Home > Flying > More flying since Sun ‘n Fun

More flying since Sun ‘n Fun

Since flying to Sun-n-fun I have been flying back and forth to our family ranch in Prescott, AZ as well as flying several other trips around New Mexico.

I have found the new cursor functionality to be a major plus. I even use it to mark the place on my flight plan to remind me of top of descent! It has incredible utility and makes accessing information really easy. I have also had the chance to practice using the back-up capabilities of the MFD1000. The MFD 1000 not only has a full suite of AHRS and ADC sensors, but in reversion mode it provides exactly the same display layout as the PFD.  (see reversion mode picture below).

Having exact primary flight display redundancy provides for a very safe transition to backup in case of failure. The quick transition means that I can focus on the emergency at hand instead of readjusting my scan to either steam gauges or another representation of the data. I also occasionally flip to reversion mode on the MFD1000 and use it as a way to keep an eye on all of my instruments to detect early on if something is not matching or going wrong. Just another added item of comfort for my flying.

As I mentioned earlier I plan to keep sharing my thoughts on flying  and flying with the Aspen system. With Oshkosh coming up (yes I will be taking my airplane to Osh!) and many new features and functions coming from Aspen I am excited about getting to use them and write about them.

Categories: Flying
  1. James Curry
    August 2, 2010 at 12:15 pm

    Hi John,

    Love my new panel with the (2) Aspens and would do it again in a heartbeat. I am still learning a lot about the systems. I too have an MFD1000 for backup capability. One item that is developing a very keen interest to other users AND POTENTIAL users is the drop out of everything, especially attitude, with loss of pitot. So regardless of reversion mode on the MFD there is still a single point of failure that would ‘kill’ both units simultaneously. Is there a chance this will change in the future?


  2. August 3, 2010 at 9:18 am

    Thanks very much for your feedback. It’s great to see your enthusiasm for the Evolution system and we appreciate having you as a customer.

    At Aspen we understand that our customers want us to continue to improve upon the increased levels of safety and redundancy offered by the Evolution System, and we are listening. In response to inquiries such as yours, we are investigating improvements to the AHRS system performance.

    In the meantime, here’s a little background info to help explain why our AHRS does what it does.

    The underlying sensor technologies used in many modern AHRS systems typically require an “aiding” input to assist in determining the aircraft attitude. Aiding generally comes from either Air Data systems, GPS systems, or both. When aiding inputs become degraded or fail, the AHRS solution can also become degraded.

    At Aspen we chose to use air data information as the primary aiding input to the AHRS. We deliberately chose an aiding source that is independent of systems external to the Aspen system for two reasons. The first was to avoid being dependent on another manufacturer’s equipment for our AHRS to operate correctly – this was important from the perspective of our broad equipment compatibility. The second was to avoid a limitation seen in our competitor’s systems that prohibit IFR operations whenever the GPS constellation is not fully operational (i.e. GPS is NOTAM’d out ). Unfortunately, NOTAMs advising of unavailable or unreliable GPS signals are a near daily phenomenon for vast portions of the United States.

    A blocked pitot line, such as may be seen during an inadvertent ice encounter, could affect the AHRS performance. Aspen implemented a monitor to detect this condition and inhibit the display of any potentially degraded data. This ensures that the pilot will use the unaffected backup attitude indicator. In most cases a pilot can easily restore normal AHRS operation by activating pitot heat. If we relied only on GPS aiding this would not be an option.

    Of interest is a comparison of this failure condition to the alternatives. Comparing a pitot blockage to the traditional vacuum pump failure scenario we find that a pitot blockage is more easily detected by the pilot, is less likely to present misleading data, is more easily remedied by pilot action, and is less likely to occur than a failure of the vacuum pump. When compared to GPS aiding, we find that a pitot blockage has a lower likelihood of occurrence and is more easily resolved by a pilot action than would be the case for a failure of the GPS receiver or a loss of GPS satellite signals.

    I hope this gives you some more insight into the types of things that were considered during the development and certification of the Evolution system. Thanks again for your feedback and let me know if you have any further questions or clarifications.


  3. Chen Au
    August 24, 2010 at 7:17 am


    I am considering acquiring a Diamond DA20-C1 with the Aspen EFD1000. I also want to equip the plane with the Avidyne TAS600 system to improve situational awareness. Are you aware of any compatibility issue between the Aspen remote sensor module and the Avidyne TAS? I would appreciate your comment. Thanks,

    Chen Au

  4. August 30, 2010 at 8:05 am

    I installed the Avidyne 610 on my airplane at Santa Fe Aero. The installation was part of my Aspen installation and it went very well. The antennas were installed on the top and bottom with the traffic computer in the rear area. The system works great and I really don’t know how I have flown without it before. The interface to the Aspen is seamless with traffic displayed on the HSI portion of the PFD. Since I have 2 MFDs, it is also displayed on the Nav Map which is very useful. Pictures of my installation can be found under the “Installation” category of my blog.

    The issues we had with the RSM were totally related to magnetization of the RSM by the mounting bolts. Make sure that they use the brass bolts AND nuts provided with the installation kit. Pay special attention to any magnetic sources close to the RSM as specified in the installation manual. If you follow those directions everything will be ok. I am not sure what happened with the Avidyne TAS as the first computer just failed in the first few flights. Santa Fe Aero replaced it very quickly and I have now over 90 hours on the system and it works perfectly.


  5. Mike Kobb
    August 30, 2010 at 5:47 pm


    Thanks so much for the great info here.

    I’m puzzled by your response to Jim’s question regarding the pitot. I’m installing a three-tube Aspen system in my SNJ-6, and I have no plans to install a backup AI (in fact, I have removed the vacuum system). I was told and have also read in the press that this would be a supported configuration because a software update would be forthcoming to address the pitot issue (presumably by falling back to using GPS).

    Your response makes it sound as if that option is farther away than I expected.

    Can you please clarify? Has Aspen committed to eliminating the need for an AI, or not?

  6. August 31, 2010 at 2:43 pm

    Thanks for your feedback.

    Backup instruments are always required by the rules. In the case of the Evolution 2000 and 2500 packages, the FAA has approved an “Equivalent Level of Safety” proposal that Aspen made that allows the MFD1000’s reversionary PFD to satisfy the regulatory requirement for backups. The Equivalent Level of Safety approval requires that an EFD1000 MFD be installed along with the Aspen EBB-58 Emergency Backup Battery, and allows for removal of backup mechanical airspeed and altitude instruments under all circumstances.

    To remove the backup mechanical attitude indicator, the MFD and PFD must either be connected to independent pitot probes (most GA airplanes do not have two pitot systems), or the AHRS must be robust to a pitot input failure.

    The bad news is that until this R&D effort is completed, a backup mechanical AI will need to be retained. The good news is that we are actively working on this improvement, and are confident that we’ll have a solution in the market during 2011.

    I hope this helps. Let me know if you have any other questions.


  7. Mike Kobb
    August 31, 2010 at 4:41 pm

    Thanks for the info, John.

    I should have been clearer in my message. I meant “no separate backup AI” — of course I knew that backup instruments are required, and this is why my panel is spec’d to include the EBB for the MFD1000.

    Where I’m disappointed is in the timing. I was led to believe that approval of the MFD1000 as the backup AI was coming mid-2010, not “during 2011”, and my panel was designed based upon that information.

    This is a brand-new, CNC-cut panel, and I’m not going to put a hole in it for a temporary instrument. That means that I don’t have anyplace to accommodate a separate backup AI unless I omit the MFD500, at least temporarily. Given your own writings on the benefits of the dual MFDs, you can understand why I don’t like that solution.

    I also don’t like having to buy an instrument that I don’t intend to keep. The AI in the SNJ isn’t usable in the new panel (it’s 60 years old and huge!), and the cost savings of not having to buy another one was part of why I decided to go glass to begin with. I’m also flush-mounting the Aspen displays, so temporarily accommodating a backup AI in the MFD-500’s location will require additional metal work and expense.

    I certainly understand that you can’t anticipate everything when developing a product, especially one that faces an extremely strict regulatory environment. Overall, Aspen has done an impressive job, which is why this single point of failure in a system obviously designed to provide redundancy was such a surprise when I first heard about it.

    Mostly, I feel let down in terms of having been given dates that were well off the mark (by about a year, in this case), not to mention the multiple delays in initial product shipment. This has all combined to delay my aircraft’s completion substantially. I hope your company will be much more careful with your estimates in the future.

  8. September 1, 2010 at 12:33 pm

    Hi Mike-
    First I would like to apologize if anyone at Aspen misled you in our plans. We work hard to communicate clearly with our customers. Over the last three years there has been a lot of excitement about our products. One of the most exciting features about our design is the ability to work with anything in the cockpit and not require major upgrades or overhauls to get glass cockpit technology to our customers. We pride ourselves in being focused on the retrofit market, understanding the needs of the market, and delivering products to meet those needs.

    It has been in our sights from the very beginning to eliminate all mechanical back-up instruments. We have been successful so far in moving in that direction; Aspen is the only EFIS manufacturer who has secured an FAA approval to remove any mechanical backup instruments. Our existing approval allows for removal of the mechanical airspeed indicator and altimeter, and we are working on the approval to remove the back-up attitude indicator. And as mentioned in my previous blog entry, should be complete in 2011. As you might imagine this requires an extensive development and certification effort.

    The backup attitude indicator requirement stems from our strategy of broad interoperability – Aspen equipment works with what’s already installed in the aircraft. Our philosophy and approach is different from our competitors, where you are first required to upgrade your GPS system which can be very expensive. To achieve this goal, one of our design decisions was to use pitot input data to aid the AHRS computations. For aircraft with a single pitot probe, this does create the possibility where a single input could affect dual installed AHRS systems, not unlike how a single vacuum pump affects both the vacuum powered AI and DG in legacy cockpits. This requires a back-up attitude indicator until we complete our development to eliminate that dependency.

    The operational and safety benefits possible with a dual AHRS installation is unique to Aspen’s solution. It’s important to understand that in most operations the pitot input is not prone to blockage. Aircraft with a known-ice certification have a proven reliable anti-ice capability on the pitot system, and aircraft without a known-ice capability are limited from operating in icing conditions. Should an inadvertent icing condition be encountered, the Aspen system architecture alerts the pilot to the condition and ensures that sufficient data is available to safely continue the flight to the destination.

    Our policy for product announcements is to provide guidance through our dealers and through our website for planned future product availability. Up to this point we have not given any formal guidance on when the backup AI can be removed. I am sure there have been many people discussing this and possibly setting expectations outside of our formal process. We have tried to be careful about setting expectations on important development like this as there are a lot of factors involved in getting this completed. When we talk to customers that are making installation decisions we always refer our customers to the formal announcements that we use. I will look into this to ensure that we are not causing our customers undue issues because of anything like this.

    Again I am sorry about the situation and appreciate your need to keep the integrity of your new panel set. I understand that an Aspen representative has already been in contact with you to assist you in any possible workarounds that may make sense for you. I greatly appreciate your feedback and look forward to hearing about your aircraft and system. I hope you take the opportunity to submit your installation to our customer gallery when it is finished.


  9. Mike Kobb
    September 1, 2010 at 1:07 pm

    Thanks, John. Although I’m unhappy, I am also extremely pleased that you take the time to respond personally and with such detail. It further reinforces your reputation as a classy company.

    I certainly understand that a pitot blockage is an uncommon circumstance. (Although, I’ve experienced one, during my private pilot training, due to a spider that made a home inside the tube! I’m careful to use the pitot tube cover on my own aircraft!)

    I do also truly appreciate that Aspen is the only company offering an approved redundant system. That is, in fact, one of the main reasons why I chose Aspen.

    I absolutely plan to submit my panel to your customer gallery. I expect it will be a real showpiece for a three-screen Aspen installation. I’m sorry that it sounds like I’ll be submitting it later than planned. I’ve had to cancel my purchase of the MFD-500 until this situation is resolved, so that I can use its panel space for the backup AI. :-(

    Thanks again for taking the time to respond,

  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: