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Dan Lloyd RV-10 "Factual" report out...

Second Post on this Subject

What has come out of this thread so far for me is that I would not even consider an auto engine installation or any engine installation for that matter that relies on a constant application of volts and amps to an ECU or other non redundant system in my plane. Subaru engines are great engines in the environment that they were designed for. However for me the risk is too great. Lycoming development and improvements has come on leaps and bounds in the last few years. With new technology available from third parties in terms of electronic computerised magnetos that generate their own backup power and are now available for the experimental market, I feel there is no need to take the risk by going elsewhere. Some readers of this post my not agree with me and to be honest I do not care. If someone chooses to go down the auto engine conversion route thats their decision and lookout. I wish them luck and I hope they take sensible precautions to eliminate the risk of loosing power to the ECU or other vital non redundant systems.

I would like to know other peoples opinion on this and also I would like to know if sales of Subaru conversions have suffered because of this incident. Some of the comments in this thread so far do not put the Florida based supplier in such a good light.
 
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Single Ground on the Battery?

I have multiple ground paths from the engine to airframe, but only one from the battery to the airframe. If I lose that connection, will my system still work due to the polarity being set up with the alternator, right?

Hans
 
Your first mistake is asking for other peoples opinions...

What has come out of this thread so far for me is that I would not even consider an auto engine installation that relies on a constant application of volts and amps to an ECU in my plane. Subaru engines are great engines in the environment that they were designed for. However for me the risk is too great. Lycoming development and improvements has come on leaps and bounds in the last few years. With new technology available from third parties in terms of electronic computerised magnetos that generate their own backup power and are now available for the experimental market, I feel there is no need to take the risk by going elsewhere. Some readers of this post my not agree with me and to be honest I do not care. If someone chooses to go down the auto engine conversion route thats their decision and lookout. I wish then luck and I hope they take sensible precautions to eliminate the risk of loosing power to the ECU.

I would like to know other peoples opinion on this and also I would like to know if sales of Subaru conversions have suffered because of this incident. The some comments in this thread so far do not put the Florida based supplier in such a good light.

I really think that what you should take away from this thread is:
1. Be prepared to fly you plane without the engine running.
2. Take you time with the build. Make sure all safety system are working.
3. Take your time with the phase I testing. Make sure that your planes flies correctly.
4. If you don't have the experience (and most of use don't), use an EAA flight adviser.
5. Don't take short cuts. See 2 and 3 above.



When I started building, I considered the Egg system, but decided against it because it would not save me any money and I didn't see where it would increase performance enough to warrant leaving traditional aircraft engine behind. I also thought that it would take me longer to get my plane flying. Any engine can fail, do what you can to minimize the chance.

I install only one EI and still have one mag. I have two alt., but only one battery.

I regularly practice stall recovery and engine out procedures.

Kent
 
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Absolutely agree with Kevin here. Testing and practice are vitally important.

As far as automotive engines being used in aircraft, this has been discussed at length. The number of core engine failures on properly assembled and operated engines is extremely small. We have seen in the last year or so several failures due to things as small as spark plug heat range and inadequate fuel octane. These can be attributed to a lack of experience and indeed proper testing. But the general feeling that the Lycoming route is more proven is certainly true IMO.

Other failures recently have be attributed to insufficient bearing clearances and FOD internally. I rank these under improper assembly (for the intended application) and certainly has nothing to do with the engine design. Subaru engines in particular have demonstrated excellent core reliability in hundreds of thousands of hours of flight operations. Having been involved in this field for a number of years, electrical issues are the #1 cause of inflight power loss and fuel issues are #2 on auto conversions.

Relating back to this accident, had Dan's RV10 been equipped with an IO-540 and twin Jeff Rose EIs for instance, the result would likely have been the same. Indeed we have seen a number of twin EI failures/ issues on RVs over the last couple years. Pointing the finger at the Subaru engine in this case is simply illogical.

No matter which engine you have, if it has electrically dependent ignition and fuel components, address the potential for losing primary power to these.

As far as sales of Subaru conversions go, none of the current vendors have had the best of customer service or performance reviews lately so this has had much to do with a general cooling of interest towards these engines as of late. This is no surprise. IMO all vendors in this field do nowhere near enough ground validation and flight testing of their products before release for sale. This just comes back to haunt you. Any time vendors have delays in supplying equipment or poor customer service (either perceived or actual), the long term viability of the product line is in question. We can only hope that newcomers to this field address these concerns diligently.
 
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What has come out of this thread so far for me is that I would not even consider an auto engine installation that relies on a constant application of volts and amps to an ECU in my plane.

I'm not an "alt engine" guy, though I would like to be if the right turbodiesel was available. Having said that - I think you should remove the "auto engine" part of your statement entirely, and let's focus on the core problem you have stated, that of having a critical flight parameter dependent on electrical power. In that case, it's not fair to pick on auto engines, or indeed even jet engines or Lycomings for that matter. There are very many certified Lycomings flying around that require constant power to keep turning, due to dual EI's and/or electric-only fuel systems.

More and more aircraft these days are being constructed to be electrically dependent, whether it's fuel, or nav, or spark - both VFR and IFR. Once you commit to having an aircraft that is electrically dependent, it DOES NOT MATTER which of the flight-critical components are electrically dependent, YOU MUST have a backup electrical system, in good working order, for reliability and safety. If you have that good working electrical backup, then there is no valid reason NOT to use the desired equipment and accept the electrical dependency.

The fact that an auto engine was installed (in this case) had nothing to do with it, and I would hate to see someone be scared away from an auto conversion for that reason. There may be reasons to choose NOT to do an auto conversion - but this is not one of them.

For the record, I am planning on a fully redundant electrical system (dual battery, dual alternator, dual buss) with glass panel, IFR capable, 2-axis AP, one mag and one EI, and dual electric-only fuel pumps, on a Lyclone. My aircraft will be electrically dependent. I accept that up front, and will plan the equipment appropriately.
 
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I'll add a few more:

4. If safety depends on backup systems, the response to failure of the primary system should be demonstrated. This testing should be done on the ground, if possible. I've participated in more than one test, on aircraft from multiple manufacturers, where the response to failure of a major primary system was different from what had been predicted. Some of these bad responses would probably have resulted in an accident had they occurred in service.

5. If safety depends on backup systems, the serviceability of those backup systems should be checked at some reasonable interval.

6. Emergency procedures should not only be reviewed, they should be practiced. Too many people are killed because the pilot mishandles an engine failure.

7. System failure procedures should not only be reviewed, they should be practiced. I'm aware of multiple fatal accidents where the accident was caused by poor pilot response to a switchover to a backup system.

I can say from experience the original Subby back up system designed by Gary Newsted with the famous "bus master" switch worked very well.

My H6 quit one day climbing through 6000' and selecting back up power restored engine operation immediately. (the poly fuse protection of the primary power source had tripped) The comfort level of the back up operation was not all that comfortable as I had no idea how long it would run, but it sure was better than a totally silent engine. It did get me to a runway without incident. That same system was checked occasionally on the ground by simply selecting it and pressing the start button and the engine came to life. No other switch had to be on. The system was not designed in a vacuum. I was involved in the original forum discussion with Gary and Jan and other early Subby guys - just about every conceivable problem was covered. Changes were made as we gained experience with the system and there were a few like when the H6 quit due to 02 sensor heaters kicking in, over loading the circuit.

It is a good system but not quite good enough to save Lloyds's RV-10. He must have had a back up feature very similar to the original design even though EXPBUS was gone. The NTSB report states "the "BUSS SELECTOR" switch was in the "ON/MAIN" position". If it had been moved to "EMERGENCY", the second battery would have kicked in and maybe kept the engine running assuming its cables were attached. With due credit to the EGG factory, they have preached since day one if there is any indication of engine trouble, select EMERGENCY (or BBAT as it was called in the beginning) immediately.

But no electric system will work if it is not wired properly. The report states there were many unconnected wires....that's not so good.
 
I think you should remove the "auto engine" part of your statement entirely, and let's focus on the core problem you have stated, that of having a critical flight parameter dependent on electrical power. In that case, it's not fair to pick on auto engines, or indeed even jet engines or Lycomings for that matter. There are very many certified Lycomings flying around that require constant power to keep turning, due to dual EI's and/or electric-only fuel systems.

Point taken airguy. Original post has been edited. However I still would not consider an auto engine conversion, especially one from Florida. Lets be careful however just in case we get "off topic" and have the posts pulled.
 
I think Greg is doing this in the most reliable and safest way possible. I approve if that counts for anything. My RV10 has 2 pumps, 2 batteries and 2 alternators.

When we sell EFI systems for Lycomings or Continentals, almost invariably redundancy of fuel and spark is discussed. My recommendation is generally to retain one mag for spark and a simple mechanical system with nozzles, the original carb or even the entire mechanical FI left in place for fuel backup. Just leave the mixture in idle cutoff.

Mike Dacey's Reno racer retains one mag and has fuel nozzles mounted in the intake manifold for backup along with a second battery and two pumps. It has been flight tested and runs pretty well at a fixed throttle setting. Simple, cheap and light.

Despite all this, we should not overlook the basic requirement of getting electrons to those backup systems if primary power fails for any reason. We warn people repeatedly about good wiring practices and good system design and keeping things simple. Your life may depend on it.
 
Sorry it may not last!

Mike can rant, the NTSB can cloud the issue with pages and pages of paper, others can defend the "right to choose" any engine for their project, but the facts are that if an airplane engine were in use on the airplane in question, it would not have failed in the fashion it did. I know airplanes with airplane engines crash as well, but they would not have failed in this manner if a battery connection came apart.

FWIW
 
Dual EI failures?

Indeed we have seen a number of twin EI failures/ issues on RVs over the last couple years.

Just curious, what kind of failures of dual EI as I have not personally heard this before (as a dual LSI powered Lyc I am curious about this statement)
 
Mike can rant, the NTSB can cloud the issue with pages and pages of paper, others can defend the "right to choose" any engine for their project, but the facts are that if an airplane engine were in use on the airplane in question, it would not have failed in the fashion it did. I know airplanes with airplane engines crash as well, but they would not have failed in this manner if a battery connection came apart.

FWIW

even if it has dual EI?

or dual EI and electronic controlled FI?

or lycomings IE 2?
 
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The point I was trying to make was with dual electrically dependent EIs on a Lycoming, the engine would have stopped just as surely as it did with the Sube in this instance.

The cases I was referring to involved Emag/ Pmags (sorry I can't keep these straight) and software/ mystery issues. One if I remember led to a successful forced landing on a highway. The search feature here unfortunately gives hundreds of hits so I can't find what I'm looking for. There have been other EI failures as well (fortunately only one at a time).

Point being primarily though is that any electrically dependent EI is going to go dark if power is interrupted and some are going to go dark for other reasons even with power there- sensor failures, mechanical failures, software glitches and maybe even board failures. In this case the Subaru had an SDS EMS (digital fuel and spark control) on it- which needs electrons to work.

The nice thing about a Lycoming is that it is set up for twin ignition already and you can use two different EIs, two of the same, two mags or a mag and an EI.
 
I think we are concentrating on side issues.Things mechanical and electrical. Some people should not be flying aeroplanes
 
Thread deterioration

I am afraid this thread may be running its course to a conclusion if it is going to morph into the dreaded AUTO CONVERSION ENGINES ARE EVIL! vain.

Come on guys if you want to debate auto engines or proclaim your disdain or acceptance of them there are other threads to do that in. This thread holds a great deal of value in its content without rehashing that debate.

Go somewhere else to rehash please! :(:(:(:(
 
It sounds like he had a backup electrical system, with X-TIE and Buss Selector switches. Those switches were found in the off and normal positions.

Did he have dual batteries? Do you even need a battery if the alternator is supplying power?

If only he would have slowed down and become familiar with what he had.
 
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Not accurate

The point I was trying to make was with dual electrically dependent EIs on a Lycoming, the engine would have stopped just as surely as it did with the Sube in this instance.

The cases I was referring to involved Emag/ Pmags (sorry I can't keep these straight) and software/ mystery issues. One if I remember led to a successful forced landing on a highway.

The event in which you speak happened to a friend of mine. Although a Pmag failed, it was all pilot error from there. He failed to isolate the mag, (do a mag check in flight), went to full rich at a high altitude, didn't throttle back to get the temps under control and slow the advanced timing and ultimately VOLUNTARILY shut the engine down. If he would have simply switched to the good mag he would have been fine. He is a low time pilot with very little fixed wing time prior to building the RV.

I know you are a huge proponent of Alt engines and probably one of the few that can make them work. I am not and have seen too much in the way of lack of success for airplanes. They seem to work fine on Gyro copters and in cars but in RV's the success just isn't there. No real significant numbers of hours to show success. Quite the contrary. The collection of broken planes is growing faster than the success stories.
 
This isn't about auto engines or electrical dependence....or shouldn't be.

There are perfectly reasonable ways to approach the construction and testing of even the most radical flying machine. And there are perfectly unreasonable ways.
 
This has been a helpful thread. A practical result--I did the TC bit yesterday, looking over a nicely put together 40% RV-9A. I probably listened more for "attitude" than I had before, and I had a better sense of responsibility than a few weeks ago. I came away knowing I hadn't met another out of control accident waiting to happen.

Bob Kelly
 
The enemy is us.

Captain Obvious here.

I think we (the homebuilding community) have created some of this mindset by selling airplane kits with the sales pitch, "Anybody with a moderate skill set can build an airplane ... it's affordable ... great performance ... etc."

If many first-time builders would limit their building and flying to the light sport class, we'd probably have a better track record. However, when a low-time, low-experience pilot buys into the concept of building his dream machine, it's often MUCH faster, MUCH more complicated than the spam can that he's been flying.

Maybe Mr. First-time Builder buys a basic RV kit but then wanders the rows of fabulous RVs at Oshkosh ... and strolls the candy-filled rows of vendors in the exhibition halls ... and reads threads here on VAF about how others have built in redundancy in their electronic ignition systems ... and suddenly his basic, VFR-equipped RV has sprouted various antennae and pretty boxes chock-full of information that he now has to process.

As others have said, building the airframe isn't all that demanding. However, when we start adding all of the bells and whistles that make our dream plane a reality, there's a requisite amount of time and energy that must be spent learning not only how to install the systems, but also how to interpret and process the information that those systems present while we're flying.

Some people, lured into the myth that building a plane is really not all that hard, find themselves ill-equipped to deal with the intricasies of installation, calibration and evaluation of their dream planes and would be better served to build a simpler plane and settle for less speed, less "wow" and more safety. However, they would probably be fishermen instead of pilots were that the case.

The more RVs that are completed, the higher the accident stats will climb, sadly. It's just an actuarial fact that we need to expect. However, building and flying within our true skill set and not our finances or egos will help insure that we don't become part of those statistics.

Captain Obvious out. :D
 
The event in which you speak happened to a friend of mine. Although a Pmag failed, it was all pilot error from there. He failed to isolate the mag, (do a mag check in flight), went to full rich at a high altitude, didn't throttle back to get the temps under control and slow the advanced timing and ultimately VOLUNTARILY shut the engine down. If he would have simply switched to the good mag he would have been fine. He is a low time pilot with very little fixed wing time prior to building the RV.

I know you are a huge proponent of Alt engines and probably one of the few that can make them work. I am not and have seen too much in the way of lack of success for airplanes. They seem to work fine on Gyro copters and in cars but in RV's the success just isn't there. No real significant numbers of hours to show success. Quite the contrary. The collection of broken planes is growing faster than the success stories.

No Darwin, this is not the incident I was referring to. The aircraft had twin EIs and the engine just stopped if my memory serves me correctly (and perhaps it does not!).

I fly a Sube but steer many people over to Lycomings every year who consult me for advice. I can't agree with you on your statement about alt engine powered aircraft. I'm very involved in this on several forums- Geo/ Suzuki, Titan T51 (Suzuki, Honda), Subenews, Flysoob and Rotary Wing Forum. My company is involved in supplying EMSs for all types of aviation powerplants and has been since 1994. I see the successes and failures on a daily basis and help people weed out the issues to be able to enjoy their aircraft with whatever engines they choose. We have had 4 new success stories on EG33 powered aircraft already alone this year, one guy who has been flying his for 10 years now is banging on 30+ hours a month at the moment. We see the potential in Randy Crothers' amazing STI/RV7A. Some of the forums have just been excellent for people to share what works and what doesn't with newbies- this is just so valuable. We have a number of clients now pushing over 400 hours with auto engines and some over 600 with minimal maintenance. We don't usually just give up because we encounter a problem. We work through it and solve it. While some here would seem to want to ban auto engines from the sky based on knee jerk reaction perhaps, that is no more logical than banning medical helicopter flights due to their high accident rates. Solutions just have to be found.

I try not to let my past experiences or choices bias my opinions about engine types. I know you had a terrible experience with an auto engine vendor and I've helped 4 other ex clients get through similar experiences and get flying successfully. This thread is not about the old cert vs. auto war again however, it is about learning I hope. If we focus on the cause and enlighten other builders about the importance of electrical system layout, EI choices and quality work, then we have done a small service to keeping others safe perhaps.

I certainly don't take glee when a buddy suffers a cracked head on his Lyconental and say "you fool, if you had a Subaru you wouldn't have that problem". We make our choices here based on many different factors. We have to live with those choices and there are no perfect ones out there suiting everyone.

If discussion of this accident makes people think twice about using an auto engine in their project, then again we have done a service in my view. I don't really care what engines people use as long as they are comfortable and safe. We have systems for auto engines, Rotax 912/914s and Lyconentals!
 
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This isn't about auto engines or electrical dependence....or shouldn't be.

There are perfectly reasonable ways to approach the construction and testing of even the most radical flying machine. And there are perfectly unreasonable ways.

Dan:

Respectfully, many of us, most remaining silent, would vigorously disagree that in some manner "this isn't about auto engines or electrical dependence....or shouldn't be", but I think we all agree that "There are perfectly reasonable ways to approach the construction and testing of even the most radical flying machine. And there are perfectly unreasonable ways."

FWIW
 
Electric pumps?

For the record, I am planning on a fully redundant electrical system (dual battery, dual alternator, dual buss) with glass panel, IFR capable, 2-axis AP, one mag and one EI, and dual electric-only fuel pumps, on a Lyclone. My aircraft will be electrically dependent. I accept that up front, and will plan the equipment appropriately.[/QUOTE]

Hi Greg,

"Dual electric fuel pumps"? Wouldn't it be more redundant to have one mech and one electric pump? Just curious...

Jerry
 
Hi Greg,

"Dual electric fuel pumps"? Wouldn't it be more redundant to have one mech and one electric pump? Just curious...

Jerry

Jerry,

Drifting a bit off-topic for this thread again, I know, but you asked. Mods - move this as you see fit.

The problem with the mechanical fuel pumps in a low-wing aircraft is that they are inherently vulnerable to vapor-lock, due to the fact that they are pulling fuel uphill (lower than ambient pressure in the supply line) and are heated by the block that they are bolted onto, which will in turn heat the fuel as it enters the mechanical fuel pump, which raises its vapor pressure. Both of these factors will reduce the margin for fuel vaporization in the fuel pump supply side immediately before the pump grabs the fuel. The way the mechanical pumps work when they are "struck" by the cam follower to start the inlet portion of the cycle actually further reduces the pressure in a split-second pulse as the pump draws fuel into the pressure side of the pump, further aggravating the problem.

Add to this the fact that Van's aircraft are very tightly cowled (for low drag) and this tends to raise under-cowl temperatures, and the increasing numbers of pilots who fly with Mogas or even E10 (which arguably have higher vapor pressures than 100LL) and our margin of safety against vapor lock narrows even further. Now factor in the fact that I intend to use this airplane for long-distance travel, cruising in the mid-teens where the ambient pressure will only be one half that of sea-level, and we are getting into scary territory.

The idea of running twin electric pumps is not new, and I don't claim it for my own - I actually got the idea from Frankh here on VAF, I don't know where he got it from. The concept is that we can greatly reduce, if not totally eliminate, the issue of vapor lock by designing the fuel system in a "hydraulically correct" fashion. That means minimizing the areas in the ENTIRE fuel system where less-than-ambient pressure can be present, and minimizing the areas of the fuel system that are exposed to above-ambient temperatures. Both these actions add to the margin between ambient pressure and the boiling pressure of the fuel and reduce the possibility of vaporlock. In this scenario, the electric pumps are placed in the wingroot (one each) and pull cool fuel directly from the tank through a large-diameter feed line with virtually no pressure drop. From that point, pressurized fuel is routed to the engine, and all the fuel lines FWF will be fire sleeved and insulated to reduce heating. The pressurized fuel will not boil under any conceivable set of circumstances that does not involve a crash or engine-compartment fire, so vapor lock possibilities are then removed until you get to the carb or FI itself. If you can supply cool fuel to the carb or FI, you are MUCH less likely to ever experience vaporlock in flight. In this case, I will run an AFP injector system which utilizes a purge valve, to enable me to rapidly dump the fuel in the injector body and replace it with cool fuel in flight, in the highly unlikely case of vapor lock.

The biggest mind-numbing shock most people have when you mention doing away with the mechanical pump is that you have no backup. In this case, we do - I will have one pump for each tank, controlled through separate electric circuits. Changing tanks is no longer accomplished through a fuel valve, but rather by turning one pump on and the other off. If one pump dies or fails to come online as you change tanks, simply go back to the good tank and land at the nearest convenient airport before the fuel imbalance in the wing becomes obnoxious. This, of course, implies that for safety of flight the pilot should not routinely run the tanks dry - as in that case you would truly have no backup if the other tank pump failed to come online. Each pump has it's own pressure relief and check-valve to prevent backflow, so on takeoff and landing, both pumps are operated just the same way a certified aircraft would operate it's boost pump in those realms of flight.

It has been pointed out by others that it is entirely possible to chain multiple pumps in series, with one set of pumps as primary and one as secondary for emergency backup, but I believe that's going a bit off the deep end and loosing sight of the big picture. One level of backup is good enough for the ignition, the nav, the comms, and the electrical system - why should it not be good enough for the fuel as well? You will not find a certified aircraft with more than one layer of backup fuel planning, and I don't believe it's necessary here either.

I will point out that having any electrically-dependent critical flight parameter, whether that be fuel, ignition, or navigation, REQUIRES a redundant electrical system in the aircraft for common sense and safety of flight. I will have a standard primary electrical buss, with a secondary E-buss consisting of a separate accessory-pad alternator and battery to power all the flight-critical items for a long enough period of time to make a safe controlled landing.
 
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I'm happy to leave most of this thread alone but my day job (which includes process safety analysis) has taught me the following; YMMV:

* Dissimilar redundancy in critical systems is good.
* Single point of failure designs (i.e., single failure results in catastrophic results) are not good.
* Engineers and operators (e.g., polits) need to understand the failure modes of individual components and the system as a whole.

TODR
 
Jerry,

Snip

I will point out that having any electrically-dependent critical flight parameter, whether that be fuel, ignition, or navigation, REQUIRES a redundant electrical system in the aircraft for common sense and safety of flight. I will have a standard primary electrical buss, with a secondary E-buss consisting of a separate accessory-pad alternator and battery to power all the flight-critical items for a long enough period of time to make a safe controlled landing.

Thanks Greg,

I think I'm understanding your plan... So, if your main battery became disconnected like Dan Lloyds, you are still OK?

Jerry
 
As long as my backup electrical system is not compromised, yes. My second bus, battery, and alternator will be independent and will be able to power the electric fuel pumps, one nav/comm, GPS, transponder, and landing lights. If the primary electrical goes TU for whatever reason, simply flip off the master to isolate it, and flip on the E-buss to restore power to the engine and partial panel.
 
The Lloyd airplane went in for lack of electric power (it would seem) although moving one switch might have saved the day - we may never know for sure. That and personal experience with mandatory dual electric sources has me back in the stone age with regard to these matters.

I am running with the mechanical pump and both electric pumps left over from the Subby install out of a fuel vaporization concern just ahead the engine pump as expressed by Greg. There is no question not a few Lycoming have had a problem in this area and in fact some certified installations recommend using the electric pump during climb.

I have been using the electric pumps, one at a time, very liberally but I am also getting used to running on the engine pump only. I've been turning it off at about 1500' when the ram air valve is opened for the fuel injection system and turning it back on before landing when the ram air valve is closed. Absolutely no indication of a problem so far and the weather has been rather warm lately.
 
The Lloyd airplane went in for lack of electric power (it would seem) although moving one switch might have saved the day - we may never know for sure. That and personal experience with mandatory dual electric sources has me back in the stone age with regard to these matters.

I am running with the mechanical pump and both electric pumps left over from the Subby install out of a fuel vaporization concern just ahead the engine pump as expressed by Greg. There is no question not a few Lycoming have had a problem in this area and in fact some certified installations recommend using the electric pump during climb.

I have been using the electric pumps, one at a time, very liberally but I am also getting used to running on the engine pump only. I've been turning it off at about 1500' when the ram air valve is opened for the fuel injection system and turning it back on before landing when the ram air valve is closed. Absolutely no indication of a problem so far and the weather has been rather warm lately.

And there's nothing wrong with that belt and suspenders approach. If it feels good, do it. I think I've found another way - but that does not at all mean your way is incorrect.
 
Welcome to VAF!!!!

Mark, welcome to VAF.

I thought your login name was referencing your preference in beer.

Good to have you aboard.

What kind of RV you building----status.
 
Mark, welcome to VAF.

I thought your login name was referencing your preference in beer.

Good to have you aboard.

What kind of RV you building----status.

Thanks Mike -

Heh. I get the beer reference a lot, it helps people remember me!

I have a flying RV-7A, N407V, and am in the process of building an F1 Rocket. It's about 50% done with another 80% to go :)

This accident really struck a chord with me. I think there's something in this that just about anyone can identify with; perhaps the resultant exposure and discussion will save the life of someone else that may be going down the same path.

The old saying "haste makes waste" has never seemed more appropriate.
 
I looked over most of the data here and some things don't fit together. All the witnesses state that the engine appeared to be running right up to impact. The propeller analysis says the prop was NOT turning at impact. Somebody is mistaken. Given the position of where one blade was found, this would seem to support the conclusion that the prop was not likely turning at impact.

Tox says no CO present. Seems unlikely that the aircraft was on fire prior to impact.

The photo of the contactor connection doesn't allow us to conclude much. The aircraft was absolutely destroyed in the impact judging from the photos. The cable to the contactor could easily have been pulled out of the lug on impact.

The photos of the terrain suggest that there were plenty of open fields to put a plane down in the event of a power loss.

The GPS data is most telling IMO along with the witness statements. GS was down to about 60 knots while the aircraft was in a very tight, banked turn at very low altitude, over 1.5 miles from the airport. Why, we'll never know. In the last 39 seconds before impact, the turn radius tightens up to about 450ft. In the last 10-15 seconds speed bleeds from 90 to 60 knots. If the aircraft was in clean configuration and banked as sharply as the witnesses state with speed bleeding back that rapidly, a stall was imminent. Even with full flap, the aircraft was likely to stall performing this banked turn at such low speed. The last 4-5 seconds saw a loss of altitude of 150-200 feet. Why was he maneuvering at about 200 feet AGL for the last minute of flight so far from the runway?

Best fit is simply a stall while performing a very tight turn at low altitude IMO. Wings level just prior to impact from witness statements suggests the pilot was not incapacitated but perhaps attempting to recover too late. Given that the aircraft slid about 100 feet, this suggests that the impact angle was towards the lower side of the 35-60 degrees estimated and that the final GPS GS report of 71 knots makes sense.

Additional items I noticed on the weight and balance report was that it included the weight of 10 quarts of oil. Perhaps this would have been a clue to an experienced person signing off the aircraft that the whole report was bogus since these engines hold about half that amount. Second, the rear baggage bulkheads were not found at the site. Either not installed or consumed by the fire. These are structural and must be installed for flight.
 
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Thanks Mike -
The old saying "haste makes waste" has never seemed more appropriate.

I am in the final throws of finsihing my RV7A. Everyone asks "When will it fly?" I have been telling them Ocotber. After digesting this report, the answer is now "It will fly when it flies. I will not be rushed."
 
After digesting this report, the answer is now "It will fly when it flies. I will not be rushed."
"I usually tell people that it will not fly until it's finished. If I change my mind and decide to fly it before it's finished, I'll call you first."
 
I'll fly on Tuesday

I am in the final throws of finsihing my RV7A. Everyone asks "When will it fly?" I have been telling them Ocotber. After digesting this report, the answer is now "It will fly when it flies. I will not be rushed."

I always told anyone who asked when I would be finished that it would be Tuesday. They would give me a shocked look, and ask the follow up question "This Tuesday?". I would respond, No, but by claiming Tuesday I will not be more than 3 days off.
 
Saturday

I always used Saturday.
And actually, it turned out that way after saying it for 7 years.....
 
Jerry,

Drifting a bit off-topic for this thread again, I know, but you asked. Mods - move this as you see fit.


The idea of running twin electric pumps is not new, and I don't claim it for my own - I actually got the idea from Frankh here on VAF, I don't know where he got it from. The concept is that we can greatly reduce, if not totally eliminate, the issue of vapor lock by designing the fuel system in a "hydraulically correct" fashion. .

A friend and colleague, John D, who is a pneumatic aircraft systems engineer, has been flying his -6 for some 10 yrs on this same setup. He has an H2AD which does not have a pad for a mech fuel pump (as I understand it). So he has 2 electric pumps on 2 separate circuits with 2 batteries. He (being a Systems Engineer) did a detailed failure analysis and has an involved pre-flight procedure to check both and he replaces one battery every 2 yrs (despite my insisting that he should cycle it and measure capacity before replacing it).

So he has something that I believe provides and equivalent or better level of safety compared to the standard mechanical with electric backup. I would argue that it is likely better from a reliability point of view because of the vapor lock issue and the crappy reliability of those ancient mechanical fuel pumps with their rubber diaphragms which crack etc. They always remind me of the pump on the well at my great grandfathers circa 1850 dairy farm - you know the type with the big arm on it? The electric pumps are small, cheap, easy to swap out and you can even carry one in the spares compartment along with some tools so you can deal with a failure on a trip.

But, like has been mentioned elsewhere, the devil is in the details. One could use a similar scheme, but the wrong type of switch (a left or right selector that if it fries kills both pumps), with incorrect plumbing or venting etc etc and make it a ticking time bomb. You can do that with ANY system. You really need to do your research and a lot of planning and thinking about what-ifs. John did his homework and he has a system that works and has been very reliable. Probably replacing batteries as often as he does is the main downside, but that is a choice he made. I would run the batteries on condition personally, monitoring their health, since I have a battery cycler.
 
NTSB files

are "not found". I have not been able to access either of the referenced files. Not sure what is happening.

Cannot locate by name of pilot or type of aircraft. Worth the read, but cannot see it right now.
 
Sorry to bump this thread since it involved loss of life. However there are
several broken links. NTSB report search for RV10 or RV 10 or RV-10 will
not find report. It was listed as "Trish's Ride Home" not RV-10. The best
way to search for report I found was the tail number: N289DT

Location: Greenville, PA
Accident Number: NYC08FA023
Date & Time: 11/02/2007, 0832 EDT
Registration: N289DT
Aircraft: Daniel R. Lloyd Trish's Ride Home
Aircraft Damage:Destroyed

It is still a good lesson. As builders we need to take great care with anything to do
with Engine, Prop, Fuel, Exhaust, Flight Control's & electrical system, EVERYTHING.
Considering going duel EI that is electrical system dependent. Will I change my
mind? Electrical system should be the most reliable robust thing in the plane, but
the system has to be well designed, redundant, and assembled to highest standards.
Will it be as reliable as a standard dual magneto? Well it depends, but I think yes.
 
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