Update on Catalina Baron crash

[ateamer]

Ah, so nothing would have prevented this pilot from departing, as his personal limits included this takeoff.

Sounds like it would have prevented the accident.

True, gotta have reasonable personal limits. Many pilots don’t, or are quite willing to say “normally I wouldn’t fly in these conditions, but…”.

 

[Pinecone]

The default is no-go. Only go if and when everything is inside the Go parameters. That applies to everything from flying across the country to once around the pattern.

Agreed.

But most people are set to Go and only cancel if things are bad enough. Gethomeitis is a form of this.

 

[Pinecone]

Where are the Go parameters published?

You, as the PIC make those parameters.

But you make then outside of planning any specific trip. Such as, Go only if ceiling is forecast to be 1000 feet or higher. Then when the day comes, you check the weather and the ceiling is forecast 900, you don't go, as you have not met YOUR Go parameter.

 

[MauleSkinner]

You, as the PIC make those parameters.

But you make then outside of planning any specific trip. Such as, Go only if ceiling is forecast to be 1000 feet or higher. Then when the day comes, you check the weather and the ceiling is forecast 900, you don't go, as you have not met YOUR Go parameter.

But the implication of the post I replied to was that somehow it would have made a difference in this accident. We have no evidence that this pilot exceeded any of his personal minimums.

 

[woxof]

Juan says that if you try to charge a dead battery with an alternator, there is a good chance that you will 'fry' that alternator.

Is this actually true?

 

[texasclouds]

Juan says that if you try to charge a dead battery with an alternator, there is a good chance that you will 'fry' that alternator.

Is this actually true?

Possibly from overheating/overworking it.

 

[Ed Haywood]

Juan says that if you try to charge a dead battery with an alternator, there is a good chance that you will 'fry' that alternator.

Is this actually true?

I think that's backwards.

If you recharge a dead battery off an alternator, it can damage the cells of the battery due to the high rate of charge. Better to put the battery on a charger at a lower amperage.

 

[Stevel]

Juan says that if you try to charge a dead battery with an alternator, there is a good chance that you will 'fry' that alternator.

Is this actually true?

That's what happens every time someone gets a jump-start in their car. That large data set refutes the alternator claim. The battery risk mentioned above is supported by that data set, although I think deep-cycling a battery that is not built for it contributes to the battery's demise in addition to the previously mentioned charge-rate.

 

[Barrett50]

Juan says that if you try to charge a dead battery with an alternator, there is a good chance that you will 'fry' that alternator.

Is this actually true?

Not generally. The internal resistance of the battery when discharged plays a part in this, as does the regulator on the alternator. In aircraft, the full load of all electric loads on an alternator cannot exceed 80% of the rated amperage of the alternator installed. So, there are situations where the alternator can be loaded up to 60-80% of its rated capacity, and then adding a large current draw to recharge a batt may exceed the thermal dissipation of the alternator.

If the load on the alternator is very low, like 10% of the alternator rating, then charging a battery should be ok as long as the alt is getting plenty of cooling air. Where it comes into damaging alternators, is a large electrical load on the alt, plus a large batt charging load, and very little cooling air like sitting at the ramp on a hot day. In that case, it may overload the regulator of the alt and fry the diodes inside.

Like everything else in aviation; 'it depends'. If you must charge a dead batt, the best thing to do is leave all other loads off, and when the engine is running, leave the field switch or master switch off until the plane is in the air, and then turn on the alt or field and monitor the charging or voltage gauge. When the batt recovers and the load is much lower, the electrical loads can be added carefully.

 

[Fearless Tower]

That's not what the prelim says. It says, "Information provided by the flight school indicated that the responding airplane was not operated by the flight school and belonged to an acquaintance of the owner of the flight school."

The flt school owner calling a buddy with a plane and asking him to go pick up some stranded folks would be consistent with the prelim (as would other scenarios).

Yeah, I might have gotten confused from the earlier reports that implied the PIC was the Flight School owner.

Apparently the PIC had been a longtime SMO Flight School owner and shut his business down within the past year. It was a different school that was operating the stranded aircraft.

 

[Bell206]

Is this actually true?

Depends how you define a "dead" battery and what caused it to discharge. But in general, an alternator is not designed to properly recover a battery that is discharged. Unfortunately, lead acid batteries do not handle excessive discharges well and are usually damaged unless it is properly recharged. This is partly the reason you see people complain their batteries only last 3 or 4 years vs 7+ years. So yes an alternator can be damaged when you have an excessive battery discharge event and do not properly handle the situation per the OEM recommendations.