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DG-1000試飛報告
作者: 林寬明
DG1000 TEST FLY
DATE: NOV. 19, 2001
BY: ALBERT LIN
(Chinese version follows the English one,
中文報告在英文報告之後)
1. DATE OF TEST FLY: NOV. 17TH & 18TH
, 2001.
2. PLACE: SAI-CHIA AVIATION PARK, PING-TUNG, TAIWAN.
3. MODEL: DG-1000, 3.7 m, scale.
4. TEST TEAM:
4-1. Pilot: Albert Lin
4-2. Winch operator: Mr. Jinn Tsai
4-3. Ground assistant: Mr. M.S. Lin
4-4. Video photographer and observer: Mrs. Tsai.
5. Test fly procedure:
* Day one (AM of Nov. 17th, 2001)
5-1. Bungee ground towing test:
a. First test with a very minimum bungee tension to see if DG-1000
can
move straight and smoothly on grass runway. DG-1000 slid for
about 15 meters pretty straight after release.
b. Second test with about a double tension of the first one,
DG-1000 slid for more than 50 meters pretty straight as the first
one .
c. Third test with much more tension to see the airborne situation
of DG-1000.
It slid on the grass run way for just about 10 meters and took
off the ground for almost 2 meters in height, then sliding touch
down successfully. The C.G. was ok and no need for adjustment
at the time being.
5-2. Winch ground towing test:
a. First test with a very minimum winch towing time also to see
the sliding situation of DG-1000 on grass runway, it slid just
for about 10 meters same as the above first test of bungee towing.
Result is almost identical as above 5-1-a.
b. Second test with a bit longer winch towing time and DG-1000
got airborne
for about 2 feet in height and sliding touch down smoothly.
c. Third test with full winch towing. DG-1000 went airborne in
less than 10 meters' slide. The elevator was not touched, DG-1000
was pulled into the air at about 45 - 50 degrees and went up
to the max. height, it then was pulled leveled by controlling
elevator down and then with a slight up elevator to release tow
hook. The release of tow hook seemed a bit reluctant.
With heavier weight of almost 4 kgs, estimated
height is about 90 - 100 meters. After tow hook released, it
banked apparently to the left side, with trimming of aileron,
it glided levelly well. Since it was the first real airborne,
no attempt to find thermal and just gliding circles around the
flying field for 4 or 5 circles. Duration performance was much
better than expected. After setting the approaching course, spoilers
were deployed and it lost altitude quite fast and sliding touch
down with a bit of velocity.
d. With 3 more winch launches from the
ground to familiar with it's flying characters. No attempt for
searching thermal, just circling around the flying field. The
control response and gliding character were not as good as F3J
model, but it's flying performance was much better than expected.
The test fly was successful under the team's great assistance.
* Day two (AM of Nov. 18th, 2001)
5-3. Winch launch flying:
Before flying DG-1000, Mr. Tsai flew his
"Stork" to get thermal situation around the flying
field, it was quite helpful for the two actual flights of DG-1000
in that morning.
A slight "Zoom" was tested at
the first launch, but it did not gain much height, the pulling
strength of winch seemed easing down and velocity of DG-1000
was slow down at the climax of launch. Probably the heavier weight
of DG-1000 was the reason.
It was luckily to find a thermal at the
south sky of flying field and it did thermal quite well and got
higher in the thermal for almost 11 minutes before the thermal
dispersed.
An apparent "Zoom" was tested
at the second launch, DG-1000 gained much height for about 130
- 150 meters, but it stalled at the climax of zooming although
down elevator was applied at the climax. The stall recovered
ok with a bit loss of height.
This time, the DG-1000 flew close to the mountain area near the
flying field and found a strong lift and staying in the thermal
for more than 10 minutes before DG-1000 being carried too far
away.
5-4. Conclusion:
a. The key points of this successful test fly are:
* Mr. Tsai's experience in bungee and winch launching.
* The two tow hooks position on both side of the fuselage right
under wing root which is about 1.5 cm ahead of C.G.
and the use of "Y" harness connected to tow line.
This provides a very straight towing and greatly reduced the
risk of stall during the beginning of launching from the ground.
b. Flying characters is satisfactory if not compared to F3J models.
DG-1000 can thermal quite well in a moderately weak thermal
Which surprised the test team a lot.
Landing should be with some velocity for safety reason..
Spoilers works pretty efficient and do not affect any balance
during Landing.
---------- End of Report --------
DG-1000試飛報告
撰寫日期: 民國九十年十一月十九日星期一
作者: 林寬明
1. 試飛日期: 民國九十年十一月十七, 十八日
2. 試飛地點: 屏東賽嘉航空公園, 飛行傘降落場.
3. 試飛機型: DG-1000, 3.7 公尺, 像真滑翔機.
4. 試飛組員:
4-1. 試飛員: 林寬明
4-2. 絞盤機操作員: 蔡進先生
4-3. 地面輔助員: 林明星先生
4-4. V8攝影觀查員: 蔡太太(唐沛湘小姐).
5. 試飛步驟與程序:
* 第一天 (11月17日早上)
5-1. 彈射繩地面拖曳測試:
甲、 第一次測試使用極低之張力, 目地在測試DG-1000是否可以在草地上直線滑行.
當往前助推放手後, DG-1000平順直線滑行約15公尺後停止.
乙、 第二次測試使用約大於第一次測試二倍之張力,
DG-1000平順直線滑行約50公尺後停止.
丙、 第三次測試使用更大之張力足以讓 DG-1000離地起飛,
以便觀察其離地之狀態. 當往前助推放手後, DG-1000僅滑行約10公尺就離地起飛,
高度約 2 公尺, 保持飛機平穩順利滑降. 重心位置不錯, 因而未做配重調整.
5-2. 絞盤機地面拖曳測試:
甲. 第一次測試使用一次點踩即放開, 目地在測試DG-1000是否可以在草地上直線滑行.
當往前助推放手後, DG-1000平順直線滑行約15公尺後停止. 情形同第一次之彈射地面測試.
乙. 第二次測試則持序踩住開關直至 DG-1000
離地約2英尺後放開. 保持飛機平穩順利滑降.
丙. 第三次測試則同正常起飛, 當往前助推放手後,
DG-1000滑行不到10公尺即離地起飛, 在水平尾舵並未操縱之下, DG-1000以約 45-50 度角升空, 至最高高度後拉平並拉水平尾舵使機鼻往上以脫勾,
隨後推 DOWN使機身平飛. 脫勾時有感覺稍為延遲脫勾之情形. 由於接近4公斤之重量, 估算飛機高度在 90-100公尺左右.飛機拉平後有明顯之左傾情形,
微調副翼後, 水平平飛情況OK. 由於是第一次試飛, 因此並未嘗試尋找熱氣流, 僅在飛行場所上空盤旋4-5圈後,隨即設定降落航線下降.
滯空滑行之表現遠比預期的情況好很多, 下降時使用阻風板, 高度降低蠻快的, 但是仍能帶速平穩下降著陸.
丁、 隨後再試飛了3次, 也是沒有尋找熱氣流,
都在飛行場所上空盤旋,主要還在熟悉 DG-1000之飛行性能.操控反應沒有 F3J 比賽機敏銳, 但仍為適中, 整體飛行性能與滑降比遠超過預期的好.
在試飛小組的大力幫忙之下, 使本次試飛得以圓滿完成,
謹致最高之謝意!
* 第二天(11月18日早上)
5-3. 絞盤機地面起飛試飛:
在試飛前, 蔡進先飛他的 "STORK"
以瞭解場所附近熱氣流之情況, 對隨後之 DG-1000試飛有相當之幫助.
第一次起飛後做了輕微之"Zoom"
, 但並無太大之上升高度, 絞盤機拉到頂點時有力道變軟, 飛機速度減慢之情形, 或許是DG-1000較重所致.升空後往南飛行,
很幸運的馬上碰到一個熱氣流, 盤旋約11分鐘後, 該熱氣流逐漸消散, 隨後即返回飛行場下降著陸.
第二次起飛後做了明顯之"Zoom",
此次有明顯之高度增加, 約為130 - 150 公尺, 但是在最高點時有失速的狀況, 拉平後損失了一些高度. 此次飛往山邊接近飛行傘之起跳山頭,
碰到強勁之上升氣流直往遠處山頂帶去, 盤懸約10分鐘後, 避免太遠看不清楚飛機狀態而轉回飛行場降落.
5-4. 結論與感想:
本次試飛能順利成功主要在於以下因素::
* 蔡進先生的彈射起飛與絞盤機起飛的豐富經驗.
* 使用機身二側拖曳勾的方式, 拖曳勾置於主翼下方之機身二側, 較重心位置往前約 1.5 公分. 並使用"Y"
形拉繩與拖曳線連接. 此方式把地面起飛之偏轉失速的危險降至最低.
對DG-1000之飛行性能相當滿意, 雖然無法與
F3J比賽機相提並論. 其飛行性能, 滯空表現與較弱熱氣流盤旋能力著實讓試飛小組感到驚喜.
降落時為了安全理由, 帶點速度是比較好的.
阻風板相當有效率, 而且不會對飛機之平衡有任何影響. 對降落 過程中之高度控制相當不錯.
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