Actually it measures the wake turbulence behind the tail of the aircraft
Yeah, I read an article how some folk are protesting the expansion of the Airbus facility in Hamburg because they're scared the wake turbulence caused by the A380 will demolish a church which is nearby. Also of blowing tiles off the roofs of houses.
CitationJet From United States of America, joined Mar 2003, 2235 posts, RR: 3 Reply 17, posted (8 years 2 weeks 6 days 7 hours ago) and read 2254 times:
Quoting AeroWeanie (Reply 8): Guess again. Its a trailing cone, which provides an accurate static pressure for reducing the flight test data.
AeroWeanie has the correct answer above...
Quoting Andz (Reply 15): I wonder why it wasn't there for the first flight....
They weren't taking flight test data on the first flight that would require accurate static pressures. Also, the chase plane would provide a cross check of airspeed data.
At Cessna, we never use a trailing cones on prototype first flights.
OldAeroGuy From United States of America, joined Dec 2004, 3206 posts, RR: 66 Reply 19, posted (8 years 2 weeks 6 days 3 hours ago) and read 2114 times:
It's a trailing cone for measuring static pressure remotely from the influence of the airplane. This is necessary to calibrate the airspeed system and the altimeters.
This is more involved than it looks. The cone is to stabilize 150' to 200' of cable and hose that is reeled out when the airplane is on test condition. A length of pipe with flush pressure ports in its sides is spliced into the hose ahead of the cone. Static pressure as detected at the ports is measured by instrumentation within the airplane.
Trailing cones are one of the real pains of flight testing as they frequently break off especially if the airplane is doing stalls or windup turns. When they depart the airplane, you go home because your test day is done.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis