BLEED HPSOV R

[Richard McDonald Woods 168]

I am getting this message on the lower EICAS and cannot determine its source or action I should take.

 

Can someone point me to the instructions on how to handle this message, please?

 

Ta

[Budbud 227]

Hi,

 

There was a discussion about it in the following topic:

 

http://forum.avsim.net/topic/423746-hpsov-failure-and-its-effects/

 

Hope you will find your answer there.

[wde12 19]

 

 

I am getting this message on the lower EICAS and cannot determine its source or action I should take

 

Just out of curiosity, I assume this is being triggered in random failures mode? I ask because lately, I've been having the same "random failures" on all a/c. It's typically this HPSOV failure, a fire loop failure, and one other, I can't remember right now. I wanna say there was a post about these recurring failures awhile back, I probably should check.

 

Is this your experience too? I always clear the failures, set random back to 2 per 10hrs, no limits, and these always reoccur. 

[Budbud 227]

Hi,

 

I have set to service-based failures and get quite often these fire loop and HPSVO failures even when I service the relevant systems.

I can recall that I ask sometime ago about the recurrence of these failures and here is the topic. By the way it answers also the question from the OP regarding the actions to take.

 

http://forum.avsim.net/topic/466831-pneumatic-failure-rate-on-real-aircraft/

[Richard McDonald Woods 168]

Hi William & Romain,

 

I have Failures>All systems>Random enabled and set at 1x. I have not been in the habit of servicing all items, nor clearing them before each flight.

 

In flight, I had tried the non-normal checklists but could not find the message. So I tried the manuals, but got no actions required from them.

 

Mea culpa! I just landed without further trying to solve the problem because I was so busy with other items.

 

I am still not able to find the message in the Non-normal.

 

Any help much appreciated.

[Budbud 227]

 

 

I am still not able to find the message in the Non-normal.

 

 

 

You cannot because there is no non-normal checklist for that. It is a advisory message and there is no action to take here. Just a maintenance to do once on the ground.

[Driverab330 74]

It's a status message. In boeing terms, pilots do not need to check status messages in flight as it has no effect to the safety of the flight and no pilot actions are required, that's why the Blue status cue on the upper EICAS is inhibit after engine start until 30mins after take off.

 

Like Budbud mentioned above, the sts msg only means that some maintenace actions is required once it airplane is on the ground, and quite often it may affect the dispatch of the airplane in the next sector. Because of this if we spot it during cruise we will send an ACARS msg to ground to give engineering a heads up, and write the msg in the maintenance log after landing. Because some item can be a no go item unless it's fixed, or if leave un-fixed will lead to a restriction on ETOPS operation etc.

 

There's an index page in the MEL which we can use the status or EICAS msg to search for applicable MEL procedure.

 

In your case BLEED HPSOV R. means some problem with the R ENGINE high pressure bleed valve.

 

I have had this before in real life. And we ended had to apply the MEL and lock out the HP bleed valve before we can dispatch the airplane for the next sector on the same day. If you can find an MEL online here is the code 36-11-02.

 

The implication of this failure is, there will be insufficient bleed air pressure from the R engine (in your case) at low power setting (<55%). This is no big deal as we just follow the (O) procedure. But there's a trap that the MEL doesn't mention. That is when you start your descend, you will get IDLE DISAGREE msg, due to the bleed air demand from the packs. We get this msg, as mentioned in MEL, because the L engine is commaded to a higher idle thrust setting to compensate for the lost of bleed air supply from the other engine at low thrust setting. This in turn will affect your descend profile management because now there is extra thrust on the L engine ( from my experience it's quite a bit higher than normal idle thrust). As a result the idle descend path is quite a bit shallower than normal idle descend path with both engine in normal idle thrust. But VNAV path wouldn't know that, so if you follows the computed VNAV PATH you will need to use speedbrakes to keep the speed in check, or just go a bit lower than the VNAV profile.

 

This issue becomes more interesting when people are already using speedbrakes to maintain the speed while blindly holding on to VNAV path and then ATC gives a short cut.

 

Hope it help to illustrate the idea.

 

Happy flying

[Budbud 227]

But there's a trap that the MEL doesn't mention. That is when you start your descend, you will get IDLE DISAGREE msg, due to the bleed air demand from the packs. We get this msg, as mentioned in MEL, because the L engine is commaded to a higher idle thrust setting to compensate for the lost of bleed air supply from the other engine at low thrust setting. 

 

Interesting! However I'm not sure this is simulated as I have that failure quite often and never see that message and behaviour on PMDG's. 

[Richard McDonald Woods 168]

Thank you, gentlemen, for your interesting inputs. Very informative.

 

PS This seems to be my 1000th post!