Active Glide ratio Indicator - iFly General Discussions

We have a new Forum! Go here to get started: https://adventurepilot.community.forum.
The new forum is easier to use and much more capable than the old, we hope you will join our community!

Below is a copy of the old forum. This will remain available for a short period so you can access and review the information contained here. To continue a conversation, or start a new one, please register and create a post at our new forum location.

Search

Home

Discussions

iFly General Di...

Active Glide ratio Indicator

2/19/2021 5:27 PM

John Miller

Joined: 9/12/2010

Posts: 644

Re: Active Glide ratio Indicator Modified By John Miller on 2/21/2021 9:05:10 AM

Not quite the same thing.

I like Baseline, but I'm sure the IFLY staff will make it more suited for fixed wing pilots.

I cut the engine and by looking at the screen I know how to adjust the pitch to get max glide.

Just found out that 50 MPH indicated seems to be optimal in my Avid Flyer MK4.

This is interesting since my stall clean is 40 mph and dirty is 35 mph.

John M

2/20/2021 6:25 PM

N854HC

Joined: 2/8/2019

Posts: 77

Re: Active Glide ratio Indicator

John M,

When you say 'max glide' are you meaning max distance or max time aloft? As I understand it, these two 'max' glide operations can require two different airspeeds to achieve each one.

Best,

John

2/20/2021 11:08 PM

Alasdair

Joined: 10/12/2011

Posts: 411

Re: Active Glide ratio Indicator

Yeah good question - John: 50 MPH sounds kinda slow to be best L/D speed. Even in a C150 that wouldn't be much above stall and so likely closer to min-sink.

2/26/2021 5:50 PM

John Miller

Joined: 9/12/2010

Posts: 644

Re: Active Glide ratio Indicator Modified By John Miller on 2/27/2021 8:38:06 AM

N85...

I'm referring to the speed that will give the best distance to reach that safe landing spot.

After many tests and with 20 gallons and only me in my avid MK4 I have found that, with no head or tail wind 50-55 MPH indicated works to give me the best distance.

I am seeing a solid 10:1 ratio.

Of course, wind will have an effect. If in a 50 mph head wind I would make little forward progress. That gives a couple options: Decrease AoA to increase speed if you absolutely have to continue on the same course or do a 180 and pick up a tail wind and increase your AoA (reduce speed) and maximize your available distance.

My tests were done from 5000 AGL with engine idling. Next I will fly to a local dry lake and actually shut the engine off for glide tests down to the surface.

I have the glide ratio app on my phone at present and will use it more when IFLY has it in their app. Sem like a no brainer and another sales incentive.

Just another tool that might help save your bacon when it goes silent.

John M

2/26/2021 6:03 PM

John Miller

Joined: 9/12/2010

Posts: 644

Re: Active Glide ratio Indicator Modified By John Miller on 3/15/2021 6:37:41 PM

Alsander:

My clean stall is 40 mph and 35 mph ind dirty. Not close to a Cessna 150-152.

So it would seem that my induced and parasitic drag are minimum at that speed.

You should know that my Avid MK 4 has an undercamber wing. Not great for speed, but gets me in those short unimproved back country strips.

I'll have a better idea of my best no wind glide speed when I do actual engine off tests at a local dry lake.

In over 8000 hours in Cessnas, ultralights and my two Avid Flyer ecperimentals I have had 5 engine failures. Fortunately I have have only slightly damaged one aircraft. I owe this to practicing engne off landings frequently.

The last failure was Last September. Took 4 months to get a warranty replacement.

John M

Page 2 of 3

Active Glide ratio Indicator

iFly GPS Forum

Adventure Pilot LLC