B190 Autofeather

[Prop Job]

Hallo Everybody,

Just had an interesting autofeather discussion today with my Captain. We had some problems ground testing the autofeather system. We called the Engineers to have a look and they subsequently did the usual, i.e. cleaned the plugs, checked the pressure switches and circuit boards. After all that we ground tested the aircraft again and it was still slow to feather, but at least it worked.

On the empty flight to our Home Base we were wondering if there is a way to check the system in-flight. The only solution we could think of was to physically cut the engine using the Fuel Cut-Off, which we weren't comfortable with so we didn't go that route.

Did we fail to think of another method?

Regards,

Prop Job

[kijangnim]

Greetings,
Be carefull, long time ago on a BE100A, I had both engines going to feather just after rotation :eek: , low pitch stop test problem, as no recorder cause aircraft weight, I could not prove anything :{.
Although it is a different King Air, my advice is be carefull....:E

[ahramin]

I am not positive that this applies to the 1900 but sometimes Beech autofeather systems do not test properly on the ground because the torque doesn't get down to 200 pounds at idle. If this is the case lift the power lever into the beta range to get the torque down below the 200 pounds.

As for autofeather test in flight it is very simple: Make sure you are in VMC, put the power levers high enough to arm the autofeather, and put the condition lever to cutoff. Do not use the firewall shutoff valve as this can damage the fuel pump. Engine should feather very rapidly.

If you do not feel comfortable shutting down one engine for a short period then by all means DO NOT do this. But please speak to your training department about this as you really should not be flying people around in this case.

If the right seat pilot has air gyros then the aircraft must be flown from the right seat during relight as the checklist calls for avionics master off. If only the standby gyro is available it is usually better to have the right seat pilot fly anyway.

[Cardinal]

That absolutely applies to the 1900. If you can't get the torque low enough at idle, sneak into ground fine and you'll get a prompt feather. Power lever cable rigging might be something to think about, but not critical.

We have a line in our manuals that specifically addresses this issue.

[V1... Ooops]

PropJob:

When you say that the autofeather system was 'slow to feather', do you mean it was slow initiating the feather, but once it began the propeller feathered at the normal rate of speed, or do you mean that the propeller began feathering at the correct time but was slow to move from normal blade angle to the feather position?

The causal factor would be different for the two conditions.

[kijangnim]

Greetings,
The incident happened in 1983 .. long time ago :*, anyway for the record dont rely too much on the autofeather ( the system was design to help rich farmers cop with engine failures when taking off form their farms :})

[Prop Job]

Thank you to everybody for the replies,

ahramin
We did contemplate cutting the engine with the Fuel Cut-Off like you discribed. The only reason we didn't do it is because the aircraft is fitted with a Telematics as well as an ADAS system and we thought it might trigger all sorts of bells and whistles at home base. Thought we better advise them before we attempt it, just in case.

V1... Ooops
When we pulled back the power lever during the test it took a long time for the propeller to start the feathering process, but once started it seemed normal. In other words the first condition you described.

Thanks again,

Prop Job

[Gooneyone]

You mean your company allows you to test a possibly malfunctioning autofeather system in flight??
And if they don't, you meant to try it??
Folks, let's get real. It ain't worth it. Write it up and let the engineers fix it. I don't think any of us are test pilots.:ugh::ugh::ugh:

[Trogdor]

I've never tried this, but theoretically this may work:

In cruise, with the power set sufficiently, you could hold the autofeather switch in TEST. The system should arm, and then you would simply perform the test as you would on the ground. I would be extremely cautious if you had to lift the power lever though to get the torque below 350 due to the probability that the prop blades would go into ground fine, which would cause obvious problems.

In the end, I agree with the previous poster, probably best to write it up and let maintenance figure it out.

[Scruggs007]

Same thing happened to me today. Lifting the power levers over the gate did the trick. Discussed with the crew and seems to be a rigging issue.

[ahramin]

Let me be very clear:

1. Lifting the power levers into beta is ONLY for the autofeather test on the ground when the torque is too high at idle. If the power levers are lifted in flight you are gambling with your life and at least one pilot has killed himself doing this.

2. The test function on the autofeather is ONLY for ground use. The only way to test autofeather in the air is to shut down an engine.

Prop Job, I would be very interested to learn more about this Telematics system. Any information / links? Good call on not freaking out the flight followers. We have a very poor install on our satellite tracking system which has an emergency switch that is all too often hit while getting into the seat. The emergency alert then flashes for the next 24 hours on the flight follower's screen.

[Prop Job]

Hi ahramin,

I am not exactly sure how the systems operate, but we've got two systems installed.

1. Telematics: Telematics (http://www.telematics.co.za/)
2. ADAS Trend Monitoring: Altair Avionics Ground Station (http://www.altairavionics.com/altairhome/products/ADASPlus.cfm)

Operationally, our office is able to track our altitude, speed and position using the Telematics system and an add-on to Google Earth. They are able to log on to Google Earth and get an overall picture of our whole fleet's positions. The system also has an emergency switch, but we've never had problems with accidental activation.

The engineers usually download the trend information from the ADAS system once per week. The system is programmed with all our limitations and will warn us in th cockpit if there has been an exceedance. As far as I am aware the ADAS system monitors N1, N2, ITT, fuel flow and bleed information every few minutes during flight.

[rigpiggy]

Not an approved procedure, but in flight pull one engine to idle, put autofx to test this bypasses the column switch prop should immediately start to feather. if it does not, DO NOT LIFT THE POWER LEVERS. GROUND THE A/C TILL FURTHER WORK IS DONE I repeat DO NOT LIFT THE POWER LEVERS. GROUND THE A/C TILL FURTHER WORK IS DONE. Oh BTW AFX is a NoGo item on the 1900. Around this time of year with lower temps you will find that doing the AFX test on the ground will require you sneaking the Power lever into Beta

[Cardinal]

I concur with piggy, the autofeather test is quite functional while airborne.

[Desert Budgie]

When you do the autofeather check, make sure you have the condition levers in low idle. Ive never had to pull the levers momentarilly into beta in order to get a successful autofeather test.

Pretty common to be driving around the airport in high idle if your running the aircon. Make sure you pull the condition levers back to low idle when you do the test and it should work. If you close the left or right power lever and you can't get below 250ft/lbs of torque when in low idle, I'd say there is something seriously wrong with your rigging!

My 2 cents

Cheers

DB :ok:

[rigpiggy]

Yer forgetting the thicker air density up in the frozen North

[Scruggs007]

Interesting thread. Slightly off topic but B190 related, what is the maximum amount of time you should leave the engines running whilst feathered on the ground to avoid causing heat damage to the windows? Had to do a quick unload today in the B1900 and left the starboard engine running in feather. Had a good breeze on the nose so figured the exhaust gas would get dispersed fairly quickly.

[Desert Budgie]

Engine Exhaust Heating of Cabin Windows and Airframe

1. Do not operate the engines with the propellers feathered except during external power starts and propeller feather checks, except that the propellers may be operated in feather at temperatures not to exceed +5*C for a maximum of 3 minutes for purposes of airframe deicing.

That is straight out of my company ops manual. From personal experience, to be used as a guideline along with a bit of common sense.

Cheers

DB :ok: