This document summarizes testing of fall arrest equipment for the C-17 military transport plane. It conducted 21 tests dropping weighted manikins from heights up to 14 feet while harnessed to evaluate the maximum arresting forces. The testing found that forces exceeded the safety limit of 1800 pounds for falls over 8 feet. Previous qualification testing had reported much lower forces that were now considered questionable. The findings indicated the equipment was only safe for falls of 9 feet or less as required for compliance with safety regulations.

1. Andrew C. Sulowski, M.Sc.,P.Eng.
International Fall Protection Symposium
A+A 2011, Düsseldorf
www.fallpro.com

2. The selected issues:
1. FP in a hangar
1.1 Aircraft assembly
1.2 Aircraft maintenance
1.3 Servicing helicopters
2. FP at an airport
2.1 At a regular, concrete surface tarmac
2.2 At a temporary landing field
3. Special projects
3.1 FP for the C-17 military transport plane
3.2 FAS for an open-door helicopter
4. R&D in Fall Protection – Possible Applications
5. Regulations

3. 1.1 Fall Protection During Aircraft Assembly
Operations.

12. 1.2 Fall Protection During Aircraft Maintenance
Operations in a Hangar.

16. Mansafe HLL by Latchways Co. –
Principle of Transfastener Operation

33. 1.3 Fall Protection when Servicing Helicopters.

39. 2.1 Fall Protection at a Regular Airport.

49. 2.2 Fall Protection at a Temporary Landing Field.

55. 3.1 Special Projects – Fall Protection
for C-17 Military Transport Plane

56. Maximum Arresting Force Measurement of
the C-17 Shock-Absorbing Lanyard, Full-
Body Harness, 225 lb. Torso Manikin from
Free-Fall Distances up to 14 ft.
23 October 2006
Chris Albery
General Dynamics – AIS
chris.albery@wpafb.af.mil
Deken Keil
Mission Systems Engineer
516th Aeronautical Systems Wing
deken.keil@wpafb.af.mil
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

57.  Fall protection required when working
10 ft or more above next level
• Fall Restraint is preferred
• Fall protection is allowed
 Safety regulations limit allowable free-fall with a
fall protection system to 6 ft.
• Exception allowed if documentation exists to show
maximum arresting force (MAF) limited to 1800 lbs.
• C-17 fall protection system allows free-falls up to 14 ft.
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

58.  Deficiency Report generated over
concerns with:
• Ground contact
• Exceeding 6 ft. free-fall distance
• Ground contact risk mitigated by restricting
lanyard length and use of specific
receptacles
• 6 ft. free-fall mandate exceeded
 Miscalculation of free-fall distance
 Documentation existed for free-falls only up to 9 ft.
 Safety regulations required documentation of MAF
for free-falls up to 14 ft.
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

59.  Measure the Maximum Arresting Forces (MAF) a
person may experience if they were to free-fall
between 9 ft. and 14 ft. while wearing the C-17 fall
arrest system.
• Verify system compliance with safety regulations
 Previous qualification data indicated MAFs from
926 -1190 lbs. for 9 ft. free-falls with
9 ft. lanyard
 Previous lot testing data indicated MAFs
from 651 -1081 lbs. for 9 ft. free-falls
with 9 ft. lanyard
• Test setup and procedures per
ANSI Z359.1-1992 (R1999)
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

60.  Fall Arrest System
• Full Body Harness (Falls Creek)
 Wraps around waist, shoulders and legs
 D-ring – upper/center of the back (connect lanyard)
 Distributes impact force throughout the trunk - not just the
abdominal area
 MAF limited to 1800 lbs. (AFOSH, OSHA, ANSI)
• Shock-Absorbing Lanyard (Decent Control)
 Folded portion of the lanyard stored in the area above buckle
 Dissipates & limits amount of energy on someone during fall
arrest
 Torso Manikin
• Model T Parachute Dummy
 95th percentile, 6’1” male torso
 Internally ballasted to 225 lbs. & 300 lbs.
 HybridIII manikin vest, abdomen foam
(for harness fit)
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

61.  Subject free-fall Device
• Platform at end of 4 ft. spring loaded, hinged
arm
 Spring ensures the arm clears the path of the manikin once
initiated
• Bomb-shackle locks and releases arm
(electronically)
 Vertical Deceleration Tower
• 60 ft. tower used to expose humans/manikins to
ejection seat acceleration profiles
• Only the tower’s main structure was used for this
program
• Carriage raised/secured at 25 ft.,
• 10,000 lb. capacity force load cell rigidly
attached under the carriage
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

62.  Manikin upright, standing/jump fall posture
 Free-falls from 7 ft. to 14 ft. - total of 21 tests
 New lanyard and harness for each test
• Lanyard length set before each test, attached to
harness D-ring
 Manikin hoisted to platform, lanyard
attached to load cell
• If additional length needed heavy duty chain used
(between lanyard and load cell)
 Load cell and D-ring in-line (no horizontal
offset)
• Pure Z-axis free-falls
 Load cell zeroed just before free-fall
 Voltage sent to bomb shackle initiating free-
fall
 Data collected at 1,000 samples/sec. (120Hz
filter)
Video: 9 ft. free-fall, 9 ft. lanyard
MAF =1684 lbf.
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

63. Free-fall
Distance
# of
Tests
Lanyard Length
9 ft. 5 Fully extended – 9 ft.
9 ft. 1 Not extended – 5 ft.
14 ft. 3 Fully extended – 9 ft.
9 ft. 2 Partially extended – 6 ft.
10.7 ft. 4 Partially extended – 6 ft.
8 ft. 1 Partially extended – 6 ft.
7 ft. 3 Partially extended – 6 ft.
7 ft. 1 Partially extended – 6 ft.
300 lb. manikin
9 ft. 1 Fully extended – 9 ft.
300 lb. manikin
Test Matrix
Video: 14 ft. free-fall, 9 ft. lanyard
MAF =2511 lbf.
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

64.  MAF = Maximum Arresting Force
 FFD = Free-fall Distance
 Lanyard Initial Length
 Lanyard Final Length (post-test, manikin
suspended)
 Δ Length (Lanyard Final Length - Lanyard Initial
Length)
 Lanyard Payout (amount shock absorber deployed)
 Lanyard Buckle Slip
 Manikin Suspended Angle (manikin angle with
respect to the ground)
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

65. Averages for configurations tested more than once
• 9 ft. free-falls, 9 ft. lanyard, (n=5) = 1683 lbs.
• 14 ft. free-falls, 9 ft. lanyard, (n=3) = 2546 lbs.
• 10.7 ft. free-falls, 6 ft. lanyard, (n=3) = 2178 lbs.
• 7 ft. free-falls, 6 ft. lanyard, (n=3) = 1766 lbs.
• 9 ft. free-falls, 6 ft. lanyard, (n=2) = 1955 lbs.
Configurations tested once
• 9 ft. free-fall, 5 ft. lanyard = 1852 lbs. (lanyard failure)
• 8 ft. free-fall, 6 ft. lanyard = 1827 lbs.
• 9 ft. free-fall, 9 ft. lanyard = 2129 lbs. (300 lb. manikin)
• 7 ft. free-fall, 6 ft. lanyard = 2105 lbs. (300 lb. manikin)
Limit = 1800 lbs.
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

66. The five phases associated with a fall while wearing a fall
arrest system are:
1. Fall Onset
2. Free Fall
3. Deceleration
4. Rebound
5. Suspension
The following figure shows a plot and lists the 5 phases
within it.
Note by ACS:There is an error in the above interpretation
of the test curve.

68. Phase 1: Free fall
Phase 2: Deceleration -Action of the
energy absorber
Phase 3 –part one (until MAF):
Continuing deceleration and the MAF.
Phase 3 –part two: post-MAF (test mass
travelling up)
Phase 4: Rebound
Phase 5: Suspension

70.  21 tests completed at Wright-Patterson AFB, OH
 Data show a 225 lb. person using these equipment:
• NOT likely to encounter MAFs greater than 1800 lbs. for
free-falls of 9 ft. or less with the 9 ft. lanyard
• ARE likely to encounter MAFs greater than 1800 lbs. for
free-falls of 14 ft. with the 9 ft. lanyard
• ARE likely to encounter MAFs greater than 1800 lbs. for
free-falls greater than 8 ft. with a 6 ft. lanyard.
• Both tests done with a 300 lb. manikin resulted in MAFs
greater than 2100 lbs.
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

71.  MAFs higher than anticipated
 Previous MAF qualification and lot testing resulted
in 900-1100 lbs. (9 ft. free-falls with 9 ft. lanyards, 225 lb.
block)
• Not done at Wright-Patt
• Questionable data
 Calculations contradict these low MAFs
 One qual./lot test as low as 650 lbf.
 Neutral, third party data matches this program’s data
 Post Wright-Patt testing
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

72.  Limited lanyard length and restricted which aircraft
receptacle locations may be used with current
system
 Incorporated changes into Air Force manuals to
ensure MAFs do not exceed 1800 lb. in the case of
a fall from the aircraft
 New C-17 fall protection system currently being
developed
 Expected to be deployed in September 2007.
Approved for public release; distribution is unlimited. AFRL-WS 06-2454
The findings and conclusions in this presentation have not been formally disseminated by the Air Force and should not be construed
to represent any agency determination or policy.

73. 3.2 Special Projects – Fall Arrest
System for a Helicopter Crew

75.  STATEMENT OF WORK FOR
COMMON MOBILE AIRCREW RESTRAINT
SYSTEM (CMARS)
 Prepared by
NAVAL AIR SYSTEMS COMMAND
 Aircrew Systems Program Office (PMA202)
 Human Systems Department (AIR-4.6)
 Note: from A.Sulowski: this is not a restraint but a fall
arrest system (see the slides below)

82. 4. R&D in Fall Protection – Possible Applications

86. Based on the above data Sulowski
recommended, at the IFPS’2006 in
Seattle,WA, new, revised legal limits for
the MAF according to its direction and
the point of application to the human
body as follows:
6 kN (1,350 lbf) for +Z; subpelvic,
2.75 kN (620 lbf) for +X; spinal (waist)
4 kN (900 lbf) for +Y; hip/waist area.

87. Fall Protection for the Air Force

89. Fall Protection for the Air Force

97. 5.1 Fall Protection Regulations - USAF

98. Chapter 13— FALL PROTECTION
13.1. General Requirements.
13.2. Personal Fall Arrest Systems (PFAS).
13.3. For fall protection on aircraft
surfaces, see AFOSH Standard 91-100,
Aircraft Flight Line – Ground Operation &
Activities.

99. General Requirements
• FAS required above 10ft elevation
• Max. free fall distance (FFD) – 6ft
• Min. anchorage strength – 5,000 lbs
• Full body harness in FAS

100. 5.2 Fall Protection Regulations – US NAVY

101. Information from:
Mr.Basil Tominna,P.E.,a safety engineer
for the U.S.Department of the Navy
and vice chair of the Z359 Accredited
Standards Committee (ASC) for Fall
Protection/Arrest.

102.  The most common fall hazards in the Navy include falls
from roofs, ladders, equipment, cranes and
during aircraft maintenance and other typical general
industry exposures.
Fall hazards and exposures in ships, submarines and
shipyards may include falls from ships and submarines
in the water, when climbing masts or ladders and other
falls to lower surfaces.

103.  Contractors and subcontractors performing
construction and demolition work on DOD sites are
required to comply with the fall protection
requirements specified in the EM 385-1-1 Health and
Safety Requirements Manual.The fall protection
requirements in EM 385-1-1 (latest version) are based
on and reference the Z359 Fall Protection Code by
incorporating best practices and applications of fall
protection systems and equipment.

104.  Per EM 385-1-1, contractors as part of the contract are
required to develop a fall protection program and to
submit a site-specific fall protection and prevention
plan to the government-designated authority.
 The fall protection and prevention plan requirements
are similar to the written fall protection procedures
specified as part of the ANSI/ASSE Z359.2-2007
Minimum Requirements for a Comprehensive Managed
Fall Protection Program Standard

105. Protection against floating away
into space.

110. 1.While attempting to comply with its
own safety regulations both, the USAF
and the Navy seem to be trying to
develop an in-house expertise.This is
commendable and they will eventually
succeed however, it would be much less
expensive and better to use the existing
civilian expertise in fall protection.

111. 2.1 The helicopter crew CMARS system
should employ a quick disconnect
harness to prevent drowning if the
machine plunges into the sea.
2.2 The CMARS is not a restraint system
but a fall arrest system.

112. 3.The Maximum Arrest Force (the shock
load) limits are different for the X,Y,Z
directions and depend on the point of
application to the body.This fact should
be recognized.

114.  We are gathered here safely ONLY because thousands
of military personnel of NATO in the army, the navy, the
air force and the special forces, secure our safety
every hour of the day.
 As much as the military subjects are not popular in
many circles, the above statement represents a reality.
 The USA, the NATO, Russia, China and others – keep
developing new planes of which speed and
maneuverability exceed the pilots’ capacity to
withstand the g’s and wind effects when ejecting.
 As long as the arms races continue, and as long as
there are young people who understand the geopolitics
and are willing to defend us, civilians – we owe them a
lot - including the best available fall protection.