Monday, 29 June 2015
FLIGHT PATH VISUALISATION
(Acknowledgements: Air Facts – Dick’s blog)
Dick says: “I have flown with a lot of pilots and have worked hard to help them develop the ability to visualise the flight path of the airplane.
Glass cockpits show a flight path vector in the middle of the display – unfortunately we can’t all afford the head-up display or synthetic vision system that includes the flight path vector, but I’ll always remember the first time I flew with one of these. Being able to see where the airplane was going seemed like magic – BUT, can one visualise it without such technology? Indeed yes.
I was vaguely aware of how this worked when an article came in at the Air Facts on the subject of precise approaches and landings. The author was Captain Gordon Graham, USMC, who was at the time an instructor at Pensacola. Gordon’s explanation of how to do it was based mainly on visual cues from the ultimate head-up display, THE GREAT OUTDOORS. He led the reader through the visual cues found on downwind, the constant turn around to line up on finals, and short finals.
The key to developing the ability to see the flight path vector without instrumentation is in simple terms to ensure that the point toward which you require the airplane to fly remains stationary in your windshield. For example, if on finals the touchdown zone is moving lower in the windshield, you are overshooting. If it is moving higher in the windshield, you are undershooting. If it is remaining in the same place in the windshield, things are fine so long as the airspeed is good and the approach path is steep enough to clear any obstacles. No pilot who has broken an airplane in an under-shoot or over-shoot accident could have paid heed to that.
I would recommend using 500 feet above the ground as the place to make a decision on the approach. At that height, if the view out front doesn't look right, it is time to go around and start again. Most go-arounds that result in crashes start much later than that.
I have found flight path visualisation to be of particular value for night approaches to runways without visual approach slope guidance. In such a case I would get established with the touchdown zone remaining stationary in the windshield and the airspeed on a correct value, and then consult the vertical speed. If this shows less than a 600 fpm rate of descent I would consider the approach too shallow and take steps to steepen it. Fortunately, most runways do have visual approach slope guidance, but if inoperative for any reason then the ability to visualise your flight path comes into its own.”