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IDProjectCategoryView StatusLast Update
0000048Falcon BMS Known BugsAvionicspublic2021-05-06 23:12
Reporteranonymous Assigned ToI-Hawk  
PrioritylowSeveritytrivialReproducibilityalways
Status assignedResolutionopen 
PlatformPCOSWindowsOS VersionWindows 10
Product VersionBMS 4.35 
Summary0000048: HUD symbology not fully following SPI/STP logic in NAV mode
DescriptionAccording to Dash-34, HUD symbology (tadpole, range, time to go) in NAV and AA master modes will refer to the STP even if the SPI points somewhere else. This is true for slant range and range to STP, time over steer point but not for time en-route. If you slew the SPI away from the selected STP you will see that the ETE on HUD will adjust to the SPI and not stay fixed for the selected STP. If you mode select TOS on the CRUS page, time over STP will not be affected by SPI slewing.
Steps To ReproduceIn NAV mode switch FCR to GM mode and start moving the radar cursor away from the selected steer-point. Observe in the HUD how the diamond moves but the tadpole and ranges to STP stay fixed, ETE on the other hand follows the SPI.
TagsHUD
Theatre of OperationsKTO

Activities

Blu3wolf

Blu3wolf

2021-01-11 22:46

manager   ~0000089

1.2.7.6.4 Steerpoint Diamond Symbol - In the air-to-ground and navigation modes, the steerpoint diamond (Figure 1-82) is positioned at a point equal to the selected steerpoint plus cursor corrections.

1.2.7.7.10 Window 10 - Displays the measured range from the highest priority tracking sensor and a mnemonic identifying that sensor.
(Blu - as an aside, options are F (FCR), T (ATP IMU), L (ATP Laser), R (Radar altimeter), B (steerpoint elevation/barometric data), P (DTS passive ranging) or H (HTS provided ranging). Note that for MULT, PRE, VIS post designate, and MPPRE, its horizontal range instead of slant range.)

1.2.7.7.13 describes window 13, but its got a lot of text. For A-G with no defined target, or for navigation mode, air to air missile, dogfight, or MRM modes... "time to destination is displayed in minutes and seconds; or time of arrival is displayed in hours, minutes, and seconds if TOS mode is selected."

1.2.7.7.14.1 describes window 14, same deal as above. "The selected steerpoint number is displayed at the extreme right side of the window. Distance-to-steerpoint data and steerpoint number are separated by a greater than (>) symbol."

1.3.3.1.4.2.1 Cursor Corrections and Cursor Zeroising - The pilot can slew the navigation solution to correct it to the required performance or to acquire targets. Pilot induced corrections are accumulated and placed in different cursor “buckets” depending on the master mode/VIP/VRP/Snowplow state.

So, in summary. Moving the GM cursor in NAV mode is slewing the navigation solution. The diamond is displayed at the steerpoint location, plus cursor corrections. 4.35 does this correctly. Most of the time and distance data should refer to the corrected steerpoint location, but in 4.35 (and older versions) instead refers to the uncorrected steerpoint location.

Does that sum it up?
anonymous

anonymous

2021-01-12 03:26

viewer   ~0000096

It does sum it up with a remark that in BMS this behaviour is documented (see attached manual entry).
grafik.png (144,676 bytes)   
grafik.png (144,676 bytes)   
Blu3wolf

Blu3wolf

2021-01-12 05:20

manager   ~0000098

This is unusual to me, because the MMC doesn't distinguish between the STPT and the SPI. They are the same thing.

Window 13 (ETE or ETA) shouldn't change between master modes. Same for window 14 (Distance to go).

Issue History

Date Modified Username Field Change
2021-01-11 16:53 anonymous New Issue
2021-01-11 16:53 anonymous Tag Attached: HUD
2021-01-11 22:46 Blu3wolf Note Added: 0000089
2021-01-12 03:26 anonymous Note Added: 0000096
2021-01-12 03:26 anonymous File Added: grafik.png
2021-01-12 05:20 Blu3wolf Note Added: 0000098
2021-01-12 06:10 I-Hawk Assigned To => I-Hawk
2021-01-12 06:10 I-Hawk Status new => assigned
2021-04-09 01:08 anonymous Tag Detached: HUD
2021-05-06 23:12 Blu3wolf Tag Attached: HUD