Phase One and the APP


Gyroplane CFI
Staff member
Oct 30, 2003
Santa Maria, California
Givens Predator
Total Flight Time
2400+ in rotorcraft
Some thoughts on the Federal Aviation Administration (FAA) phase one flight testing for Experimental, Amateur Built aircraft (EAB) and the Additional Pilot Program (APP).

I am thankful for the freedom the FAA allows and want to do what I can to foster the trust and responsibility that is necessary for freedom.

Phase one is the test phase in the life of an EAB aircraft where a test pilot explores the stability and systems of the aircraft.

The V speeds, limitations, weight and balance are determined during phase one for the Pilot’s Operating Handbook.

Often the phase one is conducted by pilots who know little about flight testing leading to a lot of mishaps. A surprising number of mishaps (18%) happen on the first flight and 65% happen during the first eight hours of flight testing based on accident numbers from 2011.

There is an advisory circular available to help create a test plan: AC 90-89B:

I feel there are a lot of useful concepts covered by AC 90-89B and recommend it to anyone doing any flight testing.

The National Transportation Safety Board (NTSB) felt there were a lot of accidents that may have been prevented by a more skilled pilot and suggested the FAA address this.

In response 9/23/2014 the FAA issued an advisory circular 90-116 to clarify the changes in phase one flight testing from the APP and better define the limitations.

It is my observation that the APP for phase one flight testing is poorly understood.

The full text may be found here:

I have found that despite the AC; the lack of clarity still exists so I felt that there would be value in articulating my thoughts. Please understand I am not a lawyer and I do not speak for the FAA. I am simply a Commercial Pilot, Rotorcraft-Gyroplane and a Certificated Flight Instructor (CFI) with opinions.

I will try to touch on the highlights because I have heard a lot of misinformation about having two people on board during phase one testing.

Quoting from AC90-116:

  • PURPOSE. This advisory circular (AC) provides information and guidance on the Additional Pilot Program (APP) for flight testing experimental aircraft. The APP was developed to improve safety by enhancing Builder/Owner Pilot (BP) skills and mitigate risks associated with Phase I flight testing of aircraft built from commercially produced kits through the use of a qualified additional pilot and powerplant testing. The APP is an optional program which provides another pathway to conducting Phase I flight testing. The traditional option for a pilot to test their aircraft solo during Phase I is not covered or affected by this AC, and remains an option for those who choose to do so in accordance with their aircraft’s operating limitations.
2. APPLICABILITY. This AC provides information for any person who chooses to utilize an additional pilot on board in accordance with the APP described herein for a Phase I flight test.

Setting Qualifications. The difficulty is determining when an additional pilot should be allowed on board, and what minimum qualifications that additional pilot should possess. The objective is to set the qualifications of the additional pilot high enough to mitigate the risks of LOC, but low enough to yield a useful pilot population as illustrated in Figure 2, Balancing the Pilot Qualifications to Ensure an Acceptable Level of Safety.

So this is what they came up with for the second Pilot Qualifications.

Again quoting from the AC:

7. DETERMINING APPLICANT ELIGIBILITY. A builder or owner of the aircraft being tested who meets the qualification requirements to utilize the APP is known as a BP. This individual(s) must:

a. Own all or some portion of the aircraft being tested.

b. Hold at least a sport, recreational, private, commercial, or Airline Transport Pilot (ATP) Certificate with the appropriate category and class ratings for the test aircraft, and have received all necessary endorsements, as required per § 61.31, appropriate to the test aircraft. For light-sport aircraft, have at least a Sport Pilot Certificate and the appropriate logbook endorsements for the category and class of the aircraft to be flown, as required per § 61.317.

c. Meet the requirements of § 61.56, Flight review.

d. Meet the requirements of § 61.57(a), Recent flight experience: Pilot in command, in the same category and class as the test aircraft.

e. Denote the name of the additional pilot in the pilot logbook for each flight utilizing an additional pilot.

I have seen many people approach the phase one testing for experimental amateur built aircraft as a “forty hour fly off” ignoring the elevated risk and not adhering to the guidelines. Often their operating limitations do not have the blanks filled it.

If there is a mishap and there is an unqualified person on board there will likely be consequences.

After phase one the operating limitations are relaxed and there is much less scrutiny.

I feel I have much to be thankful for so Happy Thanks Giving everyone!


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Gold Supporter
Jul 2, 2007
London/ Kilifi Kenya
Gyrs, RAF 2000/Mgni/Bnsn/Hrnet/Mrlin/Crckt/MT-03/Lyzlle AV18-A/Prdtor. GT-VX1&2, Pax ArrowCopter
Total Flight Time
100+ gyro, 16,000+ other
Good post Vance.

Hope everyone had a happy Thanksgiving, we all certainly have good reasons for being thankful, despite the inevitable glitches that are part and parcel of this ongoing ride we are all on.