Monday, July 31, 2006

Going Somewhere



Cessna recently revealed it has been working at a new high-performance aircraft they are calling NGP, which stands for Next Generation Piston (aircraft), by making a fly-by at Oshkosh. The plane sports a high-wing cantilever design, vaguely reminiscent of the Cardinal, with some Cirrus-like features. A castering nose wheel and what looks to be a laminar-flow wing, not to mention the tail, are all reminiscent of the Cirrus as Ron mentioned. I don't attribute this to outright copying so much as engineers coming to the same design conclusions. Look at automobiles and you will see that most have similar shapes in an effort to reduce the coefficient of drag.

Cirrus aircraft have numerous drawbacks, some serious, that Cessna could capitalize on with its new NGP design. The Cirrus have had door problems from the get go. I have a nice bruise on my right forearm from trying like hell to get my door shut and latched (top and bottom) on a SR22 G2 earlier this week. There I was, holding the brakes with the engine running, repeatedly closing and opening my door. The temperature on the ground was about 104˚F and by the time I finally found a way to get the door latched, I was wringing wet with perspiration. Part of the SR22 G2 (second generation) marketing claims was that the doors would shut easily. Since all the late model Cessna aircraft have positively locking doors, one would think that the Cessna NGP would offer the same.

A new 182 is much more fun to hand fly than the Cirrus, but it has very heavy heavy elevator control pressures. You really need to trim the 182 or have a lot of upper body strength to hand fly it successfully. The new 182 reminds me of a Caravan, which is probably why I have a soft spot for it. The heavy control feel makes the plane very stable when flying IFR, but it can be tiring. The Cirrus is a weird plane to fly by hand, but if you have a very sensitive touch, there is some control feel you can establish in spite of the spring-loaded trim cartridges. Given all that horsepower and torque up front, the lack of rudder trim in the SR22 I fly is a shame, really. The Cessna NGP could really have an advantage if it is a more pleasant to fly aircraft, but laminar-flow wings, while offering good cruise characteristics, tend to be temperamental at slower speeds.

Cirrus has electrical system problems and its Master Control Unit is widely recognized as a potential Achilles Heel. The Cirrus I fly has had repeated ALT2 failures and at least one complete MCU replacement that I know of. I'm not the first SR22 pilot who has considered the possibility of a complete electrical system failure in IMC and I know at least one SR22 owner who flies with a hand-held Garmin GPS as a backup.

Another issue with the Cirrus is the ridiculous placement of circuit breakers, alternate air, and alternate static source controls, which would be pretty easy to address in the new Cessna design.

The pitiful ventilation in the Cirrus is barely better than the Diamond Katana (aka Ka-sauna), though you can leave the Cirrus doors open during taxi and that helps a bit. I'm told there is an after market air conditioner available for Cirrus, but I'm also told that the installation requires some serious modifications. A high-wing aircraft is not immune from being hot, but a high wing does give you some shade from the sun and shelter from rain in bad weather. Air conditioning as an option in the new Cessna would be ... cool.

The Cirrus is a noisy beast, hence the Bose headsets that Cirrus markets with the plane. I found my LightSpeed Mach1 works well in the Cirrus, easily dampening the loud racket. Still, one would expect the new Cessna would be quieter inside.

The Cirrus have had brake issues that, combined with the unfortunate placement of the fuel sump drains, has resulted in some ground fires that have completely consumed a few SR22s. With a castering nose gear, the Cessna NGP will need some beefy brakes and Cessna has not had a great track record with its brake systems on single-engine aircraft. Even some Caravans I have flown had some brake problems, so Cessna better get the brake system right on the NGP. The fuel sumps being far away from the wheels should obviate the fire danger and one assumes the NGP, like all late model Cessna, will have a bevy of fuel sumps.

Other things that could help make the NGP serious Cirrus competition?

TKS icing with known icing certification.
A vacuum-driven attitude indicator.
A back-up alternator similar to the one on the Caravan and just one battery.

And if I win the lottery and Cessna does produce the NGP, I'd opt for a turbine engine version.

9 comments:

Christian Goetze said...

Did you notice it seemed to have 4 doors? I hope they make it so that you don't have to move the seat every time you get in.

I disagree with the vacuum pump idea. I'd rather have redundant and independent power supplies, perhaps a second alternator, and continue to work on the reliability of the electronic displays.

John said...

Yes, the 4-door option would be cool and even more car-like that the Cirrus.

The electronic displays are not the issue so much as the idea that a completely separate system be used to power the back-up attitude indicator.

The Cirrus electrical system illustrates how a theoretically separate essential bus is not actually separate at all. When the logic is physically contained on one circuit board, the two systems are not separate and the worst could happen - a complete electrical system failure.

A vacuum driven AI doesn't seem so bad when you look at it that way. The other option would be to have a separate, alkaline battery powered AI as used in the Diamond DA40.

SloppyPilot said...

I'm for the battery unit ala DA-40.

Also your right about the how noisy the SR-22 is. I made a comment about that on a demo ride that was talked around by the sales pilot.

It was pretty obvious since I had just done a ride in trinidad and a saratoga(had my headsets off in that one).

I looke forward to seeing what Cessna does here. Compitition is a good thing.

Greybeard said...

A question to address your turbine comment: Are you serious, or just suggesting given unlimited funds you'd STC a turbine on one?

How much more would a turbine version cost, compared to something with, say, a TIO-540?

My point of reference is the Robinson R44 compared to the Bell JetRanger. The recip. powered R44 runs away from the older technology Bell at less than half the initial cost, (but the Bell can seat another very cramped person, and has marginally more storage space.) The R44 also burns half the fuel. (25 per hour of JetA vs. 15 of 100LL)

Robinson has statistics showing their engines fail at a lower rate than small turbines on other helicopters. Why would you want the higher initial $$$ hit/sustained higher fuel burn?

John said...

Greybeard,

I'd like to see a small, reliable, relatively low-cost turbo-prop option for the new Cessna, though I know that such an engine does not yet exist. If it did, perhaps Cessna could call it the NGT (next generation turbine)?

I imagine it's hard to compare piston engine reliability between airplanes and helicopters for a variety of reasons, even when basically the same engine is being used.

For one, helicopters have more moving parts than airplanes. I suspect there's a much greater opportunity for shock cooling a piston engine in an airplane when compared to a helicopter.

You're right about the higher initial cost of a turboprop, at least with the current technology. But Jet A is a pretty safe bet, while the future (availability and cost) of 100LL is uncertain.

Personally, I'm much more comfortable in IMC over the mountains or over the ocean in a turboprop aircraft than in a piston engine-driven airplane.

Power management in a turboprop is soooo much easier than a piston. And you can make rapid power changes for steep descents, pretty much with impunity.

Anyway, those are my reasons. Of course I was just do a little blue sky day-dreaming. Pratt & Whitney or some other engine manufacturer will need to do some pretty extensive engineering to create a reasonably priced, smallish turbine engine to install in my day-dream plane.

Lee said...

Cessna better have a decent payload of at least 800#. Then it will be the "Cirrus Killer". They are short on useful load and payload and the new Cirrus G3 Turbo has barely a 500# payload with 3.75 hours of fuel @ 20 GPH. I hope Cessna does get it right.

Anonymous said...

Cessna should come up with both the 2.0 Thielert turbo-diesel and the new 3.2 turbo-diesel currently under development. That will give a tremendous performance / range improvement.

Anonymous said...

I don't know if I will be a big fan of flying with the Joystick on the door, although it will give alot of extra space. I guess its just something to get used to. Lets just hope that the cost is still low.

Maconcrete@aol.com said...

The Cirrus G3 built prior to the advent of the "Perspective Cockpit" has an extremely serious and possible fatal flaw in that when alternator #1 and subsequently battery #1 is lost (and this happens frequently) the pilot is left with absolutely no cockpit ventilation what so ever. There is no ram air ventilation. This can and has resulted in a zero visibility situation in the cockpit, depending on ambient conditions. This will manifest particularly during the critical descent phase.This can possibly lead to a serious or fatal accident and may have contributed to past unexplained incidents. I have filed a complaint with the FAA to force Cirrus to address this issue, as Cirrus has not moved forward in addressing this issue in an expeditious manner.It is my opinion that all G3 aircraft with this defective ventilation system should be grounded, including my own aircraft.This situation is not addressed in the aircraft POH or the ventilation supplement, it is ignored. Maconcrete@aol.com