REFLECTOR: Gliding Distance
Tom Irion
tirion at comcast.net
Tue Jun 19 20:46:27 CDT 2012
Mark,
I lost your cell number give me a call.
Tom Irion
722XL
On Jun 19, 2012, at 6:40 PM, Mark Magee wrote:
> You boys got me all confused here? Glide ratio: Three to One (F-4
> Phantom II), at Best Glide speed airplane goes three feet forward
> and goes down 1 foot. Three to One Glide Ratio. You guys are
> throwing in some trigonometry that's confusing (possibly
> frightening) folks? At 10,000' AGL an F4 Phantom II in flameout at
> best glide has a 30,000 ft 'cone' below it at which touchdown (or
> ejection) will occur. Turns lessen the Three to One.
> Fairly simple: if an XLFG clean and stopped prop does a 15 to 1
> glide ratio, then at 10,000' AGL, I have a 150,000' 'cone' below me
> inside which my wheels will touch down, turns diminishing the cone.
> Airplane moves 15 feet forward, and falls 1 foot. 15 to 1 glide ratio.
> Fairly simple.
>
> Mark B. Magee
> PS (F-4 Phantom II was a template subject of my flight training:
> proof that with enough thrust a lead brick can fly!)
>
> On Tue, Jun 19, 2012 at 7:34 PM, Brooke Wolf <bwolf1 at tds.net> wrote:
> Tom
>
> I was using the aviation standard of 6000ft/nautical mile.
> Admittedly, it is more like 6076 feet. Anyway, using 6000 ft., 1.41
> nautical miles is 8460 ft. Hence, 8.4:1 glide ratio. Man…I like
> this stuff. Great discussion! Keep it up.
>
> Brooke
>
>
>>
>>
>> From: Tom Falls <tomfalls6 at gmail.com>
>> Subject: Re: REFLECTOR: Reflector Digest, Vol 87, Issue 104
>> Date: June 19, 2012 6:40:02 PM EDT
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org
>> >
>>
>>
>> Correct me if I'm wrong but I think Brooke got 7.4:1 (1.41 miles is
>> 7445 ft/1000). And John Abraham is worse at 5.4:1 to 6:1 (2.5-2.8
>> nm is 15,190 to 17,000 ft. Divide that by 2800).
>>
>> Tom
>>
>> Sent from my iPad
>>
>> On Jun 19, 2012, at 5:07 PM, Mark Magee <edjonesbrady at gmail.com>
>> wrote:
>>
>>> Hi John,
>>> What was your speed, do you recall?
>>> Is Glide Ratio similar for XLFG as to XLRG gear up?
>>>
>>> Mark
>>>
>>> On Tue, Jun 19, 2012 at 2:46 PM, John Abraham <john at velocityaircraft.com
>>> > wrote:
>>> You should see around 15:1 +/- for building variations with a zero
>>> thrust setting and gear up. I have done a 2.5-2.75 NM glide from
>>> 2800 feet back to the runway with a windmilling propeller on an XL
>>> before. (yes engine was out so no additional thrust) best glide
>>> airspeed is 85KCAS at gross. So L/D will decrease if you are
>>> lighter slightly. We cleared the fence by about 5’ or so.
>>>
>>>
>>>
>>> John
>>>
>>>
>>>
>>> From: reflector-bounces at tvbf.org [mailto:reflector-
>>> bounces at tvbf.org] On Behalf Of Mark Magee
>>> Sent: Tuesday, June 19, 2012 2:56 PM
>>>
>>>
>>> To: Velocity Aircraft Owners and Builders list
>>> Subject: Re: REFLECTOR: Reflector Digest, Vol 87, Issue 104
>>>
>>>
>>>
>>> I don't have the manual here at work, is the XLFG a 12 to 1 glide
>>> ratio with a stopped prop?
>>>
>>>
>>> Old Long EZ glided 20 to1 on a stopped prop.
>>> I told myself I'd never fly the heavies... :(
>>> Mark Magee
>>>
>>> On Tue, Jun 19, 2012 at 12:44 PM, Brooke Wolf <bwolf1 at tds.net>
>>> wrote:
>>>
>>> Steve….Just to be clear, do you mean 9.5 to 1, i.e., 9500 feet
>>> forward for every 1000 ft altitude loss? It looks like mine is
>>> nearer 8.5 to 1. Somehow, somewhere I got the idea it would be 15
>>> to 1! Maybe that is with a stopped prop.
>>>
>>>
>>>
>>> Brooke
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> From: steve korney <s_korney at hotmail.com>
>>>
>>> Subject: Re: REFLECTOR: Gliding Distance
>>>
>>> Date: June 19, 2012 1:13:22 PM EDT
>>>
>>> To: Reflector Reflector <reflector at tvbf.org>
>>>
>>> Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org
>>> >
>>>
>>>
>>>
>>>
>>> At 85 KIAS @ 6000ft , you have about a 9.5 glide ratio.... What
>>> are you expecting to see....?
>>>
>>>
>>> Steve
>>>
>>> > From: bwolf1 at tds.net
>>> > Date: Tue, 19 Jun 2012 12:26:23 -0400
>>> > To: reflector at tvbf.org
>>> > Subject: REFLECTOR: Gliding Distance
>>> >
>>> > I am planning some overwater trips in the near future and the
>>> subject of gliding distance naturally comes to mind. I have done
>>> some limited test flying with my airplane (XLRG w/Aerocomposite
>>> variable pitch prop). The results of my gliding performance are
>>> not too good. All tests were done around 6000ft with throttle at
>>> idle and wheels up. Here are the results:
>>> >
>>> > 80 KIAS - 900fpm…….. yields a glide performance of 1.38 miles/
>>> 1000 ft altitude
>>> > 85 KIAS - 1000fpm……..yeilds a glide performance of 1.41 miles/
>>> 1000 ft altitude
>>> > 100 KIAS - 1250fpm …..yields a glide performance of 1.34 miles/
>>> 1000 ft altitude
>>> >
>>> > As you can see, 85 KIAS appears to be the best glide speed.
>>> >
>>> > I know there may be a big difference in what I tested and what
>>> happens in the real world with a windmilling or stopped prop. Have
>>> any of you brave test pilots done any testing with a windmilling
>>> or stopped prop? What were the results? What kind of glide
>>> performance did others get with throttle at idle? Is there anyway
>>> to correlate throttle idle glide performance with windmilling or
>>> prop stopped performance? What is the best way to stretch a wheels
>>> up glide on a Velocity?
>>> >
>>> > I would like to get a discussion going on this and find what
>>> others have experienced. Thanks.
>>> >
>>> > Brooke, N108BG, XLRG-5, 145 hours
>>> >
>>> >
>>> > _______________________________________________
>>> > To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>>> >
>>> > Visit the gallery! www.tvbf.org/gallery
>>> > user:pw = tvbf:jamaicangoose
>>> > Check new archives: www.tvbf.org/pipermail
>>> > Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>
>>>
>>>
>>> _______________________________________________
>>> Visit the gallery! tvbf:jamaicangoose
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>>>
>>> Visit the gallery! www.tvbf.org/gallery
>>> user:pw = tvbf:jamaicangoose
>>> Check new archives: www.tvbf.org/pipermail
>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>
>>>
>>>
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 2012.0.2178 / Virus Database: 2437/5079 - Release Date:
>>> 06/19/12
>>>
>>>
>>> _______________________________________________
>>> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>>>
>>> Visit the gallery! www.tvbf.org/gallery
>>> user:pw = tvbf:jamaicangoose
>>> Check new archives: www.tvbf.org/pipermail
>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>
>>> _______________________________________________
>>> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>>>
>>> Visit the gallery! www.tvbf.org/gallery
>>> user:pw = tvbf:jamaicangoose
>>> Check new archives: www.tvbf.org/pipermail
>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>
>>
>>
>>
>> From: Scott Derrick <scott at tnstaafl.net>
>> Subject: Re: REFLECTOR: Reflector Digest, Vol 87, Issue 104
>> Date: June 19, 2012 6:50:49 PM EDT
>> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>> Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org
>> >
>>
>>
>> That sounds way to exciting John!
>>
>> -------- Original Message --------
>> Subject: Re: REFLECTOR: Reflector Digest, Vol 87, Issue 104
>> From: John Abraham <john at velocityaircraft.com>
>> To: 'Velocity Aircraft Owners and Builders list' <reflector at tvbf.org>
>> Date: 06/19/2012 01:46 PM
>>> You should see around 15:1 +/- for building variations with a zero
>>> thrust setting and gear up. I have done a 2.5-2.75 NM glide from
>>> 2800 feet back to the runway with a windmilling propeller on an XL
>>> before. (yes engine was out so no additional thrust) best glide
>>> airspeed is 85KCAS at gross. So L/D will decrease if you are
>>> lighter slightly. We cleared the fence by about 5’ or so.
>>>
>>>
>>>
>>> John
>>>
>>>
>>>
>>> From: reflector-bounces at tvbf.org [mailto:reflector-
>>> bounces at tvbf.org] On Behalf Of Mark Magee
>>> Sent: Tuesday, June 19, 2012 2:56 PM
>>> To: Velocity Aircraft Owners and Builders list
>>> Subject: Re: REFLECTOR: Reflector Digest, Vol 87, Issue 104
>>>
>>>
>>>
>>> I don't have the manual here at work, is the XLFG a 12 to 1 glide
>>> ratio with a stopped prop?
>>> Old Long EZ glided 20 to1 on a stopped prop.
>>> I told myself I'd never fly the heavies... :(
>>> Mark Magee
>>>
>>> On Tue, Jun 19, 2012 at 12:44 PM, Brooke Wolf <bwolf1 at tds.net>
>>> wrote:
>>>
>>> Steve….Just to be clear, do you mean 9.5 to 1, i.e., 9500 feet
>>> forward for every 1000 ft altitude loss? It looks like mine is
>>> nearer 8.5 to 1. Somehow, somewhere I got the idea it would be 15
>>> to 1! Maybe that is with a stopped prop.
>>>
>>>
>>>
>>> Brooke
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> From: steve korney <s_korney at hotmail.com>
>>>
>>> Subject: Re: REFLECTOR: Gliding Distance
>>>
>>> Date: June 19, 2012 1:13:22 PM EDT
>>>
>>> To: Reflector Reflector <reflector at tvbf.org>
>>>
>>> Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org
>>> >
>>>
>>>
>>>
>>>
>>> At 85 KIAS @ 6000ft , you have about a 9.5 glide ratio.... What
>>> are you expecting to see....?
>>>
>>>
>>> Steve
>>>
>>> > From: bwolf1 at tds.net
>>> > Date: Tue, 19 Jun 2012 12:26:23 -0400
>>> > To: reflector at tvbf.org
>>> > Subject: REFLECTOR: Gliding Distance
>>> >
>>> > I am planning some overwater trips in the near future and the
>>> subject of gliding distance naturally comes to mind. I have done
>>> some limited test flying with my airplane (XLRG w/Aerocomposite
>>> variable pitch prop). The results of my gliding performance are
>>> not too good. All tests were done around 6000ft with throttle at
>>> idle and wheels up. Here are the results:
>>> >
>>> > 80 KIAS - 900fpm…….. yields a glide performance of 1.38 miles/
>>> 1000 ft altitude
>>> > 85 KIAS - 1000fpm……..yeilds a glide performance of 1.41 miles/
>>> 1000 ft altitude
>>> > 100 KIAS - 1250fpm …..yields a glide performance of 1.34 miles/
>>> 1000 ft altitude
>>> >
>>> > As you can see, 85 KIAS appears to be the best glide speed.
>>> >
>>> > I know there may be a big difference in what I tested and what
>>> happens in the real world with a windmilling or stopped prop. Have
>>> any of you brave test pilots done any testing with a windmilling
>>> or stopped prop? What were the results? What kind of glide
>>> performance did others get with throttle at idle? Is there anyway
>>> to correlate throttle idle glide performance with windmilling or
>>> prop stopped performance? What is the best way to stretch a wheels
>>> up glide on a Velocity?
>>> >
>>> > I would like to get a discussion going on this and find what
>>> others have experienced. Thanks.
>>> >
>>> > Brooke, N108BG, XLRG-5, 145 hours
>>> >
>>> >
>>>
>
>
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery! www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/
> maillist.html
>
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery! www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/
> maillist.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20120619/166d66b9/attachment-0001.htm>
More information about the Reflector
mailing list