Lear 60 vs. 45

[ultrarunner]

ultrarunner....is it just on the newer lears?

The winglet buzz? Yeah, it's pretty much a standard deal on the 31/55/60 series.

I can speak for the 28/29 series, since I have never flow that series. It's not really an issue on the 31, but the 55 and 60 wings are pushed pretty hard as mentioned earlier in this thread, and at the heavy weights and higher altitudes, you will get a bit of "rumble" as you approach MMO. Just keep the power back the first hour and you're fine.

 

[vixin]

I would say more short runways and TR's being pinned. I am sure other operators dont fly for as long with them pinned. Thats because of the flying we do. Our maint. is top notch. We just need the time to get it done.

 

[ultrarunner]

Pinned TR's. OK, bring me up to speed. I have just over a year in the 60, are the TR's prone to needing to be pinned on a regular basis? I haven't had a fault yet.

 

[vixin]

A normal corp operation I would say it wouldnt happen all that often. The Flex operation they get pinned occasionally. Thats also when we go to ASE 4/5 times that week with repo's to SMO. Just kidding on that, but my point is there are other reason why we may or may not go through the breaks a little quicker then most. Plus it is better to plan on an inadvertant TR stow by getting stopped then to baby the breaks on a 5-6000 ft runway. Nothing like using minimal breaking and then having a TR stow with the thrust still there. It is like a sling shot. The end of the runway seems a little closer for some reason. I think most of us like to be sure the plane is stopping then we let off the breaks. When we go to Dulles the breaks are hardly used.

 

[LJ45]

Wing buzz

No problems at all in the 45...better winglet design and more wing area. The wing on the 45 is a "new" wing" even though it looks like the old longhorn wings. The 45 MMO is .81 all the way up to FL510. No wing buzz at any altitude, speed or weight.

The 31a MMO does decrease at altitude also to .78 but it has no buzz due to the light weights.

When you get to .81, or by accident a little pass .81, in the 31a you will know by the rumble, not so in the 45. Due to new cert. requirments the 45 has a larger margin before things start to happen pass the MMO

just a little more info!

 

[Throttlebender]

Hey Lead Sled,
May be a silly question, but when you said hot wings degrade performance was that because of bleed air usage or some other reason?

 

[LJ45]

not lead..but..

It uses lots of bleed air from the engines. Thus, less thrust or less power.

 

[Lead Sled]

Hey Lead Sled,
May be a silly question, but when you said hot wings degrade performance was that because of bleed air usage or some other reason?

Throttlebender...
There's no such thing as a silly question, just silly answers. Remember, you can't get something for nuttin. If you take energy (bleed air) from the core of the engine to heat the wings, stab, and engine inlets it won't be there to "blow" out the back of the engine and provide thrust. As I mentioned in a previous post, heated leading edges are considered anti-icing (as opposed to de-icing) devices and you must turn on the heat whenever you are in conditions conducive to the formation of ice. This is compared to de-icing devices like the Astra's boots which are cycled to remove ice that has formed on the wing's leading edges. The other typically encounted option out there is TKS used by Hawkers, some Citations, and some piston powered aircraft. TKS systems can be used either as anti-icing or de-icing.

'Sled

 

[Throttlebender]

Thanks. I assumed as much, but didn't really think it would rob enough bleed air to cause noticable performance loss. Now I know

 

[banned username 2]

Thanks. I assumed as much, but didn't really think it would rob enough bleed air to cause noticable performance loss. Now I know

In the Falcon 20 with the CF700-2D2 engine we really couldn't climb above FL180 with the Anti-Ice on if we were heavy... (of course even with it off it was a chore to climb much above that anyhow!)

There is a noticable difference in performance in most every jet when you turn on the anti-ice...