flaps

On Tue, 10 Jul 2007 16:40:28 -0700, "Al G"
wrote:


Basically, the lawyers have set it up so that Nav III aircraft have
stricter limits on what equipment is required than in the older
aircraft that you're used to by creating a KOEL (effectively a MEL).
The way it was explained to me is that just like a MEL, in these ones
(and I'm pretty sure the 172 Nav III has it as well but don't have a
POH or IM handy) since the flap motor and indicator are listed as
required by the table in the limitations section, they have to be
working or you're not in fact airworthy - regardless of the operation.
The POH has effectively removed the decision from you in an aircraft
with a MEL or KOEL.

So if the flap switch is inop, you're good to go?

If you can somehow prove it's the switch and not the motor without
being an A&P and re-rigging the electrical wiring to show the motor
and indicator are both working, I guess. The intent of the limitation
- flaps have to be working - is obvious. They don't say you have to
actually use them, but they do have to be in working order.

Peter Clark wrote:
The intent of the limitation - flaps have to be working - is obvious.
They don't say you have to actually use them, but they do have to be in
working order.

There is some logic in this. All the Cessna AFMs I've seen (i.e. for
various flavors of their piston singles) have nice detailed performance
charts showing how much runway you need to land with various combinations
of weight, temperature, elevation, wind, and phase of moon, but the numbers
always are for full flaps. There is NO data on how much runway you need
without flaps, therefor there is no way you can comply with 91.103 which
requires that you familiarize yourself with the takeoff and landing
distances.

Now, you know, and I know, and every body hanging out in the airport coffee
shop knows that you can land a 172 with no flaps on a 2000 foot paved
runway without any problems (assuming you know what you're doing). But,
that doesn't count when it comes to determining if the airplane is
airworthy. Remember, airworthy is a state of paperwork, nothing more,
nothing less.

Roy Smith wrote in
:

Peter Clark wrote:
The intent of the limitation - flaps have to be working - is obvious.
They don't say you have to actually use them, but they do have to be
in working order.

There is some logic in this. All the Cessna AFMs I've seen (i.e. for
various flavors of their piston singles) have nice detailed
performance charts showing how much runway you need to land with
various combinations of weight, temperature, elevation, wind, and
phase of moon, but the numbers always are for full flaps. There is NO
data on how much runway you need without flaps, therefor there is no
way you can comply with 91.103 which requires that you familiarize
yourself with the takeoff and landing distances.

Now, you know, and I know, and every body hanging out in the airport
coffee shop knows that you can land a 172 with no flaps on a 2000 foot
paved runway without any problems (assuming you know what you're
doing). But, that doesn't count when it comes to determining if the
airplane is airworthy. Remember, airworthy is a state of paperwork,
nothing more, nothing less.


The POH for the 1977 C172N Skyhawk (D1082-13-RPC-1000-9/89) has
exactly one landing table, on page 5-21, marked "Short Field". This table
ONLY shows landing distance based on max weight of 2300 lbs. In Section 4
"Normal Procedures" on page 4-19, under "Normal Landing", the POH states
"Normal landing approaches can be made with power-on or power-off with any
flap setting desired."

An interpretation of 91.103 requiring that you know how much runway
you need to land or your not airworthy combined with the information
provided in this POH implies that you can never legally land a 1977 C172N
uless you are at max weight, doing a short field landing, full flaps, and
have the capability of inflight refueling (or some other means of ensuring
fuel burn doesn't reduce your weight below max) during the landing!

I guess no one has ever landed an airworthy 1977 C172N!


--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)

"Roy Smith" wrote in message
...
Peter Clark wrote:
The intent of the limitation - flaps have to be working - is obvious.
They don't say you have to actually use them, but they do have to be in
working order.

There is some logic in this. All the Cessna AFMs I've seen (i.e. for
various flavors of their piston singles) have nice detailed performance
charts showing how much runway you need to land with various combinations
of weight, temperature, elevation, wind, and phase of moon, but the
numbers
always are for full flaps. There is NO data on how much runway you need
without flaps, therefor there is no way you can comply with 91.103 which
requires that you familiarize yourself with the takeoff and landing
distances.

Now, you know, and I know, and every body hanging out in the airport
coffee
shop knows that you can land a 172 with no flaps on a 2000 foot paved
runway without any problems (assuming you know what you're doing). But,
that doesn't count when it comes to determining if the airplane is
airworthy. Remember, airworthy is a state of paperwork, nothing more,
nothing less.

Since the '60s, '70s, and '80s models showed no flap landing data, and flaps
were considered optional this question really boils down to what the POH
says for the particular aircraft being flown. Students learning at busy
commercial airports almost never used flaps as a normal procedure.

Of course we taught recovery from fully developed spins to instructors back
then also. Isn't it interesting that some modern aircraft could be
considered out-of-service for inop flaps, but only a few years ago they were
very optional. I imagine that today a DER or FSDO inspector would have a
stroke if we used all 60 degrees we had on the old O-1s or rolled on a wheel
landing with them at zero.

--
Jim Carter
Rogers, Arkansas

"Roy Smith" wrote in message
...
Peter Clark wrote:
The intent of the limitation - flaps have to be working - is obvious.
They don't say you have to actually use them, but they do have to be in
working order.

There is some logic in this. All the Cessna AFMs I've seen (i.e. for
various flavors of their piston singles) have nice detailed performance
charts showing how much runway you need to land with various combinations
of weight, temperature, elevation, wind, and phase of moon, but the
numbers
always are for full flaps. There is NO data on how much runway you need
without flaps, therefor there is no way you can comply with 91.103 which
requires that you familiarize yourself with the takeoff and landing
distances.

Now, you know, and I know, and every body hanging out in the airport
coffee
shop knows that you can land a 172 with no flaps on a 2000 foot paved
runway without any problems (assuming you know what you're doing). But,
that doesn't count when it comes to determining if the airplane is
airworthy.

Well said Roy. I can see Cessna adding it to the "Operating Limits",
after all the charts
for that aircraft using specify their use, hence the KOEL. The 1967 172H
manual I'm looking at has a single page limitations section, with no mention
of flaps. Just the Day/Night/VFR, with instruments, IFR, normal category.
The landing chart is a single line assuming short field over an obstacle,
with 40 degrees of flap.

Remember, airworthy is a state of paperwork, nothing more, nothing less.

Interesting concept, what would Orville, Wilbur, or Dudley think? You
don't happen to have an "FAA" definition of airworthy do you?

Al G

"Roy Smith" wrote in message
order.

There is some logic in this. All the Cessna AFMs I've seen (i.e. for
various flavors of their piston singles) have nice detailed performance
charts showing how much runway you need to land with various combinations
of weight, temperature, elevation, wind, and phase of moon, but the
numbers
always are for full flaps. There is NO data on how much runway you need
without flaps, therefor there is no way you can comply with 91.103 which
requires that you familiarize yourself with the takeoff and landing
distances.

Well, you certainly haven't seen all the Cessnas POHs. Mine has performance
numbers for "SHORT FIELD" only.

Normal landings can be conducted with ANY amount of flaps, per the FLAP
LIMITATIONS section.

Karl