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In April, 2003 the initial installation and testing was been completed on the second integrated Meggitt installation in the Cessna Conquest II fleet. As of December, 2004 we have about 300 hours with the new configuration.
The installation was performed by Executive Beechcraft at Spirit of St. Louis (SUS) airport near St. Louis, Missouri. They were selected because of their extensive knowledge of the Cessna 441, as well as a very good experience with their installation of a Bendix-King IHATS system in the aircraft in early 2002. We have a long and excellent business relationship with them. The work they performed during the Meggitt installation was excellent. We recommend them should you choose to perform this work.
The installation differs slightly from the STC aircraft in that we elected to move the King IHATS system up one slot since access to it seemed more important than the audio panel. We also substituted a PS Engineering PMA-7000B audio panel for the Garmin panel used in most installations. We found that with the various additional voice annunciations that the additional unswitched inputs on the PS Engineering unit were an advantage. In addition, it has no knobs on the right hand side so issues of being difficult to access when the power levers are forward are resolved. Experience has proven this to be a correct decision although even in its current position the IHATS cursor knob is difficult to use in flight. Fortunately it is seldom needed.
Because of the extensive changes, it was necessary to weigh the aircraft. We were happy to discover that it is 109 pounds lighter and the CG was moved slightly forward.
The ADAHRS (Air Data, Attitude, Heading, and Reference System) has some limitations on its air data capabilities. Although temperature and TAS information was planned it the original design it was never implemented. For complete functionality of the combined Meggitt/King/Garmin system you will need an Air Data Computer of some sort. We used the Shadin unit already in the aircraft for fuel totaling needs.
One of our reasons for selecting Magic® was Meggitt's intention to certify the 441 for RVSM. The autopilot appears to hold altitude well enough for RVSM (typically ±20 feet) and the two ADAHRS remain within 30 feet of each other through FL330.
We are happy with the EIDS unit. A few observations:
The fuel gauge and fuel usage indication is remarkably accurate. In fact, if we didn't need the Air Data Computer function, I might consider removing the Shadin fuel unit -- the Meggitt is more accurate.
The EIDS programming for the EGT indicator has some
interesting features. The intent is for 450 degrees or higher to display
in red.
One could argue about whether 450 should be red or not since the POH is ambiguous on that subject.
The programmed behavior is that after red is indicated, the display color does
not go back to normal until the EGT drops somewhat below
450 -- perhaps 448 or 447. As a consequence, a perfectly legal
temperature (such as the 449 shown in the picture) can be in red. The
logic for doing this is to insure that the pilot is aware of any very short
transgressions at or above 450 and to provide some hysteresis so that the
colors don't constantly flash.. However, since the engine limiting is not that
precise, very short excursions about the indicated temperature appear to be
common. The POH allows ±2.4° F. While the intent of the
implementation was fine, the reality is that this creates false red
indications which tend to create pilot complacency about the meaning of the
red indication. After some amount of experience these characteristics
are easy to live with.
The EGT indication doesn't do anything special during manual mode. Of course, the old analog displays don't either. It would have been nice if the EIDS automatically calculated the correct maximum EGT in manual mode.
The autopilot has a lot of authority and for those used to the anemic Cessna autopilot it will be a revelation. Ours even overcame a maladjusted trim system. The thirty-degree banks that it performs when necessary may be startling to some but roll-in/roll-out is sufficiently gentle that this is only surprising -- not objectionable.
The GPSS steering (NAV and APR mode GPS-assisted courses) is generally very good but is prone to slight overshoots. This is related, to some extent, to commands from the Garmin GPS and thus may not really be the fault of the autopilot. Meggitt/S-Tec is aware of this issue.
A minor nit is that the HDG mode does a good job of controlling a turn until near the finish when it rolls out too soon and then literally creeps to the correct heading. Meggitt has verified this behavior and has agreed to investigate future modification. There is also a tendency to stay a degree or two off of the heading. After some experience we the unit we believe that this error is related to rudder position. If the rudder is properly trimmed the error appears to decrease.
The autopilot is hard-wired to the #2 ADAHRS. In fact, both ADAHRS must be on-line to use the autopilot. The explanation is long and involved but ultimately rests in the fact that the most likely failure mode of the ADAHRS is a soft-rollover versus the hard rollover of traditional gyros. The FAA was concerned that the pilot might miss the subtle change, so the autopilot compares the output of the two ADAHRS and disconnects if they disagree by more than a certain amount. Since the only failure we've ever had with a conventional gyro in flight was a soft rollover we can only wonder why the FAA ever certified any aircraft with a single conventional gyro connected to the autopilot.
The unit has been reliable after a couple of very early failures. In hte last eighteen months of operation the only downtime related to Meggitt/S-Tec equipment has been four or five business days to exchange the displays with updated units. Meggitt/S-Tec cooperated on the scheduling and this caused no disruption in aircraft use.
Meggitt seems to work well with the avionics technician assigned to our aircraft, although answers are not always prompt.
While we had some early difficulties in communicating with Meggitt this appears to have changed and they are eager to listen to their users. To be honest, Meggitt at this point may be better than many of the general aviation suppliers. We had a number of issues with Bendix-King during the IHATS installation and have had some issues with Garmin. None provide the level of service that would be expected in most other industries.
In June 2003 I attended my first recurrent training at FlightSafety Wichita since the Meggitt implementation. I was anxious to see how training would be in an older panel after operating a number of hours with the Magic®.
FlightSafety is currently rehabbing simulator #45 which was the old Cessna/Sperry-equipped sim. It has been out of routine service for several years. It was recently equipped with a Garmin 530 so I chose it for training since that would at least allow use of the same GPS/NAV/COMM as I normally use.
While I expected the lack of EFIS to be an impediment to training, the primary difference I noticed between this and the Meggitt-equipped panel was how inconvenient it was to have the 530 mounted in the center of the panel. The mounting position in the Meggitt-equipped aircraft with EIDS is very close to the pilot’s line-of-sight and it is simple to include it in the instrument scan. It becomes an important tool for situational awareness.
The other significant difference was, of course, the lack of automatic course setting. This was a minor nuisance until we flew the DME arc.
Our migration to Meggitt was driven not just by the Meggitt “gee-whiz” marketing but also by the increasing cost – both in maintenance and downtime – of the factory avionics and instrumentation. The Conquest market is ripe for upgrades and if Meggitt doesn’t capture the market, someone else will. But training will become a key issue as many insurance companies are absolutely insistent on simulator training. FlightSafety is going to have to equip a simulator with completely modern avionics to meet these needs.
Installation of the Meggitt Magic® system in a FlightSafety Conquest simulator would not only be a tremendous training tool. It would be an effective marketing tool for Meggitt and permit perspective customers to actually train on the product prior to or during implementation. Meggitt has indicated that as the number of Magic®-equipped 441's increases that they'll work with FlightSafety to get a simulator properly equipped.
As of this writing (December, 2004) the #45 sim at FlightSafety is being completely refurbished. There has been some mention of the possibility of the finished unit having EFIS but as of October 2004 they claimed that no decision had been made on that matter.
We endorse the Meggitt Magic® product with some very minor reservations. As with any major avionics product we would recommend that any perspective buyer comprehensively manage the installation process and insure that Meggitt is committed, in writing, to delivery dates and to support of any particular instruments that you are attempting to interface with. In addition, make sure that your shop receives the latest drawings and documentation. There have been many changes as well as a revised STC that may have been approved by now.
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(MJM 12/25/2004)