Archive for December, 2010

First FAST taxi

Well, got the aircraft out of the hangar this morning for some high-speed taxi tests.  It was great that everything went as it should, almost 100%. The bird performed flawlessly.

Pulling it out for first high-speed taxi

Only issue was a right-side oxygen regulator that got stuck in the closed position. The mechanic/engineer in the right seat couldn’t use it and did not know how to turn off the hot mic.  So I had a lot of background noise with his mask off. And the airplane is loud.

One thing I am going to start doing is taxiing on one engine.  Two-engine taxi runs eats the brakes, consumes way too much fuel, and doesn’t do a thing except burn dollars.  The mechanic doesn’t like that, but he’s used to much bigger prop driven planes.  I don’t need differential power for steering or speed.  Hell, it’s too fast as it is now.

No radio issues. All OK.  First taxi was moderate to 50 knots to check steering and brakes.  Then back around again for another. This time I held the brakes until 60% and let ‘er go. Power up to 80%. Even with that little bit she took off like a shot.  Up to 70 knots.  All OK.  Don’t really need to use power steering above 60 knots so I have to learn to turn it off as I accelerate.

Even with power at idle it does not like to slow down.  So thrust attenuators are a must.  Next power runs I will shut one engine down on runway as it slows.  Brakes are adequate, but certainly not going to write home about them. Just have to get used to the quirks of the bird until it is natural to the touch. Right now I am “thinking” about everything, and that’s not the way it is supposed to be done.

So, we put the plane away after 50 minutes of ground work, radio checks, accellerations and stops, steering, engine instrument checks, system checks, etc.  All perfect. And I used a lot of fuel just doing the taxi runs (2). Figure about 125 gallons.  OUCH!  It’s a hell of a lot more efficient in the air.

Perfect testing.

Sweet Engine Sounds

With the starter back in, it was time to turn them over and burn some fuel. Starts were prefect and cool.  All gauges readings perfect. No problems. So maybe time to drive it around.  Boy, is that bird LOUD!  Will have to be careful when operating or else I am going to annoy some neighbors.  You can feel the bird just trying to break loose, even at idle.  (By the way, it is best to taxi on one engine–too much power).

When we pulled the bird out of the hangar and lit her up, we had gathered a small crowd of gawkers.  They came out of nowhere with cameras, still and video. 

Left brake was “squishy”, if there is such a word. Decided to investigate before driving too far. Found a small hydraulic leak in the copilot’s master cylinder swivel inside cockpit (a common problem with these swivels).  Took some time this weekend and pulled it out and repaired, then re-bled the brakes, filled master cylinders. Now looks and feels ok.    Seeing as the bird was on jacks we did gear retractions, checked the gear horn, cycled all systems, etc.  Perfect.  Was dead tired after two days of tool thrashing, so we quit yesterday with almost half a day remaining.

Will do high speed taxi next. Will try to do this week, rather than waiting for weekend. Holidays coming up so time is squeezed for all of us.  With family coming in, it would be great to do some taxi tests with someone who can write down engine indications, call out ground-personnel checklist, etc. One runway is closed at KTMB which may be a good thing. I may be able to use it for taxi only without bothering local traffic.

If for some reason I do not post during holiday, may I extend my best wishes to you that are just “plane crazy”. May you have tailwinds and other good fortunes, all.

Charlie (Dragon 921)

Starter In, Intercom fixed

Rebuilt starter went in (again!!) today. All locked up. And, took apart the intercom. The radio guru was able to rebuild the transmission amplifier. It works perfectly. 

It was interesting–the radio issue.  The microphone/earphone cable, (4-wire), is unshielded.  So it puts out a lot of RF. It jumps right into the transmitter with a loud squeal.  The amplifier fixed it. But I would have thought a shielded cable would work almost as well. 

Next time I’ll replace with a new type of shielded cable to eliminate any feedback. 

I was able to change the squeal by simply running my hand up and down the cable.  Learning new stuff all the time.

The Classic Jet Aircraft Association has an upcoming annual convention in March at Nellis AFB, Las Vegas Nevada. March 17-20. My bird won’t be there but it is a good group. Hope to see you all there.