Thank you.

I have a no idea but there's no way I would take a non TR bird into anything like this. CJs are cool but the legacy birds do a lot of things a CJ cannot at 1/9th the cost.

If you ever wondered how I make all these Citations, I put two in the hangar together for a night and they usually get amorous. It just takes me a few months to nurture and grow them into adults.

Keep the posts coming Michael - great looking paint and performance - maybe some day.

Till then will keep flying the Duke - but will be looking to pick up some Turbine time and keep reading your posts.

On a light jet they’re not as useful as you’d think. With a ref speed around 100 and a touchdown speed around ten knots below that you’re already pretty slow. From weight on wheels if you’re quick with the spoiler switch the TRs can be deployed in about five seconds or so. On a short field you’re already on the brakes and you need to have the thrust back to idle at 80 kts. The result is that there is maybe enough time to get the engines to max reverse before you have to shove the handles back down. That doesn’t make for a big difference in stopping distance but it comes at a cost of weight, complexity, maintenance, and acquisition cost.

Perhaps surprisingly, they can be more helpful on long runways where you can leave them at idle reverse and save your brakes, but it takes a lot of brake linings to pay for a set of TRs.

Larger, heavier aircraft benefit more from reversers because their landing speeds are higher and so the reverse thrust can be used longer.

Some errors in your analysis.

The TRs come out in about 3 seconds (go time it in the first video posted on this thread). So they come out faster than you assumed.

On legacy small cabin Citations, the TRs can be reverse thrust up to 60 KIAS, not 80 KIAS, so they have more effective time than you assumed. Going from 95 knots at touchdown to 60 knots at reverse idle is removing 60% of the landing energy and at least half the landing distance. That is a lot of usefulness.

The biggest benefit of the reversers is that you can leave them out below 60 KIAS, you just are limited to idle reverse thrust. This effectively kills the residual idle thrust of the engines, which can be a few hundred pounds. You can do this all the way down to zero speed.

In my V, I can land and not use brakes at all and stop simply because my TRs kill the idle thrust. I've done this multiple times and stopped in about 4000 ft ground roll. If you do that on the later airplanes without TRs, you will end up off the runway.

As to maintenance, my TRs have bene trouble free and don't seem to be that complex to maintain. They can actually save money because they save brakes and tires. Even for taxi, I will pop TRs to not use the brakes. My brake stacks have nearly all their life left and one of them is 10 years old since last overhaul. CJ owners don't get that kind of life.

Also, TRs give you a big edge when it comes to contaminated runways. The chart in the manual give distances for that which are enabling when those conditions occur. Without TRs, the distances are enormous and would eliminate many airports.

TRs are not used in the general distance computations, so you have a built in margin when you do use them. The planes without TRs don't have that margin.

As to why TRs went away, the early CJ series didn't have FADEC so they had higher than ideal idle thrust. Cessna put on "thrust attenuators" which were just paddles the poked into the jet blast.


Later, the engines got FADEC which allowed very low idle thrust (the engines could be safely run at lower RPMs without fear of bogging down or flameouts with FADEC control). Then even the thrust attenuators went away. This was to save weight and cost but did make using contaminated runways difficult and reduced margins for pilot errors. Those jets REQUIRE braking to stop, mine doesn't.

Nearly all the Cessna jet runway overruns are CJ series (no TRs) as a result. You rarely hear of a legacy Citation with TRs running off a runway.

Mike C.

Aside from contaminated runways I find the CJ series to have excellent brakes. The brakes of the 2+, 3, 3+ are nothing short of incredible. I can routinely stop those planes quicker than my 58P Baron without much effort.

We just got an Excel and it's nice to have TR's but the landing weight is about double that of the 525s although the speeds are about the same. That said, we are electing to take our managed CJ into Mackinac Island (3500ft) over the Excel.

-Citation Jet Exchange

I was counting from WoW to full deploy for my 5 seconds. That's hand off throttles, flip up the spoilers, hands back on the paddles, pull, one, two, three... I think I was being generous.

I did forget the 60 knot speed for idle reverse, which as you rightly point out makes a big difference. The residual thrust cancellation is worth a lot too, both of them thanks to the low 60 knot stow speed.

Time the video at the start of this thread. ~3 seconds and the buckets are coming out.

Another example: https://www.youtube.com/watch?v=VtATRAQvcmM

Single pilot, your hand is already on the speedbrake switch before touchdown. You move it there after closing the throttles crossing runway threshold. At touchdown, flip the switch, move hand to throttles, pull paddles. It can happen pretty quickly.

In a crew situation, the PM/PNF handles the speedbrakes and deploys them at touchdown, thus the PF pulling the TR paddles right at touchdown. There's an interlock pin that pulls when the WoW switch activates to prevent premature activation.

I've seen videos where the pilot anticipates the touchdown and the speedbrakes are already coming out before the wheels touch. While not technically kosher per the manual, seems mostly harmless. The speedbrakes actually don't make that much difference to the outcome. In this case, the pilot can be on the TR paddles a bit quicker.


It isn't a "60 knot stow speed", it is a 60 knot idle reverse speed. The TRs can be left out below 60 knots, just not above idle reverse. If you stow at 60 knots, it will make a huge difference to the outcome, particularly in my airplane which has an elevated flight idle versus ground idle (the 501 doesn't have ground idle). When someone mistakenly pushes the paddles past idle reverse and stows them at 60 knots, the plane decidedly lurches forward with the extra thrust.

Mike C.

Not if it is raining when you get there. The length adders for a wet runway are quite large when lacking TRs.

Mike C.

https://www.youtube.com/watch?v=g-mzfsAjjP4

Easy Takeoff! In the air in under 2000 feet.

The Naval Aviators of BT approve this statement (and video).

Looks like an awesome approach to an airport I've always wanted to visit, thanks for posting. One question: is it possible (or legal) for Mountain Air to install a non standard PAPI? (IE one that guided to a TDZ 100' down the runway or something). It seems like something that would help. (though maybe they want to keep out the types that would "need" the PAPI)

Disregard - just re-watched and noted the single cue VASI to the left of the rwy.

That would be about right for the book runway distance of ~3500 ft.

The book number assumes engine failure at V1, reaching Vr, and then reaching 35 ft AGL height. You got about 35 ft AGL at the end of 2900 ft runway with both engines operating, so taking another 600 ft to do that one engine out seems plausible.

Had an engine failed just prior to V1, trying to stop on the downhill runway 14 would have been dicey!

Mike C.

That would be about right for the book runway distance of ~3500 ft.

The book number assumes engine failure at V1, reaching Vr, and then reaching 35 ft AGL height. You got about 35 ft AGL at the end of 2900 ft runway with both engines operating, so taking another 600 ft to do that one engine out seems plausible.

Had an engine failed just prior to V1, trying to stop on the downhill runway 14 would have been dicey!

Mike C.