Flight Design "Safety Box" & possible LSA Implications

[drseti]

How can there be no 5 year rubber replacement? Remos is Rotax powered. Remos is an SLSA, no?That's a Rotax requirement which the airframe manufacturer has no authority to waive.

[snaproll]

Paul is right... 5 year hose replacement is required..
VR.. Don
Remos GX N29GX

[howardnmn]

This is probably worth new thread, and of course ...I could be mistaken, but

Doesn't Remos GmbH prevail over rotax? If rotax says throw away your spare fuel pump after five years and Remos says it's good if it works, who has final say? Conversely, if rotax says 10% ethanol is ok but aircraft manufacturer says don't use ethanol gasoline, what would you do?
If an aircraft manufacturer says you can't upgrade your Skyview operating system without our approval, but dynon says upgrade, what would you do? I would apply the 'common sense rule' in these situations.

My simple stupid understanding of the LSA oversight rules is that basically the aircraft manufacturer steps in for the FAA thus making LSA-building less bureaucratic. Of course the manufacturer has to meet ASTM standards. I think of ASTM as the grand ayatollah of the LSA-manufacturing world. Does ASTM say parts are 'life limited' or 'on condition.' Frankly I don't know.

I do know that it is possible to make fuel hoses that safely last way beyond five years. And in certain environments, way less. On my previous S-LSA I observed cracking in the fuel lines coming down from
The wing tanks so I replaced them even though the plane was less than two years old (airplane had baked in Arizona sun)

Flying legal and flying safe are not always the same thing. If FAA bumps the weight limit to 1500 lbs is it still smart to depart at 1500 lbs from airport with 10k density altitude? (Even if weight and balance calculation says you're legal). Margin of safety matters more to me than government rules. Common sense is what has kept me out of trouble so far

[drseti]

Let's use your ethanol question as an example. Rotax makes the engine, and determines that ethanol is safe - in that ENGINE. They didn't make the airframe, and don't know what ethanol might do to that. So, yes, you can use ethanol in the ENGINE, just maybe not in the AIRFRAME - only the airframe manufacturer can authorize that.

Turn it around: if the airframe manufacturer says their tanks can accommodate diesel fuel, would you then want to run that through your Rotax?

Similarly, the fuel, oil, and coolant hoses in the engine are not airframe parts, so Rotax gets to set the maintenance standards and replacement intervals. And, to my mind, that IS common sense.

[MrMorden]

That is the dramatic advantage of CT's composite construction, and not its aerodynamic performance.

Very true, Pete. The usual reason for going to composites is sleek compound curves, allowing significant drag reduction, hence high cruise speeds. Since speed is limited for an LSA, we cannot enjoy this particular advantage of composites. However, composites are definitely lighter than metal structures of similar strength, so plastic LSAs end up with higher useful loads than metal ones (at essentially the same speeds and glide performance).

We can't get the most of the speed advantage, but drag reduction does have advantages for an LSA. Better climb, less fuel burn, better power off glide ratios, etc would seem to be benefits of lower drag (and lighter!) airframes.

[MrMorden]

Let's use your ethanol question as an example. Rotax makes the engine, and determines that ethanol is safe - in that ENGINE. They didn't make the airframe, and don't know what ethanol might do to that. So, yes, you can use ethanol in the ENGINE, just maybe not in the AIRFRAME - only the airframe manufacturer can authorize that.

Turn it around: if the airframe manufacturer says their tanks can accommodate diesel fuel, would you then want to run that through your Rotax?

Similarly, the fuel, oil, and coolant hoses in the engine are not airframe parts, so Rotax gets to set the maintenance standards and replacement intervals. And, to my mind, that IS common sense.

My understanding is that the FAA has ruled that the 5yr rubber replacement cannot be required by Rotax, so it technically doesn't really apply to any of us anymore.

However, if the engine manufacturer has made a recommendation strongly enough that they want it to be a requirement, I'm going to comply unless there is a *very* compelling reason not to do so.

Howard, I'm glad you like your Remos, I think they are fine airplanes. There are some weak points, just like there are with the CTs (or any airplane). In the Remos specfically I think the following are some of the less ideal aspects:

1) Some hate the fuselage fuel tank. Personally I'm okay with it, but I'm putting it on the list because a lot of people object to it. All airplanes are flying bombs; there is really no "safe" place to put 20+ gallons of gasoline in a very lightweight vehicle.

2) The Remos has great useful load, better than most CTs, but it's harder to use the load for baggage because the baggage spaces are smaller and harder to get to.

3) The aileron interconnect where the wing folds is a particularly flimsy design. Honestly, this is the only thing I've seen that would give me pause about owning a Remos or flying one a lot. I'd take it E-LSA jsut to fix that and make it stronger and more secure.

There maybe be other things about the Remos that are not ideal, but my experience with the Remos is limited. I do believe based on others' comments that the Remos probably flies a bit better than the CT.

Here are the things I don't like about my CTSW as it comes from the factory:

1) The factory CTSW landing gear is not great. It was made better in the CTLS, but honestly unless you just get lucky or upgrade to Matco wheels and brakes, you are going to have alignment issues and excessive tire wear. Before mid-2006 the gear legs are also too thin and bend too easily.

2) The electrical system is adequate, but not great. There are frequently grounding and RF noise issues unless the owner makes some small tweaks to the system.

3) Some maintenance items are in very inconvenient locations. The fuel filter was put in the factory location simply to taunt owners and mechanics.

4) The airplane has a short tail, leading to adverse yaw and an a high amount of "tail happiness" in any turbulence. As a plus side, the airplane makes one a better pilot by forcing us to actually use the rudder.

There are a few others, but that's off the top of my head. Again, there are no perfect airplanes and every design has flaws. Luckily, most of them have much more positives than negatives. People who attack a certain design usually are just nit picking about the few flaws in an otherwise good design, though there are exceptions (*cough* Zodiac *cough*).

[dstclair]

The five year Rotax rubber replacement is a recommendation for S-LSAs in the US according to the FAA (lots of discussion with facts in this and other forums). Might be a great recommendation but it does not have the force of regulation.

[Merlinspop]

Flying legal and flying safe are not always the same thing. If FAA bumps the weight limit to 1500 lbs is it still smart to depart at 1500 lbs from airport with 10k density altitude? (Even if weight and balance calculation says you're legal). Margin of safety matters more to me than government rules. Common sense is what has kept me out of trouble so far

W&B are only part of the answer to that question. What do the performance charts show (assuming the POH has charts)? What if at 1500# and 10K DA, the charts show that your aircraft can take off in 1/2 the available runway and have a climb gradient that will get you well over any surrounding terrain? I'd say you're not being unsafe to attempt to launch.

If the charts say (or there are no charts) that you'll need every inch of available runway and that you'll be lucky to get a foot per minute of climb out of it...well...that's very different.

[howardnmn]

Hi Bruce. My point exactly. You're preaching to the converted. Like most of here I'm an amateur pilot. I fly for fun and don't want to operate at the edge of my skills envelope. If I had a heavier LSA I would get a room and take off at lower D.A the next morning

[howardnmn]

Hi Andy :

I agree w.r.t. Relatively small storage volume on Remos. There are work-arounds. I also have a bad motorcycle habit and i decided that relatively small baggage volume is one non-safety compromise I can Live with. Wish the Remos had a belly pod option like FD. Wish it had a fancy-pants WAAS enabled GTN750. And on and on.

The fuel tank in the fuse is a plus for me. The single tank is like a big header tank. The tank outlet is always flooded if there is fuel and no negative G. In cessna 172/182 or equal, on finals in cross wind flying uncoordinated with low fuel it's possible to uncover fuel tank outlet and stall. It's happened. Also there's no chance to syphon fuel from missing or leaky fuel cap since filler and tank venting on Remos not in low pressure region. Also no rain water ingress since filler not on horizontal and fuel cap much better than anything on my 172/182/310 cessnas. Also, We think nothing of driving around in cars with gas tanks in chassis.

The aileron (and elevator) connections are pretty solid on my model. Three dabs of "j.b. Weld" would allay your concerns. This problem comes up when wings are folded: A very infrequent event for Remos owners like me. In one fatal accident, not only were preflight warnings ignored, the chute was also padlocked making chute inop. Does the expression "pilot error" come to mind? BTW Remos POH says max chute deploy speed is 120 knots

With respect to shortcomings of CTSW; we fly the planes we own, not the ones we wish we owned. I feel the lighter SW -- in the hands of an experienced driver -- is safer than the heavier, fully optioned out LS ( now that should draw some flak)

The earlier Remos models had undercarriage problems too. And given enough time in the pattern the CT should be easy to land too. However I can't say that it's a good newbie's aircraft. I think the CTflier web board is the best. And envy the Larger FD community.

My Remos is the only LSA that has doors that are easily jettisoned in flight in prep for an emergency landing. But that is secondary concern in my mind. My primary is to avoid the chain of events leading to a crash in the first place. No safety cell or air bag or parachute will save you if 'stuff' really hits the fan.

Safety Cage is certainly praiseworthy; avoiding trouble altogether is priceless.

[MrMorden]

Hi Andy :

I agree w.r.t. Relatively small storage volume on Remos. There are work-arounds. I also have a bad motorcycle habit and i decided that relatively small baggage volume is one non-safety compromise I can Live with. Wish the Remos had a belly pod option like FD. Wish it had a fancy-pants WAAS enabled GTN750. And on and on.

The fuel tank in the fuse is a plus for me. The single tank is like a big header tank. The tank outlet is always flooded if there is fuel and no negative G. In cessna 172/182 or equal, on finals in cross wind flying uncoordinated with low fuel it's possible to uncover fuel tank outlet and stall. It's happened. Also there's no chance to syphon fuel from missing or leaky fuel cap since filler and tank venting on Remos not in low pressure region. Also no rain water ingress since filler not on horizontal and fuel cap much better than anything on my 172/182/310 cessnas. Also, We think nothing of driving around in cars with gas tanks in chassis.

The aileron (and elevator) connections are pretty solid on my model. Three dabs of "j.b. Weld" would allay your concerns. This problem comes up when wings are folded: A very infrequent event for Remos owners like me. In one fatal accident, not only were preflight warnings ignored, the chute was also padlocked making chute inop. Does the expression "pilot error" come to mind? BTW Remos POH says max chute deploy speed is 120 knots

With respect to shortcomings of CTSW; we fly the planes we own, not the ones we wish we owned. I feel the lighter SW -- in the hands of an experienced driver -- is safer than the heavier, fully optioned out LS ( now that should draw some flak)

The earlier Remos models had undercarriage problems too. And given enough time in the pattern the CT should be easy to land too. However I can't say that it's a good newbie's aircraft. I think the CTflier web board is the best. And envy the Larger FD community.

My Remos is the only LSA that has doors that are easily jettisoned in flight in prep for an emergency landing. But that is secondary concern in my mind. My primary is to avoid the chain of events leading to a crash in the first place. No safety cell or air bag or parachute will save you if 'stuff' really hits the fan.

Safety Cage is certainly praiseworthy; avoiding trouble altogether is priceless.

I hear you about working around the small baggage space. It really only comes up when you are flying long distances with a passenger. When solo you have the whole right side of the airplane to fill up, and for short hops you don't need baggage anyway!

There may very well be various versions of the aileron interconnect; I can only talk about the one I saw. I'm sure owners have figured out ways to work around any bugs. The fatal accident at the Light Sport Expo was *definitely* a case of inadequate pre-flight by the pilot, and I don't know of any other accidents attributed to this feature...and folding wings sure are convenient!

Regarding the CTSW vs the CTLS, I like the SW better because of the better useful load; I want to *do* stuff with my airplane! I had not really thought of the lighter weight as being a safety feature, but that makes some sense as well. The SW is more tail-happy in turbulence has has more adverse yaw; that just means you have to be a little more proficient in rudder use. The SW is not really an easy airplane to land, but once you get good at it I think your skill level is a little higher than many other planes demand. You are right it's not really a newbie plane, but I bought one as a newbie and it has forced me to learn fast!

The fuselage fuel tank in the Remos is fine, as I said it's doesn't bother me personally. The only downside is you can't really get enough fuel pressure to gravity feed the engine if the fuel pump fails. Does the Remos have an electric aux pump? If so, problem solved.

Interesting about the doors, I didn't know that...can you fly with them off in the Summer? My CTSW has removable doors and you can fly with them off, but I have not done it. Others who have say it's a wind tunnel and you really want to stay around 70kt or below to stay comfy (90kt max is allowed with doors off).

I agree with you 100% on staying out of trouble...the best way to use any safety feature is not to put yourself in a position to need it.

[Wm.Ince]

. . . "the best way to use any safety feature is not to put yourself in a position to need it." . . .

Could not have been said better.

[zaitcev]

The fatal accident at the Light Sport Expo was *definitely* a case of inadequate pre-flight by the pilot, and I don't know of any other accidents attributed to this feature... and folding wings sure are convenient!

There was another, and likely poor preflight was involved again:
http://www.ntsb.gov/aviationquery/brief ... 4118&key=1

We do not fold wings on N28GX and N831RC (nee N78GX) because, according to the owner, it takes 2 people to do safely, and many renters fly solo or with non-inducted passengers. I imagine we could fold N28GX because the old gal is now relegated to students, but since we have the hangar space now, it's not needed.

Since I wasn't looking, there were 2 more fatals in Remos, for the total of 4 (I count the Sebring as 1 case). Both of the 2 involved stalling at low altitude. And in 1 of them passenger survived, amazingly enough. I didn't see any pictures from it.

[howardnmn]

When I look at the CT crash photos that Andy posted it seems none of these were high impact events. The props don't look all smacked up nor is there crumple zone deformation. Even the gear is intact on most. The terrain looks flat. I would bet they were all in VMC and basically under-control emergency landings. The cirrus crash that fast Eddie provided looks more like an advert for safety cage, although without the NTSB investigation narrative it's pretty hard to know what happened.

The fatal Remos accident where the pax "amazing survived" was caused by the CFI trying to maneuver at low altitude so that the mother of the pax could get good video. The CFI wanted another student. Relatively high impact. Tragic and so avoidable. Even high time, professional pilots seem to get too cocky at times

I am comforted by my chute, and the idea that some Remos engineer probably did a finite-element structural analysis of the passenger compartment. But what really puts me at ease is the information I get from my panel: WX, traffic, fuel totalizer, AOA and the occasional "pull up, pull up" from the annoying GPS lady when near terrain.

I would bet that 95% of small plane accidents have relatively few causes: bad weather; fuel starvation; pattern problems I.e., stall on base to final or air to air collisions. Wings falling off a zenith, or pilot having an M.I. or air show mishaps likely account for no more than 5% but get a lot of publicity.

[MrMorden]

The fatal accident at the Light Sport Expo was *definitely* a case of inadequate pre-flight by the pilot, and I don't know of any other accidents attributed to this feature... and folding wings sure are convenient!

There was another, and likely poor preflight was involved again:
http://www.ntsb.gov/aviationquery/brief ... 4118&key=1

Taking off with the BRS system PADLOCKED?!?