Ask the DAR

Know your limitations.


Editor’s note: This month our DAR in residence is going to start a short series that looks into the details of operating limitations, a document each Experimental/Amateur-Built aircraft carries that defines its scope of use.

When you received the airworthiness certificate for your Experimental/Amateur-Built aircraft, you also received a document called operating limitations. Do you have any idea what this document contains? Have you read it? In far too many cases, it falls into the same category as the operating manual for your family automobile. Bet you haven’t read that either.

Believe it or not, the operating limitations are an integral part of your airworthiness certificate. It even says so on the certificate itself. Look at the wording in block E of the certificate. It states that "OPERATING LIMITATIONS DATED XX/XX/XXXX ARE A PART OF THIS CERTIFICATE." This means that in the absence of the operating limitations, your airworthiness certificate is worthless.

Why is it so important? Well, in the certified world of standard certificated aircraft, you are required to have a Pilot Operating Handbook (POH). Your Experimental aircraft is not required to have a POH. Instead, the operating limitations provide that necessary information.

The information required to be in your operating limitations is spelled out in FAA Order 8130.2F, soon to be 8130.2G. There are 28 paragraphs. In the next few months we will attempt to demystify this document, which is too often ignored.

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Operating limitations must be designed to fit the specific situation encountered, and the inspector may impose any additional limitations deemed necessary in the interest of safety. The inspector must review each imposed operating limitationto ensure that it is understood by the applicant.Some inspectors may not emphasize this requirement enough, possibly contributing to the lack of attention paid by the aircraft owner/builder. Let’s take a look at the limitations one paragraph at a time.

"(1) No person may operate this aircraft for other than the purpose of meeting the requirements of 91.319(b) during Phase I flight testing, and for recreation and education after meeting these requirements as stated in the program letter for this aircraft. In addition, this aircraft must be operated in accordance with applicable air traffic and general operating rules of Part 91 and all other limitations herein prescribed under the provisions of 91.319(i). These operating limitations are a part of Form 8130-7, and are to be carried in the aircraft at all times and be available to the pilot in command of the aircraft."

Right off the bat we are told that this aircraft is to be used for recreation and education purposes-not commercial ones. As far as meeting 91.319(b), that’s the part that defines Phase I flight testing rules pertaining to operating area and minimum testing requirements. The program letter basically defines the aircraft and the purpose of the experiment. We see that Part 91 applies to the operation of this aircraft; 91.319(i) allows the inspector to add additional limitations in the interest of safety. This paragraph also emphasizes that the document must be kept in the aircraft at all times.

"(2) During Phase I flight testing to meet the requirements of 91.319(b), all flights must be conducted within the geographic area described as follows:

This area, which will obviously vary with the builder’s location, must be described by radius, coordinates or landmarks. The area must be over open water or over sparsely populated areas with light air traffic. The size of the area must be that required to safely conduct anticipated maneuvers and tests. The size should also reflect the speed of the aircraft being tested." While a flight-test area of a 25-mile radius may be appropriate for a Light Sport-compliant aircraft, it would not be practical for a Glasair III or Lancair IV.

It should be noted here that flight testing may not be permitted from an airport completely surrounded by a densely populated area. Many airports that once were surrounded by farmland, for example, are now part of urban sprawl having predefined corridors developed by users and the local FSDO to allow Phase I to take place at the airport but to limit exposure to surrounding civilians. If there is no reasonably safe corridor intoand out of the airport, the aircraft must be moved to a more suitable location.

Let’s take a break to let you digest those two paragraphs. Next month we’ll look further into the operating limitations.

Please send your questions for DAR Asberry to with Ask the DAR in the subject line.

Mel Asberry is an experienced Designated Airworthiness Representative specializing in Experimental/Amateur-Built aircraft. He and his wife, Ann, have built seven amateur-built airplanes including two ultralight types, a Moni Motorglider, a Dragonfly Mk2, two RV-6s and a Zenair CH 601HDS. They are currently building a scratch-built biplane.


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