There is value in a good preflight!

Vance

Gyroplane CFI
Staff member
Joined
Oct 30, 2003
Messages
18,363
Location
Santa Maria, California
Aircraft
Givens Predator
Total Flight Time
2600+ in rotorcraft
After a lovely flight up some hidden valleys and over Lake Lopez to San Louis Obispo, Ed and I removed the Predator’s rotor blades and loaded her on the trailer Sunday

We took the Predator up to Smokey’s shop in Atascadero on Monday to get a feel for what it will take to install the IO-320.

We are hoping to do it in a couple of weeks. My fuel injection is on the flow bench now. My propeller is scheduled for July production.

Monday night we pulled the Predator off the trailer and installed the rotor blades. I didn’t have time to do a maintenance flight.

Today after my meeting I went to the airport and performed a preflight and found that one of the two 3/16 bolts that hold the upper vertical stabilizer support was missing.

Part of the preflight is to check for cracks in the rotor mast and check for loose fasteners.

Having the one bolt missing puts a tremendous load on the other bolt because now the support has leverage.

If I had lost the second bolt it would be possible for the support to come loose and get into the prop. The entire vertical stabilizer could have come losse.

I feel fortunate to have found it.

I have looked at her so many times without finding anything it would be easy to get sloppy with the preflight.

Thank you, Vance
 
Vance, Are you going to do a play-by-play on your O-320 conversion. I have a chance to buy a running take-out O-320 and toyed with idea of putting it in a RAF 2000. (with H-stab).

John K.
 
Hello John,

I am afraid it wouldn’t be much of a story.

We will be replacing a 135 horsepower O-290D with a 160 horsepower IO-320B1A.

The weight of the engine is essentially the same.

It has dynafocal mounts so we have to make a new engine mount and we are going to raise the engine 3 inches and raise the tail support 3 inches so we can use a 3 blade 72 inch Catto prop. We are also going to move the engine forward 1.25 inches so we can use a prop extension that will give us a better place to mount the propeller hub and the longer mounts. We have a mount for the engine, it is a matter of cutting off the part that interfaces with the fire wall and making new legs for it that puts the engine where we want it and bolts to the existing firewall.

The engines are relatively self contained so it is a matter of hooking up the fuel and oil cooler, instruments, P leads and controls.

We will be building a custom exhaust system because I would like to quiet her down some.

At some future date we would like to build or adapt a cowl and clean up the aerodynamics a little but that is really a separate project. In the mean time we are going to use the existing cooling duct “eyebrows”.

I will report on the difference in performance in a sort of haphazard way because we don’t really have an accurate way to test her. My preliminary numbers suggest a 20% increase in static thrust would be a reasonable expectation. I have never done a static thrust test.

My current performance numbers solo are roughly 85kts straight and level, 8,800 foot ceiling and around 800 feet per minute sustainable climb at sea level. I burn somewhere between 6 and 10 gallons per hour. The weather and fuel load make such a big difference that the numbers will not be accurate. With Ed in the back and full tanks I can just see the other side of 70kts and get around 200 feet per minute climb on a cool day. I think the practical ceiling with Ed is somewhere around 6,000 feet. We have been over 5,500 feet on a cool day and been stuck around 4,200 feet on a hot day. There have been days where we have not been able to climb above 2,000 feet in the 19 miles from Santa Barbara to the Gaviota pass. At Buckeye with Terry in the back seat and full tanks on a 110 degree night flight to Gila Bend it took us a half hour to climb from 1,000 to 2,000 feet MSL and keep the temperatures in the green. .

We are going to try to maintain the quality that Mark Givens did throughout the aircraft.

My friend Smokey Alleman will do the welding and I will manage the fitting and details.

Ed will take some pictures.

Thank you, Vance
 
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Way to go Vance!
I still do the same pre-flight I was doing when I was a new pilot! And proud of it!!! It's not a car and you can't just pull over.

I have never found a problem that grounded a plane I was about to fly. (My brother really does good maintenance) But still I keep looking, just the same and I All ways check the color of the fuel and stick my finger in it an smell it!

This doesn't include retrieving wrecked aircraft out of Mexico for insurance co's, some of these were tie-wired together, but they never came apart in flight, either.
 
Thank you Jeff,

I received 8 emails.

I cannot tell you how many times the manuals have helped with my O-290G.

I expect this will be equally helpful.

Thank you very much, Vance
 
Thank you John,

When I found the missing bolt and recognized the ramifications I realized how easy it is after finding nothing over time to become careless with the prefight inspection.

This is only the second time I have found anything. This missing bolt was hard to see because of gussets and things in the way.

I felt I should remind my friends here on the forum that there is never a good enough reason to slack off on the preflight inspection.

That is a good thought Tom,

I happened to have two replacement bolts so I used them. I suspect it came loose rather than breaking. There was no indication on the one that was left that it was under stress but I replaced it anyway.

I did not find the pieces so I don’t know.

I will think on it.

Thank you, Vance
 
...My current performance numbers solo are roughly 85kts straight and level, 8,800 foot ceiling and around 800 feet per minute sustainable climb at sea level. I burn somewhere between 6 and 10 gallons per hour. The weather and fuel load make such a big difference that the numbers will not be accurate. With Ed in the back and full tanks I can just see the other side of 70kts a...

Vance, it might be useful to get some baseline specs before the swap. If you record temp, barometric pressure (the one the tower gives you) and humidity, much can be done to adjust mathmatically for "standard conditions" or, for that matter, to use a spreadsheet to generate performance predictions for a wide range of other conditions. Such a performance chart is in every standard category aircraft.

The test pilot's working year would be a short one if the job could only be done at sea level when the temp was 59ºF.
 
Hello Paul,

I continue to develop baseline performance specifications so I can predict how things will affect me.

I regularly calculate density altitude.

With all the hills around here it is hard to find consistent air.

My numbers have not been repeatable enough to consider accurate. They vary by as much as 7%. There are too many variables.

I feel that the IO-320B will perform better that the O-290G that is in her now.

I will have no way to separate the propeller change from the engine change.

I don’t know how much power the O-290G is putting out so the performance comparison numbers will not be useful for anyone here on the forum.

Thank you, Vance
 
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Vance, The engine I got has mount pads that is angled to the outside of a circle and toward the rear of the engine. Is this the same type of mount you have now? If so could you send some pics on how you set-up the mounts.
Thanks, John K.
[email protected]
 
Hello John, I need to go to work now.

I will see if Ed will take some pictures of the engine mount and post them on this thread.

This is a standard Lycoming Dynafocal engine mount for some unknown aircraft.

The big round things are for the Dynafocal mounts.

We are going to use the part that goes to the engine and the circle that joins them. We will redo the part with the legs that bolt to the firewall.

Thank you, Vance
 
the se are the pictures you requested!

the se are the pictures you requested!

Vance, The engine I got has mount pads that is angled to the outside of a circle and toward the rear of the engine. Is this the same type of mount you have now? If so could you send some pics on how you set-up the mounts.
Thanks, John K.
[email protected]

Please let me know if you need any other photos I'd be more than happy to take them!
Cheers! Sgurl*Ed

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Vance- It will be most interesting to see your perfomance reports. I bet you will be able to put a banana in your mouth sideways you will be smiling so much! I got to tell you Vance....you and that gyro deserve each other....it loves to fly and you sure like flying it. What a marriage.

That bigger prop and more ponies, along with little change in weight.....is all going to be kick in the pants results....imho.

See ya at Mentone.

Stan
 
Thank you Ed, nice pictures.

Hello John,

The four large circles are the part that goes toward the engine.

The smaller washer looking things with the straight tubes are the part that goes toward the firewall.

We will keep the large circles with the circular piece that connects them.

We will cut off the straight legs and make new ones that are located to match up with the bolt holes in my fire wall.

You framework is very different but the principle is the same.

Someone needs to look at the challenge that understands load paths and design an interface that will work.

Most Lycomings can also use some kind of bed mount that may work better to interface with your keel.

It is a large displacement four cylinder engine and it needs to be able to move around on the mounts to avoid shaking the airframe.

The dynafocal mounts are aimed at some point in space that they feel is the source of the vibration so that part can move around and not transmit the vibration into the air frame.

Thank you, Vance
 
Based on the engine type you are using and looking at the mount, I would say it is from a Piper Twin Comanche.
With that in mind, the engines on the Comanche are tilted. I would suggest when everything is finished and you are ready for the oil, drop the first three quarts and check the dipstick. You will probably need to remark it. Add each additional quart and mark accordingly.
 
Hi Vance,

I can't wait to see and watch you fly after the conversion. Too cool dude! I know we both agree that this conversion will make the predator a whole new aircraft. Now if I drop 70 lbs off my personal gross weight ...

John, I've been contemplating the same type of conversion you are speaking of. If you're going to put an O-320 on the RAF, do the AAI drop keel conversion too. Take a look at the following thread and video of a Continental O-200 powered RAF built and flown by Jimmy Meredith.

Wayne

http://www.rotaryforum.com/forum/showthread.php?t=18584&highlight=continental+o-200&page=2
 
Sgurl*Ed
Thanks for the pics, I can see I will need to do something a little different to mount the engine to a mast on an RAF 2000.

John K.
 
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