Ex Bonanza Bucko
Well Known Member
How do you remove the cowl on and RV12 to get a good look at the engine in preflight? I'd love to see a picture/video of that.
EBB
EBB
Van's Air Force
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Getting a good look at the engine
- Thread starter Ex Bonanza Bucko
- Start date
Sam Buchanan
been here awhile
Non of the RVs have cowls designed to open or be removed for pre-flight inspection.
I can remove or replace a (well fitted) top cowl on an RV-12 in about 2 minutes, but as already stated, few people do that for a pre-flight inspection.
Many of us are used to certificated aircraft that have cowls that easily open.
I reality, for most (I didn't say all) of those airplanes, if you evaluate what you are really able to inspect and see, it is not all that much. Unless it is important to you to check the brake fluid level (I just look for a puddle under the main wheels) or something else simple like that. If you don't believe me, ask an experienced mechanic how many of the problems he finds during FWF inspections, would have been detected without removing the entire cowl.
The context of this question is exactly why I say that oil quick drains should not be used to make for an easy oil change on RV's (or any airplane for that matter). Conscientious maintainers, pull the entire cowl and do a though inspection of the entire FWF while the oil is draining. An oil quick drain should only be used to simplify the process.
Many of us are used to certificated aircraft that have cowls that easily open.
I reality, for most (I didn't say all) of those airplanes, if you evaluate what you are really able to inspect and see, it is not all that much. Unless it is important to you to check the brake fluid level (I just look for a puddle under the main wheels) or something else simple like that. If you don't believe me, ask an experienced mechanic how many of the problems he finds during FWF inspections, would have been detected without removing the entire cowl.
The context of this question is exactly why I say that oil quick drains should not be used to make for an easy oil change on RV's (or any airplane for that matter). Conscientious maintainers, pull the entire cowl and do a though inspection of the entire FWF while the oil is draining. An oil quick drain should only be used to simplify the process.
Ex Bonanza Bucko
Well Known Member
Thanks for the input. I've read on the net that it's a good idea for a good inspection of a Rotax engine to be made pretty frequently to look for coolant and fuel leaks. I'm an old CFI and I've owned and loved 7 airplanes....restored two antiques. I'm used to a "Trust but verify" approach to any airplane and I certainly like to get a good look at the engine--all of it--- at least once every couple of flights.
I once had a brand new (17 hours of Ferry time only) Cessna Turbo 206 lose the following on a flight from KLVK (San Francisco) to KOSH: 30 gallons of gas out of the port wing tank due to no O ring; the XPNDR on climb out in IFR (fell out of the rack); the turn gyro on approach to KMKC (defective); the artificial horizon on approach to KRFD (not due to vacuum failure and defective); the #2 Nav enroute; the #1Com enroute and the O2 system just as I got to altitude at 12000 in IFR out of KOGD. Then to make my full day the engine quit on the runway at KRNO where we stopped for a potty break....the failure was due to a clevis coming loose on the throttle at the engine. Trust...or don't trust....but verify!!
It was a good airplane after some heavy duty maintenance on new stuff installed and inspected by 1975 type "labor" at the factory all of whom must have been at least A&Ps in waiting.
EBB
az_gila
Well Known Member
I think the real question should be -
"How many aircraft have been taken to that experienced mechanic after the pilot found something wrong in the engine compartment during a pre-flight?"
I personally have found oil leaks, baffle material problems, a broken bolt on an oil cooler mount and an exhaust support rod broken during pre-flights. I'm sure the VAF members with many more hours than me have found much more when flying certified aircraft with more engine visibility.
I once had a brand new (17 hours of Ferry time only) Cessna Turbo 206 lose the following on a flight from KLVK (San Francisco) to KOSH: 30 gallons of gas out of the port wing tank due to no O ring; the XPNDR on climb out in IFR (fell out of the rack); the turn gyro on approach to KMKC (defective); the artificial horizon on approach to KRFD (not due to vacuum failure and defective); the #2 Nav enroute; the #1Com enroute and the O2 system just as I got to altitude at 12000 in IFR out of KOGD. Then to make my full day the engine quit on the runway at KRNO where we stopped for a potty break....the failure was due to a clevis coming loose on the throttle at the engine. Trust...or don't trust....but verify!!
It was a good airplane after some heavy duty maintenance on new stuff installed and inspected by 1975 type "labor" at the factory all of whom must have been at least A&Ps in waiting.
EBB
And to top it off your car was parked at Livermore...........
Thanks for the input. I've read on the net that it's a good idea for a good inspection of a Rotax engine to be made pretty frequently to look for coolant and fuel leaks. Then to make my full day the engine quit on the runway at KRNO where we stopped for a potty break....the failure was due to a clevis coming loose on the throttle at the engine. Trust...or don't trust....but verify!!
EBB
I don't think it is any more important to inspect a Rotax than it is a Cont. or Lyc. True, there are some things specific to the Rotax, that aren't there on the others, but they each have the potential for specific problems.
I think any conscientious pilot wants to inspect as well as possible but the reality is you can't inspect everything. There are very few problems that can crop up in 25 or 50 hrs between oil changes, that would cause a serious problem. If people take the time to look everything over real well while the cowl is off, the likelihood of a serious problem occurring is extremely remote.
The best thing any pilot can do for safety is always fly the same airplane and become intimately familiar with that airplane. That is one of the things that makes homebuilts so popular with a lot of pilots.... they have personal knowledge of every part of the airplane, and because they are personally inspecting and maintaining it, they are trusting no one.
You quoted my post Gil, but I haven't the foggiest idea what this question means.
az_gila
Well Known Member
Your words -
Many of us are used to certificated aircraft that have cowls that easily open.
I reality, for most (I didn't say all) of those airplanes, if you evaluate what you are really able to inspect and see, it is not all that much. Unless it is important to you to check the brake fluid level (I just look for a puddle under the main wheels) or something else simple like that. If you don't believe me, ask an experienced mechanic how many of the problems he finds during FWF inspections, would have been detected without removing the entire cowl.
Comparing the ability for a pilot to inspect an engine compartment as part of a pre-flight vs. your comment that a mechanic can't do a complete FWF inspection from just an open top cowl.
Even if you as a pilot can't inspect a lot "..you are really able to inspect and see, it is not all that much..." - an inspection before each flight is still a valuable safety feature. The mechanic does not see the engine compartment as often as a pilot with a plane that has an easy access top cowling.
A look around inside the engine compartment at a more frequent schedule than a 50 hr oil change is always a good thing.
A couple of the problems I spotted at pre-flight - a broken bolt on an oil cooler mount and an exhaust support rod broken - certainly could have become serious problems if left for 25 to 50 hours.
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I never said it wasn't...
So, it appears to me that you misunderstood the point I was try to make (maybe my fault the with way I wrote it), so I wont both with it anymore.
I will let you explain to the OP that he shouldn't buy any RV because it is not possible to inspect the entire engine during a preflight
Sam Buchanan
been here awhile
I once had a brand new (17 hours of Ferry time only) Cessna Turbo 206 lose the following on a flight from KLVK (San Francisco) to KOSH: 30 gallons of gas out of the port wing tank due to no O ring; the XPNDR on climb out in IFR (fell out of the rack); the turn gyro on approach to KMKC (defective); the artificial horizon on approach to KRFD (not due to vacuum failure and defective); the #2 Nav enroute; the #1Com enroute and the O2 system just as I got to altitude at 12000 in IFR out of KOGD. Then to make my full day the engine quit on the runway at KRNO where we stopped for a potty break....the failure was due to a clevis coming loose on the throttle at the engine. Trust...or don't trust....but verify!!
We Rvers never let our planes get in such decrepit condition....especially if we built it!
It's the difference between a taxicab that came of an assembly line and a lovingly maintained show car.
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Specific answer. Six screws at the front of the cowl. Two more screws holding the left and right longitudinal pins which you easily pull out and reinsert. Two more screws holding a small plate that secures the transverse pins. Removing/re-inserting one of those pins is a bit tougher because it is more curved, but not that bad.
I'd like to see a youtube of doing this in two minutes though! I wipe the pins clean and lube them before reinserting. And you have to put the top cowl down carefully somewhere, towel,on the wing maybe if in the hangar. It is very light and can low around.
More like 5 minutes to take off and the same to put back, with a power screwdriver and boelube on the screws.
I'd like to see a youtube of doing this in two minutes though! I wipe the pins clean and lube them before reinserting. And you have to put the top cowl down carefully somewhere, towel,on the wing maybe if in the hangar. It is very light and can low around.
More like 5 minutes to take off and the same to put back, with a power screwdriver and boelube on the screws.
This is an instant replay of this previous thread
http://www.vansairforce.com/community/showthread.php?p=754412#post754412
with the same protagonists.
Coming off a Bonanza, you'll find the engine inspectability far inferior. Coming off a Cherokee - same thoughts. Mechs used to brag they could do a Cherokee FW Fwd Annual just through the open cowl. Two Dzus per side. Open and close faster than you can sneeze.
I've gotten pretty good at pulling the top cowl; bottom cowl is still a two man operation. Still wish there was a fore-aft support beam with piano hinges that allowed you to pop the cowls open.
Bottom Line: Frequent looking is good; less frequent looking is bad. Anything rationalizing the less than optimum cowl situation is....well, just rationalizing.
Bob Bogash
N737G
Second oil change coming Monday - all cowls off. Detailed FW Fwd inspection planned.
http://www.vansairforce.com/community/showthread.php?p=754412#post754412
with the same protagonists.
Coming off a Bonanza, you'll find the engine inspectability far inferior. Coming off a Cherokee - same thoughts. Mechs used to brag they could do a Cherokee FW Fwd Annual just through the open cowl. Two Dzus per side. Open and close faster than you can sneeze.
I've gotten pretty good at pulling the top cowl; bottom cowl is still a two man operation. Still wish there was a fore-aft support beam with piano hinges that allowed you to pop the cowls open.
Bottom Line: Frequent looking is good; less frequent looking is bad. Anything rationalizing the less than optimum cowl situation is....well, just rationalizing.
Bob Bogash
N737G
Second oil change coming Monday - all cowls off. Detailed FW Fwd inspection planned.
Sam Buchanan
been here awhile
Absolutely. Any oil change should be an opportunity to give the engine compartment the same attention it would receive during a condition inspection.
And what some people call rationalizing, other people call being realistic.
All of the RV's are an engineering compromise; balancing cost, complexity (the customer has to be able to build/assemble it), and weight, against the perceived value of doing it differently. I wont argue that access couldn't have been made better. It could. But it would impact all of the factors I already mentioned.
Selling kit airplanes is a business, competing against other players in a free market. Evaluating the merits of a particular design should compare it to the entire market, not just a few examples that can be found on the internet. Compared to the entire general aviation fleet, I don't think RV's are any better or worse than the average as far as inspectability of the engine compartment during preflight. Sure, better examples can be found. I could probably also find worse examples.
The bottom line is that the design is as it is for very specific reasons.
If people choose, steps can be taken to greatly mitigate any risk involved with the reduced level of inspectability. If that feature is of high importance to someone, then maybe an RV is not the best choice for them.
Post is not a responce directed to you Bob... It is an attempt to explain to the 1000's of lurkers on VAF why RV cowls are the way they are, so call it rationalizing if you want... I call it realistic engineering.
Case in point...
Some of the most vocal rants about some aspects of the RV-12 come from the same people that rave about the handling qualities, performance, low empty weight, and great useful load. Those great attributes all require that hard engineering decisions be made, and the cowl design is definitely one of them.
bhassel
Well Known Member
Sounds like a great mod to me!
Getting rid of the piano hinges on the cowling sides would help that process...
Bob
Ex Bonanza Bucko
Well Known Member
We Rvers never let our planes get in such decrepit condition....especially if we built it!
It's the difference between a taxicab that came of an assembly line and a lovingly maintained show car.
Hey Sam:
Read the message again. I said it was a BRAND NEW C-206 with 17 Ferry Hours on it. I took delivery from the DEALER and flew it to OSH and back. All those failures had nothing to do with "letting our planes get in such a decrepit condition"....the "condition" was BRAND SPANKING NEW!! I don't think any of the problems and failures I had on the trip could have been discovered by a full preflight.....well, maybe the missing O ring.
But I think any pilot would think he was in a decent and well maintained airplane outside the dealer's show room.
EBB:-(
tfarrell839
Active Member
We've done a mod like this on a quite a few RV-10's. It changes your pre-flight inspection world completely. We call it a big oil door, but it measures about 2.5ft x3ft and opens in about 20 seconds with camlocs. I am sure it would be a great mod to the RV-12 as well. Here are some pics:
http://www.aircraftersllc.com/hatch_mod.html
Ex Bonanza Bucko
Well Known Member
az_gila
Well Known Member
Looks great, does anyone see a reason a similar DIY mod would not work on a RV-6, -7 or -9?
Sam Buchanan
been here awhile
I caught your statement that it was a brand new airplane on the first read.
Guess the "winky" at the end of my post wasn't sufficient to show I was poking a little fun at the "factory built" planes. Sorry you misunderstood the intent of my message.
Everyone who has built an RV knows they are far superior in quality to those factory-built taxi cabs.
(There's that winky again....)
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Ex Bonanza Bucko
Well Known Member
Sam:
And ditto to you too!....I'm sorry I missed the winky. We are on the same page. That 1976 Cessna was to airplanes what the Detroit Iron of the day was to cars. It was not airworthy and the factory left it that way. I wonder how many "pilot error" accidents resulted from that kind of stuff.
I am transitioning from 40 years of flying just about everything except a Van's airplane to an RV 12 and I'm really looking forward to it. The Boss (wife) and I will be in Aurora next month for three days to try for a demo flight (WX permitting) and to tour the factory. The Boss also will insist on a tour of the Columbia River parks
And ditto to you too!....I'm sorry I missed the winky. We are on the same page. That 1976 Cessna was to airplanes what the Detroit Iron of the day was to cars. It was not airworthy and the factory left it that way. I wonder how many "pilot error" accidents resulted from that kind of stuff.
I am transitioning from 40 years of flying just about everything except a Van's airplane to an RV 12 and I'm really looking forward to it. The Boss (wife) and I will be in Aurora next month for three days to try for a demo flight (WX permitting) and to tour the factory. The Boss also will insist on a tour of the Columbia River parks
