FAA approves gross weight increase in Alaska

[astjp2]

I just got this email from a friend that has a Luscombe, does anyone know of its validity?


From: Dan McNeill
To: [email protected]
Sent: Sunday, October 28, 2007 9:19 AM
Subject: Re: [luscombe-silvaire] Re:Maximum Weight

Hey Steve,

Lets set aside the new Luscombe for a moment and discuss safety of gross weight conditions for the original Luscombes. I'll get back to the new Luscombe later...

You asked if it was safe to operate a Luscombe at 1470 lbs. The answer is, yes, absolutely. And it's even fully approved by the FAA for operations at a gross weight of up to 1600 lbs... if you are an air taxi operation in Alaska. Think about that for a second. Whoa. For hire operations at 1600 lbs.

It's not an approval only for the Luscombe, of course. It is for any aircraft certified under the early regs (Aeronautics Bulletin 7a and CAR 4a... Luscombes were approved under CAR 4a). What the Alaska folks discovered is that some of these early airplanes made very good bush planes for hauling folks and stuff. Airplanes like Fairchilds, Howards, Noorduyn Norseman, Pilgrims, Beech 18, etc. But the gross weight allowance wasn't always quite enough to allow a full "Alaska" load.

The justification and subsequent approval for higher gross weights was really quite simple and logical. Aircraft certified under these earlier regs had to meet a design load factor requirement of at least 4.5. But newer airplanes certified under FAR part 23 were certified to load factors of 3.8 for normal category and 4.4 for utility category (FAR 23.337). The older planes are structurally stronger by design.

So, the FAA approved operations for these older airplanes at gross weights not to exceed;

1) 12,500 pounds,
2) 115% of the max gross weight listed on the TCDS,
3) The weight at which the aircraft meets the positive maneuvering load factor of FAR 23.337 for the normal category,
4) The weight at which the aircraft meets the climb performance requirements under which it was type certificated.

If you do the math, the Luscombe is good for 1658 lbs (load factor 3.8) under the Alaska rule blessed by the FAA. So, a 1470 lb load is safe (the T-8F is actually approved for 1470 lbs in the restricted category). Safe and legal can be two different things, though... 1400 lbs is the legal limit. You will lose any argument with the FAA or your insurance company if you claim otherwise.

Back to the new Luscombe. It is basically a late model 8A/F structurally (as far as I know). So, as described above it should be safe for a higher gross weight. But under the LSA regs, 1320 is the legal limit. All of the nouveau classics have the same issues with gross weight. A 100 h.p. two seat LSA airplane must have an empty weight of 890 lbs or less. At 890 lbs., you only have a legal useful load of 430 lbs. That's where some of the European glass and carbon airplanes really shine by comparison...

Dan


----- Original Message -----
From: Steve Glasgow
To: [email protected]
Sent: Saturday, October 27, 2007 6:19 PM
Subject: [luscombe-silvaire] Re:Maximum Weight

How about the new Luscombe which is probably stronger and more capable of higher GW but is obviously limited to 1320 just to make it a LSA? The problem is using 1320, the plane is over gross with two people and full tanks.

Certainly this plane would be fine at 1400 and probably fine at 1470 lbs but is limited for one reason only to fall under the LSA rule?

Of course insurance would be invalid. But would it be safe at 1470 and within CG?

Just curious????

Thanks

Steve Glasgow

[Guest]

Re: FAA approves gross weight increase in Alaska

I just got this email from a friend that has a Luscombe, does anyone know of its validity?


From: Dan McNeill
To: [email protected]
Sent: Sunday, October 28, 2007 9:19 AM
Subject: Re: [luscombe-silvaire] Re:Maximum Weight

Hey Steve,

Lets set aside the new Luscombe for a moment and discuss safety of gross weight conditions for the original Luscombes. I'll get back to the new Luscombe later...

You asked if it was safe to operate a Luscombe at 1470 lbs. The answer is, yes, absolutely. And it's even fully approved by the FAA for operations at a gross weight of up to 1600 lbs... if you are an air taxi operation in Alaska. Think about that for a second. Whoa. For hire operations at 1600 lbs.

It's not an approval only for the Luscombe, of course. It is for any aircraft certified under the early regs (Aeronautics Bulletin 7a and CAR 4a... Luscombes were approved under CAR 4a). What the Alaska folks discovered is that some of these early airplanes made very good bush planes for hauling folks and stuff. Airplanes like Fairchilds, Howards, Noorduyn Norseman, Pilgrims, Beech 18, etc. But the gross weight allowance wasn't always quite enough to allow a full "Alaska" load.

The justification and subsequent approval for higher gross weights was really quite simple and logical. Aircraft certified under these earlier regs had to meet a design load factor requirement of at least 4.5. But newer airplanes certified under FAR part 23 were certified to load factors of 3.8 for normal category and 4.4 for utility category (FAR 23.337). The older planes are structurally stronger by design.

So, the FAA approved operations for these older airplanes at gross weights not to exceed;

1) 12,500 pounds,
2) 115% of the max gross weight listed on the TCDS,
3) The weight at which the aircraft meets the positive maneuvering load factor of FAR 23.337 for the normal category,
4) The weight at which the aircraft meets the climb performance requirements under which it was type certificated.

If you do the math, the Luscombe is good for 1658 lbs (load factor 3.8) under the Alaska rule blessed by the FAA. So, a 1470 lb load is safe (the T-8F is actually approved for 1470 lbs in the restricted category). Safe and legal can be two different things, though... 1400 lbs is the legal limit. You will lose any argument with the FAA or your insurance company if you claim otherwise.

Back to the new Luscombe. It is basically a late model 8A/F structurally (as far as I know). So, as described above it should be safe for a higher gross weight. But under the LSA regs, 1320 is the legal limit. All of the nouveau classics have the same issues with gross weight. A 100 h.p. two seat LSA airplane must have an empty weight of 890 lbs or less. At 890 lbs., you only have a legal useful load of 430 lbs. That's where some of the European glass and carbon airplanes really shine by comparison...

Dan


----- Original Message -----
From: Steve Glasgow
To: [email protected]
Sent: Saturday, October 27, 2007 6:19 PM
Subject: [luscombe-silvaire] Re:Maximum Weight

How about the new Luscombe which is probably stronger and more capable of higher GW but is obviously limited to 1320 just to make it a LSA? The problem is using 1320, the plane is over gross with two people and full tanks.

Certainly this plane would be fine at 1400 and probably fine at 1470 lbs but is limited for one reason only to fall under the LSA rule?

Of course insurance would be invalid. But would it be safe at 1470 and within CG?

Just curious????

Thanks

Steve Glasgow

They (Luscombes and other old airplanes) are not certified under part 23.

Follow the red text above, he says its approved then he says its not legal, can't be both.

I don't think there is anything to it. Doesn't appear that anything at all has been approved.

[dmcneil]

Re: FAA approves gross weight increase in Alaska

Hmmm... Imagine my surprise when my post to our members only group is reposted here.

You might want to check out FAR 91.323 "Increased maximum certificated weights for certain airplanes operated in Alaska."

It's been on the books for years. As I stressed repeatedly in my original post, it is only legal if you meet the requirements of that specific FAR. Flying at anything above the approved gross weight is not legal.

Dan

[Guest]

Re: FAA approves gross weight increase in Alaska

Interesting.

I have no clue how your private info gets here.

Your reference is excellent and I stand entirely corrected by it however it is not mentioned in the post that was made here.

Shame on me for not remembering it anyhow.

Dave

[astjp2]

Re: FAA approves gross weight increase in Alaska

I got the info from a friend and I posted it because I thougt the info was interesting, it does only apply to comericial operators but it also gives insight behind the logic for the application. Its a very good reference. I did not want to offend anyone. If I did, I am sorry. Regards Tim

[dmcneil]

Re: FAA approves gross weight increase in Alaska

Hey Tim,

No offense taken. I was just taken a bit by surprise seeing it here. Anyway, I'm glad you found it interesting!

Cheers,

Dan

[Robert Lees]

Re: FAA approves gross weight increase in Alaska

It might have been appropriate to "disidentify" any names. That's my own policy.

Rob

[fearofpavement]

Re: FAA approves gross weight increase in Alaska

I think sometimes people forget that the internet is a pretty open and worldwide system. Unless something is only password accessed it can be read from sea to shining sea...(so write nice) Just wish there was a way to shoot a few thousand volts through the spammer's servers!