So I've uploaded this video (initially unlisted) of an example of curved latitude lines on the Miami Sectional ahead of his complaint!
53C52
I'm guessing Daniel will complain that the latitude lines in the first video (youtu.be/_v22axzvs3w) are curved only because I used an Alaska Sectional.
So I've uploaded this video (initially unlisted) of an example of curved latitude lines on the Miami Sectional ahead of his complaint!
So I've uploaded this video (initially unlisted) of an example of curved latitude lines on the Miami Sectional ahead of his complaint!
updated 5 years ago
So I've uploaded this video (initially unlisted) of an example of curved latitude lines on the Miami Sectional ahead of his complaint!
Not surprisingly, just as with the Point Barrow youtu.be/_v22axzvs3w chart and the Miami chart youtu.be/A_MZxJEKj14 , the latitude lines are all clearly curved and the longitude lines converge towards the north.
This chart tells a different story.
I threw in a couple of bonus ONC charts from the southern hemisphere.
Thanks to Florence Gomer for pointing out that although the Aireon ADS-B position reports weren't included in the logs for QE11's record-breaking circumpolar flight, they were shown on FlightAware's coverage map this week.
WheresWa11y's excellent demonstration of the difference between an aircraft's actual position and the estimated position shown by online flight trackers when a flight is beyond the coverage area of their ground-based receivers... youtu.be/zolmv5AGMCU
Here are a few photos taken by the crew of the cockpit navigation display...
Over Antarctica, roughly 1,500km from the south pole at 43,000 ft. Outside air temperature -73C
twitter.com/ActionAviation0/status/1149033326998708224
About 140km from the south pole at 43,000 ft. Outside air temperature has dropped to -80C
twitter.com/ActionAviation0/status/1149249767958036480
After crossing the south pole, outside air temperature has dropped to -83C.
As confirmed by the Aireon data, they're forced to descend to warmer air.
twitter.com/ActionAviation0/status/1149250424857403392
Loaded Jan29 QFA63 SYD-JNB flight plan route in ForeFlight app.
Added great circle route (magenta line) to show the relationship between the two routes.
Turned on winds aloft to show that the planned route takes a large detour from great circle route in order to avoid an area of very strong headwinds.
Is "Zac" deceiving POTP about his credentials and/or beliefs, or is POTP intentionally deceiving his viewers with a script full of lies?
For information from a genuine pilot, visit Wolfie6020's channel.
Note the lines of longitude converging to meet at the south pole.
First up is JeppFD, the second is ForeFlight.
Note that both apps plot the route using the shortest path on a globe.
This video demonstrates the alignment process of a Honeywell IRS as it carefully measures the slow rotation of the earth to determine the aircraft's latitude and direction to the geographic north pole.
Key points to note are:
1. The IRS consistently determines the correct direction to geographic north, even when it is initialized to an incorrect location.
2. The IRS can be initialized at a grossly incorrect longitude because it is unable to use the rotation of the earth to determine longitude, and therefore is unable to complete a reasonableness check of the initial longitude being supplied to the device.
3. The IRS uses Earth rotation to calculate an accurate latitude which it will use to cross-check the initial position that is supplied during the align mode for reasonableness. This calculation of latitude using direct measurement of Earth's rotation makes it impossible to operate the IRS in navigation mode if the initial position sent to the IRS contains a grossly incorrect latitude.
Early Inertial Navigation Systems use 3 precision mechanical gyros. The gyros are mounted so that each spins on an axis that is 90 degrees to the other two along with 3 linear accelerometers mounted in a similar fashion.
Those components are mounted on a platform that is free to rotate on gimbals within the case. In order to use an INS, it first needs to go through an alignment process. During alignment, the aircraft needs to be stationary so that the gyros are subjected to movement caused only by the very slow rotation of the earth. This rotation is sensed as gyroscopic precession which is then used to drive servo motors to rotate the platform to align it in the direction of geographic north and parallel to local level.
The video linked below is an example of an INS coarse alignment. This rapid alignment is sufficient for the instrument to output attitude information, but the full alignment process to get the instrument ready for position tracking takes several minutes.
youtu.be/w4yaNn4Xmfg
Today's Inertial Reference Systems are an improvement on that old design and use ring laser gryos in place of the mechanic gyros. RLGs are not really gyros in the traditional sense of the word because they do not consist of a spinning mass, and do not exhibit the gyroscopic properties of precession and rigidity in space. They are, however, very good at measuring very small rates of rotation.
IRS does not use a floating platform as was used with the old mechanical gyros. The accelerometer and RLG orientations with respect to the airplane are fixed. This is why this type of unit is referred to a "strap-down" inertial. Like the older INS, IRS also needs to complete an initialization process called alignment, but in the IRS there is no physical alignment of a platform taking place.
Rays converge at a point ahead of the airplane while the sun is behind the airplane.
Still image: drive.google.com/open?id=0B4aJti-aC8gAMDlFcFJBQUo3aVU