Light Duty Commuting Aircraft (??)

[sqwkvfr]

I have a student with a Comanche 250.

I wasn't thrilled about his choice at first, but it's pretty quick, has good load and is very economical.

You can pick 'em up pretty cheap and spend a little money on the panel to get it where you want.

With a little work, you'll have a fast, economical little performer that just might fit your bill.

 

[erj-145mech]

My understanding is the Dakota's engine has a dual magneto and these should be avoided. A lot of cardinal pilots dump their O-360A1B6D's for the non-D engines for the redundancy of seperate mags.

Other then that the Dakota's a good (but thirsty) workhorse.

There's nothing wrong with a dual mag. There have been documented instances with a dual mag failure on a Traumahawk (Note: two Slick mags), causing the FAA to revoke the airworthiness certificate on all PA-38's, as well as D-2000 failures. Every PA-31-325/350 Navajo's has dual mags.

There are a lot of reasons to avoid a certain airplane type, but to exclude an airplane for this reason is assinine. Perform a search in the NTSB accident files and see how many accidents attributed to dual mag failures.

 

[Be 23]

I've got to put a plug in for the BE 23 Sundowner/Musketeer. Low cost compared to the more popular airframes. It's comfortable, but you pay for the space with drag.

However, with any of the airplanes described you can run into serious trouble IFR with single vacuum pump and 70's avionics. Put the money into the panel of a solid airplane with ugly paint and frayed interior.

 

[eaglefly]

There's nothing wrong with a dual mag. There have been documented instances with a dual mag failure on a Traumahawk (Note: two Slick mags), causing the FAA to revoke the airworthiness certificate on all PA-38's, as well as D-2000 failures. Every PA-31-325/350 Navajo's has dual mags.

There are a lot of reasons to avoid a certain airplane type, but to exclude an airplane for this reason is assinine. Perform a search in the NTSB accident files and see how many accidents attributed to dual mag failures.

It's not a question of how many accidents there have been, but a question of vulnerability and risk. Dual mag systems rely on many common parts, the faliure of any results in a guaranteed engine faliure, wheras two seperate mags gives the chance to continue with power.

 

[momalley81]

There's nothing wrong with a dual mag. There have been documented instances with a dual mag failure on a Traumahawk (Note: two Slick mags), causing the FAA to revoke the airworthiness certificate on all PA-38's, as well as D-2000 failures. Every PA-31-325/350 Navajo's has dual mags.

There are a lot of reasons to avoid a certain airplane type, but to exclude an airplane for this reason is assinine. Perform a search in the NTSB accident files and see how many accidents attributed to dual mag failures.

In one year at my freight job where we flew Lance's with the O-540 and dual mags, we had TWO go in following mag failures in that year. Both resulted in off airport landings with no damage, so no NTSB report.

So I'd say its not all that uncommon.

In addition, I also lost count of the number of single mag failures I've had over the years in 402's, Seneca's and assorted singles that didn't end in off airport landings...

 

[erj-145mech]

Dual mag systems rely on many common parts, the faliure of any results in a guaranteed engine faliure, wheras two seperate mags gives the chance to continue with power.

Have you ever seen a dual mag on the bench? The only common parts are the rotating magnet, the impulse coupling (if equipped), and the cam.
There are two seperate coils, two set of points/capacitors, two distributors.

The magnet is a permanent magnet with no moving parts. The impulse coupling is only used during engine start. The cam is a block of steel ground into an oval shape with no moving parts.

 

[A Squared]

Have you ever seen a dual mag on the bench? The only common parts are the rotating magnet, the impulse coupling (if equipped), and the cam.
There are two seperate coils, two set of points/capacitors, two distributors.

The magnet is a permanent magnet with no moving parts. The impulse coupling is only used during engine start.

Uhhhh, no not true at all, the purpose of the impulse coupling is to assist in starting, for an absolute fact the impusle coupling is used as long as the engine is turning. That's what drives the magneto. An impulse coupling failure may render the entire mag inop or so badly out of timing that it might as well be inop. You ever notice how many ADs there are for impulse couplings there are? Obviously the airworthiness folks are concerned about impulse coupling failures, and an impulse coupling failure on a dual magneto. Off the top of my head I can think of 2 magneto failures I've had in GA aircraft. One was an impule coupling failure that would have made a dual mag pretty much usless, and the other was a drive failure that would have made a dual mag inop. (in both cases the engine still ran reasonably well on the other mag)

So, yeah, there *are* failures that could cause an engine failure in a dual mag airplane, which wouldn't in an airplane with seperate mags.

To suggest otherwise, or insist that this is not a concern is, to use your terms, assinine.

 

[eaglefly]

Have you ever seen a dual mag on the bench? The only common parts are the rotating magnet, the impulse coupling (if equipped), and the cam.
There are two seperate coils, two set of points/capacitors, two distributors.

The magnet is a permanent magnet with no moving parts. The impulse coupling is only used during engine start. The cam is a block of steel ground into an oval shape with no moving parts.

No.

The only dual mags I've looked at were two that had failed. One aircraft was on the ground and was towed back to the hanger and the other was an airplane that luckily glided to an airport, although it landed in a grassy area with little damage..........except to the mag that is.

Keep your dual mags.

27 years and 14,800 hours and I've never had a dual mag fail on me and never will. AOPA's sweepatakes Cardinal originally came with a dual mag, but they swapped that out at overhaul..........smart move.