Mailing List lml@lancaironline.net Message #10865
From: Scott Krueger <sky2high@hotmail.com>
Subject: L/D Max, AOA, LNC2, Practical Results
Date: Mon, 27 Aug 2001 21:05:21 -0500
To: <lancair.list@olsusa.com>
Cc: <Sky2high@aol.com>
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If anyone is interested, here's some data:

Lancair 320 N92EX, fuel injected with an empty weight of 1214 pounds was flown today with full fuel (43 gals) and 200 pounds of pilot (with clothing).  This put the total weight at 1688 pounds (gross 1800, once gingerly flown at 1960 pounds) with the CG at 25.8 (18.2% of MAC) and the 40 minute flight used 5 gallons of fuel.  Local conditions were 26 degrees C, 2300 ft density altitude, a baro setting of 29.88 and the airport elevation is 700 ft.

All the following numbers were obtained with the AOA (Jim Franz's device) at the MAX L/D indication.  The AOA was recently calibrated on a BFR with an agressive Falcon pilot.  Marv will validate its effectiveness during our recent AOA managed landing.

1. Climb out accomplished in turbulence at WOT/2600RPM 112 kts with a climb rate varying (sometimes wildly) between 1200 and 1800 fpm to an altitude of 6300 feet and smooth air.

2. Clean configuration, 6300 ft(approx 8000 ft density alt), 20 degrees C, 14.4 MP, 2100 rpm, 4 gph with 115 kts IAS, 123 kts TAS and AOA=5.9

3. Flaps out of reflex (7 degrees) and nose trimmed back up, 6300 ft, 15.5 MP, 2100 rpm, 4.3 gph with 100 kts IAS, 112 kts TAS and AOA=5.9

4. Clean, 5500 ft, 21 degrees C, 24.8 MP, 2480 rpm, 171 kts IAS, 191 kts TAS, 10.1 gph and AOA=2.2

Efficiency was about 19 NM/gal at high cruise (#4), 4.2 hours endurance with a range of 802 NM assuming no change due to fuel consumption.  I will have to try this test at a low fuel quantity.

At max L/D (#2), 37 NM/gal, 11 hours endurance with a range of 1350 NM again assuming no change because of fuel consumption.

However, at max L/D flight, in 4.2 hours only 516 NM would be covered.

Remember, this is not a glider.  If the engine stopped, Lancair recommended 104 kts glide with the prop at low pitch to minimize drag.  This is why an AOA is so important - no guesswork for max glide.

Stop fooling around with theory, guessimates and exotic calculations - get an AOA and use it.

Scott Krueger
The more I learn, the less I know.



LML website:   http://www.olsusa.com/mkaye/maillist.html
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Please send your photos and drawings to marvkaye@olsusa.com.

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