Aerial Photography and Flight Planning By: Chris Peters
Objectives • Identify some basic regulations for a flight under visual flight rules (VFR) • List required equipment • Analyze forecasted weather according to VFR weather minimums • Interpret aeronautical charts, including different types of airspace • Identify the difference between pilotage and dead reckoning • Create a final flight plan that will comply with VFR regulations, including the use of navigation systems as backup
What is VFR? • Flight is to take place using visual references • Must avoid clouds • Normally have a distinguishable horizon • Should have sight of the ground below, or in some cases, a cloud layer below as long as it will not cause spatial disorientation (vertigo) • Flight plan is NOT required
Required VFR Equipment • “TOMATO FLAMES” acronym • Tachometer • Oil pressure gauge • Manifold pressure gauge • Airspeed Indicator • Temperature gauge • Oil temperature gauge
Required VFR Equipment • Fuel level gauge • Landing gear position indicator • Altimeter • Magnetic heading indicator • Emergency locator transmitter (ELT) • Seat belts
VFR Weather • Visibility must be 3 miles or greater • Ceiling must be 1,000 feet or higher • Ceiling is defined by broken or overcast cloud layer (7/8 or 8/8 coverage)
VFR Weather • For photogrammetry purposes, clouds in the photographs are undesirable. • Can usually tell where clouds will form by obtaining the temperature and dew point for the area. • The difference between the two can be multiplied by 500 for an estimate of the altitude at which clouds will form (average lapse rate is two degrees per 1,000 feet).
VFR Weather • For example, if the temperature is 22° C and the dew point is 18° C: • 22° C - 18° C= 4 • 4 x 500 FT = 2,000 FT • Clouds on this day would form at 2,000 feet. This would probably not be a good day for aerial photography as your options would be very limited. • Look for days with a high temperature - dew point spread.
Airspace • Class B Airspace – solid blue line – busy airports (Miami International Airport, Tampa International Airport, Orlando International Airport) • Class C Airspace – solid magenta line – less busy airports still serviced by major airlines (Jacksonville International Airport, Daytona Beach International Airport) • Class D Airspace – dotted blue line – small airports with control towers (Gainesville Regional Airport) • Class E Airspace – controlled airspace sandwiched between all of these below 18,000 feet • Class G Airspace – uncontrolled airports
General Information • Minimum altitude over sparsely populated area: 500 feet above ground level • Minimum altitude over densely populated area: 1,000 feet above ground level • Use your best judgment regarding sparse vs. dense • Maximum altitude in Class E airspace: 18,000 feet mean sea level (MSL)
General Information • Above 18,000 feet is Class A airspace and requires special procedures (instrument flight rules and flight plan – no VFR) • Conservation areas request airplanes to stay at least 2,000 feet above ground level • Be aware of prohibited, restricted, warning, and military operations areas, as noted on the sectional chart
General Information • Minimum airspeed in basic single engine airplane: 60 knots • Minimum airspeed in light twin engine airplane: 88 knots • Cruise airspeed in basic single engine airplane: 120 knots • Cruise airspeed in light twin engine airplane: 152 knots
General Information • Flying at a slower speed will allow for a better turning radius • Flying too slow becomes very inefficient with regards to fuel • Best speed is one where lift and drag are equal, making it most efficient • Typically, you can plan for there to be about four hours worth of fuel on board
General Information • Crab: wind coming from the South will require an airplane flying East to use a crab angle into the wind in order to fly due East. • For example, the crab angle may be determined to be 3 degrees, and the airplane will need to fly a heading of 93° in order to achieve a course along 90° East. • This will affect the camera on board the aircraft. The crab angle will need to be compensated for in order to photograph along straight lines on the ground
General Information • Aircraft modifications: extensive modifications to the aircraft will require an FAA certificated Airframe & Powerplant mechanic to record new weight & balance data • Simple equipment brought on board for use during flight needs to be accounted for by the pilot when he or she computes weight & balance numbers for the flight
Aircraft Avoidance • Because flying height should be constant for photogrammetry purposes, this may cause a problem with normal VFR altitudes related to direction of flight. • A simple way to remember what altitude you should be flying at based on your direction is the acronym, ONE. Odd North East. If you are flying in a general north or east direction (course between North 0° or 360° and 179°), you should be at odd thousand feet intervals plus 500 feet for VFR (3,500 feet, 5,500 feet, 7,500 feet).
Aircraft Avoidance • Traffic could potentially be traveling in the opposite direction at your altitude if you are heading west when flying at 3,500 feet. • Yield to the right, and the airplane to your right has the right of way (correct your path so as to pass behind the other airplane)
Creating the Flight Plan • Navigate to http://www.skyvector.com • Pick an area you will be taking aerial photos of. • Start out from an airport within this area or near it (i.e., type “KGNV”, the airport identifier code for Gainesville Regional Airport, into the “Location Lookup” box • Zoom all the way in for greatest detail
Creating the Flight Plan • Determine the flight lines you will fly in order to cover the entire area • To set points and create the flight lines, right click a spot on the map and select the GPS point • Determine crab angle based on wind relative to flight path and plan to adjust camera accordingly
Creating the Flight Plan • Because this particular flight plan would involve flying back and forth through Gainesville’s airspace, you would want to let the tower know your intentions so the controller can help keep other aircraft separated from you • You would also want to monitor the tower frequency at all times
Creating the Flight Plan • Pilotage: flying according to visual references (landmarks clearly visible on the ground) • Dead Reckoning: estimating one’s location based on ground speed and elapsed time between checkpoints • Navigation backup: since most airplanes are now equipped with some form of GPS, if one gets “lost”, he or she can simply press the “NRST” button on the GPS equipment and find the nearest airport (or other navigational aid) and land the airplane.
References • Code of Federal Regulations Title 14 Volume 2 Chapter I Parts 61, 71, and 91 • http://www.skyvector.com • Wolf, Paul R. and B. Dewitt, 2000. Elements of Photogrammetry with Applications in GIS. McGraw-Hill.
The End! • Please fill out a lesson evaluation • I have Gleim “Learn to Fly” booklets here, which I think are a great introduction to flying. As Gleim says, “If you can drive a car, you can fly an airplane.” Please take a copy or send me an e-mail if you would like one.