Mark, what do the red encircled dash /dash asterisk as per page of catalogue I have just sent mean?

We verified oil temperature bulb resistance readings for a reference to indicated temps.

Sitting static on a warm day we found 100Ω to be 30 degrees.

We didn't know the range that the bulb might have. The first try at 200Ω was invalid. We found just a sight change in resistance would make the indication change. A 5Ω increase in resistance gave use a 10 degree rise in indication. I would imagine full scale hot/cold would be a pretty tight range of resistance (let's guess 80Ω to 120Ω)??
  
     
     
     
     
 

There are many times when we have Pitot/Static leaks in lines or fittings that have to be located and replaced.

The usual practice is to isolate the line and apply pressure to it. We then use leak detector to find the problem area (presence of bubbles).

Using this method, there is always a concern of over-pressurizing the lines and splitting one open. I've used more, but ≈ 5 PSI usually is enough pressure to locate leaks.

A low pressure regulator with nitrogen can be used, but we usually just use the Pitot/Static Test Box. Using the pitot output only..... 400 Knots is a common setting.

The question arises as to what 400 Knots is equivalent to in PSI. We use a Barfield DPS1000 . The display can be changed to show different units of measure.

Knots to inches of mercury (inHg).....
  
     
     
     
  
The tester shows two values for inHg, Pt and Qc. A little digging was required to find the difference.....

Impact Pressure (Qc) is the pressure a moving stream of air produces against a surface that brings part of the moving stream to rest. It is the difference between the total pressure (Pt) and the static pressure (Ps). These pressure properties are related by the formula: Qc = Pt - Ps  (From Mensor.com )


The link above is worth a look. Needless to say, we want to reference Qc. Using a online conversion, we found the value 8.38 inHg to be a little over 4 PSI.
  
     
  
A quick PDF might help explain all this.
  
  
 
 

The explanation above is wrong dealing with the flapper.

When a blower is operating..... it pulls "its own" flapper flush to the mount. This isolates the plenum and the secondary blower system from the airflow. All air is drawn from the tubes on the cargo pit ceiling. Air is pulled through "both" sensors and then exits the running blower.

In other words..... it the flapper fails on the running blower, air is drawn backwards through the non-running blower and not through the tubes and sensors.

I don't have an answer for this.

Have you got a chance to look into?

Mark, with regard to Boeing SB737-55A1070, two pages of compliance was emailed, It is a little odd that according to table5 (page2) putty has to be applied to the elevator tab hinge bolt and the bolt has to be inspected initially???? before every flight as a preflight task????!!!!

We still don't think in terms of "quality". A electric pump can either do the job or it can't. If you've changed the pump and still have the same issues, you could have a electrical issue or possibly an hydraulic power output issue.

Has anyone done...

Mark, My question is not specifically about 737 model, the issue was experienced in F27 Mk0050 for which hydraulic pressurization by electric motor driven pump is an approved ICA without any limitation so that you should normally expect both main gears and even nose gear retract simultanously , so I am asking in general whether three phase supply power quality can affect the performance of electric motor driven pump, regardless of airplane type and model?
I have just emailed MM pages.......