."

 

Waiter

[Cozy Girrrl]

Or; " I swear, I heard a Chevy on short final..."

 

Waiter

Now, THAT is funny, but you may have to explain it to a few folks who are slow on the uptake

[TMann]

Where the h3ll are all the geese? I keep hearing them!

[Waiter]

Hey, did a couple crosswind landings yesterday, 12kts, 90 deg to runway. No problems.

 

Waiter

[TMann]

....... I'm drooling. Maybe I can do a little taxi test while the wings are curing.

 

Sounds most inspiring!

[Kent Ashton]

My cowling is close to the prop (2 inches, ???) I seem to recall from my original Phase I, that the bow wave from the prop was pushing air back into the cowl.

Yep, there are some strange things going on around that prop hub. For example, one time I had fuel leaking out of vents on top of the fuselage. It blew back along the cowl and then up under the cowl and left blue stains on the inside of the upper cowl, 8 inches forward of the aft edge. -Kent

[argoldman]

As we can see, many times air doesn't go where logic says. A great case in point is the Mooney M-20C and similar. This plane had its oil cooler mounted in the front of the cowl, its face into the prop blast and the air flowing into the low pressure part of the undercowl area. It would seem that the air would flow from the high pressure area just behind the prop, through the cooler and thence to the low pressure area and then out. The cooler worked well and was used, in this position until LoPresti redesigned the cowel to make the VW of the skies into the speedster that they now claim it to be.

 

What flow tests showed was that instead of the air flowing through the cooler from the front of the cowl exhausting out the back, it was actually going through the cooler from the cowl backward into the prop blast:irked: --- Go figure.

[longez360]

I recall a story of a flight in a Berkut where a passenger noticed a bottle of water bubbling in the backseat, but when passed forward, it stopped. The owner/pilot mentioned that cutting the cowl back to allow for the prop bow wave eliminated what was observed throughout the cabin length. Perhaps it moved the node to a new location outside the cabin.

 

Vibration is a funny thing.

 

With my old Berkut cowls, I had air coming back out the 'wingpit' inlets and a hot engine. Really important to stick to the fundamentals here (such as Bernoulli's theorem, etc). For cooling; 'Let' the air in by using an efficient inlet ie diffuse, creating an effective sealed plenum, and throttling using the outlet as required.

[Waiter]

I cut 1-1/2 inches off the cowl. SIGNIFICANT difference in noise (much quiter,) and, about 10-15 degrees cooler (390-400 CHT) There is now about 3-1/2 inches between the cowl and the prop.

 

Oil Temp is cooler, but still higher than it should be (240 - 250 at the Cooler input). I think I found out why!

 

The left gear leg doesn't seem to be retracting completely. The tire is hanging on the edge of the well and its sticking out about 6 inches. I need to get a chase plane to confirm this, but I think I can see the gear leg when I look through the window in the bottom of my strake.

 

I'll put the plane on jacks this weekend and see if I can duplicate this on the ground. (Air flow is pushing the gear leg aft, I may need to reshim the 1/2 fork to gain clearence on the aft edge of the well.

 

With the left gear in this position, its blocking airflow to my oil cooler. The oil cooler air intake is a small armpit intake on the left side, just aft of the gear.

 

This gear hanging out is also impacting speed.

 

Waiter

[Cozy1200]

Waiter, That's fantastic.

 

Where are you keeping the plane based. I may have to fly and visit you sometime. Or better yet you can fly down and visit me!

[Firefly-YCTTSFM]

I cut 1-1/2 inches off the cowl. ... There is now about 3-1/2 inches between the cowl and the prop.

Waiter, when you're not busy (ha!) could you post a pic of that?

[Lynn Erickson]

 

The left gear leg doesn't seem to be retracting completely. The tire is hanging on the edge of the well and its sticking out about 6 inches. I need to get a chase plane to confirm this, but I think I can see the gear leg when I look through the window in the bottom of my strake.

 

I'll put the plane on jacks this weekend and see if I can duplicate this on the ground. (Air flow is pushing the gear leg aft, I may need to reshim the 1/2 fork to gain clearence on the aft edge of the well.

 

 

 

This gear hanging out is also impacting speed.

 

Waiter

may be the air loads are pushing it back. all things retract work different in the air

we had a problem where the strut would compress but by the time the gear got raised the pressure in the strut would bleed off allowing the strut to extend just enough for the gear to hang on the edge of the wheel well. it always worked on the ground but intermittent problem in the air. also if the tires are still spinning when it is going into the well it could hang and needs to be recycled. stepping on brakes just before retraction seems to help.

Waiter, do you have pressure gauge on the up and down? I would like to know if you see a increase in the up pressure during a flight without the pump coming on.

[Waiter]

Lynn;

 

I'm about 99% sure its the airload pushing the strut aft. I don't see any skid marks on the well or lip, so I don't think the tire is spinning.

 

The airspeed at the time of retract is around 70 kts and the pitch angle is 30-35 degress.

 

I have pressure guages on the UP and DOWN lines. ( I didn't look to see what the pressure was, I'll take a look tonight. I seem to recall I had them adjusted to about 650psi for UP and 450psi for DOWN ????)

 

ALSO, I don't use switches to check that the struts are physically compressed. Instead, I use a pressure switch (1100 psi) to check the pressure on the strut compression line. Although there are failure modes where you could have 1100 psi, but the struts are not compressed (Internal strut leak; Fluid has leaked from the bottom side of the strut (hydraulic side) to the interval oleo side of the strut). Regardless, The worst case scenero would be the struts decompressing inside the wheel well.

 

If physical switches are used, adjustment of the switches is critical to ensure that if the struts decompressed inside the well, the switches would be able to sense this. I felt that that sensing pressure would be a better solution for this particular scenerio.

 

I didn't like the complexity of mounting and adjusting physical switches, so I decided to just use a pressure switch.

 

The best solution would be to use both, i.e. a physical switch on each leg to sense the strut is in the compressed position, AND, a pressure switch to sense that strut compression pressure has been reached. The strut switches would verify that the struts are indeed fully compressed and its OK to start the retract. The pressure switch would catch the drop in pressure from struts decompressing inside the well, yet the struts haven't moved far enough to deactivate the physical strut switches. In this configuration, the three switches (two physical and one pressure) would be wired in series, All three switches must be closed to satisify the controller that the struts are retracted)

 

BIG NOTE - The wheel wells must be installed with a slight angle so that if the struts decompress inside the wheel well, the gear will still come out even though the tires are pressing firmly against the inside of the wheel wells. I have tested this scenerio; my gear has no problem coming out with a normal extend cycle, even if the struts are decompressed. They will also pop out under gravity if there is no UP pressure, but I need to give it a couple good jolts.

 

CONTROLLER DIFFERENCES

 

ALSO - One of the major differences in my gear controller and the original controller is, My controller continously monitors the strut compression, even after the gear has been retracted.

 

In the original controller, When the handle was moved to the UP position, the struts were compressed, once that was satisified, the gear would retract. The only time that a "Struts Compressed" check is made is during the initial cycle, once the struts are compressed and the actual retract begins, the struts are never checked again. If the struts started to uncompress, the controller didn't care, it would continue to retract the gear.

 

 

In my controller, The sequence is the same, except for one major difference;

 

The Strut compression switch (or switches) are continousely monitored, through the entire retract sequence, and when the gear is fully retracted. If at any time the strut switch opens (the strut is leaking down or the strut is uncompressing) the Retract sequence is restarted.

 

i.e. The Strut Valve is energized the UP pump is cycled until the struts are compressed, the strut valve then closes and the UP pumps continues to run until the UP pressure is reached.

 

 

Waiter

[Waiter]

Drew;

 

The Plane is at KTDZ (Toledo Metcalf) in Northwestern Ohio.

 

Waiter