CJ technical questions
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CJ technical questions
I'm trying to collect tech questions for the CJ series (all of them) and assemble them into a database to enhance our annual refresher training. At the moment I use questions that I make up or come up during line training but I would really like some new ideas. If you have any that you either want answered or already have the answers but consider an important or interesting issue please could you post them on here. I will make the resulting database available to anyone that wants it. My intention is to build a web app that generates random questions and logs the score so perhaps that would be of interest. I have been trying for some time to get a 6 monthly meeting of CJ minds from across the operators to collect and discuss tech and operational issues - if anyone is interested please get in touch.
There won't be any charges for any of the above by the way just in case anyone was wondering.
All the best
Tom
There won't be any charges for any of the above by the way just in case anyone was wondering.
All the best
Tom
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Copyright may be an issue...
If you have ever done a Flight Safety course on the CJ then you have (in your folder and on the CD) their entire question bank. I would not suggest straight plagiarism, but it's a heck of a good pointer for where to start.
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Here's a good one that likely would trick many pilots with previous CE500 experience:
What setting does Cessna recommend flaps be retracted to on a CE525-series aircraft after landing?
What setting does Cessna recommend flaps be retracted to on a CE525-series aircraft after landing?
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Flight safety questions already looked at.
Flaps is interesting. They are on cables and in the up position they remain under a lot of tension because the flaps are pulled against the stops. When parked it is a good idea to leave the flaps at take off and approach because the cables stretch if you leave them in the up position. Nice question. Thanks.
My understanding of the pressurisation controller is that although there are small differences in the wording in the Cessna manual, the pressurisatrion controller itself is essentially the same unit for all 525's. There is a slight difference because the max diff is different for the 1's and 2's. So what I was told when I was at Wichita was that for all models of 525/A/B you need to set destination pressure altitude. The original 525 had instructions to set 200 feet above the destination pressure altitude and that instruction was supposed to allow for inaccuracies in the controller. However, I can't see how that matters all that much as the cabin equalises with the ambient pressure on touchdown as the squat logic opens the outflow valves anyway. So I think the answer is set destination pressure altitude (not elevation as the C525A manual suggests) and if you feel like adding 200 feet, that won't hurt. Another good question as it brings up other technical points. Thanks Jon
I will check my instinctive responses with Cessna to make sure and then they will go in the databank.
Keep them coming!
Tom
Flaps is interesting. They are on cables and in the up position they remain under a lot of tension because the flaps are pulled against the stops. When parked it is a good idea to leave the flaps at take off and approach because the cables stretch if you leave them in the up position. Nice question. Thanks.
My understanding of the pressurisation controller is that although there are small differences in the wording in the Cessna manual, the pressurisatrion controller itself is essentially the same unit for all 525's. There is a slight difference because the max diff is different for the 1's and 2's. So what I was told when I was at Wichita was that for all models of 525/A/B you need to set destination pressure altitude. The original 525 had instructions to set 200 feet above the destination pressure altitude and that instruction was supposed to allow for inaccuracies in the controller. However, I can't see how that matters all that much as the cabin equalises with the ambient pressure on touchdown as the squat logic opens the outflow valves anyway. So I think the answer is set destination pressure altitude (not elevation as the C525A manual suggests) and if you feel like adding 200 feet, that won't hurt. Another good question as it brings up other technical points. Thanks Jon
I will check my instinctive responses with Cessna to make sure and then they will go in the databank.
Keep them coming!
Tom
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From the most recent Direct Approach:
Of course this hydraulic flap operation is different than the electric flaps on many legacy 500-series Citations, where almost everybody leaves the flaps in TO/APCH for parking due to "cable stretch".
Team CJ has received reports of flaps extending or drooping on CJ3 airplanes that have been parked for long periods. The condition is normal and
may occur if flaps are left in a position other than fully retracted.
CJ3 flaps are operated hydraulically, and mechanical locks inside the flap actuators
positively lock the flaps in the fully retracted position. However, trapped
hydraulic fluid holds the flaps in the 15° and 35° positions.
Each of the hydraulic components in the flap control system has a manufacturer
acceptable internal leak rate. Due to the leak rate, the flaps may extend
or droop down over time. Several operators have reported the flaps have been
found fully extended after one to two weeks of downtime.
To prevent flap drooping while the airplane is parked, operators should set
the flaps at the fully retracted position. At that setting, the mechanical locks
within the actuators prevent the flaps from extending.
Questions, please contact:
Team CJ
1-800-835-4090
[email protected]
may occur if flaps are left in a position other than fully retracted.
CJ3 flaps are operated hydraulically, and mechanical locks inside the flap actuators
positively lock the flaps in the fully retracted position. However, trapped
hydraulic fluid holds the flaps in the 15° and 35° positions.
Each of the hydraulic components in the flap control system has a manufacturer
acceptable internal leak rate. Due to the leak rate, the flaps may extend
or droop down over time. Several operators have reported the flaps have been
found fully extended after one to two weeks of downtime.
To prevent flap drooping while the airplane is parked, operators should set
the flaps at the fully retracted position. At that setting, the mechanical locks
within the actuators prevent the flaps from extending.
Questions, please contact:
Team CJ
1-800-835-4090
[email protected]
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boilerup you're a genius. This is exactly why we need this. I was told all that junk by an engineer at Wichita so now I will have a proper look at what you've sent me and make sure the answer is correct.
perfect
Tom
perfect
Tom
Jon wrote:
"On the Classic, why is it necessary to put the ignitions on before descent from high altitude?"
i believe this to be in order to minimise the risk of an inadvertent flame out when descending from altitude (above FL350, power reduced below 90% N2) and until the engines have re-stabilised at the new thrust setting ??
"On the Classic, why is it necessary to put the ignitions on before descent from high altitude?"
i believe this to be in order to minimise the risk of an inadvertent flame out when descending from altitude (above FL350, power reduced below 90% N2) and until the engines have re-stabilised at the new thrust setting ??
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ignitions from high alt....
dunno,
am guessing that the air is thin and cold and the sudden reduction in combustion chamber temperature can cause flame out. Will have a read. Do you know the answer? cos this is supposed to be an information sharing suggestion not an "I can pee higher than you" competition. And I have a head start - I am quite tall
dunno,
am guessing that the air is thin and cold and the sudden reduction in combustion chamber temperature can cause flame out. Will have a read. Do you know the answer? cos this is supposed to be an information sharing suggestion not an "I can pee higher than you" competition. And I have a head start - I am quite tall
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Ok..
Flaps on shutdown, a definitive answer.
I happen to be picking an aircraft up today from a major service centre and have just had a conference call with America and with two engineers sat in at my end.
And the reason that Cessna say Flaps 15 on the shutdown checks is...
because that give the correct hydraulic fluid level indication
otherwise it doesn't matter at all. The company I am at regularly leave theirs in land so that they can clean them properly.
so there you go..
Flaps on shutdown, a definitive answer.
I happen to be picking an aircraft up today from a major service centre and have just had a conference call with America and with two engineers sat in at my end.
And the reason that Cessna say Flaps 15 on the shutdown checks is...
because that give the correct hydraulic fluid level indication
otherwise it doesn't matter at all. The company I am at regularly leave theirs in land so that they can clean them properly.
so there you go..
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Ignitions:
I don't know the answer. I think Ben C. once told me that there was an instance of a double-engine flame-out on a Williams engine, but maybe he didn't tell me, didn't tell me that, or someone told me but it wasn't him. I dunno.
I also dunno anyone that actually does it, but it's in the AFM.
I don't know the answer. I think Ben C. once told me that there was an instance of a double-engine flame-out on a Williams engine, but maybe he didn't tell me, didn't tell me that, or someone told me but it wasn't him. I dunno.
I also dunno anyone that actually does it, but it's in the AFM.
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Jon,
You do know at least one person that always used the ignitions on when descending from high altitude in the classic as that was how I was taught to do it in the Sim in Wichita and also during my line training (think you may be right about the BC source too as that's who did some of my line training).
Hope you're well mate.
You do know at least one person that always used the ignitions on when descending from high altitude in the classic as that was how I was taught to do it in the Sim in Wichita and also during my line training (think you may be right about the BC source too as that's who did some of my line training).
Hope you're well mate.
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you ALWAYS leave the flaps up at shut down so when you have loaded pax and the flaps wont go to 15 you take off anyway using the moutrie flapless method and get the job done !!
no brainer heh !!!!
now ask us something difficult
no brainer heh !!!!
now ask us something difficult