Cessna 501 or 551 Single pilot versions. What is involved?

And remember things like WAAS, LPV, RVSM and the like can be horrendously expensive on these old jets. That said, people have done g1000 upgrades and have a CJ for example which has glass and is essentially between a CJ1 and a CJ1+ for less than a million USD.

Mooney_Driver wrote:

So why is it near impossible to do a WAAS upgrade and reach RNP1 and LPV approval, if it is not quite a piece of cake but still manageable for a SEP with exactly the same hardware?

You still need an STC for the upgrade. And developing one for a Part 25 certified jet is not the same as doing one for a PA-28. Even for a Part 23 Mustang, the G1000 software and ADS-B upgrade that is done for almost nothing in a Cirrus (mostly the transponder charge from Garmin) took Cessna 5 years and costs $16,000.

A pilot I know very well flew and managed a Citation 650 (Citation III) for a business owner which was on the Cayman (VP) register. Cayman was very close to FAA standards initially but is now rather similar to EASA part NCC. In order to comply with some requirements (don’t remember which, maybe TCAS 7 and/or EGPWS and/or RNP) they needed to install a newer FMS. The hardware was installed and wired in three days, but the aircraft was grounded for 6 months until the paperwork was sorted out between Cessna, the FAA and the Cayman authorities. The cost of certification was twice as high as the cost of the FMS hardware. The owner sold the aircraft the day it was certified and bought himself a German registered Citation Excel instead…

Basically when the JT-15D engines come up to TBO, you’re going to spend north of $800K to do both. Add to this the fact they burn about 50% more fuel than more modern FJ44’s or PW’s and the very high possibility it’s not RSVM certified, which means you’re stuck at FL280 burning probably close to 180gal/hr (guess). Now of course, you can always factor this into the much lower price and still get value out of it. Get in on one for $200-300K with 1000hrs left, fly that and sell it for scrap or parts at the end and recoup maybe $80K. Or, you could buy used engines when the time comes to overhaul and hang those on and keep on trucking.

If you want jet, and can live with the fact that it’s value will decrease considerably, it can still be a “good” deal.

Basically when the JT-15D engines come up to TBO, you’re going to spend north of $800K to do both…

Maybe if you take them to some backyard tinkerer. At Pratt&Whitney or one of their contract companies is’s going to be more like that amount per side. But at least you can fly again after six weeks. And not, maybe, after six months or six years (if you know what I mean…).

So yesterday I had another of those minor glitches on a Citation Bravo (at least 20 years younger than the ones which are the topic of this thread): The battery switch performed strangely – luckily once again on the last sector of the day which brought us home

It has three positions:
ON (top) which powers the main buses from the battery and/or connects it to the generators
OFF (middle) which disconnects the battery from all buses except from the hot battery bus
EMER (bottom) which connects the battery to the emergency bus that powers essential items like COM1, NAV1, cockpit floodlights and a few more

Switching the battery off as last item of the shutdown checklist resulted in the emergency bus still being powered, which could be seen because the two radios remained illuminated. Toggling the switch a couple of times finally removed all power. But this malfunction needed to be reported to maintenance who immediately grounded the plane. A fault like that is not to be taken easily because there is no backup to the battery switch. If it fails in flight the aircraft may be left completely without electricity which means that absolutely nothing will work. No flaps no hydraulics (which uses electrical valves), no pneumatics (pressurisation, de-icing – again operated by electrical valves). No wheel brakes either apart from the nitrogen powered emergency brake. The same nitrogen will be needed for the emergency extension of the gear.

The switch is on order, installation will take one technician a full day (such is the way that Citations are made – Learjets are even worse in that respect I am told). Three days ground time and a cost of maybe 1500 Euros (the switch alone costs more than 500). If one bought a 150.000Euro C501SP then this little fault would be one percent of the purchase price. And a 1976 Citation will develop a similar problem once a week… and not always at home base which will at least double the maintenance cost.

I was sent a pic of a little LVDT flap position transducer for a Lear and it was something like $20k.

So probably the way to run these cheap is to have a spare one can steal bits from it.

what_next wrote:

Switching the battery off as last item of the shutdown checklist resulted in the emergency bus still being powered, which could be seen because the two radios remained illuminated. Toggling the switch a couple of times finally removed all power. But this malfunction needed to be reported to maintenance who immediately grounded the plane. A fault like that is not to be taken easily because there is no backup to the battery switch. If it fails in flight the aircraft may be left completely without electricity which means that absolutely nothing will work. No flaps no hydraulics (which uses electrical valves), no pneumatics (pressurisation, de-icing – again operated by electrical valves). No wheel brakes either apart from the nitrogen powered emergency brake. The same nitrogen will be needed for the emergency extension of the gear.

Interesting point of failure. We have the same switch. As you say with a failed switch you could have all power go off in flight. We would have engine anti-ice but as you say need the two N2 bottles for gear and brakes. Fadec would continue to work but only standby instruments and the only nav instrument would be the wet compass.