Jeff,
I flew my Mooney for 5,900 hours most of it on fine wire plugs with almost no problems. They have had some changes in the management and the process for these plugs. I bought fine wires for my LIV and the L360 and I have had many problems with them the first plug failed in less than 50 hours and since then I have had frequent failures including some irritating potential failures where it fails in a irregular fashion where it just intermittently misfires. We spend time trying to find the bothersome plug. On the testing machine (Champion) sometimes we could find the bad plug and sometimes not. The misfiring was intermittent enough that it either did not show up on the Ultimate EGT or just barely.
I sent the first plug to fail (it failed completely in MEM) back to Champion in June and finally got a replacement plug in November. The time lag was irritating too. I have finally had enough and am replacing them with Massive plugs. G&N said that they have had similar problems, I wanted to replace the plugs in the C421 with fine wire and they said that the reliability was better with the massive. Quality control seems to be poor compared to the massive plugs.
On another issue about descents, ATC normally plans for a flight to descend along a 3 degree flight path. We used that for many successful years at the airlines including the FMS equipped aircraft. This gives a 300 foot per mile descent. If you are 100 miles out your altitude should be 30000 above the surface and your rate of descent would 1/2 of your ground speed in knots. Ex 250 kts would make a descent rate of 1250 ft/minute. This is a rule of thumb but works very well. Plus it is close to optimum efficiency, needless to say if you use fuel to gain altitude and airspeed, using the speed brakes to slow wastes efficiency. An old pilot that I flew with said to ATC 'the speed brakes are for my mistakes not for yours.' Using them without need is wasting the fuel you used to gain altitude and/or speed. Plan your flight.
Jack Webb
L360, LIV
BSAE
From: "Jeffrey Liegner, MD" <liegner@embarqmail.com>
To: lml@lancaironline.net
Sent: Saturday, November 15, 2008 7:36:20 AM
Subject: [LML] Fine Wire Iridium aviation spark plugs in TSIO550?
Has anyone used the Fine Wire Iridium aviation spark plugs (RHB32S) in their TSIO550?
Comments?
Jeff Liegner
LIVP
Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200=F higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, Champion has favored platinum for their long life or performance automotive spark plugs due to its high melting point, also the technology did not exist to machine and bond iridium on a spark plug electrode (at least in a cost effective manner). Champion spark plugs
has made iridium industrial and aviation plugs since the 1960's, But advances in late model engine design have necessitated the need for iridium in automotive applications. The strength, hardness and high melting point of iridium allow Champion to manufacture their iridium ultra-fine wire center electrode to 0.7mm. One of the finest firing points in the industry! (Thus far there has been no problems reported regarding use of iridium plugs with nitrous oxide.)