DHC6 , both propellers play up
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Re: DHC6 , both propellers play up
well, there goes the "there has never been an inflight prop reversal" talk from the groudschool. nice job by the crew!
jet.
jet.
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lostinthebattle
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Re: DHC6 , both propellers play up
Looks like it was Provincial (Innu Mikun), and from what I gather from the initial post-the prop was feathering which is the opposite direction than reversing. Beta light cycling-props min gov.; prop feathering-torque increasing-pull beta breaker. I know I'll get hammered but me thinks proper checklist was not followed. The groundschool statement stands 
PS -100 series is known for uncommanded reverse: keep those breakers in!
PS -100 series is known for uncommanded reverse: keep those breakers in!
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seniorpumpkin
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Re: DHC6 , both propellers play up
Reading this article makes me frustrated.
Shutting down the engine is not the correct procedure for a beta light whether it be flashing or on solid. If the light was on solidly, as is indicated by the remedy, it should be a memory item involving pulling the torque back, pulling the circuit breaker, then returning the power to normal and have a nice day. I've even heard rumours of some 300 series DHC-6's having the beta back-up system removed all together.
Also having two engines malfunctioning in a different manner would be quite extraordinary for the same flight.
Is there a cadors out there that maybe has some more accurate reporting?
Shutting down the engine is not the correct procedure for a beta light whether it be flashing or on solid. If the light was on solidly, as is indicated by the remedy, it should be a memory item involving pulling the torque back, pulling the circuit breaker, then returning the power to normal and have a nice day. I've even heard rumours of some 300 series DHC-6's having the beta back-up system removed all together.
Also having two engines malfunctioning in a different manner would be quite extraordinary for the same flight.
Is there a cadors out there that maybe has some more accurate reporting?
Flying airplanes is easy, you just need to PAY ATTENTION. Finding a good job on the other hand takes experience, practice, and some serious talent.
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rightseatwonder
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Re: DHC6 , both propellers play up
doesnt borek have an STC to remove the beta back-up system? in anything other than the best environments, the damn things cause more crap than they're worth! In one salty part of the world, every beta breaker was pulled permanently .
Re: DHC6 , both propellers play up
There may be a time to disarm the beta system, that is up for argument/conversation. However, this doesn't sound like a system failure. This sounds like a driver mistake (probably a couple of them). The twin aint the most complicated machine out there; but, if you screw the pooch, you've screwed the pooch. It is good to see that everything turned out O.K.
This is a good time to learn, rather than just play touchy goody feelings and pretend that a "good guy" saved the day from some poor engineering.
"You don't @#$! up, and I won't yell at you." -- some of the best advise I've heard in a CRM class.
Edited for PC.
I haven't heard from anyone involved -- If the engine was shut down for other reasons than a blue light, I reserve the right to re-evaluate.
This is a good time to learn, rather than just play touchy goody feelings and pretend that a "good guy" saved the day from some poor engineering.
"You don't @#$! up, and I won't yell at you." -- some of the best advise I've heard in a CRM class.
Edited for PC.
I haven't heard from anyone involved -- If the engine was shut down for other reasons than a blue light, I reserve the right to re-evaluate.
Re: DHC6 , both propellers play up
norOntair Twin Otter 300 series suffered the same situation years ago, probably 1983 or 1984.
It happened when the prop de-ice was turned on. Not sure if these guys needed prop de-ice at this time of year, but maybe they were in icing conditions.
Metal wiring wraps (tie wraps) running through the wings, which hold wiring to the prop de-ice and auto-feather systems, had cut through the wire coverings with age and vibration, and when the prop de-ice was turned on, shorted out, and every time the props went thru their 30 or 40 second de-ice cycle, would cause the props to feather, and unfeather when the cycle was over. This would continue until the prop de-ice was turned off.
Of course the crew, would deal with an over torque when the prop feathered at cruise power, and reduce power, probably to idle, thence the beta light would come on. Then the de-ice cycle would cease, and the props would go back to normal.....If the prop de-ice was on, guess what happened about 40 seconds later..same thing.
Be interesting to know if the guys were using prop de-ice??
It happened when the prop de-ice was turned on. Not sure if these guys needed prop de-ice at this time of year, but maybe they were in icing conditions.
Metal wiring wraps (tie wraps) running through the wings, which hold wiring to the prop de-ice and auto-feather systems, had cut through the wire coverings with age and vibration, and when the prop de-ice was turned on, shorted out, and every time the props went thru their 30 or 40 second de-ice cycle, would cause the props to feather, and unfeather when the cycle was over. This would continue until the prop de-ice was turned off.
Of course the crew, would deal with an over torque when the prop feathered at cruise power, and reduce power, probably to idle, thence the beta light would come on. Then the de-ice cycle would cease, and the props would go back to normal.....If the prop de-ice was on, guess what happened about 40 seconds later..same thing.
Be interesting to know if the guys were using prop de-ice??
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lostinthebattle
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Re: DHC6 , both propellers play up
Hey bep, interesting situation. Reminds me of a situation I heard at Air Bc. The engineers did a engine wash and for got to put the glowplugs back in all the way. As the crew applied take-off power the engine fire light illuminated because of blow-by past the plugs. As soon as the crew saw the warning light they would power to idle-the light would extinguish. That went on for a few times and then they said @#$! it and called her a day.
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Mad Flying Ace
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Re: DHC6 , both propellers play up
All of Kenn Borek's twotter have had the Beta Back Up System removed - yes they own the STC to do this.
There has never been an in flight prop reversal in Borek's history.
regards,
Mad Flying Ace
There has never been an in flight prop reversal in Borek's history.
regards,
Mad Flying Ace
Re: DHC6 , both propellers play up
What other PT-6 aircraft have a beta back up system? Was surprised when I discovered that the King Air and 99 didn't have them. Was it a Twin Otter thing only?
Re: DHC6 , both propellers play up
The Beech products did have a secondary low pitch stop system installed. Not sure if it was installed on all a/c but I know I did quite a few removals IAW a Beech SB. We would then use the SLPS wiring to hook up chip lights in cockpit which the original B-99s didn't have. Go figure.
Cheers,
ETTW
Cheers,
ETTW
1. The company pays me to make money for it.
2. If the company doesn't make money neither do I
3. I still hate simulators
2. If the company doesn't make money neither do I
3. I still hate simulators
Re: DHC6 , both propellers play up
Is there anything else involved with this STC other than removing the associated parts ?Mad Flying Ace wrote:All of Kenn Borek's twotter have had the Beta Back Up System removed - yes they own the STC to do this.
There has never been an in flight prop reversal in Borek's history.
regards,
Mad Flying Ace
