Assumed temperature on B737NG

[cmcjma]

Guys,
What is the max assume temp you are allowed to set in your daily operations?
The FCOM2 Chap 11, N Limit page - Preflight says the maximum allowable entry is 70 deg C.
The FCOM1 PI10.16 (for me) Assumed temperature Reduced Thrust provides a table according to OAT and airport pressure altitude.
Our (Boeing) RTOA provides temp up to 70 deg C according to the TOW.

I was recently blamed for not accepting to set 70 deg C, even though our SOP states a max of 55 deg. I was explained that SOP is not up to date, but Boeing manuals are, and SOP should be considered as a complementary manual...

Just tell me you experience just for sharing.
Thanks

[Kiltie]

cmc unless you are operating in an obscure state of operation, what you have been told is utterly misinformed.

Your company SOP invariably over-rides any manufacturer publication. If your company SOP dictates a maximum of 55 degrees, you must abide by it. If Boeing subsequently update their procedures you must wait until your company updates your SOP accordingly before you accept Boeing's 70 degrees.

Manufacturer's methods only apply if there is no such guidance or rule offered by way of company SOP.

As I say if your governing authority promotes manufacturer's SOP as a priority over company SOP it would be a new one on me. Guidance on the sequence of referral to publications, and what takes priority, should be given in the introduction of your company Part B SOP (or its equivalent in your operation).

Furthermore, you should be able to find an absolute performance guarantee to prove 70 degrees is a safe assumed temperature. If you use third party published performance tables such as Flygprestanda, EAG etc. and 70 degrees doesn't appear in there, you would then have to spend considerable time extrapolating the performance from the Boeing Performance publication. Most perf tables I have used reach a maximum of 64 degrees.

There is a growing cancer among many Boeing 737 pilots I have met who proclaim "ah but Boeing says....." which is nonetheless a total contradiction to their company's SOP. There are many of my employer's SOPs which I don't particularly like, but are not unsafe, so I adhere to them without argument. If I felt so strongly that an SOP was unsafe only then would I go raise it with the Flight Safety department to ask for review. So far I have never had cause to do that.

You should ask your colleague who "blamed" you to leave the airline industry and go and get a job flying for Boeing.:)

[JB007]

Totally agree, what your SOP say's, goes...ignoring is the first 'chink in the armour'!

I would be interested to know the reason for up to a maximum assumed temp of 55 degrees though, is it specific to where you were on the day or every departure?

[punk666]

The company he is working for is based in indonesia.