Hypothetical - Robinson Total Electrical Failure

[Robbiee]

,...then you land, and the mechanic asks, "did you overspeed it", you say, "no". He replies, "how can you tell?"

[RandomPerson8008]

Fan scroll nut cotter pin is still aligned with stripe? As described here at 7m 40s? Not sure if there's another way

You Tube

[Bell_ringer]

Originally Posted by Twist & Shout

The throttle corelator is good.

That might work well at sea level, less so at higher density altitude.
It was suggested to roll the throttle back so rpm drops slightly (a few percent), at that point you can fly it without issues or further adjustment.
The aircraft will operate just fine with a slight droop and it eliminates any chance of an overspeed for the throttle challenged.

[homonculus]

How long will the battery last once the ALT failure light comes on? It depends. I'd say between 15 min and 60 min

On the Astros, in the UK at least, the POH had the number of minutes the battery would last assuming shedding all non essentials bar radio. It certainly turned my one Alt failure from an emergency into a no event. Does anyone know why this was discontinued? I accept it was an estimate but mine was 38 minutes with just over 20 minutes flight back to engineering late at night with nowhere closer open...

[cattletruck]

Had a gen failure followed by a battery failure in a jetbox (it was cart started). The press-to-test button didn't light up anything on the enunciator panel during the flight, the radios went dead, however the baro instruments, engine indicators and tachos were still working. Don't know if the FCU has electrics but both fuel pumps read zero pressure and a slight lateral twitch was observed confirmed by the Tq gauge flickering 1%. A smoothly handled steep approach back to base was no drama.

Young people tend to get too focussed on the numbers with these relatively simple machines (I know I did), but at the early learning stages they should step back a bit and it will be easier to keep the numbers where they should be, as experience builds they can then do things in a jetbox like keeping the RRPM right at the very bottom of the green arc in a stretched auto as the audible horn screams. Should the electrics go TU and the donk is still running then the situation is still quite salvageable - don't panic as they say.

[Twist & Shout]

Electronic tachs and governor - need electricity from somewhere. Either Alt or Bat. That’s it.

Bell 47, with total electrical failure. Lose radio/ICS, strobe light, the ability to turn the hydraulic’s off, and the starter motor.
Depending where you are, you might not notice till you try and restart it.

I fly a twin turbine computer now. Autopilot fails the test a few times? - Shut it down, and “restart” it - painful. (Both engines off, all power off - almost expect an “Apple” symbol somewhere on the restart......)

That’s why they call them the GOOD old days....

Although I love the “synthetic vision”

[Hot and Hi]

Originally Posted by RandomPerson8008

Fan scroll nut cotter pin is still aligned with stripe? As described here at 7m 40s? Not sure if there's another way

https://www.youtube.com/watch?v=2VcBXjMGhIM&t=07m40s

Sorry, “no” again. The scroll nut will not move relative to the scroll if there is engine (or rotor) overspeed in flight. (It may indicate though that engine was started with open throttle, which sometimes is referred to at overspeed at startup.)

[RandomPerson8008]

Originally Posted by Hot and Hi

Sorry, “no” again. The scroll nut will not move relative to the scroll if there is engine (or rotor) overspeed in flight. (It may indicate though that engine was started with open throttle, which sometimes is referred to at overspeed at startup.)

What's the answer then? I cannot find anything mentioning post-flight indications of an overspeed in the POH or learning materials. MR gearbox teletemp?

[Robbiee]

Originally Posted by RandomPerson8008

What's the answer then? I cannot find anything mentioning post-flight indications of an overspeed in the POH or learning materials. MR gearbox teletemp?

The mechanic will have to pull the blades to check the spindles (at least I'm pretty sure that's what they said, its been five years since I was at the Safety Course so,...?) if an overspeed is suspected.

It often depends on how high the overspeed was,...and with no tach, well,...?

This is why trying to continue flying after total electrical failure is stupid. Sure you could pull it off with your Superman ears, but unless there was absolutely no place to land before your battery finally dies, you'll probably get fired upon your triumphant return.