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e-flight Forum <strong>2019</strong><br />
它 山 之 石 :eVTOL 发 展 借 鉴<br />
Lessons learnt from other aircraft for<br />
development of eVTOL<br />
张 曙 光<br />
Prof.Dr. ZHANG <strong>Shuguang</strong><br />
October 16, <strong>2019</strong> Shijiazhuang, Hebei<br />
1
Outline<br />
e-flight Forum <strong>2019</strong><br />
• eVTOL for UAM<br />
• Safety objectives<br />
• Lessons review<br />
• Conclusions<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
2
eVTOL for UAM<br />
e-flight Forum <strong>2019</strong><br />
Power lifted<br />
takeoff & landing<br />
Propelled wing or tilted<br />
propulsion for cruise<br />
Electrification<br />
by motors & power<br />
electronics<br />
Urban Air<br />
Mobility<br />
Operation and air<br />
space management<br />
Batteries or other<br />
clean energy sources<br />
Automation from<br />
embedded computing,<br />
sensors & algorithms<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
3
eVTOL for UAM<br />
e-flight Forum <strong>2019</strong><br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
4
Some e-aircraft accidents<br />
e-flight Forum <strong>2019</strong><br />
Date Place Type Flight<br />
Phase<br />
13-OCT-<br />
2018<br />
03-JAN-<br />
<strong>2019</strong><br />
14-AUG-<br />
<strong>2019</strong><br />
Netherlands<br />
Switzerland<br />
Norway<br />
Pipistrel Alpha<br />
Electro<br />
Pipistrel Alpha<br />
Electro<br />
Pipistrel Alpha<br />
Electro<br />
Approach<br />
Initial<br />
climb<br />
En route<br />
Brief description<br />
Crashed under unknown circumstances, pilot<br />
killed. Post-impact fire.<br />
Shortly after take-off, power loss followed by an<br />
emergency landing in a field. Severely damaged.<br />
Following a loss of engine power shortly after<br />
takeoff, Norway’s 1 st e-plane force landed and<br />
tipped into a pond on his way back to the<br />
airport. No injury.<br />
Source: aviation-safety.net<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
5
Some e-aircraft accidents<br />
e-flight Forum <strong>2019</strong><br />
Date Place Type Flight Phase Brief description<br />
31-MAY-<br />
2018<br />
Hungary Magnus eFusion<br />
powered by a<br />
Siemens SP45D-V9<br />
Manoeuvring<br />
Flying along the right traffic circuit, roughly at<br />
the place of the second turn of the right traffic<br />
circuit when, after a steep descent, it crashed<br />
to the ground at a low angle, and caught fire.<br />
2 occupants died. No Battery Fire.<br />
Source: aviation-safety.net<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
6
Safety objectives?<br />
e-flight Forum <strong>2019</strong><br />
EASA SC-VTOL-01 Issue 1 on 02-07-<strong>2019</strong>: AMC VTOL.2510<br />
Probability?<br />
Single failure safe?<br />
EASA SC-VTOL-01 AMC VTOL.2510 15 Oct 2018<br />
• AMC VTOL 2510: Flight crew on board.<br />
• AMC VTOL 2510 Issue 1 : No<br />
considerations of the system<br />
architecture for a DAL reduction are<br />
acceptable.<br />
• VTOL.2510(a)(1): Any catastrophic<br />
failure condition must not result from a<br />
single failure.<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
7
High energy rotors<br />
e-flight Forum <strong>2019</strong><br />
VTOL.2240(c) The aircraft must be designed to minimise hazards to<br />
the aircraft due to structural damage caused by high-energy<br />
fragments from an uncontained lift/thrust unit or rotating-machinery<br />
failure.<br />
Jul-19-1989, DC-10 accident at Sioux City, due to<br />
fan blade material problem, causing the blade to<br />
break and debris and damage all the hydraulic<br />
controls – unconstained rotor burst<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
8
Lithium-ion battery<br />
e-flight Forum <strong>2019</strong><br />
Safety events:<br />
• 2016 Samsung Galaxy Note 7, recalled for<br />
battery fires due to a manufacturing design<br />
fault in batteries which caused internal<br />
positive and negative poles to touch.<br />
• Four serious typical lithium-ion battery fires,<br />
or smoke, on the Boeing 787, due to<br />
• defect not caught by inspection<br />
• no test for worst-case battery<br />
failures<br />
• Inadequate certification process<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
9
From automation toward autonomy<br />
e-flight Forum <strong>2019</strong><br />
Augmentation<br />
Autoflight<br />
Emergence<br />
management<br />
Communication,<br />
detect & avoid<br />
Monitor,<br />
decision, &<br />
planning<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
10
Related accidents/incidents<br />
e-flight Forum <strong>2019</strong><br />
Date Type Cat. Narrative Probable Cause Safety actions<br />
1988- A320- CFITground<br />
Destroyed when it impacted trees during 1) Flyover lower than surrounding<br />
06-26 111<br />
a low pass over the runway. A fire broke obstacles; 2) Very slow speed; 3) Late<br />
out, killing three occupants.<br />
application of GA power from idle.<br />
1990- A320- CFITground<br />
Crew training<br />
02-14 231<br />
2001-<br />
02-07<br />
A320-<br />
214<br />
Wind<br />
shear/<br />
Down<br />
draft<br />
Final approach descending well below<br />
the normal approach profile until<br />
striking the ground.<br />
Windshear with 1.25G dynamic gust at<br />
just 70 feet agl, GPWS sounded, the<br />
captain called for a GA. Combination of<br />
dynamic winds and the crew actions<br />
triggered the AoA protection, with both<br />
pilots pulling back their sticks, the AoA<br />
protection law reduced the nose-up<br />
command, the aircraft struck the runway<br />
with a vertical speed of 1,200 fpm.<br />
Failure of the pilots to realize the<br />
situation and respond immediately<br />
towards proper action of moving the<br />
throttles<br />
Activation of the AoA protection under<br />
a particular combination of vertical<br />
gusts and windshear and the<br />
simultaneous actions of both crew<br />
members on the sidesticks, not<br />
considered in the design, prevented the<br />
aeroplane from pitching up and flaring<br />
during the landing.<br />
Enhance operation management and<br />
crew training<br />
Modification to its flight control<br />
software, preventing the protection<br />
against stall from being activated by a<br />
high AoA rate. An interim AD issued<br />
requiring A320/319 operators to fly at<br />
least 10 kts faster and to use only<br />
"CONFIG 3" during approach with<br />
gusts higher than 10 kts or when<br />
moderate to severe turbulence is<br />
expected on short final.<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
11
Related accidents/incidents<br />
e-flight Forum <strong>2019</strong><br />
Date Type Cat. Narrative Probable Cause Safety actions<br />
2009-<br />
06-01<br />
2018-<br />
10-29<br />
A330-203 LOC Destroyed when it crashed into the<br />
sea while on transatlantic flight from<br />
Rio de Janeiro-Galeao International<br />
Airport<br />
B737-<br />
MAX8<br />
LOC During takeoff the DFDR recorded a<br />
difference between left and right<br />
AoA of about 20°. During rotation<br />
the left control column stick shaker<br />
activated. After flaps retracted, the<br />
FDR recorded automatic aircraft nose<br />
down (AND) trim for 10s followed by<br />
flight crew commanded aircraft nose<br />
up (ANU) trim. Eventually the aircraft<br />
impacted the sea.<br />
Following obstruction of the Pitot Pitot sensitive to icing<br />
probes by ice crystals during cruise, replaced, flight procedure<br />
the AP disconnected, the failure to modified when AP/Ath<br />
understand the situation and the switched off into backup<br />
de-structuring of crew cooperation mode, AoA sensor<br />
fed on each other until the total loss assessed, etc.<br />
of cognitive control of the situation.<br />
Erroneously high single AOA sensor Revising certificate<br />
input activating MCAS in wrong way. limitations and operating<br />
procedures of the<br />
AFM, ensuring system<br />
safety assessments,<br />
incorporating design<br />
enhancements, etc.<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
12
Concluding remarks<br />
e-flight Forum <strong>2019</strong><br />
• We are at an exciting age to meet a new era of air traffic .<br />
• Technology pushes certification, and certification guarantees application of<br />
technology – always staying clear-minded on risk identification, management, and<br />
mitigation.<br />
• Look in the both directions, from viewpoint of technologies and development<br />
process to predict risks, and from lessons in the history to illuminate development.<br />
• Right time to call for experts-based associations to work on the safety problems and<br />
contribute to a sustainable development of new air traffic system.<br />
Prof.Dr.<strong>Shuguang</strong> <strong>Zhang</strong> October 16,<strong>2019</strong><br />
13
e-flight Forum <strong>2019</strong><br />
Thank you for your attention!<br />
Prof. Dr. <strong>Shuguang</strong> <strong>Zhang</strong><br />
gnahz@buaa.edu.cn<br />
+86 13701144375 (wechat)<br />
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