investigating Bombing solution seems to use Barometric Altitude only

[YoYo]

I've done some testing, using different altitudes and different maps. I haven't touched QNH (its from briefing). I only use CCRP for the drop, and it seems to be working fine. However, there are a few things worth observing. Ideally, the airspeed should be around 750-850km/h, the altitude should be 2000 m or less (though it's hard to say what the radar altitude is). I turn on the laser manually, but wait until I'm relatively close to the target (less than 4.5 seconds), and indeed, without adding different QFE, I hit very well.

[IvanK]

10 hours ago, AeriaGloria said:

2. target altitude and QFE must be set for CCRP (this part works and is seemingly correct) 

Why are you talking about QFE ? 

The ME entry for atmospheric pressure is QNH that is Altitude Above Mean Sea Level (AMSL)

QFE is Altitude above the airfield elevation ... setting QFE will have the altimeter reading zero.

The DTC Altitude entry is AMSL so you need to be setting QNH on the aircraft Altimeter.  The DTC in DCS is not interested in QFE !

IRL

I believe standard Russian practice is indeed to use QFE rather than QNH certainly for airfield operations. However At present the DTC and therfore the MIG29 weapons calculation are only interested in QNH as the altitude datum.

Our only reference we have found so far is the Alan R . Wise version of the MIG29 manual that talks about setting a Delta H value for target elevation into the system. Now if this is indeed correct then QFE would indeed be what the weapon system references.

Here in lies the conundrum, DCS DTC is using QNH as the datum 

DEVS

A clear description from the devs on how the MIG29 actually does its ranging (in DCS) would solve this argument once and for all. At present we are all groping in the dark just a little.

 

[Кош]

19 минут назад, IvanK сказал:

Why are you talking about QFE ? 

The ME entry for atmospheric pressure is QNH that is Altitude Above Mean Sea Level (AMSL)

QFE is Altitude above the airfield elevation ... setting QFE will have the altimeter reading zero.

The DTC Altitude entry is AMSL so you need to be setting QNH on the aircraft Altimeter.  The DTC in DCS is not interested in QFE !

IRL

I believe standard Russian practice is indeed to use QFE rather than QNH certainly for airfield operations. However At present the DTC and therfore the MIG29 weapons calculation are only interested in QNH as the altitude datum.

Our only reference we have found so far is the Alan R . Wise version of the MIG29 manual that talks about setting a Delta H value for target elevation into the system. Now if this is indeed correct then QFE would indeed be what the weapon system references.

Here in lies the conundrum, DCS DTC is using QNH as the datum 

DEVS

A clear description from the devs on how the MIG29 actually does its ranging (in DCS) would solve this argument once and for all. At present we are all groping in the dark just a little.

 

Why do you use non original manuals?

[AeriaGloria]

50 minutes ago, IvanK said:

Why are you talking about QFE ? 

The ME entry for atmospheric pressure is QNH that is Altitude Above Mean Sea Level (AMSL)

QFE is Altitude above the airfield elevation ... setting QFE will have the altimeter reading zero.

The DTC Altitude entry is AMSL so you need to be setting QNH on the aircraft Altimeter.  The DTC in DCS is not interested in QFE !

IRL

I believe standard Russian practice is indeed to use QFE rather than QNH certainly for airfield operations. However At present the DTC and therfore the MIG29 weapons calculation are only interested in QNH as the altitude datum.

Our only reference we have found so far is the Alan R . Wise version of the MIG29 manual that talks about setting a Delta H value for target elevation into the system. Now if this is indeed correct then QFE would indeed be what the weapon system references.

Here in lies the conundrum, DCS DTC is using QNH as the datum 

DEVS

A clear description from the devs on how the MIG29 actually does its ranging (in DCS) would solve this argument once and for all. At present we are all groping in the dark just a little.

 

Sorry QNH. 
 

I found the phrase from the Alan Wise manual in the L-18 Yugoslavian manual where it’s likely translated from 

[IvanK]

1 hour ago, AeriaGloria said:

I found the phrase from the Alan Wise manual in the L-18 Yugoslavian manual where it’s likely translated from

Can you show us that in both English and the native ? Be great to see it. I have the L18 (VTU-01.VTUP.001/01.0) manual got a page reference for the statement. I struggle with the Yugoslav translation though.

 

1 hour ago, Кош said:

Why do you use non original manuals?

I do but struggling with the translation

Edited Tuesday at 11:10 PM by IvanK

[AeriaGloria]

1 hour ago, IvanK said:

Can you show us that in both English and the native ? Be great to see it. I have the L18 (VTU-01.VTUP.001/01.0) manual got a page reference for the statement. I struggle with the Yugoslav translation though.

 

I do but struggling with the translation

“

The introduction of ballistic data of the aircraft bombs is carried out before the PK flight by a special team, by setting the coated switches (code guidance) in positions corresponding to the code of the aircraft bombs being used. Depending on the conditions of combat use and the mode of bombing with the PVK, the elevation, the target's descent relative to the take-off airport (HEA) and the specified bomb drop angle are additionally introduced when bombing from a climb.

In addition, ballistic data input is also provided for all aircraft bombs with PVK.”

Uvodjenje balističkih podataka avionskih bombi vrši se pre leta PK od strane posebne ekipe, postavljanjem obloženih preklopnika (kodno vodjenje) u položaje koji odgovaraju kodu avionskih bombi koje se upotrebljavaju. Zavisno od uslova borbene primene i režima bombardovanja sa PVK, dopunski se uvodi nadvišavanje, priniženje cilja u odnosu na aerodrom poletanja (Hea) i zadati ugao odbacivanja bombi pri bombardovanju iz kabriranja (penjanja).

Pored toga, za sve aviosnke bombe sa PVK se obezbedjuje takodje informaciono uvodjenje balističkih podataka.
 

It is page 324. Gonna try and find it in the Russian version. When bombing from a climb implies to me that this primarily meant for CCRP. 

Edited Wednesday at 12:33 AM by AeriaGloria

[IvanK]

Ok thanks. found it too

[UWBuRn]

On 11/11/2025 at 11:13 AM, BIGNEWY said:

 

Good to hear, so I can mark this issue correct as is as it does seem to be working as intended. 

 

Sorry, i don't know if i'm doing something wrong but to me it still looks like that if target elevation is set in the DTC, the laser rangefinder is ignored and accuracy is degraded.

PLease see the track.

Maybe if somebody else can make a test for this it would be helpful.

server-20251113-062137.trk

[AeriaGloria]

4 minutes ago, UWBuRn said:

Sorry, i don't know if i'm doing something wrong but to me it still looks like that if target elevation is set in the DTC, the laser rangefinder is ignored and accuracy is degraded.

PLease see the track.

Maybe if somebody else can make a test for this it would be helpful.

server-20251113-062137.trk 1019.16 kB · 0 downloads

Even if you don’t set target altitude it ignores the laser for bombing mode 

[UWBuRn]

20 minutes ago, AeriaGloria said:

Even if you don’t set target altitude it ignores the laser for bombing mode 

Nope, if you don't load the DTC or your DTC has not points defined you will see the laser works.

Edited Thursday at 05:52 AM by UWBuRn

[AeriaGloria]

2 hours ago, UWBuRn said:

Nope, if you don't load the DTC or your DTC has not points defined you will see the laser works.

You are right! I don’t know how I missed it. So without DTC set the CCIP works within laser range, and CCRP seems to work better then completely off, but not as accurate as target altitude set (as long as the CCRP sequence is started from within laser range). It seems the closer the range CCRP is begun and the less the pitch up the greater the accuracy. In some tosses my CCRP seemed pretty accurate without DTC, but it seemed oddly situational. 
 

Changing the altimeter QNH seemed to have an effect on CCRP but of course not at all on CCIP, that is without DTC/target altitude set as you said. 
 

It is not the biggest sacrifice as it still allows you to accurately bomb from 3.5 km away. 

[UWBuRn]

1 hour ago, AeriaGloria said:

You are right! I don’t know how I missed it. So without DTC set the CCIP works within laser range, and CCRP seems to work better then completely off, but not as accurate as target altitude set (as long as the CCRP sequence is started from within laser range). It seems the closer the range CCRP is begun and the less the pitch up the greater the accuracy. In some tosses my CCRP seemed pretty accurate without DTC, but it seemed oddly situational. 
 

Changing the altimeter QNH seemed to have an effect on CCRP but of course not at all on CCIP, that is without DTC/target altitude set as you said. 
 

It is not the biggest sacrifice as it still allows you to accurately bomb from 3.5 km away. 

CCRP might work worse because laser might lose LOS (or never achieve it), so it may revert to INS memory or baro/alt, i haven't tested that so much. Honestly, i think that if you're looking pinpoint accuracy CCIP is better.

The whole point is that having the laser working only without DTC (or with DTC without points) seems inconsistent to me. @BIGNEWY Can you check this with the team? Please see the track in my post above.

[ldnz]

This matches my testing too, no DTC and laser is clearly used (see slight jumping around in solution as laser passes over objects), but with a DTC loaded its back to barometric.

[BIGNEWY]

28 minutes ago, UWBuRn said:

@BIGNEWY Can you check this with the team? Please see the track in my post above.

yes I have asked the question, wating for a response from the team, they need some time as they are busy 

thanks