Flight Testing

Planning your first flights.

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For those building a modern, home-built Experimental aircraft, the light at the end of the tunnel—the pot of gold at the end of the rainbow—is the thought of soaring through the sky in their completed craft. There are few builders who don’t spend at least a little time thinking about that first flight. They wonder what it will feel like to leave the earth in their creation, to pick up speed and maneuver at will, to look back at the shop as it disappears below, satisfied that they have done what they set out to do: build a flying machine with their own two hands. They build a picture in their minds of freedom and the ability to go wherever they want, whenever they want, and the truth is, this really will happen. But before builders get to that point, they are faced with the reality of a first flight and the follow-on test program, and that requires considerable thought.

The flight-test organization that I have helped to build over my career in the aerospace industry has a motto: “Plan, Train, Fly!” In the simplest terms, that is exactly what we do. We plan for flights and operations, we train ourselves and others involved to perform those planned operations, and only then do we go and fly the test or operation. Thousands of people contribute to the three pillars of our existence, and those same three pillars can be applied to flight-testing homebuilts. You don’t need thousands of people; you can get by with just a few. But you need to consciously step up and perform each segment to get the full benefit, so let’s take some time and discuss each one in detail. In this and the following articles, we will look at the elements that go into planning a flight, how you can train yourself to be better prepared for the unique aspects of a first flight, and then, finally, we’ll talk about some tips to make that flight happen.

Not every first flight requires a parachute, but if your safety analysis shows that it adds value, then adding a helmet and flight suit is a good idea to provide the pilot maximum protection in case of a bailout.

Planning for a Test Flight

Planning for your first flight should begin well before you get the airworthiness inspection for your new homebuilt. We all think about flying the new plane, but that is not the same as really getting down to planning an appropriate test program. While there are many EAA flight advisors who can help you prepare and plan, you can start without talking to anyone. Just download a copy of the FAA’s advisory circular on the topic: AC 90-89A. This well-written, illustrated and sometimes humorous publication is a great guide to all of the things you should think about in planning your program. Notice that I didn’t write that you need to observe every single point in the AC, because many won’t apply to your situation. The point is not to make you strictly adhere to every recommendation, but rather to make you ask and answer the questions that it raises. For instance, there are a lot of recommendations on engine run-in that apply if you have overhauled an engine and hung it on your new homebuilt. But if you have received a brand new engine from a custom builder who ran it in their test cell for an hour or two before delivery, much of this is already done. (You’ll still want to run the engine to check for installation issues, of course!) So read through the AC and sort each recommendation into three categories: Done, Need to Do or Not Applicable Because (Reason). That reason is important, by the way, because it’s too easy to rationalize away a safety requirement.

A safe flight operation begins with a thorough briefing with everyone involved. This is the time to go over the plan in detail and make sure everyone’s questions are answered.

If you follow (or address) all of the steps in the AC, you will have done a great job of initial preparation for your flight. You will have educated yourself. The next thing you want to do is to sit down and write out your particular test plan. You don’t need to make a novel of it, and you don’t need to try and write the entire plan at once. Let’s concentrate on the first and second flight for now. You’ll have plenty of time to catch your breath and flesh out the rest of the test program once you get those done. Each plan, for each airplane and each pilot, is going to be a little different. But a common structure is to set out the objectives, the rules by which you are going to fly, the personnel duties and responsibilities, contingency plans and the detailed plan for the flight.

Let’s take a look at an example for a first (and second) flight that we performed in our most recent build, a Van’s RV-3. This example can be used to help those of you staring at a blank sheet of paper to get started. For this plan, we had the following sections.

Objectives

This section of the plan describes the real objectives of the day, and for a first and second flight they should be extremely simple. In our case, the No. 1 objective was that everyone would come back home healthy at the end of the day. Everything else was secondary. We’re not, after all, fighting a war here.

Overview

Here we describe the basic plan in general terms, the outline of the flight(s) from which the pilot cards would be developed. Rationale for the plan is included here, so that when this is used for the briefing, everyone is aware of why things are being done the way they are.

Personnel Roles and Responsibilities

In this part of the plan, we describe the jobs that each person will be assigned and their responsibilities. This clearly delineates what everyone should be concentrating on. It also helps, in the planning process, to keep the team as small as possible. Small is good, because it makes the team more flexible and lowers pressure on the test pilot (or anyone else involved) to make the flight happen because people have come out to see it. It can be difficult to abort the flight because the wind is over your limits when a lot of people are watching. Here’s a hint: Spectators have no role in the test plan.

Chase Plane Purpose

Chase planes are often used in test flying, but they are not required. Unfortunately, many folks decide to use one simply because they think they should, and this is a fast way to get into serious trouble, especially if the chase pilot does not understand why he is there or what he should be doing. By clearly delineating the duties of the chase aircraft, and then analyzing if those are good and rational reasons for having one, you can determine if one is needed at all.

If a chase plane is to be used, make sure that its performance matches that of the test aircraft and that the pilot and observer are experienced and clear on their roles.

Communications (VHF and Cell Phone)

This is where you put down all of the useful information that you don’t want to have to go hunting for in flight. It might include frequencies that will be used in the air and on the ground, frequencies that might be used (for alternate airports or emergency services), and cell phone numbers for everyone involved, in case ground coordination is needed. Don’t make your team go searching for a chart for the neighboring tower frequency; put it where you can easily find it.

Abort Modes

As we are all taught in basic training, you need to know where you are going to go at each point in the flight if you have an emergency. Up to what speed will you brake to a stop on the runway? At what altitude can you chop the power and land straight ahead? At what altitude can you reach one of your pre-planned emergency fields? At what altitude will it be safe to return to land on the departure runway? And, heaven forbid, what is your bail-out plan (if you intend to wear a parachute)? These should all be delineated here so that the team and pilot know the game plan. Writing it down makes it real and therefore more likely that you will stick to the plan.

If it is impractical to circle over your airport due to airspace limitations, choose a flight-test area with lots of emergency landing options. The oil field roads in southeast Texas make excellent runways!

Facilities

Where is the flight going to start? What is the home base? Are you going to use facilities elsewhere (in the case where your first landing will be someplace other than the departure point)? Making sure that everyone knows these locations will save cell-phone calls later when the team is waiting for someone to show up.

Weather

The time to decide if the weather is good enough to fly is before you have to stand there trying to rationalize the crosswind away. Specify here, in advance, what you believe to be reasonable limits for winds and weather. Then use these rules on flight day to keep you safe and honest. Don’t put down a limit that you’re not willing to respect, but make sure that your limits have a basis in fact.

Emergency Operations

If something goes wrong, what is the team supposed to do? If the test pilot ends up on a gravel road or in a cornfield, who will do what? How will you establish the location to which everyone needs to respond? Will you have good communications? If the worst should happen, who calls 911, and is 911 even appropriate in your part of the world? These are the questions that need to be answered in this section. Being specific is good.

Flight datacards should cue the test pilot on key aspects of the flight without being distracting. Include emergency contact numbers and frequencies on the card in case the pilot ends up setting down in an unexpected location.

Detailed Flight Plans

Finally, with all the preamble out of the way, the rules and guidelines set, and everyone’s job well defined, plan the actual flight(s). Put it all down, step by step, and then condense it onto pilot cards that will fit on a kneeboard. Make sure that at each step, you know where the test airplane will be, where the ground crew will step in and where the chase plane (if any) will be. Define the flight from engine start to engine stop, and when you build the test cards, make sure to leave room for notes.

Good planning takes time. It is an involved process. Throughout that planning process, constantly ask yourself “Why?” to make certain that the plan makes sense. Start planning for your first flight well in advance, especially if you are not going to be making the first flight yourself. This way, you can maintain control over the process when you bring in the person that you have decided is qualified for the job. Believe me, as one who has done first flights, I build a huge amount of respect for (and comfort with) the individual who shows that he is taking the process seriously enough to create a plan in advance. It shows an attention to detail that probably indicates the airplane is built just as well. With a good plan, you can progress to the next step: training for the mission.

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Paul Dye
Paul Dye, KITPLANES® Editor at Large, retired as a Lead Flight Director for NASA’s Human Space Flight program, with 40 years of aerospace experience on everything from Cubs to the Space Shuttle. An avid homebuilder, he began flying and working on airplanes as a teen and has experience with a wide range of construction techniques and materials. He flies an RV-8 and SubSonex jet that he built, an RV-3 that he built with his pilot wife, as well as a Dream Tundra and an electric Xenos motorglider they completed. Currently, they are building an F1 Rocket. A commercially licensed pilot, he has logged over 6000 hours in many different types of aircraft and is an A&P, FAA DAR, EAA Tech Counselor and Flight Advisor; he was formerly a member of the Homebuilder’s Council. He consults and collaborates in aerospace operations and flight-testing projects across the country.

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