Why is it that airline A and airline B can have different (though similar) procedures for exactly the same operation and exactly the same aircraft?

Why don't they all use the same procedure since it is the same aircraft?

Isn't this a safety hazard with every airline doing their own thing?

  • 2
    $\begingroup$ An example would be useful $\endgroup$
    – MikeB
    Commented Jan 23 at 9:44

1 Answer 1


Beyond the Flight Manual, which is a certification document, the manufacturer's operational procedures (as per the Flight Crew Operating Manual) are basically an operational foundation that allows some customization.

There are variations from airline to airline in operational needs and internal culture, so different regulatory agencies allow airlines under their control to customize their procedures to suit the airline's safety and operational programs, as long as they meet certification requirements and the Regulator's own standards.

The variations are often to impose additional restrictions the airline feels are necessary.

A couple of examples:

  • OEM approves unrestricted use of flight spoilers for descent flaps up per the AFM.
  • Airline A allows use of flight spoilers for descent with no restrictions other than certification limits per the OEM's procedures.
  • Airline B's management feels that use of flight spoilers scares passengers, and/or wastes fuel, so it may to try to limit flight spoiler use in its own operations manual by incorporating some sort of language discouraging their use unless absolutely necessary.

I recall that on the CRJ200, the minimum speed flaps up per the AFM was 180kt. Some operators however, thought that was too low, and they modified their own operations procedures to limit flaps up speed to not less than 200kt.

You also see it with things like checklists. There is an OEM checklist, but most airlines just use it as a baseline and customize it to suit their needs, usually with extra steps, or possibly rearranging steps for better efficiency. The local Regulator will judge whether it meets requirements for safety.

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    $\begingroup$ Why would spoilers scare passengers? (Didn’t the airline post a spoiler warning?) $\endgroup$
    – Dai
    Commented Jan 23 at 4:01
  • $\begingroup$ The rumble, quite noticeable on the CRJs. Some regional operators discouraged their use as the FAs would report pax that were alarmed. Also, if you are using flight spoilers, unless it's to deal with a surprise that forces you to descend quickly, you've basically screwed up the descent planning. $\endgroup$
    – John K
    Commented Jan 23 at 5:45
  • $\begingroup$ @JohnK - in the case of airlines that's probably a less common reason. A couple of times I have been on flights where the speed brakes were used for about three minutes during descent. In both cases I asked the pilot about it on the way out, in both cases they said ATC had kept them higher than normal as they approached the airport. $\endgroup$ Commented Jan 23 at 15:58
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    $\begingroup$ @JohnK I think you may have missed the joke: "spoiler warning"... :) $\endgroup$
    – FreeMan
    Commented Jan 23 at 18:36
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    $\begingroup$ @FreeMan Oh crap. Yeah. LOL :0 Having no shame, I'll leave the comments up anyway... $\endgroup$
    – John K
    Commented Jan 23 at 21:08

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