Lift Reserve Indicator

[thomas]

Unfortunately, Kelly Meiste closed up shop and no longer produces his LRI kits. I reached out to Kelly to see if he still had access to one of the 3d printed probes that he could sell me. Kelly did not have any inventory but he had a new probe printed on an industrial machine and mailed it to me for $50. See photo. The smoothness and rigidity of this print is amazing - definitely not the rough quality of what comes off my son's desktop 3d printer.

For those wanting to build their own LRI yet shave off some fabrication time, you can email Kelly at kelly@meiste.com. He's great about responding quickly and a joy to correspond with.

Paul

[michaelaskew]

A Lift Reserve Indicator is a device used in aviation to provide pilots with information about the aircraft's remaining lift capability. This indicator helps pilots determine the aircraft's current lift margin and whether it can safely maneuver or continue flying without stalling.

The Lift Reserve Indicator typically operates based on the difference between the aircraft's current angle of attack (the angle between the aircraft's longitudinal axis and the oncoming airflow) and its critical angle of attack (the angle at which the aircraft is on the verge of stalling). The indicator's purpose is to provide pilots with a visual or auditory cue to avoid reaching the critical angle of attack, which would lead to a stall.

[Onex107]

A LRI should be required on every airplane. There are all kinds of them available, mine was home made from plans on the internet and did not require power. Install it where you can see it while landing and you will never make another bad landing.

[Bryan Cotton]

Hey michaelaskew welcome to the forum! Tell us about yourself and your interest in Sonex!

[daleandee]

Install it where you can see it while landing and you will never make another bad landing.

I wish this were true ... lol ;~)

3.0 Corvair/Tailwheel

[Area 51%]

If Cessna had installed an LRI on the stabilator of the Cardinal, it would probably still be in production.

Someone tell me why you don't need the LRI on both wings? If you're flying close enough to the edge to need an LRI, wouldn't it be beneficial to know which wing is about to go on break? .

[DCASonex]

In a turn, the inside wing will stall first as it is not moving through the air as fast as the outside wing. I put my LRI under the left wing, as most turns in the pattern are left turns.

David A.

[daleandee]

Someone tell me why you don't need the LRI on both wings? If you're flying close enough to the edge to need an LRI, wouldn't it be beneficial to know which wing is about to go on break? .

Using an LRI isn't about always using it to fly "close enough to the edge to need an LRI" as it is very useful for displaying other information. I can tell by the LRI in straight & level flight when I'm in the flap deployment speed range, what is the best position for a short field landing, & Vx or VY etc. If one were to lose the ASI the LRI can give a great deal of speed information.

There is math to determine the difference in stall speed across the wing span in level turning flight but the difference isn't huge. If you are flying that close to the edge you'd likely feel it and I'd also suggest if flying close enough to feel it that the pilot have a few thousand feet of altitude ...