Fuelling and stabiliser setting

[jjf 23]

Hello,

On stand at CYVR fuelling for a trip to RCTP. Planned fuel load was ~154,000 kg, and I was using ground services for fuelling. Ground contacted to inform me that, for this fuel loading to start, the stabiliser needed to be set to 6, and I followed his request to pressurise hydraulics 2&3 and then I set stabiliser to 6 as requested, and the captain's voice confirmed it was set to 6, then I depressurised 2&3 hydraulics. After a couple of minutes he requested the same thing, even though the stabiliser was set to 6 already, and fuelling did not commence. Not sure what I did wrong though.

[scandinavian13 5,192]

51 minutes ago, jjf said:

After a couple of minutes he requested the same thing, even though the stabiliser was set to 6 already, and fuelling did not commence. Not sure what I did wrong though.

You sure you set it at 6 or below, and it wasn't sitting at just above 6?

[Qavion2 39]

Quote

Ground contacted to inform me that, for this fuel loading to start, the stabiliser needed to be set to 6, and I followed his request to pressurise hydraulics 2&3 and then I set stabiliser to 6 as requested, and the captain's voice confirmed it was set to 6, then I depressurised 2&3 hydraulics.

According to my training notes, on earlier 744's, the stabiliser must be between 5 and 7 units. On later aircraft the stabiliser position sensing switches were removed and fuelling could be carried out with the horizontal stabiliser at any angle.

[tcas_climb 45]

9 hours ago, Qavion2 said:

According to my training notes, on earlier 744's, the stabiliser must be between 5 and 7 units. On later aircraft the stabiliser position sensing switches were removed and fuelling could be carried out with the horizontal stabiliser at any angle.

I thought that setting ensured that the maximum amount of fuel could be carried in the stab trim tank, why remove the sensors?

[jjf 23]

12 hours ago, scandinavian13 said:

You sure you set it at 6 or below, and it wasn't sitting at just above 6?

Yes, sure it was 6

[Qavion2 39]

On 31/07/2017 at 7:48 AM, tcas_climb said:

I thought that setting ensured that the maximum amount of fuel could be carried in the stab trim tank, why remove the sensors?

Why indeed :D

My notes didn't say.

[Copper. 78]

4 hours ago, Qavion2 said:

Why indeed :D

My notes didn't say.

It was determined, after a few delays due to switch failure, and a bit more 744 operational service experience, that the hori stab position, including outside of 5 or 7 units, had no affect on FQIS accuracy during refuelling. For these two reasons, the stab fuelling lockout circuit was deactivated/removed. The mod was offered to operators in the 90's with no time limit to incorporate.