Jump to content

QFE for Pressure Altimeter not correct


SnapRoll

Recommended Posts

There seems to be an offset on the QFE scale on the Pressure Altimeter.

 

It is not possible to set QFE as directed by the tower. Only values above 947 can be set, but normally it is much lower. With 947 set it is far below sea level.

PC Specs: Win10, 7800X3D, 64GB DDR5CL30@6000Mhz, ASUS ROG STRIX X670E-F, MSI RTX 4090 Suprim X, 2x Samsung 990 Pro 2TB, LG OLED42C2, Pico 4
Flight Sim Gear: VPC MongoosT-50CM2 Grip with WarBRD Base and 6cm extension, VPC MongoosT-50CM3 Throttle, VPC SharKa-50 Collective Grip with Rotor TCS Plus Base, BRD-F1 Rudders(Su-35), 3x8"LCD 1024x768 with TM-MFDs, DIY dashboard with 60 buttons and 8 axis MMJOY2, POV-HAT(no TrackIR)
Aircraft: F/A-18C, F-16C, F-14, F-5E, Mig-21bis, Mig-15bis, AH-64D, Mi-24P, Mi-8MTV2, Black Shark 2 & 3, Uh-1H, FC3, SpitfireLFMkIX, P-51D, I-16, Mosquito FB VI, Bf109K-4
Terrains: NTTR, Normandy, Persian Gulf, Syria, Channel, Sinai

Tech: WWII Assets Pack, Supercarrier

Link to comment
Share on other sites

Does the Su-33 use a different type of altimeter then the Su-27? If so, it should be changed in the Su-33 documentation I suppose.

 

What do I have to set when the Admiral Kuznetsov sends me this?

altimeter.thumb.jpg.77fd4b81cd778289fbf87f9be8ffebed.jpg

PC Specs: Win10, 7800X3D, 64GB DDR5CL30@6000Mhz, ASUS ROG STRIX X670E-F, MSI RTX 4090 Suprim X, 2x Samsung 990 Pro 2TB, LG OLED42C2, Pico 4
Flight Sim Gear: VPC MongoosT-50CM2 Grip with WarBRD Base and 6cm extension, VPC MongoosT-50CM3 Throttle, VPC SharKa-50 Collective Grip with Rotor TCS Plus Base, BRD-F1 Rudders(Su-35), 3x8"LCD 1024x768 with TM-MFDs, DIY dashboard with 60 buttons and 8 axis MMJOY2, POV-HAT(no TrackIR)
Aircraft: F/A-18C, F-16C, F-14, F-5E, Mig-21bis, Mig-15bis, AH-64D, Mi-24P, Mi-8MTV2, Black Shark 2 & 3, Uh-1H, FC3, SpitfireLFMkIX, P-51D, I-16, Mosquito FB VI, Bf109K-4
Terrains: NTTR, Normandy, Persian Gulf, Syria, Channel, Sinai

Tech: WWII Assets Pack, Supercarrier

Link to comment
Share on other sites

Does the Su-33 use a different type of altimeter then the Su-27?

 

Yes it does :)

 

If so, it should be changed in the Su-33 documentation I suppose.

 

Very much agree - other instruments are also different; ADI, VVI, mech systems, fuel gauge.

 

What do I have to set when the Admiral Kuznetsov sends me this?

 

The pressure altimeter in the Su-33 shows values in kPa, for which 101,325 corresponds to 760 mmHg.

 

You can use this for conversion: https://www.convertunits.com/from/mm%20Hg/to/kPa

 

So in your screenshot, the required QFE value(760.13) transmitted to you corresponds perfectly to the kPa value(101.34) the altimeter shows :) .

JJ

Link to comment
Share on other sites

Correction to the above(lol).

 

The Su-33 altimeter uses hectopascal as the unit - I should have picked up on the "гПа" caption.

 

Conversion mm Hg to hPa: https://www.convertunits.com/from/mm+Hg/to/hPa

 

So when your Su-27 altimeter shows 76 mm Hg, it corresponds to 101.34 hPa in the Su-33 altimeter.

 

I think I got it right this time :)

 

 

Hi Alfa, thanks for the replay and info. How does it work in real life, do pilots request QFE in Hg or hPa from the tower?

PC Specs: Win10, 7800X3D, 64GB DDR5CL30@6000Mhz, ASUS ROG STRIX X670E-F, MSI RTX 4090 Suprim X, 2x Samsung 990 Pro 2TB, LG OLED42C2, Pico 4
Flight Sim Gear: VPC MongoosT-50CM2 Grip with WarBRD Base and 6cm extension, VPC MongoosT-50CM3 Throttle, VPC SharKa-50 Collective Grip with Rotor TCS Plus Base, BRD-F1 Rudders(Su-35), 3x8"LCD 1024x768 with TM-MFDs, DIY dashboard with 60 buttons and 8 axis MMJOY2, POV-HAT(no TrackIR)
Aircraft: F/A-18C, F-16C, F-14, F-5E, Mig-21bis, Mig-15bis, AH-64D, Mi-24P, Mi-8MTV2, Black Shark 2 & 3, Uh-1H, FC3, SpitfireLFMkIX, P-51D, I-16, Mosquito FB VI, Bf109K-4
Terrains: NTTR, Normandy, Persian Gulf, Syria, Channel, Sinai

Tech: WWII Assets Pack, Supercarrier

Link to comment
Share on other sites

Hi Alfa, thanks for the replay and info. How does it work in real life, do pilots request QFE in Hg or hPa from the tower?

 

I have no idea mate. I don't know what the deal is with the Su-33 altimeter.....I guess this is just another mystery concerning "the blue wonder" :D .

 

At first I thought it could have something to do with its naval application, but then the MiG-29K(9.31) had a pressure altimeter with QFE in mmHg(like most russian military aircraft) and so does the Ka-27, while the Yak-141 had the same altimeter as the Su-33.....so :hmm:

JJ

Link to comment
Share on other sites

  • 2 weeks later...

Gentlemen,

 

I found a nice site to calculate/convert the pressures and thought I would share. Have fun :thumbup:

 

Aviation Calculations & Conversions by Joachim K. Hochwarth

Rack Rig: Rosewill RSV-L4000 | Koolance ERM-3K3UC | Xeon E5-1680 v2 @ 4.9ghz w/EK Monoblock | Asus Rampage IV Black Edition | 64GB 2133mhz | SLI TitanXP w/ EK Waterblocks | 2x Samsung 970 EVO Plus 1TB | Seasonic 1000w Titanium | Windows 10 Pro 64bit | TM Warthog HOTAS w/40cm Extension | MFG Crosswind Rudders | Obutto R3volution | HP Reverb

Link to comment
Share on other sites

  • 5 years later...
1 hour ago, razo+r said:

Either contact ATC, which will then give you QFE, or fly very low over the airfield/carrier and set your altimeter to 0.

Will it work if I fly right over the sea level, then set it to QNH provided in the mission briefing?

Link to comment
Share on other sites

50 minutes ago, JayJ said:

Will it work if I fly right over the sea level, then set it to QNH provided in the mission briefing?

What do you mean? If you set it to QNH then you are not setting QFE.

But if you want to use QNH to get the QFE, then you need to calculate a bit. As a rule of thumb 30ft = 1hPa.

Link to comment
Share on other sites

12 minutes ago, razo+r said:

What do you mean? If you set it to QNH then you are not setting QFE.

But if you want to use QNH to get the QFE, then you need to calculate a bit. As a rule of thumb 30ft = 1hPa.

Isn't QFE at altitude of 0 (ASL) --> QNH?


Edited by JayJ
Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...