How to: CAT approaches

[PatrickM 2]

Hello,

I flew from EDI to MAN this night. I put the FMC to ILS23R via ROSUN1B, than I changed to the "blue needles" and put my course to 233°. The same procedure on the F/O side.

I was Intercepting the ILS on 3500ft, selectet HDG, changed the NAV source to NAV1 (same on the F/O side) and the PFD says I am on ILS1 than I hit the approach button. The plane followed the ILS completly, but at 1500ft (or 1000ft - I doesn't renember) an "NO DUAL" sign occured on the PFD! HSI and AP was on both sides... What have I done wrong?

The Dash 8-Q400 can do an CATII approach (?) and a CATIII approach only with HUD:

[PatrickM 2]

Has anyone an idea? My second attempt has failed completely... LOC and GS was captured (changed to green in the PFD) but after a few seconds it changed to WING LVL and to PITCH HLD... I have no idea...

Please, please help me!

[groentesoep 22]

Did you set the F/O Nav source to Nav2 and tuned the ILS Frequency on both the NAV Radio's?

 

The WING LVL and PITCH HLD will usually occur when you have to low airspeed. Try to keep the speed at around 10 kts above Vref.

[PatrickM 2]

I put NAV1 and NAV2 frequency in the FMC (both radios were set to FMC as tuning source).

 

And for WING LVL and PITCH HLD - I will keep my eyes on the approach speed on my next leg! Thank you for the tip!

[groentesoep 22]

I put NAV1 and NAV2 frequency in the FMC (both radios were set to FMC as tuning source).

 

And for WING LVL and PITCH HLD - I will keep my eyes on the approach speed on my next leg! Thank you for the tip!

 

You're welcome. It is important that the NAV source on the captian's side is NAV1/ILS1 and the Nav source on the F/O's side is NAV2./ILS2. This is described in the manual as follows:

 

This automatically arms the ILS Approach mode, as described earlier. The Dual FD submode is activated if:

• Both FGMs are available.

• Both AHRS are valid for both FGMs.

• The EFIS ATT/HDG Source Selection switch is set to the NORM position.

• Both ADCs are valid for both FGMs.

• The EFIS ADC Source Selection switch is set to the NORM position.

• ILS data from both VOR/LOC Receivers is valid and agree for both FGMs.

• The VOR/LOC 1 is the selected left Nav Source Selection.

• The VOR/LOC 2 is the selected right Nav Source Selection.

• Both VOR/LOC 1 and 2 receivers are tuned to the same Localizer frequency.

• Both left and right courses are the same.

22

• The lateral and vertical active modes are Localizer Track and Glideslope Track.

• The Radio Altitude is valid and below 1200 feet.

• The left and right side FGMs Flight Director commands agree.

• Touch Control Steering is not active.

 

[PatrickM 2]

Oh man :blush:

I thought I have read the manual?! :t0103:

 

Many thanks for your help, Bastiaan!

[groentesoep 22]

You are welcome ;-)

[PatrickM 2]

Ok i got it!

But now I have another issue with the ILS. While flying an ILS approach on Hannover and Düsseldorf it seems that the plane is never fully aligned with the ILS course. My course I have put in was 232° (23L in Düsseldorf) and 272° (27L in Hannover) according to the current charts that I have (FMC cycle is 1305).

Could it be a Magnetic deviation?

[lodestar 186]

Ok i got it!

 

But now I have another issue with the ILS. While flying an ILS approach on Hannover and Düsseldorf it seems that the plane is never fully aligned with the ILS course. My course I have put in was 232° (23L in Düsseldorf) and 272° (27L in Hannover) according to the current charts that I have (FMC cycle is 1305).

 

Could it be a Magnetic deviation?

 

The course for Hannover is right, but for Düsseldorf 23L is 233 http://nav.vatsim-germany.org/files/edgg/charts/eddl/public/EDDL_AIO.pdf

 

Just landed there this evening with Q400, no problems  

 

BTW, have you updated your FSX navaids?  http://www.aero.sors.fr/navaids.html

[Adamski_NZ 947]

I've occasional had the same "drift" as described above - but more often than not, the Dash gets it right.

 

However - I've had many issues with other aircraft (notably the QW 146) where it simply ignores the [OPUS/live weather generated] crosswind in its localiser calculations - ending up being carried a fair way of to one side. As soon as I manually over-ride the original real weather wind with a manual 0kts, it lines up perfectly.

 

So ... try a few approaches in the Dash with various (but ILS-legal) crosswinds and see if it factors it in. As I said, so far I've had some good crosswind approaches - but the odd one does seem to go astray, not sure why.