Aircraft Weight Question

Consider the following aircraft:

Seats ---------------------------------------------- 2

Empty Weight (typical) -------------------- 920 lbs.

Maximum Gross Weight -----------------1320 lbs.

Useful Load ----------------------------------- 400 lbs.

Payload with Full Fuel (18 Gals) -------- 292 lbs.

Suppose I wanted to add additional equipment to this aircraft. Obviously,
this would raise the Empty Weight, and lower the Useful Load and the
Payload.

Is there any sort of "minimum" Useful Load or Payload that must be
maintained when equipment is added, or is it simply a matter of operating it
within the "weight envelope"?

You now have a single-place airplane

Bill Denton wrote:
Consider the following aircraft:

Seats ---------------------------------------------- 2

Empty Weight (typical) -------------------- 920 lbs.

Maximum Gross Weight -----------------1320 lbs.

Useful Load ----------------------------------- 400 lbs.

Payload with Full Fuel (18 Gals) -------- 292 lbs.

Suppose I wanted to add additional equipment to this aircraft. Obviously,
this would raise the Empty Weight, and lower the Useful Load and the
Payload.
Is there any sort of "minimum" Useful Load or Payload that must be
maintained when equipment is added, or is it simply a matter of operating it
within the "weight envelope"?

Bill Denton wrote:
Consider the following aircraft:

Seats ---------------------------------------------- 2

Empty Weight (typical) -------------------- 920 lbs.

Maximum Gross Weight -----------------1320 lbs.

Useful Load ----------------------------------- 400 lbs.

Payload with Full Fuel (18 Gals) -------- 292 lbs.

Suppose I wanted to add additional equipment to this aircraft. Obviously,
this would raise the Empty Weight, and lower the Useful Load and the
Payload.

Is there any sort of "minimum" Useful Load or Payload that must be
maintained when equipment is added, or is it simply a matter of operating it
within the "weight envelope"?


There's no rule about having to leave a certain amount of useful. In
fact to show you how dumb some of these people are a guy across the
taxiway from me built a Kitfox. He put so much **** on it that with him
and full fuel he was 50 pounds over gross.

On Jan 24, 10:21 am, Newps wrote:
In
fact to show you how dumb some of these people are a guy across the
taxiway from me built a Kitfox. He put so much **** on it that with him
and full fuel he was 50 pounds over gross.

Doesn't the builder determine the gross weight of a homebuilt?

John Galban=====N4BQ (PA28-180)

John Galban wrote:

On Jan 24, 10:21 am, Newps wrote:
In
fact to show you how dumb some of these people are a guy across the
taxiway from me built a Kitfox. He put so much **** on it that with him
and full fuel he was 50 pounds over gross.

Doesn't the builder determine the gross weight of a homebuilt?

Within certain limits, yes. But you don't get to say the Kitfox has a
3600 pound gross weight just because it suits you. The FAA has oversight.

A homebuilder can build a SuperCub with a 200 hp engine and
set the GW at 1320 pounds with one seat.


"Newps" wrote in message
. ..
|
|
| John Galban wrote:
|
| On Jan 24, 10:21 am, Newps wrote:
| In
| fact to show you how dumb some of these people are a
guy across the
| taxiway from me built a Kitfox. He put so much **** on
it that with him
| and full fuel he was 50 pounds over gross.
|
| Doesn't the builder determine the gross weight of a
homebuilt?
|
| Within certain limits, yes. But you don't get to say the
Kitfox has a
| 3600 pound gross weight just because it suits you. The
FAA has oversight.

John Galban wrote:
On Jan 24, 10:21 am, Newps wrote:
In
fact to show you how dumb some of these people are a guy across the
taxiway from me built a Kitfox. He put so much **** on it that with
him and full fuel he was 50 pounds over gross.

Doesn't the builder determine the gross weight of a homebuilt?


Along with a healthy dose of physics.

Bill Denton wrote:
Consider the following aircraft:

Seats ---------------------------------------------- 2

Empty Weight (typical) -------------------- 920 lbs.

Maximum Gross Weight -----------------1320 lbs.

Useful Load ----------------------------------- 400 lbs.

Payload with Full Fuel (18 Gals) -------- 292 lbs.

Suppose I wanted to add additional equipment to this aircraft.
Obviously, this would raise the Empty Weight, and lower the Useful
Load and the Payload.

Is there any sort of "minimum" Useful Load or Payload that must be
maintained when equipment is added, or is it simply a matter of
operating it within the "weight envelope"?

I guess for day VFR you would have to have at least a useful load weight =
your weight + the weight of 30 min of fuel. That gives you ZERO range and if
you added a few pounds over the holiday you are over gross.

There was a famous Las Vegas entertainer, who bought a very
nice turboprop twin and took it to a completion center in
Omaha to have the cabin done in his style. The completion
center advised that the list of cabin furnishings was very
heavy and probably not a good idea.
But the entertainer insisted.

The completed airplane was over gross without payload or
fuel.



"Bill Denton" wrote in message
. net...
| Consider the following aircraft:
|
| Seats ---------------------------------------------- 2
|
| Empty Weight (typical) -------------------- 920 lbs.
|
| Maximum Gross Weight -----------------1320 lbs.
|
| Useful Load ----------------------------------- 400 lbs.
|
| Payload with Full Fuel (18 Gals) -------- 292 lbs.
|
| Suppose I wanted to add additional equipment to this
aircraft. Obviously,
| this would raise the Empty Weight, and lower the Useful
Load and the
| Payload.
|
| Is there any sort of "minimum" Useful Load or Payload that
must be
| maintained when equipment is added, or is it simply a
matter of operating it
| within the "weight envelope"?
|
|
|
|
|
|
|

I've noticed that new souped up Mooney has almost no useful load with
full fuel. (Less than 1 big pilot)

It strikes me that there are two limits to gross weight in a single.
The structural and climb performnace limits and the statutory limit that a single engine
stall speed must be less than 61K( I think this number is right)

So this makes me think that the new souped up mooney is probably flown over gross
on the asumption that the only real limit here is the artifical statutory limit.
This would make me feel very uncomfortable. If you routinely fly at over gross weight
you never know close you are to the real structural limits.


I grew up in Alaska and a lot of the bush planes are routinely flown
well over gross.... both knowingly by the pilots and via fudged paperwork.
I've was personally involved with reweighing a Beaver DHC-2 where the official
paperwork had the empty weight suspiciously low. The last weighting paperwork accounted for
Full Fuel, and when we weighed it it was heaver than it should be by this amount.
I suspect that the previouse weighing had the tanks empty and accounted for full.
A lot of the forrest service contracts in South East Alaska had contact limits that said
the aircraft provided must have XX useful low. These numbers were unreasonably low for
most of the specified aircraft models, encopuraging the operators to cheat or go out of business.