IFR Nav Lights needed during day?

[Sergio Corsi]

I was about to take a student out on an IMC IFR training flight
when it was discovered the NAV lights were INOP. Beacon, strobes, and
landing light were all functional on the C172. It was daylight with 3
miles vis and 700 foot ceilings. The FAR's state that for IFR flight NAV
lights are required. I canceled the flight but later called the DuPage
FSDO which stated it would have been legal to fly in daylight IMC without
the NAV lights functional. Seems hard to understand considering the IFR
equipment requirments are not divided into "night" and "day" and I would
assume that NAV lights come in handy during foggy conditions etc. What
is your take?

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David O. Corsi - sco...@orion.it.luc.edu, Dave...@aol.com
Certified Flight Instructor - Airplane, Instrument
Ground Instructor - Advanced, Instrument
Commercial Pilot - Single Engine Land, Instrument
what good is it to fly ... eh, a quoi bon l'enfant qui vient de naitre?
********************************************************************************

[John Freas]

Previously on IFR Nav Lights...

sco...@orion.it.luc.edu (Sergio Corsi) wrote in article
<4r6ubp$d...@artemis.it.luc.edu>...

> I was about to take a student out on an IMC IFR training flight
> when it was discovered the NAV lights were INOP. Beacon, strobes, and
> landing light were all functional on the C172. It was daylight with 3
> miles vis and 700 foot ceilings. The FAR's state that for IFR flight
NAV
> lights are required. I canceled the flight but later called the DuPage
> FSDO which stated it would have been legal to fly in daylight IMC
without
> the NAV lights functional. Seems hard to understand considering the IFR

> equipment requirments are not divided into "night" and "day" and I would

> assume that NAV lights come in handy during foggy conditions etc. What
> is your take?

Well, according to my slightly outdated home copy of the regs (1995), your
reading of the requirements is incorrect. Someone with the current regs
to hand can confirm that there are no changes (Doug?).

Anyway, according to my copy of the regs, there IS a differentiation
between day and night IFR. to wit: 91.205(d) "/Instrument flight rules/.
For IFR flight, the following instruments and equipment are required:
(1) Instruments and equipment specified in paragraph (b) of this section,
and for night flight, instruments and equipment specified in paragraph (c)
of theis section..."

Paragraph (b) refers to VFR day, and (c) refers to VFR night.

As to the need for nav lights during foggy conditions, consider that in
the daytime, ambient light will often wash out anything as dim as a nav
light. In fact, the beacon is often seen long after the airplane is
spotted. The only light that is of any real use in daylight is the
landing or taxi light. Even in conditions of reduced visibility, by the
time you spot the nav light you are about to be run over by it.

Personally, I use the beacon as a warning for folks on the ground, to
indicate that the airplane either is running or soon will be. Beyond
that, if they can't see a big white airplane, they aren't likely to see a
dim little light attached to it, mostly because they probably aren't
looking.
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| #### #### John Freas, ATP/CFII-ME | Lear 23/24/25
| # # === === === === === === === === === === ===
| ####### #### john....@worldnet.att.net | Anytime, all the time.
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