Learjet23 From , joined Dec 1969, posts, RR: Posted (5 years 8 months 1 week 3 days 16 hours ago) and read 7529 times:
As I understand it, it was the early Learjet engine and is now outlawed in the states because it is so earsplitting loud. Is this the reason so many old biz jets have been junked? How much would it cost to somehow make this thing quite down? Why was it Ok years ago but so forbidden now? I saw a learjet on ebay for only $200.000 and the remarks were that it had these motors and they would need to be replaced in order to fly the plane again. I am not a well read avation person, but this really interests me.
KBFIspotter From United States of America, joined May 2005, 729 posts, RR: 1 Reply 1, posted (5 years 8 months 1 week 3 days 15 hours ago) and read 7534 times:
It was the GE CJ610 that powered the Lear 23, along with the lear 24, 25, 28, and 29, as well as the Hansa Jet, and the Aero Commander 1121. This engine is still very much alive in the US, as it is based on the J-85, and engine that is used in the T-38, T-37, CT-114, and Scaled Composites White Knight.
I am interested in knowing where you heard it is outlawed...
Tb727 From United States of America, joined Jun 2005, 1462 posts, RR: 4 Reply 2, posted (5 years 8 months 1 week 3 days 15 hours ago) and read 7528 times:
The engine you are talking about is GE's CJ-610. The CJ-610-4's were the original engine on the 23, most 20-series Lears today are powered by CJ-610-6's which put out 2950#'s of thrust and easily exceed 100 decibels on takeoff and the CJ-610-8A are the best ones, rated up to FL510 but just as loud. I think the company record for a noise violation is up over 110 decibels.
Nope, it isn't outlawed in the US, they are in Europe for the most part. I flew a Lear 25 today for the first time in about a year and as I pushed the throttles up on takeoff I remembered just how loud they are. There are a few airports that ban them at night in the US but you are good to go in the US with them. It is the CJ-610 engine that also powered some other bizjets. 20-series are considered Stage 2 unless you have the "fast wing" on them, then they are considered Stage 1. 30 series have TFE-731 motors on them and are Stage 3 although you can still set off noise sensors.
A side note, the 610 was originally designed as the engine to power long range missiles for a one time use. They are still going strong 45 years later still powering 20-series Learjets. It's a nearly bullet-proof engine that loves to suck down fuel but is more reliable than anything else out there.
KELPkid From United States of America, joined Nov 2005, 6164 posts, RR: 4 Reply 3, posted (5 years 8 months 1 week 3 days 15 hours ago) and read 7524 times:
Quoting Learjet23 (Thread starter): As I understand it, it was the early Learjet engine and is now outlawed in the states because it is so earsplitting loud.
Very loud-yes. Outlawed, no. Marshalling an aircraft powered by the CJ-610 in my lineboy days definitely required the ear protectors...those and the Mitsubishi MU-2's (not sure which engine the MU-2's used).
Learjet23 From , joined Dec 1969, posts, RR: Reply 6, posted (5 years 8 months 1 week 3 days 3 hours ago) and read 7399 times:
Someone said the cost of putting brand new jets on and old learjet could cost one million dollars alone, exceeding the putright perchase price of a used lear without these engines... $1.000.000.00 for these tiny tubes? How much is the CJ-6 engine in good shape worth that came with say a lear 23?
KBFIspotter From United States of America, joined May 2005, 729 posts, RR: 1 Reply 7, posted (5 years 8 months 1 week 3 days 1 hour ago) and read 7355 times:
Quoting Learjet23 (Reply 6): How much is the CJ-6 engine in good shape worth that came with say a lear 23?
Here, this should give you a rough idea on the cost of a CJ610... www.whiteindustries.com/Turbojet.htm While not a true representation of the cost of a overhauled engine, it is still good for ballparking the price.