Altitude errors...

[Ken Hall 2]

Alex, I posted the following on the Radar Contact forum but copied to yourself as i believe theye may be a connection (?).

W10; P3Dv5.3+; Radar Contact; LittleNavMap v2.8.12 (32bit), N2313; ASP3D + Cloud Art.

Radar Contact has been my must have addon for almost 20-years to the extent that I never fly without RC4 running!

Just recently I have been chastised unmercifully by ATC for not observing my 'given' altitude - this always associated with the descent phase of flight.

For example: "descend to alt 9000ft" - done - altitude 9000ft indicated on all instruments (including GoFlight MCPPro).

ATC keep calling me to stay with my assigned altitude - I am - warnings about being hauled in front of the FISDO and loosing licence.

I note that in the LNM map my aircraft is showing an altitude around 555 - 895 ft above 9000ft !!!🤕 despite all other indicators at 9000ft.

I have even changed my deviation to 1000ft in the General settings in RC4 - still receive warnings!

If I run P3D with only LNM the altitude numbers are correct at all levels - only when running RC4 am I having this 'fault'.

Am I missing something that I have not noticed/experienced previously?

Some 'assistance' would really, really be appreciated.

I have also posted this item on the LNM forum section.

Ken H.

[albar965 1,074]

LNM shows different altitude values like indicated or actual in the progress tab and elevation profile. You can configure this in the tools menu. Check if you look at indicated which should show the same values as the aircraft instruments.

There is also a deviation depending on cold weather where you have to apply a correction. Not sure if P3D models this. X-Plane 12 and MSFS do.

Alex

[Ken Hall 2]

Alex, thanks for your response.

The 'deviation' link made for interesting reading but I have not found any reference to it within P3D - will make further enquiries.

I do recall seeing the OAT being very cold! Will make a point of recording OAT for future issues.

My LNM is configured for Altitude in 'Tools' as:Indicated, Actual, AGL, Grd Elev, AP selected.

Will try another flight (up to Keflavik where it should be quite cold!) and report back.

Thanks,

Ken H.

 

[albar965 1,074]

4 hours ago, Ken Hall said:

I do recall seeing the OAT being very cold!

Hi Ken,

this might be the reason. Maybe it was implemented in P3D. LNM does not do cold weather correction. It simply reads what is provided by the simulator.

Indicated should always match what you see in the cockpit. No matter what baro settings are applied.
Actual will differ from indicated in the flight levels using the standard baro 29.92.

The aircraft position in the elevation profile uses indicated, by the way. Therefore you can see "kinks" in the profile aircraft trail when adjusting the baro setting.

Alex

[Ken Hall 2]

Hi Alex,

as a courtesy I copy my recent reply to Ray Proudfoot (RC).

"Made a flight EGSS - Vienna and monitored the altitude all the way!

Once above TA from Stansted the variations started with a difference between 'Indicated' and 'Altitude' of 350 - 480 feet.

Another 'interesting' challenge today was noted after crossing a VOR and changing frequencies for the next VOR the aircraft (freeware 777) started  'porpoising' with climbs of over 1000 feet then a drop to 600 - 800 below the planned FL350! Resulting in being shouted at by ATC with the offer of further help/training 🤐.

Holding the advised QNH until reaching the TA did make a difference with only an 'odd' 30 - 40 feet above the ground. That difference could be the reason why I have 'missed' the glide slope a few times recently 🤕 by being just a tad higher than necessary to pick up the beam!!!

All goods fun 😎."

 

Alex, I apologise for not commenting sooner ~~~ the addition of the 'green banana' to LNM has been a major 'improvement' for me personnaly and has made reaching a crossing point accurately so much easier. Thank you so much 😎.

Ken H.

[albar965 1,074]

56 minutes ago, Ken Hall said:

Holding the advised QNH until reaching the TA did make a difference with only an 'odd' 30 - 40 feet above the ground. That difference could be the reason why I have 'missed' the glide slope a few times recently 🤕 by being just a tad higher than necessary to pick up the beam!!!

You should rather intercept the beam from below where it does not make a difference if you're 500 or 1000 ft below. A good autopilot (or even better: a pilot flying manually 😉) will never climb to intercept a glideslope.

 

58 minutes ago, Ken Hall said:

Once above TA from Stansted the variations started with a difference between 'Indicated' and 'Altitude' of 350 - 480 feet.

Expected if your baro is set to standard.

Alex

[Ken Hall 2]

Hi Alex,

just been advised by my VA that the 777F aircraft I had downloaded from them is not compatible with P3D4/5 - FSX model only, not suitable for 64-bit systems.

Aircraft uninstalled - challenge over (?)...

Ref the glideslope: my point was that I had overshot the beam due to the altitude variation! I do not normally have any difficulty intercepting the slope.

This altritude issue has only recently started and with this aircraft!

Ken H

[albar965 1,074]

Hi Ken,

thanks for getting back to about this. Some aircraft designers really do strange things to circumvent simulator restrictions. Thinks like SimConnect reporting zero fuel flow or the target altitude of the autopilot being off.

Alex