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citation engine questions

Old 25th Oct 2010, 20:34
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citation engine questions

Hi to all, I fly a citation cj1+, we consequently alternate the engines for starting L - R - L - R unless wind conditions dictate, which engine to start first.
Do you guys do this alternate starting too or is this some kind of obsolete ritual?

BTW, one technician recently told me to turn the fans once a week if no flight takes place. Never heard about that before, opinions are welcome!

Cheers

Cecco
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Old 25th Oct 2010, 22:47
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Hi Cecco,

I'm not sure that alternate starting makes a lot of difference. On the other hand, it probably doesn't do any harm either.

As far as regularly turning the engine is concerned; this is definitely a good idea as corrosion will build up in between the stator case and the high pressure compressor blades after shut-down. If not 'polished off' by turning the rotor every 4 weeks or so, this corrosion can build to such an extent that it will eventually seize up the whole engine.

Remember, these engines were designed to be used once only - powering a cruise missile!
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Old 26th Oct 2010, 00:40
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Remember, these engines were designed to be used once only - powering a cruise missile!
Did they ever get certfied under FAR/Jar rules to last more than a single flight?

Perhaps there is something in the limitation section to say they should be hand-turned between flights ?
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Old 26th Oct 2010, 11:48
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Cecco - Yes, excellent....you also need to sit in all the seats, run them forward and back, side to side, and move all the seats around to make sure they stay 'movable'

Look and move the Wemac air vents...left, right, forward, and back for all overheads.

Make sure when you go flying only run 1 EFIS tube at a time, to save other tube life

Once a week, get in the plane, and wiggle the control, move the flaps....

Great stuff, get right on it...
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Old 26th Oct 2010, 11:52
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I don't know about the CJ-1 but years ago a Turbo Commander that I was involved in maintaining had both engines HSI (hot section inspection) at the same time. No.1 had no damage but No.2 had to have a lot of rework.
This operator always started No.2 first and nearly always used batteries.
So the higher ITT due to battery start as opposed to Generator assist start almost certainly caused the damage.
If you are doing battery starts and alternating the engines then you will even out the damage to both engines, but wether this will cost less in the long run I don't know.

Hope this helps.
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Old 26th Oct 2010, 13:02
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@johns7022

you are just stupid, why donīt you just shut up if you donīt have anything to contribute!

No regards,
Cecco
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Old 26th Oct 2010, 20:09
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Cecco - some other things to consdier..

Once in a while you should put the plane on jacks to test whether the gear will fall down..

When on the jacks...wiggle the controls, with your headset on, so you can simulate flying, that way your ready.....

Oh and by all means, crawl into the engine inlet to spin the vanes, as fast as you can, that way you will know if they will fall off when running the engines...
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Old 26th Oct 2010, 21:53
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Hi again Cecco,

Just wanted to confirm that I was told about the engine corrosion problem by a couple of experienced, well-regarded mechanics who are both qualified on the CJ series and the Williams engine.

Coincidentally, at the time they were telling me this, a CJ had been left on the ground for about 4-6 weeks in a coastal location. The engines were started supposedly without checking for free rotation and apparently a hot start resulted.

So I think this is a serious problem which needs to be more widely known. Anyone from Williams care to comment?
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Old 26th Oct 2010, 22:43
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Hi Eckhard, thanks for your post! If no Williams people are in this forum, I am sure that our friend Johns7022 will give us the honour to post another professional comment...
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Old 26th Oct 2010, 22:55
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Cecco, I alternate the engines mainly to even the wear on the generators. The first starting starter/generator gets a real beating...
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