View Full Version : Once Each Flight Day

11th Aug 2015, 13:01
Hi guys...

One question: the mob I fly for (B737NG) has some items on it's SOP that should be tested "once each flight day". To number a few: flight deck door access system, eng/cargo fire warning system.

What happens is that some say that "once each flight day" really means just at the first flight of the day. Others say that this refers to the first flight of a particular crew on that airplane in a particular day.

How do you guys understand this ?

There's any kind of official document from boeing stating what this really means ?

I don't feel comfortable flying an airplane that might be flying with a single fire detection loop in an engine and not knowing it, but I'm a FO and sometimes while flying with skygods, it's hard to convince them about this.

By the way, English isn't our mother language here, and many (and I really mean many) have a hard time reading and understanding what's written.

All the best !


de facto
11th Aug 2015, 15:14
How about you ask your direct fleet manager/chief pilot....?

11th Aug 2015, 15:44
Yup, have the same instructions. Sometimes even worse, PF has to do engine fire tests, PM APU, which sits right smack between both engine fire tests. If i do one of those, i do all three, much simpler that way but not according to SOP...

Since i trust nobody i will do those tests on the first sector of the duty and be done with it. Don't care about those "skygods" and just do them anyway.

11th Aug 2015, 16:05
Tks De Facto...

How couldn't I have think of that ?

You were really helpful... :=


Some stuff on the SOPs are really hard to understand Denti, I fully agree with you ! Here, just to give an exemple, 90%+ of the Capts don't do the flight deck access system test. That said, how can I trust that the fellas before myself have done that and other "once per day" required checks ?

I'm aware that at least one ME operator explain this kind of statement on it's SOP, but this could be "their thing".

Anyway, as you said, I'll keep doing it ! If someone complains, I'll excuse myself, but at that time I'll already know if things are working as supposed or not.

11th Aug 2015, 17:12
I thought on the 737 that this checks apply on each crew change. Looking at the FCOM again, I guess it really says "once per flight day".

Anyway, I'd check things when I arrive at the aircraft. Why not find out things are wrong at your base, where you can have them easily fixed or aircraft swapped? Kind of like departing your base with ignition on L (even if it is your odd-numbered sector) - it just doesn't make sense.

11th Aug 2015, 17:49
Once per day is done by first flight crew for a departure after 0000L.

It is not required for the first flight by each new flight crew.

11th Aug 2015, 21:22
Given that I'm an old fart, and given that the crew access door has nothing to do with the airworthiness of the a/c, but I might check it at crew change over as it takes <20secs, and given that the fire test is slightly more critical and takes 30secs, and given the O2 test is also quite a little critical, and a heap load of other items; sometimes it's time to obey the SOP's to their minimum, and then add a few extras for yourself. Remember the SOP's for different operators are SO... Different ... and are not cast in stone as God's gift. You are at the sharp end, not the SOP guru.

12th Aug 2015, 06:27
There is nothing wrong with a little common sense like Rat 5 suggests. Just make sure that you don't modify things to a degree where you are noticeably different from other F/O's as this can have unforeseen effects.
Don't do things that are supposed to be done in the cruise ( calculations, FMC entries etc) during the pre-flight phase, any spare time should be used to make sure all is in order. Eg there is no point in having created a waypoint for PNR in the FMC but failed to notice that the refueller hasn't arrived.
My thoughts.

12th Aug 2015, 11:20
How about you ask your direct fleet manager/chief pilot....?

At the risk of being cynical some would argue from experience that would be making waves. Management pilots are not immune from personal opinions that are inaccurate. Try safer avenues in your query and avoid making a target of yourself:E.

12th Aug 2015, 11:31
My old outfit had several procedures that fell under once a day, previously done by the folks handling the first flight of the day. Time constraints, efficiency, and fairness were the reasons given for the change. Saving that negotiated quarter-hour in crew pay for the first flight of the day was most likely the real reason.

12th Aug 2015, 11:45
Saving that negotiated quarter-hour in crew pay for the first flight of the day was most likely the real reason.
Surely not. Surely it was "safety first" as always. They wouldn't have changed the procedure unless safety was enhanced.

12th Aug 2015, 12:43
Hi guys...

Thank you very much for the answers !

Clear skies to you all...



12th Aug 2015, 13:57
Surely not. Surely it was "safety first" as always. They wouldn't have changed the procedure unless safety was enhanced.

Naturally, because safety and efficiency walk hand in hand.

12th Aug 2015, 16:54
The FCOM says "first flight of the day" or "the flight crew did not do the power up supplementary procedure". So unless you did the procedure, you do the fire check.

The flight deck access check at my outfit is done on the first flight by the cabin crew once an engineer or flight crew are in the flight deck.

12th Aug 2015, 17:13
At a large 737 operator in Europe this has been clarified by way of memos that it is indeed the first flight of your own duty on that aircraft, irrespective of how many times the aircraft has flown earlier the same day.

12th Aug 2015, 17:53

Tks for your answer... Really good to know that experienced operators around the world see this matter that way.


15th Aug 2015, 11:59
Since i trust nobody i will do those tests on the first sector of the duty and be done with it. Don't care about those "skygods" and just do them anyway.

Do you do all the maintenance transit/daily check items too? :E

16th Aug 2015, 05:29
It would certainly be MY first flight of the day, rather than the aircraft's. I want to know everything works! :) (or as limited by the DD log).

No Fly Zone
16th Aug 2015, 07:32
Heavens yes, there are many ways to interpret the SOP. However, if not before the first flight of the day, perhaps the aircraft has flown without the inspection. To my thinking, it means - or should mean - before the first flight of the business day. And of course, one can quibble about that as well.
In the end, how many extra minutes do those checks require? Sometimes you know that they have been done; other times you may not know a cold airplane from a semi-warm one. Your paxs' butts are on the line, as well as your crews' -and your own. It it about crossing the 'Ts, or checking the airplane again, to ensure a safe flight? Is a more thorough check worth your extra 5-10 minutes? I think it is, but your mileage may vary. You are already going to be a little late with push-back, so does the clock matter? I hope you DO make those few extra checks. They are worth your time. :D:ok:

16th Aug 2015, 09:17
At my airline the B737NG normal procedures are very clear - some things such as flight deck door are clearly "first flight of the day" and other things such as fire tests are "each crew change". Perhaps my operator has modified the Boeing FCOM to make it clear - suits me fine.

But on the topic of non-SOP system testing, I have two anecdotes of interest:

1. Our 737-3/400 series required a test of the Emergency Lighting system during preflight. When we moved to B737NGs the Emergency Lighting system test was removed - it became an engineering function during overnight checks. One particularly thorough Captain found it difficult to adjust to the change at first - if we've been checking it all these years for good reason, why stop now? So he continued to check the lights until lo and behold they failed the test one time. Aircraft significantly delayed and instead of a congratulations from the Chief Pilot for his vigilance above and beyond, he got invited for tea and bikkies to explain why he unnecessarily delayed a flight for conducting non-SOP system checks. His protestations of the potential danger of an aircraft flying around with U/S emergency lighting did not impress the Chief Pilot one bit. He was told to follow the procedures or find another job.

2. The fire tests are normally performed by the F/O. One Captain decided to change things around one day and did it himself (actually permitted by the FCOM but not normally done). The Master Fire Warning press-to-cancel button on the LHS MCP failed to cancel the fire bell. The F/O side still worked, as did the bell-cancel on the centre console. But the DDG said no dispatch and the aircraft went off to the hanger for 24 hrs, and pax significantly delayed. The switch in question had possibly been U/S for weeks or months, who knows.

Where do you draw the line? Good question. I'm not a SOP-nazi - sometimes SOP's are declared contributing factors in investigations, true. The are usually changed accordingly after the event. But Boeing have more information and statistics at their fingertips when they design SOP's than I do. Sometimes operators change SOP's because they think they know better, sometimes pilots do too. Sometimes they are right, sometimes they are wrong, sometimes it is of no consequence. But for a pilot, I think, generally speaking, going outside of SOP's is only defendable when you genuinely believe safety is at risk. A truly subjective assessment, sometimes. An attitude of "well it worked on the DC3, so I ain't changing" may not be relevant or defendable.

Just food for thought when you make a decision to test things outside SOPs - it may improve safety, it may not. It also may affect the schedule or your career. Where you choose to draw the line may depend not only on your personality but also on the personality of those who employ you. And these are just anecdotes. I love the Tech forum on PPRuNe, there is some great advice here, but you need to sort the appropriate advice from the inappropriate. That's what experienced pilots do.

16th Aug 2015, 21:11
SCARY. I read here there are so many SOP disciples. No deviation, no rebels. I've flown for a shed load of airlines, and sure enough, as has been told here, the CP decides the SOP's. They have been so varied. That is often one person's opinion. I've come across so much dross as to be painful. Some here quote some moments. CP is not GOD; they sit on the ground; you take the beast into the ether. The SOP's are norm and a minimum. If you feel you'd like to make an extra test to make you feel comfortable with your a/c, and it is according to the manufacturer's allowances, then who is to say you are wrong?
If an extra safety check proves to be negative, inconvenient, and you are chastised for it then you know the true attitude of you company. Time to beware.

17th Aug 2015, 10:04
The Master Fire Warning press-to-cancel button on the LHS MCP failed to cancel the fire bell.

Funny, I normally use the press to cancel on one side for the engine/wheel well fire test, and then use the other press to cancel button for the cargo fire test so that I check both. :)

17th Aug 2015, 12:49
When do you check the "Bell Cutout'?

17th Aug 2015, 15:13
Completely agree with you, Rat. But like I said, where do you draw the line? Do you lower the flaps every transit and check for bird strikes? Do you check the landing and taxi lights before each night sector? What about the anti-ice?

How many of these "extra checks" will potentially reduce the chance of death or injury, or aircraft damage?

Boeing and the operator decide which checks are important enough to be conducted each flight and which are not. Maybe they're not always right, and they do tend to change from time to time - for example I recall the crew oxygen check going from every transit - to just each crew change - and back to every transit again a couple of years later. Don't know if that was Boeing or just my operator but the point is there are people looking at these things from time to time and making risk assessments versus the time required to conduct these checks and turn the aircraft around in a commercially viable time frame.

I guess the ugly truth is also that they would actually prefer less-important things to be not discovered until a maintenance check is conducted so they actually have time to fix it which would otherwise impact on a short transit. My goodness, did I just suggest that? :sad:

If I was a CP (which I never have been and never will be), I doubt I would be chastising crew for extra vigilance - within reason... ;)

Edit: I am fortunate enough to work for a very good operator with good maintenance ethic. If I didn't I might have a slightly different attitude.

17th Aug 2015, 21:05
Derfred: I agree with your suppositions. There is not black & white, right or wrong; sometimes. I've flown for differing quality C.P'.s Therefore some were excellent, some less so. Same a/c very different SOP's; all approved by both various XAA's & manufacturer. No SOP's were without comment. I can take a selection from 8 operators and arrive at an excellent set of SOP's, but none of them had the straight flush of SOP's individually. And all were reluctant to listen & learn from others. As a result their pilots, who were home grown or long servers, believed that here was the be all & end all of how to do it. It was most frustrating but one had to live wit it.

No Fly Zone
18th Aug 2015, 10:35
Professionals accept personal responsibility, especially for potential safety issues. If a particular item is of concern to you, on a particular day and airplane, why not just CHECK IT yourself, assure yourself that all is properly functional and more on. If some item become a regular cause of delay, document multiple specific instances and pass it up the line. When something goes amiss at the wrong time, you do not get to jump out early; your fanny rides the SOB to termination of flight just like everyone else. IMO, a damn good question! :ok: