Peter wrote:
I am amazed there is a single switch. The chances of a dual engine failure must be so tiny that this sort of thing ought to have been done differently, no?
Nothing realy to do with engine failure more either a dual gen failure and the switch not working to go to EMER or as what_next mentioned just the switch failing taking out electrics with perfectly good generators.
The fact that part 25 aircraft have the same arrangement means they must have assessed the risk of switch failure as very low.
Peter wrote:
Flapless, gear down, it may even do 3 degrees.
Maybe. The problem is that the best speed for emergency gear extension is 170…180KT. Once slowed down to that speed, it will continue to slow down even further on it’s own. Maybe that’s different on the newer CJs. To fly a three degree 8NM ILS with idle power all the way (on empty legs I try that sometimes) it is best to start at around 220KT at the descent point in clean configuration. Set first stage of flaps at around 5NM, gear down at 2NM and final flaps over the lights. Without residual power from the idling engines, one probably has to wait a mile longer with flaps and gear.
JasonC wrote:
The fact that part 25 aircraft have the same arrangement means they must have assessed the risk of switch failure as very low.
Not being able to power the buses is only one consequence of a failed battery switch. In flight, the buses are powered mainly by the generators. But even worse would be a situation where electricity needs to be removed and a failed battery switch prevents that. E.g. in case of an electrical fire or smoke or a battery overtemperature. The latter even has it’s own red warning light and requires immediate action. Should the battery blow up or catch fire it will take out every vital system of the aircraft (including elevator cables) in a very short time because it’s mounted in a very central position. Our failed battery switch would have prevented the isolation of an overheating battery. In that case there would be no other survivable option than to make an immediate emergency descent and put the airplane on the ground anywhere. Don’t even try to go for an airfield.
what_next wrote:
Not being able to power the buses is only one consequence of a failed battery switch. In flight, the buses are powered mainly by the generators. But even worse would be a situation where electricity needs to be removed and a failed battery switch prevents that. E.g. in case of an electrical fire or smoke or a battery overtemperature. The latter even has it’s own red warning light and requires immediate action. Should the battery blow up or catch fire it will take out every vital system of the aircraft (including elevator cables) in a very short time because it’s mounted in a very central position. Our failed battery switch would have prevented the isolation of an overheating battery.
Do you have a separate BATT DISCONNECT switch? We have BATT DISCONNECT and INTERIOR DISCONNECT switches on pilot’s side panel.
JasonC wrote:
Do you have a separate BATT DISCONNECT switch? We have BATT DISCONNECT and INTERIOR DISCONNECT switches on pilot’s side panel.
Our 560 Encore has both switches installed as an option. The two 550 Bravos on our fleet don’t have them. They had probably not yet been “invented” then…
Peter wrote:
Flapless, gear down, it may even do 3 degrees.
I somehow doubt, 3 degrees is 19:1 ratio. And that assumes still air, while the approach will normally be against the wind so you’d need an even better way. I think airlines have a glide ratio of about 15:1, with gear up.
The only approaches you might do that way (ILS with a handheld radio maybe? – Although I think they only do the LOC) are City EGLC, Lugano LSZA. At lugano even the DA40 will happily do the ILS with propeller windmiling.
some Citations really get supercheap. What is the catch…. high hour engines e.t.c.
https://www.planecheck.com?ent=da&id=36399
95k is really the cheapest I´ve seen. Adam, sorry did not want to tempt you….
and another one, airworthy by the looks of it for the price of a old cirrus…
The catch is probably the „no free lunch“ and „you get what you pay for“ rule. Sure, small variations in price are legit, but a nice jet is somewhere in the 1-3 mil range.
So, a 95k airplane will require another few hundred k to become the equivalent of those other „lower priced“ jets the market has on offer.
Maybe in some shady jurisdiction somewhere you can fly a run down jet for the price of fuel and never fix anything :)
The 95K Citation 1 has run out engines. Budget $500k each for overhaul.
So its over a million really. For that money there are more modern options.
There’s a guy over at the BeechTalk forum who does nothing but buy these old SP’s, fly them and sell them. And I gotta say, if you can live with the fuel burn of the JT15D’s, they sure offer a lot of bang for the buck. Not only that, they’re simple machines, well built and don’t break much. “Stupid simple to work on”, as he says. And there are literally tons of parts available, cheaply. Engines too. Run them over TBO, change them for one with some more time when the time’s up. But you’re looking at 120gal/hr in fuel burn and 350kts, 1000nm range.
I’d honestly go for one myself, if I wasn’t tied up financially.
He’s probably operating them under Part 91, not on a maintenance programme, plus being based in the US makes it easier to find people who know them, etc. You have a much better “ecosystem” out there for “projects”.
