IEC TR 62131-7:2020

Environmental conditions – Vibration and shock of electrotechnical equipment - Part 7: Transportation by rotary wing aircraft

IEC 62131-7:2020(E), reviews the available dynamic data relating to the transportation of electrotechnical equipment by rotorcraft (helicopters). The intent is that from all the available data an environmental description will be generated and compared to that set out in IEC 60721 (all parts).

General Information

• Status: Published
• Publication Date: 27-Apr-2020
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 19.040 - Environmental testing
• Technical Committee: TC 104 - Environmental conditions, classification and methods of test
• Drafting Committee: WG 15 - TC 104/WG 15
• Current Stage: PPUB - Publication issued
• Start Date: 19-May-2020
• Completion Date: 28-Apr-2020

Standards Content (Sample)

IEC TR 62131-7 ®
Edition 1.0 2020-04
TECHNICAL
REPORT
colour
inside
Environmental conditions – Vibration and shock of electrotechnical equipment –
Part 7: Transportation by rotary wing aircraft:
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IEC TR 62131-7 ®
Edition 1.0 2020-04
TECHNICAL
REPORT
colour
inside
Environmental conditions – Vibration and shock of electrotechnical equipment –

Part 7: Transportation by rotary wing aircraft:

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 19.040 ISBN 978-2-8322-8237-3

– 2 – IEC 62131-7:2020 © IEC 2020
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Data source and quality . 8
4.1 Vibration of Boeing CH-47 rotorcraft . 8
4.2 Set down of underslung cargo from a Boeing CH-47 rotorcraft . 9
4.3 Supplementary data . 10
5 Intra data source comparison . 13
5.1 General . 13
5.2 Vibration of Boeing CH-47 rotorcraft . 13
5.3 Set down of underslung cargo from a Boeing CH-47 rotorcraft . 13
5.4 Supplementary data . 14
6 Inter data source comparison . 14
7 Environmental description . 14
7.1 Physical sources producing mechanical vibrations . 14
7.2 Environmental characteristics and severities . 16
7.3 Derived test severities . 17
8 Comparison with IEC 60721 (all parts) [16] . 18
9 Recommendations . 21
Bibliography . 50

Figure 1 – Typical vibration spectra for CH-47 rotorcraft during straight and level flight at
160 kn [1] . 22
Figure 2 – Typical vibration spectra for CH-47 rotorcraft during hover [1] . 22
Figure 3 – Typical vibration spectra for CH-47 rotorcraft during transition to hover [1] . 23
Figure 4 – Typical vibration spectra for CH-47 rotorcraft during autorotation [1] . 23
Figure 5 – Comparison of CH-47 vibration overall RMS for different flight conditions [1] . 24
Figure 6 – Comparison of CH-47 vibration RMS severities at rotor shaft frequency (r) for
different flight conditions [1] . 25
Figure 7 – Comparison of CH‑47 vibration RMS severities at rotor blade passing
frequency (nr) for different flight conditions [1] . 26
Figure 8 – Comparison of CH‑47 vibration RMS severities at second rotor blade passing
frequency (2nr) for different flight conditions [1] . 27
Figure 9 – Comparison of CH‑47 vibration RMS severities at third rotor blade passing
frequency (3nr) for different flight conditions [1] . 28
Figure 10 – Comparison of CH‑47 vibration RMS severities at fourth rotor blade passing
frequency (4nr) for different flight conditions [1] . 29
Figure 11 – Comparison of CH‑47 vibration RMS severities across cargo bay floor during
hover [1] . 30
Figure 12 – Comparison of CH‑47 vibration RMS severities across cargo bay floor during
transition to hover manoeuvre [1] . 30
Figure 13 – Comparison of CH‑47 vibration RMS severities across cargo bay floor during
a transition to autorotation manoeuvre [1] . 31
Figure 14 – Comparison of CH‑47 vibration RMS severities across cargo bay floor during
straight and level flight [1] . 31

IEC 62131-7:2020 © IEC 2020 – 3 –
Figure 15 – CH‑47 rotorcraft ISO container set down shock severities [2] . 32
Figure 16 – Relative amplitude variations with airspeed for the Lynx rotorcraft [3]. 32
Figure 17 – Relative amplitude variations with airspeed for the Seaking rotorcraft [3] . 33
Figure 18 – Relative amplitude variations with airspeed for the Chinook rotorcraft [3] . 33
Figure 19 – Airframe to airframe relative amplitude variations for the Lynx rotorcraft [3] . 34
Figure 20 – Comparison of fleet vibration statistics [5] . 35
Figure 21 – Super Frelon rotorcraft measurements for X axis [6] . 36
Figure 22 – Super Frelon rotorcraft measurements for Y axis [6] . 36
Figure 23 – Super Frelon rotorcraft measurements for Z axis [6] . 37
Figure 24 – Vibration test severity derived for the CH‑47 rotorcraft using the approach of
Mil Std 810 [9] . 37
Figure 25 – Vibration test severity derived for the transportation of equipment in CH‑47
rotorcraft using the approach of STANAG 4370 AECTP 400 Method 401 Annex D [10] . 38
Figure 26 – Vibration test severity for equipment carried as underslung loads STANAG

4370 AECTP 400 Method 401 Annex D [10] . 38
Figure 27 – Rotorcraft specific vibration test severities for Chinook (CH‑47) from
Def Stan 00‑35 [5]. 39
Figure 28 – Rotorcraft specific vibration test severities for Merlin from Def Stan 00‑35 [5] . 39
Figure 29 – Rotorcraft specific vibration test severities for Lynx/Wildcat from
Def Stan 00‑35 [5]. 40
Figure 30 – Vibration test severities for underslung loads from Def Stan 00‑35 [5] . 40
Figure 31 – Rotorcraft specific vibration test severities for CH‑47 from RTCA/DO‑160 [11]
and EUROCAE/ED‑14 [12] . 41
Figure 32 – IEC 60721‑3‑2:1997 [17] – Stationary vibration random severities . 41
Figure 33 – IEC TR 60721‑4‑2:2001 [18]– Stationary vibration random severities . 42
Figure 34 – IEC 60721‑3‑2:1997 [17] – Stationary vibration sinusoidal severities . 42
Figure 35 – IEC TR 60721‑4‑2:2001 [18] – Stationary vibration sinusoidal severities . 43
Figure 36 – IEC 60721‑3‑2:1997 [17] – Shock severities . 43
Figure 37 – IEC TR 60721‑4‑2:2001 [18] – Shock severities for IEC 60068‑2‑29:1987 [20]
test procedure . 44
Figure 38 – IEC TR 60721‑4‑2:2001 [18] – Shock severities for IEC 60068‑2‑27 [19] test
procedure . 44
Figure 39 – Comparison of CH‑47 rotorcraft vibrations [1] with IEC 60721‑3‑2:1997 [17] . 45
Figure 40 – Comparison of Super Frelon rotorcraft X axis vibrations [6] with
IEC 60721‑3‑2:1997 [17] . 45
Figure 41 – Comparison of Super Frelon rotorcraft Y axis vibrations [6] with
IEC 60721‑3‑2:1997 [17] . 46
Figure 42 – Comparison of Super Frelon rotorcraft Z axis vibrations [6] with

IEC 60721‑3‑2:1997 [17] . 46
Figure 43 – Comparison of Mil Std 810 vibration test severity [9] with
IEC 60721‑3‑2:1997 [17] . 47
Figure 44 – Comparison of AECTP 400 vibration test severity [10] with
IEC 60721‑3‑2:1997 [17] . 47
Figure 45 – Comparison of Def Stan 00‑35 vibration test severity [5] with
IEC 60721‑3‑2:1997 [17] . 48
Figure 46 – Comparison of DO160 vibration test severity [11] with
IEC 60721‑3‑2:1997 [17] . 48

– 4 – IEC 62131-7:2020 © IEC 2020
Figure 47 – Comparison of underslung load vibration test severities [5] and [10] with
IEC 60721‑3‑2:1997 [17] . 49
Figure 48 – Comparison of CH‑47 rotorcraft set down shock severities [2] with
IEC 60721-3-2:1997 [17] . 49

Table 1 – Typical structural dynamic excitation frequencies and their source . 15

IEC 62131-7:2020 © IEC 2020 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL CONDITIONS – VIBRATION AND
SHOCK OF ELECTROTECHNICAL EQUIPMENT –

Part 7: Transportation by rotary wing aircraft

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all
national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-
operation on all questions concerning standardization in the electrical and electron
...