Jump to content

Jabiru rescues Rotax plane


Recommended Posts

Fun that it might be try not to exaggerate too much - cup half full refers to those personalities that see the opportunities in challenges - cup half empty to those who only see the limitations.

 

Read back through the responses (to this and other conversations)and you will quickly see that certain individuals (fairly consistently) seek to restrict, prophesy disaster, catastrophic breaches of the "rules/book",  etc the ingenuity of others - incase you are wondering this is the cup half empty view of life/challenges.

 

 

  • Like 1
Link to comment
Share on other sites

  • Replies 91
  • Created
  • Last Reply

Top Posters In This Topic

I was thinking Australia and 30 plus degrees. Even with a cooler the my musketeer gets close to the red line on a hot day on climb. The vernatherm cuts out the cooler when not required. Someone living in Alaska who ordered their aircraft with out a cooler (can you actually do that ?) would be stuffed if they flew to Texas in summer. 

 

I learned on a Tomahawk at Jandakot many years ago and it didn't initially have an oil cooler. Engine temps on a 30+ day (very common) were always at the top end of the green, nudging the red. So the operator had an oil cooler fitted and it just made managing the engine temps so much easier. Safer too. 

 

 

Link to comment
Share on other sites

 If a particular application needs it then it should have it. If it's OK without it then it doesn't. The inlet pipes pass through the sump on the engine you refer to so it already has a substantial oil cooler. If anyone's serious about engine temp management then they would fit adjustable cowl flaps. Often the only variable is to increase climb airspeed if it's getting too hot... Engines can run too cold  (mainly with only the oil, if it's an air cooled motor) and that's not good for them. They should reach 85+ degrees on  most flights and flight 's under an hour won't guarantee to get the temps high enough to keep condensation from occurring. There's also the questions of warm up times on the ground and descents. Long descents power off are not advised, generally. Nev

 

 

Link to comment
Share on other sites

 ... If anyone's serious about engine temp management then they would fit adjustable cowl flaps...

 

Engines can run too cold  (mainly with only the oil, if it's an air cooled motor) and that's not good for them...

 

I have fitted cowl flaps, but they're only as good as the operator. A couple of times I've forgotten to close them on descent or open them during a climb out. Perhaps we need a reliable automatic system, like the Spitfire had.

 

This morning while testing for an oil leak I ran my engine for half an hour without the cowls. Interesting to see the effect on CHTs. Eventually the rear heads got to 150 C, but it took longer than when I've had the whole lot cowled in. I presume a major role of the ducts is to even out cooling as much as possible.

 

 

Link to comment
Share on other sites

I agree old K. I have to notice my voltage and switch off the battery at 14.2 volts. Today I forgot and I hope there is not too much damage to the battery. I need an automatic system.

 

Is this not part of your voltage regulator??

 

We all forget things - fuel boost on/off, brakes on, etc etc - that's why we need a checklist .... but then you have to remember to use it !

 

 

  • Like 1
Link to comment
Share on other sites

 We can't make everything automated as each item becomes an extra "fail situation" issue.

 

    Carb heat is manual, as are flaps. Mixture, cowl flaps  Throttle too but is sometimes automated and you can have autobrake "armed" as well as gound spoilers. One plane had automatic gear extension and read up how much trouble that caused... (as you could imagine)  Yes we CAN all forget things and must constantly strive to overcome that tendency. The checklist is a check that you have DONE it. . Normally one associates certain actions with a certain stage of the flight profile. When non standard things happen that pattern gets disturbed and often things are missed due an unfamiliar situation.  WE know that happens from accident investigation. We have pressure and unfamiliarity A bad combination,

 

We are creatures of habit. and must cope with "human" failings best we can.. IF you are "missing" things on a regular basis it would be a cause for concern as it doesn't fit well with a flying environment which is, as we are constantly informed, not tolerant of mistakes or errors. Don't be rushed. Be deliberate with critical actions and don't do critical work when someone keeps interrupting you . Avoid distractions. Passengers talking to you at critical times etc.  Think "AEROPLANE when you must. Nev

 

 

  • Like 1
Link to comment
Share on other sites

I swapped the Odyssey for a LiFe battery and saved about 5 kg and got better starting amps. But the old Jabiru regulator provides about 14.8 volts, which is too much for the LiFe battery and so I switch it out at 14.2 volts, when the start-energy has been replaced. I reckon the plane is safer with the battery isolated.

 

The difficulty in designing an automatic system is that there can be no leakage current while the plane is sitting idle.

 

 

Link to comment
Share on other sites

I swapped the Odyssey for a LiFe battery and saved about 5 kg and got better starting amps. But the old Jabiru regulator provides about 14.8 volts, which is too much for the LiFe battery and so I switch it out at 14.2 volts, when the start-energy has been replaced. I reckon the plane is safer with the battery isolated.

 

The difficulty in designing an automatic system is that there can be no leakage current while the plane is sitting idle.

 

I find a "conventional"  absorbed glass mat,  motorcycle battery, made by SSB PN RB16CL-B to be an excellent start battery. Much lighter, with near double the AMP hrs than my original and without the concerns (charging and fire) attached to "lithium" style batteries - paid $140 back in 2013 and still going "gangbusters" 

 

 

  • Like 1
Link to comment
Share on other sites

 IF you can safely isolate it that's another thing not bothering you. In the early days of large aircraft , certain parts of the hydraulic systems were turned off after you got into the climb and all was settled down.. That reduced the load and risk of leakage. 

 

  Bruce I have an isolator for my van that applies current to my  3rd battery when the basic batteries are charged. It only senses voltage so why can't you apply that concept. This thing is made in South Australia but you could use a diode actuated relay that would be much lighter. Nev

 

 

  • Like 1
Link to comment
Share on other sites

 The AGM or paste battery is definitely most satisfactory for the heavy start cycles. Monitor the heat . IF it starts to get hot when charging, the plates get airspaces between them and it's over for that battery. The jabiru start set up  (flywheel) doesn't like a jumper lead approach  much and a "too good" battery but that's just something to watch. You are going to get a better cranking effort on a cold morning, which is what you often need most. Nev

 

 

Link to comment
Share on other sites

 The AGM or paste battery is definitely most satisfactory for the heavy start cycles. Monitor the heat . IF it starts to get hot when charging, the plates get airspaces between them and it's over for that battery. The jabiru start set up  (flywheel) doesn't like a jumper lead approach  much and a "too good" battery but that's just something to watch. You are going to get a better cranking effort on a cold morning, which is what you often need most. Nev

 

Thank for that Nev - my battery is located, passenger (cool) side of the fire wall, with good surrounding passive air flow,  short leed distance to starter motor and very well earthed - so hope it has what it needs for a long service life.

 

 

Link to comment
Share on other sites

 Every now and again put the battery on an appropriate charger and see if it gets hot. A new and good battery doesn't get very hot. Fast charging is not recommended at all as gas bubbles in a paste matrix don't fix them selves I love AGM batteries. They don't leak acid. Nev

 

t heal up

 

 

Link to comment
Share on other sites

 Every now and again put the battery on an appropriate charger and see if it gets hot. A new and good battery doesn't get very hot. Fast charging is not recommended at all as gas bubbles in a paste matrix don't fix them selves I love AGM batteries. They don't leak acid. Nev

 

Thanks again - I have never thought to check battery temperature  this way. I irregularly (only when aircraft has not been used for two weeks or more) charge my battery using a Ctek charger (set to motorbike) supposedly specially designed for this sort of battery. I allow the charger to go through its full charging sequence - takes quite some time.

 

 

Link to comment
Share on other sites

 Umm totally unrelated post.. but a group of us are flying into Gawler for the Cup Day weekend.  Arriving Friday and departing Tuesday.  Please say Hi if you're about.  I'll be in the RV.  ?

 

"Umm totally unrelated post" - no kidding ! I compliment you on  your "lateral thinking" 

 

 

Link to comment
Share on other sites

I swapped the Odyssey for a LiFe battery and saved about 5 kg and got better starting amps. But the old Jabiru regulator provides about 14.8 volts, which is too much for the LiFe battery and so I switch it out at 14.2 volts, when the start-energy has been replaced. I reckon the plane is safer with the battery isolated.

 

The difficulty in designing an automatic system is that there can be no leakage current while the plane is sitting idle.

 

Bruce I fitted an Aussie-made PowerMate regulator to ensure my LiFe battery gets protected from over charging.

 

Very happy with it.

 

 

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...