Guys, What is this?

It's a flight test drogue. As it is non-functional and merely a visual "feature" I recommend deselecting it in the FMS Options.

Thanks Etienne..

Its for aircraft separation. If you look closely at the red pyramid you will see the lines 'If you can read this then you are flying too close to me!'

You crack me up... So much for "maintain visual seperation".

I know it carries extra air data sensors, but I would love to know what they're measuring.

Static drogue for test aircraft. It only samples static pressure.

There's a video on youtube that explains it quite well. It's about the first 737 made, and how it's being tested by ground engineers for the trip to the museum of flight. The engineer said that when they were designing the plane they could calculate wind flow over the body of the aircraft using computers, but what the computer couldn't calculate was the exact position of the static and pitot ports. These need to be placed in an area of the aircraft not affected by turbulence. So during the initial flight tests, they had this drone chute that would measure actual pressures in a non turbulent environment, and they would experiment with different positions of the static and pitot ports. He then goes on to show all the covered up holes left in the nose of the aircraft left by moving the ports around. It's great stuff. Here's a link to it:

Today I imagine they use it to double check their calculations for the position of the ports.

Specifically, the static cone is used for when you are calibrating instruments. It is dragged along in that place so that it can measure pressure without interference from the airflow off the airframe (i.e. with no dynamically-induced pressure). You would most often see it on prototype aircraft or ones that have any kind of serious modification, when Boeing are testing them. Al

As mentioned, the drogue is used to test the static system, specifically for validating the performance of the altimeters for RVSM certification.

Aha! Thanks, for the replies... always love learning a new facts.

There's a video on youtube that explains it quite well. It's about the first 737 made, and how it's being tested by ground engineers for the trip to the museum of flight. The engineer said that when they were designing the plane they could calculate wind flow over the body of the aircraft using computers, but what the computer couldn't calculate was the exact position of the static and pitot ports. These need to be placed in an area of the aircraft not affected by turbulence. So during the initial flight tests, they had this drone chute that would measure actual pressures in a non turbulent environment, and they would experiment with different positions of the static and pitot ports. He then goes on to show all the covered up holes left in the nose of the aircraft left by moving the ports around. It's great stuff. Here's a link to it:

Today I imagine they use it to double check their calculations for the position of the ports.

Wow! that is one of the best 737 documentries i've seen. I can't beleive how many of the original systems are unchanged on the NGX. Take a look if you haven'e seen it folks!

Is it a HDU for air to air refeulling of very small aircraft?