UK F-35B Lost
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Measuring the wind & WOD is fraught for sure. Allowances +/- are made for the uncertainty of it all. Recall that a ship at sea has Six Degrees of Freedom to confound the wind. The USN LSOs have muchos gadgets to measure all kinds of things during an aircraft approach. The CAT/Launch officer relies on the measures taken - displayed elsewhere - then a traffic light and his/her own judgement about those 6 degrees of freedom before signaling GO. The USN has undertaken lots of studies to measure and mitigate the BURBLE caused by the Island at various spots behind a CVN for approaching aircraft. The FORD class has extra measures to reduce/mitigate this effect (smaller island further aft with fillets on back end of the deck. The Brits invented the 'hurricane bow' to increase the safety for aircraft Ops, whilst of course later inventing the ski jump to increase STO launch safety amongst other effects for suitable aircraft.
During the Sea Venom era particularly, HMAS Melbourne would chase the wind lanes in an otherwise calm South China Sea on hot days to be able to launch those aircraft with transverse (fore & aft) G-limited airframes. The A4G could be launched at 9G transverse limit with usually the 5-6G experienced good enough. It was not unusual to see the tops of the long Pacific swell swirling down the 100 foot catapult track, so timing the launch could be vital. I have been told that my wheels creased the water as I climbed away but I have no recollection of this happening nor could I see this myself anyway, I have other memories. :-)
Ship 6 Degrees of Freedom:
The ship rotational degrees of freedom are termed roll, pitch, & yaw. In the translational degrees of freedom, up and down motion is called heave, forward to aft motion is called surge, & port to stbd motion is called sway.”
During the Sea Venom era particularly, HMAS Melbourne would chase the wind lanes in an otherwise calm South China Sea on hot days to be able to launch those aircraft with transverse (fore & aft) G-limited airframes. The A4G could be launched at 9G transverse limit with usually the 5-6G experienced good enough. It was not unusual to see the tops of the long Pacific swell swirling down the 100 foot catapult track, so timing the launch could be vital. I have been told that my wheels creased the water as I climbed away but I have no recollection of this happening nor could I see this myself anyway, I have other memories. :-)
Ship 6 Degrees of Freedom:
The ship rotational degrees of freedom are termed roll, pitch, & yaw. In the translational degrees of freedom, up and down motion is called heave, forward to aft motion is called surge, & port to stbd motion is called sway.”
Last edited by SpazSinbad; 12th Dec 2021 at 19:42. Reason: addjpg
The wind experienced in a sailing boat is a lot more constant away from the effects of land, though it's obviously not uniform. There also tends to be quite a bit less diurnal variation; the wind at sea doesn't drop at night to the same degree it generally does on land.
Salute!
I always thot the nasal radiators used a flare on the bow and then turned the boat until the smoke went down the deck. And that would seem to work even with the angled deck. Although I unnerstan that landing would involve some different geometry and flight path, but not as much as 20 knot croswind on a land runway.
Gums wonders....
I always thot the nasal radiators used a flare on the bow and then turned the boat until the smoke went down the deck. And that would seem to work even with the angled deck. Although I unnerstan that landing would involve some different geometry and flight path, but not as much as 20 knot croswind on a land runway.
Gums wonders....
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The PDF shows the instruments (also photo) seen by CVN crew to get WOD. The USN CVN crowd are able to carry out simultaneous cats & arrests (me old MELBOURNE could not do this) so there is a compromise for WOD. LAUNCH & RECOVERY BULLETINS for each aircraft state limits for operations of that aircraft. The CVN will work within those parameters when possible. I suppose in really awkward conditions they may not operate launch/land together. The flight deck of a CVN is a busy place indeed. The deck height is about 67 feet with anenanenanennommetters recording wind speed as stated so the readings are as accurate as possible. LSOs have a swathe of instrumentation to goggle at with main LSO concentrating on approaching aircraft so 'the LSOs' know when conditions are not within limits in real time. "POWER POWER POWER don't CLIMB". The flare (fired into the air from port side out to port) was used by the 'NON-LSO' in the Sea Venom era aboard MELBOURNE to wave off aircraft when I guess the deck was foul. During that era MELBOURNE did not have LSOs. Using a flare on deck probably not a good idea due fire hazard etc. Never heard of it meself.
Last edited by SpazSinbad; 12th Dec 2021 at 23:20. Reason: addtext
WW2 era British carriers had a steam feed to the bow which could be used to give a relative wind direction indication. Some pictures show calibrated markings around it to give the angle. Probably made redundant by the steam catapult doing the same thing as a side line.
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Looks like EAGLE had the same problem as MELBOURNE with the catapult start in the landing area. We see a Buccaneer being launched after the post 1964 refit: https://i.redd.it/sa5vv5prv5s31.jpg I'll guess we can see a wisp of steam in middle of bow? Or something else? HMS Eagle R 05 Audacious class aircraft carrier Royal Navy (seaforces.org) and HMS Theseus bow markings: https://www.seaforces.org/marint/Roy...Theseus-03.jpg (ZOOM)
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(Some great reading on this thread, thanks for all the good posts).
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This is pitch
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Not only are there 6 degrees of freedom but also 'urinating into the WOD' is verboten. 
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Story here is just INaccurate: The Time a Plane Launched Directly Into a Wave (popularmechanics.com)
S-2 Tracker Free Take Off into a Wave Spray High WOD Heroes
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"...The bulk of the [Japanese F-35A] aircraft’s wreckage remains on the sea-floor, approximately 5,000 feet underwater. Although it was previously reported by local media that an extensive underwater search recovered the aircraft’s flight recorder, it was too badly damaged (crashed at an [estimated speed of 690 MPH]) for any data of the flight to be retrieved...." https://www.defensenews.com/global/a...or-f-35-crash/
Some more great reading about Naval Aviation may be found here: https://www.faaaa.asn.au/our-history/spazsinbad-a4g/
Not only are there 6 degrees of freedom but also 'urinating into the WOD' is verboten.
Not only are there 6 degrees of freedom but also 'urinating into the WOD' is verboten. Yurrrrgh.
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An example of the 'wind measuring devices' anneenenoonenomomeeters for the F-35B tests aboard CAVOUR. 6 page PDF attached.
...NAWCAD Prepares for Sea Trials By Bob Kaper... [Naval Air Warfare Center Aircraft Division]
...The first simulation session was takeoff and landing training for the ITF test pilots. “We created every sort of testing point such as taking off with different weight, center of gravity, weapons load, asymmetrical loading and wind angle and speed,” said Robert Parlett, F-35 simulation engineer/operator.
The simulator also created replicas of the forces acting on the virtual aircraft along with data from virtual measuring instruments installed on it. As an example, the upward curvature of the ramp produces more force on the nose landing gear than the main landing gear, creating an upward pitching force.
The second phase of the simulator training involved the landing signal officer and air boss in the flight control station. The third simulation phase was training for Cavour crew members.
“Cadence includes how they say things, but also the pace and phrasing,” he said. “The timing between ‘ready’ and ‘clear for takeoff’ on an airfield and on the ship can be totally different because it may take much longer to get ready on the ship.”...
...ATR’s [Atlantic Test Ranges] optical team meanwhile tracked the aircraft through video cameras placed around the ship and monitored wind conditions. To check for clean air behind the bow wake, the team installed two 38-foot-high, pole-mounted anemometers on deck—one at the bow and one at the stern. [SOME NUMNUTS at this time on the internet characterised these towers as LIGHTNING RODS!] They also placed a laser-based anemometer called a lidar at the bow to measure winds at 65 feet. [THIS ONE PARTICULARLY] “All in all, it was a pretty good team effort,” Combs said. “We got an ‘attaboy’ from the ITF. They said ‘best TM (telemetry) on a ship yet’.”
— Bob Kaper is a senior technical writer for Atlantic Ranges & Targets. https://www.navair.navy.mil/sites/g/...ng2021_web.pdf (5Mb)
...NAWCAD Prepares for Sea Trials By Bob Kaper... [Naval Air Warfare Center Aircraft Division]
...The first simulation session was takeoff and landing training for the ITF test pilots. “We created every sort of testing point such as taking off with different weight, center of gravity, weapons load, asymmetrical loading and wind angle and speed,” said Robert Parlett, F-35 simulation engineer/operator.
The simulator also created replicas of the forces acting on the virtual aircraft along with data from virtual measuring instruments installed on it. As an example, the upward curvature of the ramp produces more force on the nose landing gear than the main landing gear, creating an upward pitching force.
The second phase of the simulator training involved the landing signal officer and air boss in the flight control station. The third simulation phase was training for Cavour crew members.
“Cadence includes how they say things, but also the pace and phrasing,” he said. “The timing between ‘ready’ and ‘clear for takeoff’ on an airfield and on the ship can be totally different because it may take much longer to get ready on the ship.”...
...ATR’s [Atlantic Test Ranges] optical team meanwhile tracked the aircraft through video cameras placed around the ship and monitored wind conditions. To check for clean air behind the bow wake, the team installed two 38-foot-high, pole-mounted anemometers on deck—one at the bow and one at the stern. [SOME NUMNUTS at this time on the internet characterised these towers as LIGHTNING RODS!] They also placed a laser-based anemometer called a lidar at the bow to measure winds at 65 feet. [THIS ONE PARTICULARLY] “All in all, it was a pretty good team effort,” Combs said. “We got an ‘attaboy’ from the ITF. They said ‘best TM (telemetry) on a ship yet’.”
— Bob Kaper is a senior technical writer for Atlantic Ranges & Targets. https://www.navair.navy.mil/sites/g/...ng2021_web.pdf (5Mb)
