In general, I would agree with the "Many" others and recommend an 840 over 690. For a variety of reasons. Regardless of the model, find an airplane that has been well maintained. Similar to your 421, you don't want to be playing catch up on maintenance issues.

Pretty much what the Citations do.

We have a manual flow control valve where we can shut the flow off. We also have a high / low switch. The bleed flow doesn't stop when on the ground or gear down, which can be useful to clear the windshield before taxi. The bleed air flow clears off precip as well, something an electrical windshield can't do quickly.
Mike C.

There are many minor differences. Here are the major upgrades from model to model that are reflected in market prices. If you don't see an upgrade listed it matches the previous version.

"Jetprop 840" was a marketing name for the 690C. The straight 690 was a big upgrade over the 680/681 series, but today isn't as desirable.

690: 4.0 PSI cabin, 384 gallons in 22 bladders, FL250 max, 46ft wing, FIKI requires a SB
690A: 5.0 psi cabin, FL310 max, FIKI standard, electric windshield
690B: Potty standard, 75 lb GW increase
690C: 425 gallons standard, 474 gallons optional, much simpler fuel bladder layout, 52 foot wing, more baggage space

They all came with 717 hp TPE331-5 engines with a 5400 hr TBO, but there were slight changes in the submodel as the line progressed.

That’s good information. I’m seeing some decent 690A/B that could probably be had in the 700k range. -10 engines are awesome but for the extra price they demand, I could live with 270kts vs 300kts. A low budget 840 would probably be in the 1.1M range. My question is, is the 840 3-400,000 more valuable then a good 690A/B?

The -10 engines cost less to operate due to being more efficient, and having better HSI/OH intervals and cheaper HSI costs. If you fly long enough, they make back the extra purchase cost and then you have a more valuable asset to sell at the end.

I would try to get a -10 engine if you can, they are worth it, and it isn't mostly about speed.

Mike C.

-5 at FL 260 this week 274 knots true.

And the nose wheel system is not gimmicky - it’s really a genius design by Ted Smith which gives the plane likely the best crosswind capability in GA. One has to understand it as it’s different, but it works great. The brakes on the fat tires are also about the most effective in the business with soft field capability as a bonus. Downside is it’s not trailing link and it will tell you when you get it wrong.

There are many minor differences. Here are the major upgrades from model to model that are reflected in market prices. If you don't see an upgrade listed it matches the previous version.

"Jetprop 840" was a marketing name for the 690C. The straight 690 was a big upgrade over the 680/681 series, but today isn't as desirable.

690: 4.0 PSI cabin, 384 gallons in 22 bladders, FL250 max, 46ft wing, FIKI requires a SB
690A: 5.0 psi cabin, FL310 max, FIKI standard, electric windshield
690B: Potty standard, 75 lb GW increase
690C: 425 gallons standard, 474 gallons optional, much simpler fuel bladder layout, 52 foot wing, more baggage space

They all came with 717 hp TPE331-5 engines with a 5400 hr TBO, but there were slight changes in the submodel as the line progressed.

There are many minor differences. Here are the major upgrades from model to model that are reflected in market prices. If you don't see an upgrade listed it matches the previous version.

"Jetprop 840" was a marketing name for the 690C. The straight 690 was a big upgrade over the 680/681 series, but today isn't as desirable.

690: 4.0 PSI cabin, 384 gallons in 22 bladders, FL250 max, 46ft wing, FIKI requires a SB
690A: 5.0 psi cabin, FL310 max, FIKI standard, electric windshield
690B: Potty standard, 75 lb GW increase
690C: 425 gallons standard, 474 gallons optional, much simpler fuel bladder layout, 52 foot wing, more baggage space

They all came with 717 hp TPE331-5 engines with a 5400 hr TBO, but there were slight changes in the submodel as the line progressed.

Bladders are great, they either leak or they don’t and generally last 20+ years. Every legacy jet seems one hard landing away from 6 fuel leaks so I’ve come to appreciate bladders. The later planes have 10-12 bladders plus wet wing.

Market has been consistent like that for about 30 years so I’d say yes normally in that range with a wide variance depending on all the usual factors. But a nice -10 690 is hard to beat for the money if it has the range for the mission. I tend to be trying to get 1,300-1,600nm out of them chasing kids and tournaments so I like the extra fuel.

I've had both bladders and wet wings. I've fixed leaks in both.

Bladders do have a mostly positive way to fix leaks, but it is costly and time consuming to replace them and mechanics often get it wrong (like wrinkles, damage while stuffing them through the access hole, or even a tiny piece of grit under them). I redid all four bladders on my Comanche myself, so I know what a chore that is. Bladders definitely weigh more.

22 is a ridiculous number of bladders, lots of opportunities for nipples to leak and other points of failure. Plus I worry about all the things bladders can do wrong that wet wings can't, like wrinkles holding water (the 182 AD for example), a wrinkle holding up a fuel float so you think you have more fuel than you do, and bladder collapse silently reducing your fuel capacity.

I had wet wings on my T210L and now my Citation V. The T210L never leaked. The Citation V leaked when I got it, but was easily fixed with replacing some inspection panels and just one area of resealing. I personally did the new panels. It hasn't leaked since and I have tested the "hard landing" tolerance of the system.

Most of the leaks in the Citation series are mechanics who mess up the inspection panels. They don't mark the panels where they go back, they don't protect them when off the airplane, and they don't use the right screws and torques putting them back on. You do the right thing, they work. My Citation wing has 10,000 hours on it, and it doesn't leak.

A weak spot for leaks is the added fuel hump on Citation I Eagle and Eagle II conversions. They seem to always leak from poor design and/or workmanship.

Overall, I'd rather have the wet wing. A good one takes little to no maintenance.

There is some jet, Dassault maybe, where a huge section of lower wing skin is the "inspection panel", held on by thousands of screws. Those planes always leak!

Yup, here is a Falcon 900EX with that huge panel removed:

What a nightmare, who designs things like that?

Mike C.

Bruce, it’s funny you posted this picture. The value on this particular 840 seems really hard to beat! I have been eyeballing this plane on controller for some time now.

A pic of the byzantine bladder fuel system of the early 690 series:

I'd guess that is 200 lbs heavier than a wet wing would be, which is less than 10 lbs per tank.

Do all bladders have fuel senders in them? Probably not, but I bet there are lot of those, too, since you have lost of dihedral to account for.

Mike C.

I've never seen a 900 leaking.

Would you take a -10 690A/B or a -5 840 given they have similar engine times, avionics, maintenance pedigree, etc if they could be had for the same price?