The LR45

[airpilot]

I've heard it being called the Ann Summers flying vibrator a few times but what a machine.

Just doing a little research on this type and was hoping I could get some info.

Compared to other models the LR45 has a larger fin and rudder no doubt to increase its directional stability but not sure why the smaller delta fins and extended engine pylons.

Any thoughts would be greatly appreciated

[Chippie Chappie]

One of the purposes of the Delta fins is to improve stall characteristics and prevent "Deep Stall", something that T-Tailed aircraft are vunerable to if mishandled. They're also good for giving you a bump on the head if you're not paying attention.

Cheers,

Chips

[airpilot]

Thanx

Can I ask how they help improve stall characteristics and prevent deep stall?

I understand that the wings blank off turbulent airflow to the t tail therefore no warning of buffet etc. So do the delta fins help in this manner?

[airpilot]

I think i was talking complete crap about the wings blanking off the turbulent airflow to the tail. The t tail is just simply not in affected by turbulent airflow off the wings so the delta fins must change this?

[ICT_SLB]

The Delta Fins (on the LJ40/45 & 60) are not for stall or stick push but, quite the opposite to remove the need for the stick puller function on earlier Learjets which suffered from mach tuck. Former Learjet Chief Test Pilot Pete Reynolds was awarded the J.H. Doolittle Award for the idea. All current Lears still have a Stall Protection Computer with Shaker & Pusher. It's also been incorporated into the ASTOR variant of the Global Express but I beleive that's more for directional stability.