Can EFIS / EFMS lead to removing basic safety checks?

Beavis wrote:

In article jchKg.2674$c07.2060@fed1read04,
Sam Spade wrote:


In the modern jets and many GA airplanes too the DG automaticly aligns
the correct magnetic heading. Checking the EFIS heading prior to take
off was not on our companies checklist.


It should not have to be on any company's checklist. Some things are
basic airmanship.


No, they're equipment-specific procedures. Doing a mag check prior to
takeoff is not "basic airmanship" either, nor is realigning the DG every
15 minutes. They're specific procedures required by specific equipment,
and neither is relevant on a modern turbine-powered airplane.

Did you align the IRUs in your 152 before you started moving? Check the
landing gear doors as part of your walk-around? Of course not, because
they're not appropriate procedures for THAT AIRPLANE. See what I'm
getting at?

I think the context of the thread is air carrier equipment. Virtually
all airliners have heading bugs. They all had them at my airline when I
signed on in 1964, and that continued to the 767.

Jim Carter wrote:
This question is the result of the wrong runway issue at LEX last
weekend.



Not having flown an EFIS or EFMS myself, I'm not sure of the "into
position checklist items". For example, in a standard steam-gauge panel
one of the last things we check is to align the directional gyro with
the runway heading and compass. With an EFIS or EFMS, is there any such
last minute check, or is the heading assumed to be correct because it
was aligned by the GPS when the bird came out of the chocks?


Why would the EFIS be any different than an HSI (or as Bob already
posted the 707 RMI). It still has a heading which ought to be
verified with some real reference (Whiskey compass or runway).

Of course it's easy to get complacent. Back when I had a regular
DG that had to be set, I cross checked it against the compass/runway
on takeoff as a matter of course (since it was almost assuredly wrong).
Now that I have a slaved HSI, it's almost always right so I could see
forgetting to check it. Of course, I also have GPS plotting my position
on the Jepp airport diagram page if the field has an instrument approach
so I probably was one up on these Conair guys.

In article ,
Ron Natalie wrote:

Why would the EFIS be any different than an HSI (or as Bob already
posted the 707 RMI). It still has a heading which ought to be
verified with some real reference (Whiskey compass or runway).

It is verified, by two redundant computers that will set a warning flag
if they're off by more than a few degrees. (4 degrees in the plane I
fly.) If either gyro isn't tracking correctly, or isn't agreeing with
the actual magnetic heading (sensed by two independent flux gates), the
warning will trigger the second the airplane makes its first turn on the
ground.

This system provides MORE accuracy and MORE redundancy than correcting a
manual DG to a whiskey compass, and frees the crew to check the myriad
of things that do require human interaction to verify before flight.

Now that I have a slaved HSI, it's almost always right so I could see
forgetting to check it.

These airplanes have more than a slaved HSI. They have two (or more)
separate, independent remote heading gyros, slaved to two (or more)
separate, independent heading sensors (flux gates). If anyone ONE of
those 4+ systems reads differently from the others, a warning will trip.

I think you guys are barking up the wrong tree here. This isn't a case
of losing redundancy, it's the case of an automatic system being able to
do a better job than a human at this particular task. (Do you think an
old-style, manual variable-pitch prop is a better system than a
constant-speed prop, because it keeps the pilot more involved? I sure
don't.)