First Test Flight
The goal of a first flight is to verify the airworthiness of the aircraft. This is an important event for the pilot and aircraft but is not a social event. Everything about this flight we want to be "uneventful". You do not need distractions or pressure from friends or family so have everyone stay home but your ground crew. There will be plenty of time later to show your gem to the world, for now be a test pilot and stick to the flight test plan and test flight script.
Be sure to verify the availability and serviceability of all emergency equipment, communications and brief the ground crew even if it's one person. Check weather if you haven't already and if so re-check again. Perform a thorough preflight being sure to check all the fluids and security of items and components. Review the flight manual data. These "standard" tasks should be performed at every test flight with one exception- if a problem is noted in any test flight script- the problem needs to be fixed prior to the next flight and the previous script or check re-flown before moving on.
When should I fly? The calmest part of most days in most locations is early morning, The pilot is rested, and the daylight is arriving.
Prior to hopping in the cockpit I recommend strapping on a kneeboard to record any data or notes and it can also hold the test flight script.
Communications is so vital to safety ensure you do have good comms with ground, flight and tower personnel.
Before we climb in let's review. We have conducted a thorough preflight. The fuel on board is the proper grade or mix. The weight and balance has been computed and is at the correct location for our first test flight. All oil, brake coolant and hydraulic systems have the correct type and quantity of fluid.
It's time to strap the girl on. Get into the ship and ensure the fuel valve is in the proper position. Check any adjustable flight controls for takeoff position. Set the altimeter to field elevation. Check flight controls for freedom of movement and correct deflection direction. Have ground personnel check for security of cowlings and doors. Check communications. Secure cabin door.
The airspeed indicator should be marked, even with temporary tape for the predicted best climb, best glide and maneuvering speed. They can be determined by using the following guides to get you close. You will verify these speeds in the test flights. You can also use the manufacturers listed speeds to give you a ballpark figure to start with.
Best angle of climb (Vx)= 1.5 times predicted lift off speed.
Best glide speed = 1.5 times predicted takeoff speed.
Maneuvering speed(Va)= Check kit manufacturers listed speed as a baseline.
A chase plane can watch systems and parts not visible to the pilot, assist the pilot in progressing through the test flight script. The chase plane can also look out for and inform the pilot of other aircraft and obstacles, as well as assist in an emergency situation. The chase plane should not be a distraction or used as a photo platform. The chase plane should have two people on board and fly 100 to 200 feet to the right and slightly behind and below the test aircraft. Pilots of both aircraft have to keep each other informed of their intentions prior to executing a maneuver.
The two foremost checks that the first flight is to determine is flight control characteristics and the reliability of the engine. These are the areas where all data is to be collected. Using the starting checklist and the test flight script go ahead and get the aircraft started. Ensure all conditions are in their proper operating ranges and pay perticular attention to the oil pressure and coolant temperatures. pay attention to sound and smells as well as any unusual vibrations. If all is good, taxi to a remote area to perform your run-up checks and when ready position for takeoff.
When communicating to the tower or over the unicom frequency announce that you are experimental aircraft your "registration number" on a first flight, departing(or requesting) runway ___ at "so and so" airport. Continue to report your registration number, location and intentions about every ten minutes.
If the oil pressure or engine/rotor tachometer readings are too low, abort the takeoff. If there are any unusual vibrations or engine hesitation with advancement of the throttle, abort the takeoff.
When the aircraft approaches liftoff speed ease back on the stick. Be gentle in the maneuver. If the aircraft doesn't liftoff or the controls do not feel right, abort the takeoff. If all is good and you are about to assume flight note the airspeed that the aircraft broke ground.
After establishing a safe climb angle the FAA does not recommend that you throttle back, switch fuel tanks or make large control inputs until you have at least a thousand feet of altitude under your feet. At your target altitude slowly reduce power to avoid any rapid pitch change. During your ascent pay particular attention to control forces and try adjusting the trim to reduce stick forces but make inputs slow and small. Continue to monitor oil and fuel pressures, cylinder head or EGT temperatures and coolant temperature and follow the test flight script. Keep informing the chase plane, ground crew, unicom or tower on your location and status.
Your first flight should be no more than an hour maximum. Even with an uneventful flight the pilot will have a lot of stress and the aircraft needs to be safely brought back to the earth. You can practice your approach at altitude as often as needed(depending on fuel supply) before entering the airport.
Announce your intentions to land and complete the before landing checklist before you enter downwind. Keep all turns shallow- less than twenty degrees.
On final approach adjust your airspeed for landing and avoid over controlling. Be prepared to perform a go-around if conditions are not favorable for a safe landing. Be sure of your abort marker for roll out. If the aircraft cannot be stopped before the marker perform a go around.
Taxi back and secure the aircraft and perform a thorough post flight inspection and then debrief the support team. Refine and improve the script and coordination as needed.
Perform any necessary maintenance actions and correct any faults noted from the previous test flight before proceeding. Continue to fly off your hours methodically and safely.
I cannot count the number of maintenance test flights I have been on and every one of them was conducted by following each item on the checklist, recording data or findings and if all was satisfactory progressing to the next check. I caution you on becomming complacent. Complacency is where Murphy lives and you have enough stuff to worry about and perform than to have Mr. Murphy show up. Keep your senses high as to the feel, sound and smells. They can be early warning signs before you see any cockpit indications or feel any abrupt change of aircraft attitude. There are several books available on flight testing homebuilt aircraft and recommend getting at least one of them before starting flight testing. The EAA has an excellant workshop on test flying homebuilt aircraft and having attended I fully recommend this course as a great benefit in your preparations to conduct your flight testing. Don't leave out the friendly technical counslor for their steadfast support in your endeavor and passion.
While we have performed a virtual first flight with words there are some tools that can also help you rehearse for your first flight and coordinate the test flight script. Simulators.
Flight simulator software really can be a useful tool- to find out more see Flight Sims.