GAO-01-369R Defense Acquisitions

United States General Accounting Office

Washington, DC 20548

February 20, 2001

The Honorable Donald H. Rumsfeld

The Secretary of Defense

Subject: Defense Acquisitions: Readiness of the Marine Corps’ V-22 Aircraft

 for Full-Rate Production

Dear Mr. Secretary:

In a letter to Secretary of Defense Cohen, dated December 15, 2000, we stated that

the Marine Corps’ V-22 aircraft1

 was not ready for full-rate production and that the

Secretary had made a prudent decision to defer that production decision until the

V-22 Blue Ribbon Panel reports its findings.2 On January 12, 2001, we provided the

Panel with additional details at their request. A copy of the briefing and briefing

support material that we presented to the Panel are in enclosures I and II.

Our conclusions about the program’s readiness for full-rate production are based on

two factors. First, our “best practices” work, which has identified practices used by

successful commercial and defense programs to develop and produce quality

products in significantly less time and at lower costs.3

 Our reviews of numerous

major weapon systems has shown that failure to follow these practices has led to

cost increases, schedule delays, and performance problems. Second, our analysis of

Department of Defense assessments and data relevant to the V-22 program and

interviews with relevant Department officials.

Our best practices work over the past few years has shown that successful system

development efforts resolve major technology, design, and manufacturing

uncertainties prior to the start of production. Thorough test and evaluation, when

done early, increase the probability that systems will achieve required performance

levels within agreed-upon time and cost parameters. In July 2000, we reported on

how best commercial practices for testing and evaluating new products offer ways to

improve the way the Department conducts test and evaluation on weapon systems.4

In commenting on our report, the Department stated that it is committed to

 1

The V-22 Osprey is a tilt-rotor, short-take-off-and-landing aircraft, which was developed to satisfy

various combat missions, including medium-lift assault for the Marine Corps.

2

The Panel was appointed by former Secretary of Defense Cohen to review the V-22 Program.

3

See particularly, Best Practices: Successful Application to Weapon Acquisitions Requires Changes in

DOD’s Environment (GAO/NSIAD-98-56, Feb. 24, 1998). 4

Best Practices: A More Constructive Test Approach Is Key to Better Weapon System Outcomes

(GAO/NSIAD-00-199, July 31, 2000).
Page 2 GAO-01-369R Defense Acquisitions

establishing appropriate levels of product maturity, validating those levels with

appropriate testing and evaluation, and providing the required mix of testing and

evaluation tools necessary to validate maturity.

In contrast to best commercial practices, our work has shown that numerous weapon

system programs suffer from persistent problems associated with late or incomplete

testing. This practice pushes the burden of discovery late in development when

problems become very costly to resolve. We also found that testing operated under a

penalty environment that creates perverse incentives. For example, if tests were not

passed, the program might look less attractive and be vulnerable to funding cuts.

Managers thus had incentives to postpone difficult tests and limit open

communication about test results. These represent widespread and systemic

problems within the Department that must be addressed.

Our review of the V-22 program, which is already in low-rate initial production,

revealed that the Department planned to proceed with a full-rate production decision

without knowing whether new technology could meet Marine Corps requirements;

whether the design would work as required; or whether the design could be produced

within cost, schedule, and quality targets. This knowledge is lacking in part because

of inadequate test and evaluation. Specifically, developmental testing was deleted,

deferred, or simulated in order to meet cost and schedule goals. For example, the

original plan to test the flying qualities of the flight control system included

significant testing to be conducted in helicopter and aircraft conversion modes at

various rates of descent, speeds, and weights. This would have provided

considerable knowledge of V-22 flying qualities especially in areas where the Marine

Corps states the aircraft is susceptible to a sudden loss of controlled flight.5

 To meet

cost and schedule targets, the actual testing conducted was less than a third of that

originally planned.

Documents we reviewed indicated that test waivers and limitations reduced testing

for operational realism. For example, air combat maneuvering was prohibited and

the aircraft was not cleared to operate in icing conditions. Further, major concerns

about the aircraft’s performance and operations remain unresolved. These were

highlighted in a report prepared by Defense’s Director, Operational Test and

Evaluation.6

 For example, the report said the aircraft (1) is susceptible to sudden loss

of controlled flight under certain conditions, (2) creates downward force from the

V-22 proprotor blades that could potentially interfere with operations below or close

to the aircraft,7

 and (3) is far less reliable than what is required. These known and

potential problems and their associated costs, leave open the question of the V-22’s

real value—as demonstrated—for Marine Corps operations.

In November 2000, we briefed Marine Corps, Department of the Navy, and Office of

the Secretary of Defense officials on the results of our review and our assessment of

 5

Known as “vortex ring state.” 6

Combined Operational Test & Evaluation and Live Fire Test & Evaluation Report on the V-22 Osprey,

November 17, 2000.

7

Known as “downwash.”
Page 3 GAO-01-369R Defense Acquisitions

the risks of proceeding into full-rate production at that time. Our work was

conducted from September through December 2000 in accordance with generally

accepted government auditing standards.

We provided a draft of this report to the Department of Defense for its review and

comment. The Department stated its recently approved acquisition policy recognizes

the need for testing and evaluation and includes procedures for demonstrating

technology maturity prior to entering the system integration or low-rate initial

production acquisition phase of a program. The Department also stated that V-22

program decisions have been deferred to permit consideration of the results of the

Panel to Review the V-22 Program and of the Department of Defense Inspector

General’s investigation into fleet maintenance practices. Further, the panel and the

Inspector General’s investigation will help define the risks and responses appropriate

for the current state of the V-22. The Department also provided some technical

comments, which we incorporated into the report, where appropriate. The

Department’s comments are included as enclosure III.

*** *** ***

We are sending copies of this letter to interested congressional committees; the

Honorable Robert B. Pirie, Jr., Acting Secretary of the Navy; the Honorable Lawrence

J. Delaney, Acting Secretary of the Air Force; and General James Jones, Commandant

of the Marine Corps. Copies of this letter will also be made available on GAO’s home

page at http://www.gao.gov.

If you have any questions concerning this report, please contact me on

(202) 512-4841. Major contributors to this report were Robert L. Pelletier, Jerry W.

Clark, and Stacy Edwards.

Sincerely yours,

Signed

Katherine V. Schinasi

Director, Acquisition and

Sourcing Management

Enclosures
Page 4

PRESENTATION TO

THE V-22

BLUE RIBBON PANEL

JANUARY 12, 2001

Enclosure I
Page 5

Knowledge at Key Junctures Is Critical

to a Successful Transition to

Production

Unknowns Knowns

Knowledge Point 1: Knowledge that a match exists between technology and requirements.

Knowledge Point 2: Knowledge that the design will work as required.

Knowledge Point 3: Knowledge that the design can be produced within cost, schedule, and quality

targets

DOD Product Development

Knowledge Point 1

Knowledge Point 2

Knowledge Point 3

Program Launch Production Start

Best Commercial Product Development

Program Launch Production Start

Knowledge Point 1

Knowledge Point 2

Knowledge Point 3

Enclosure I
Page 6

Summary - Significant Risk

With Proceeding With

Full-Rate Production

• KNOWLEDGE OF V-22 DESIGN AND

PERFORMANCE PARAMETERS FALLS SHORT OF

WHAT SHOULD HAVE BEEN KNOWN BEFORE

BEGINNING PRODUCTION

• DEVELOPMENTAL FLIGHT TESTING WAS

DELETED, DEFERRED, OR SIMULATED

• OPERATIONAL TEST WAIVERS AND

LIMITATIONS REDUCED TESTING FOR

OPERATIONAL REALISM

• ASSESSMENT BASED ON REDUCED SYSTEM

REQUIREMENTS

• MAJOR CONCERNS RAISED IN OPEVAL, JAG

REPORT, OPEVAL DATABASE, DOT&E, OTHERS

Enclosure I
Page 7

Significant Risk With

Proceeding With Full-Rate

Production (cont.)

• RISKS OF MOVING FORWARD WITHOUT

ADDITIONAL KNOWLEDGE

• VALUE OF SYSTEM FOR MARINE CORPS

OPERATIONS NOT YET ESTABLISHED

• CONNECTION BETWEEN DEMONSTRATED

PROBLEMS NOT KNOWN; UNKNOWN

PROBLEMS NOT DISCOVERED

• FPIF/CPIF CONTRACT EXPOSES

GOVERNMENT TO RESPONSIBILITY TO FUND

ANY DESIGN MODIFICATIONS - SOME,

PERHAPS SIGNIFICANT, CHANGES ARE

LIKELY

• LONGER TERM RISK TO MODERNIZATION

ACCOUNT, AS COST INCREASES BEYOND

ALREADY BUDGETED FUNDS ARE LIKELY

• MARINE CORPS BUDGET IMPACTED BY

MAINTAINABILITY SHORTFALLS

Enclosure I
Page 8

Current V-22 Effort

• Current analysis (begun in Sept. 2000) based on our review of

program documents and interviews with officials responsible

for managing and overseeing V-22 development

• We reviewed numerous program documents, such as

• test plans and requirements documents

• development test reports

• early/limited operational test reports

• development/operational transition reports

• operational test database

• Navy and DOT&E reports of operational test results

• results of program oversight including deficiency reports

• JAG and other V-22 crash (April 2000) investigation

documents

Enclosure I
Page 9

Current V-22 Effort (cont.)

• We interviewed the following:

• V-22 Program Manager

• V-22 Lead Program Engineer

• V-22 ITT officials

• Navy Warfare Requirements (N-88) officials

• Navy Test and Evaluation (NO-91) officials

• Navy Bureau of Inspections and Survey officials

• V-22 Operational Test Director

• Director, Operational Test and Evaluation

Enclosure I
Page 10

Current V-22 Effort (cont.)

• Briefed our preliminary results to DOD and Navy

officials responsible for execution and oversight of the

V-22 development effort in November 2000

• V-22 Program Manager

• DOD’s Director, Operational Test and Evaluation

• Secretary of the Navy (Research, Development &

Acquisition) Deputy Assistant Secretary (Air

Programs)

Enclosure I
Page 11

GAO FINDINGS - DEVELOPMENTAL

FLIGHT TESTING WAS DELETED,

DEFERRED, OR SIMULATED

• Restructured baseline development flight test program

numerous times to meet program cost and schedule

pressures

• Deleted significant testing that would have

provided additional knowledge on V-22 flying

qualities and susceptibility to Vortex Ring State

• Deferred tests of “height velocity (HV) diagram,”

which identifies aircraft “no fly zones,” until after

OPEVAL

• Increased use of simulators proposed to reduce need

for manned flights

• However, Navy INSURV readiness for OPEVAL

report and OPTEVFOR’s V-22 OPEVAL report

concluded that simulations could not be use for

two key test areas

Enclosure I
Page 12

GAO FINDINGS - OPERATIONAL TEST

WAIVERS AND LIMITATIONS REDUCED

TESTING FOR OPERATIONAL REALISM

• Prior to OPEVAL, program management

requested and was granted operational test

waivers due to

• failure to meet criteria,

• inability to meet ORD threshold requirements,

and

• Part I deficiencies (impact missions; high

probability of aircraft loss, equipment damage,

or personnel injuries during missions; or

excessive operator compensation required to

accomplish missions) identified during

development tests

• INSURV approved the V-22 for OPEVAL with

Part I deficiencies based on plans to resolve the

deficiencies

• DOT&E reported that several waivers created

major or minor limitations to OPEVAL

Enclosure I
Page 13

GAO FINDINGS - OPERATIONAL TEST

WAIVERS AND LIMITATIONS REDUCED

TESTING FOR OPERATIONAL REALISM

(cont.)

• Additional limitations, warnings, and cautions were

imposed on operations through flight clearance

messages at various points during operational test

• Numerous shipboard operation restrictions

• Rescue hoist and rescue hoist fast rope

operations prohibited

• Operations prohibited within 25nm of lightning

activity for unmodified aircraft

• Formation flight allowed only with 250 ft.

separation

• Flight maneuver restrictions (max angle of bank

and Gs)

• Flight prohibited in icing conditions

Enclosure I
Page 14

GAO FINDINGS - OPERATIONAL

ASSESSMENT BASED ON REDUCED

SYSTEM REQUIREMENTS

Critical Operational Issues (COI) eliminated from

test master plan (TEMP) revised prior to OPEVAL

• Revised 1999 TEMP reduced number of

effectiveness COIs from 7 to 4

• Amphibious operations, Marine Expeditionary

Unit (Special Operations Capable), and joint

interoperability eliminated from previous

(1995) TEMP

Enclosure I
Page 15

GAO FINDINGS - OPERATIONAL

ASSESSMENT BASED ON REDUCED

SYSTEM REQUIREMENTS (cont.)

Performance Requirements changed in Operational

Requirements Document (ORD) prior to OPEVAL

• Land-based short take-off distance (increased

from 500 ft. to 3,000 ft.)

• On-board oxygen supply (reduced from 7

individual stations to 4)

Enclosure I
Page 16

GAO FINDINGS - MAJOR CONCERNS

RAISED IN OPEVAL, JAG REPORT,

OPEVAL DATABASE, DOT&E

Vortex Ring State Concerns

• JAG, OPEVAL, and DOT&E reports raise

significant concerns about implications of V-22

high rate of descent operations

• Susceptibility to high rate of descent and/or

loss of controlled flight can occur at any time

and consequences are exceedingly grave

• V-22 appears to be less forgiving than

conventional helicopters

• Additional testing is needed, including

exploration of formation flight

• Follow-on tests will not be completed until

CY2002

Enclosure I
Page 17

GAO FINDINGS - MAJOR CONCERNS

RAISED IN OPEVAL, JAG REPORT,

OPEVAL DATABASE, DOT&E (cont.)

Rotor Downwash Concerns

• OPEVAL report cites some concern about

downwash - V-22 operational test database lists

numerous concerns about impact of rotor

downwash

• Creates brownout and whiteout conditions

• Makes fast rope and rescue hoist operations

hazardous

• Reduces effectiveness of combatants

• Forces sand, snow, other matter into interior of

aircraft and into aircraft components

• DOT&E final report lists downwash as an area of

concern

• Testing demonstrated that some required

capabilities can be achieved with great

difficulty, some capabilities are unlikely to be

achieved, and some planned capabilities have

yet to be tested for downwash effects

Enclosure I
Page 18

GAO FINDINGS - MAJOR CONCERNS

RAISED IN OPEVAL, JAG REPORT,

OPEVAL DATABASE, DOT&E (cont.)

Cabin Dimensions/Environment Concerns

• Concerns raised about carrying 24 combat

Marines and their equipment

• Cabin environment cannot be adequately

controlled to prevent extreme temperature

conditions

Enclosure I
Page 19

GAO FINDINGS - MAJOR CONCERNS

RAISED IN OPEVAL, JAG REPORT,

OPEVAL DATABASE, DOT&E (cont.)

Suitability Concerns

• INSURV report - MV-22 fails to meet mean flight

hours between failure and built-in-test false alarm

rate test parameters - low reliability of the MV-22

aircraft weapon system poses the most significant

risk to OT-IIE (OPEVAL)

• OPEVAL report - Weapon system certified as

ready for operational test and evaluation was

immature and exhibited significant production

deficiencies, which caused excessive unplanned

maintenance actions

• DOT&E report - MV-22 demonstrated marginal

system reliability, excessive maintenance

manpower and logistic support requirements, and

inadequate availability. V-22 availability,

maintainability, and reliability rates compared

unfavorably with fleet CH-46 experience and will

pose a significant maintenance burden

Enclosure I
Page 20

GAO ASSESSMENT

• BEST PRACTICES ARE CLOSELY CORRELATED

WITH SUCCESSFUL PROGRAM OUTCOMES

• DESIGN AND PROCESS MATURITY BEFORE

BEGINNING PRODUCTION

• KNOWLEDGE GAINED IN V-22 PROGRAM FALLS

SIGNIFICANTLY SHORT OF SUCCESSFUL

PROGRAMS

• PROCEEDING INTO PRODUCTION BEFORE

ADDITIONAL KNOWLEDGE IS GAINED POSES

RISKS FOR DOD OPERATIONS AND BUDGETS

Enclosure I
Page 21

RELATED GAO REPORTS

• GAO has significant and varied experience addressing the DOD

acquisition process including system development and operational

testing

• October 1997 - GAO/NSIAD-98-13, NAVY AVIATION: V-22 Cost

and Capability to Meet Requirements Are Yet To Be Determined

• April 2000 - GAO/NSIAD-OO-75, DEFENSE ACQUISITIONS:

Need to Revise Acquisition Strategy to Reduce Risk for Joint Airto-Surface Standoff Missile

• May 2000 - GAO/NSIAD-OO-158, DEFENSE ACQUISITIONS:

F/A-18E/F Aircraft Does Not Meet All Criteria for Multiyear

Procurement

• May 2000 - GAO/NSIAD-00-74, JOINT STRIKE FIGHTER

ACQUISITION: Development Schedule Should Be Changed to

Reduce Risks

• July 2000 - GAO/NSIAD-OO-182, DEFENSE ACQUISITIONS:

Howitzer Program Experiencing Cost Increase and Schedule

Delays

• July 2000 - GAO/NSIAD-OO-199, BEST PRACTICES: A More

Constructive Test Approach Is Key to Better Weapon System

Outcomes

• August 2000 - GAO/NSIAD-OO-178, DEFENSE

ACQUISITIONS: Recent F-22 Production Cost Estimates

Exceeded Congressional Limitations

• Forthcoming - GAO-01-288, BEST PRACTICES: Better Matching

of Needs and Resources Will Lead to Better Weapon System

Outcomes

Enclosure I
Page 22

PRESENTATION TO

THE V-22 BLUE RIBBON

PANEL

BRIEFING SUPPORT MATERIAL

JANUARY 12, 2001

Enclosure II
Page 23

Briefing Support Material - Developmental

Flight Testing Was Deleted, Deferred, Or

Simulated ( Page 11)

• Development flight test program started Feb. 1997 and immediately fell

behind schedule

• Restructuring was required due to aircraft modifications, pilot currency,

added unknown test requirements, and significant unplanned

maintenance

• Concurrent testing, extension of maintenance intervals, extended flying

used to achieve restructured goals, removal of baseline test

requirements, and use of manned flight simulator

• Deferred/deleted development tests. Flight Control System

Development Flying Qualities Testing, which included tests for

the investigation of “Vortex Ring State” was reduced from 103

test conditions to 49. This reduced the scope of testing required

for cost and schedule recovery. Of the 49 test conditions only 33

were actually flown - 16 conditions not flown were at 0, 40, and

80 knots at high gross weights,

• Simulated development tests. a) INSURV concerned that

contractor simulation model does not have adequate data to

model autorotation, b) OPEVAL reported that contractor simulator

did not replicate loss of controlled flight resulting from HROD

Enclosure II
Page 24

Briefing Support Material - Operational

Test Waivers and Limitations Reduced

Testing for Operational Realism (Page 12)

• 21 operational test waivers requested

• One waiver requested for failure to meet criteria - V-22 mean time

between failure and false alarm rate

• 11 waivers requested for failure to meet requirements due to

 Part I deficiencies

• Inadequate cargo handling system

• Exterior lighting for NVG formation flight inadequate

• External loads interferes with radar altimeter

• Lower cabin door operation in hover

• Autorotation descent cannot be maintained while attempting

engine air start, etc.

• 9 waivers requested due to inability to meet ORD thresholds

• Not cleared to operate in icing conditions

• Not cleared for air combat maneuvering

• Not cleared for aerial refueling

• Unable to fastrope out of cabin door, etc.

Enclosure II
Page 25

Briefing Support Material - Operational

Test Waivers and Limitations Reduced

Testing for Operational Realism (Page 12)

• Navy Board of Inspection and Survey recommended that the MV-22 proceed to

OPEVAL contingent upon CNO (N-88) approval of a plan to resolve a number of

Part I deficiencies. These included deficiencies with published “Yellow Sheet

Reports” and others that were unpublished (draft)

• Part **I - 3 open (failure of proprotor lightning bond straps, excessive

lightning currents on internal fuel lines, and lateral instability during

shipboard vertical landings)

• Part *I - 11 open (low reliability of MV-22 aircraft, excessive lateraldirectional trim requirements during simulated in-flight refueling at 60-degree

nacelle, single mission computer dropouts, exterior lighting for night vision

goggles formation flight inadequate, etc.)

• Part I - 26 open (low reliability of the multifunction display, high false alarm

rate of BIT, unacceptable single mission computer dropouts, no indication of

longitudinal maneuvering capability to the pilot, etc.)

Enclosure II
Page 26

Briefing Support Material - Operational

Test Waivers and Limitations Reduced

Testing for Operational Realism (Page 12)

• Deficiencies considered by INSURV to have greatest impact on

operational tests were

• Low reliability of the MV-22B aircraft weapon system

• Lower cabin door operations in hover

• Air data system faults during conversion mode aerial refueling

operations

• Excessive lightning currents on internal fuel lines

• Autorotation survivability

• Inadequate cargo handling system

• Inadequate cockpit/cabin nuclear, biological, and chemical

overpressure protection

• DOT&E report states that several waivers created major or minor

limitations to OPEVAL

• Not cleared for air combat maneuvering

• Max short take-off (shipboard) weight lower than mission profile

specific weight

• Not cleared for KC-135 tanker refueling

• Unable to fastrope out of cabin door

Enclosure II
Page 27

Briefing Support Material - Operational

Test Waivers and Limitations Reduced

Testing for Operational Realism (Page 13)

• Numerous limitations were imposed at various points in time during

operational tests

• Flight envelope limitations - numerous shipboard operation

restrictions, short takeoff and landing limits, control inputs limits,

max takeoff gross weight limits, max angle of bank limits, max G

limits

• Flight control limitations - swashplate actuator fault advisory

restricting airspeed

• Cargo system limitations - ramp limits, parachute OPS prohibited,

rescue hoist OPS prohibited, external cargo OPS prohibited

• Environmental limitations - flight/ground OPS prohibited within

25nm of lightning activity for unmodified aircraft

• Fuel system limitations - hover in-flight refueling prohibited,

refueling from KC-10 prohibited

• Formation flight limitations - wingman shall avoid and not cross

lead aircraft wake during formation flights, 250 ft. lateral and

50 ft. step-up separation shall be maintained

Enclosure II
Page 28

Briefing Support Material - Vortex Ring

State (Page 16)

JAG Report - Opinion Section Quotes

• “After reviewing the evidence collected, it was concerning to see how ‘easy’

it was for the recipe of uncontrolled flight to be concocted.”

• “Aircraft performance envelopes are developed, and procedures and

guidance published (NATOPS) to prevent pilots from putting an aircraft in a

situation that would exceed safe parameters. The MV-22 performance

envelope may be one that fleet pilots can operate within, but given the rigors

of combat, real world operations, and realistic training for both, the

consequences of exceeding this particular envelope appears to be

excessively grave (departure from controlled flight with no warning).”

• “In traditional rotorcraft, Power Settling would cause uncommanded rates of

descent and, depending on altitude, may result in a hard landing or quite

possibly a controlled crash. In all likelihood, however, such an event would

result in the aircraft at least hitting the ground in an upright attitude. In this

respect, with regard to Vortex Ring State and/or Blade Stall, the MV-22

appears to be less forgiving than conventional helicopters. A V-22, because

of the approximately 8’ 8” distance because of its prop-rotors, as evidenced

by this mishap, is capable of have one rotor impacted by the effects of

Vortex Ring State and/or Blade Stall and the other not, resulting in an

asymmetrical condition. We believe that this was the case of the mishap.

The end result was a departure from controlled flight instead of a hard

landing or controlled crash ....”

• “There were, however, two other incidents that occurred during OPEVAL

where pilots reported experiencing an uncommanded roll during section

operations...The fact that the causes of these two incidents are not yet

known, coupled with limited developmental formation testing (4 flights for

11.7 hours), make it difficult to completely exclude wake turbulence or

downwash as potential contributors to the mishap.”

Enclosure II
Page 29

Briefing Support Material -Vortex Ring

State (cont.) (Page 16)

JAG Report - Recommendation Section Quotes

• “All V-22 operators should become acutely familiar with the potential consequences

of high rates-of-descent combined with slow airspeeds that are present with tiltrotor design. Though all rotorcraft have the potential to enter into a Vortex Ring

condition, recorded occurrences to date have been rare. The fact that this aircraft

no only found itself in a Vortex Ring State condition with no apparent warning to the

aircrew, but also departed controlled flight is particularly concerning. Until further

testing is conducted on the Vortex Ring State phenomenon, safe flight will require

strict adherence to procedures and limitations.”

• “PMA-275, PMA-205, and the Contractor expedite incorporation of Vortex Ring

State and blade stall warnings and procedures into the MV-22 NATOPS...The

preliminary NATOPS manual and V-22 ground school syllabus provides insufficient

guidance/warning as to high rate of descent/slow airspeed conditions and the

potential consequences.”

• “That NAVAIR continue to explore the aerodynamic effects of formation flight with

the MV-22. The MV-22 will be operationally employed in a similar fashion to

existing fleet aircraft. Multi-ship formations will be the norm as the aircraft executes

its various missions. Questions still remain concerning potential aerodynamic

influences, such as wake turbulence on wingmen during formation flight. Two

‘anomalies in addition to the mishap occurred during OPEVAL where this issue was

at least a concern.”

Enclosure II
Page 30

Briefing Support Material -Vortex Ring

State (cont.) (Page 16)

OPTEVFOR V-22 OPEVAL Report Quotes

• Summary - “The Naval Air Training and Operating Procedures Standardization

(NATOPS) manual lacked adequate content, accuracy, and clarity. Additionally,

because of incomplete developmental testing in the high rate of descent (HROD)

regime, there was insufficient explanatory or emphatic text to warn pilots of the

hazards of operating in this area. The flight simulator did not replicate this loss of

controlled flight regime.”

• “The V-22 has the potential to enter high rates of descent at high nacelle angles

with low airspeed. This condition occurs very rapidly with little to no warning to the

pilots. In simulation at 95 degrees nacelle, 39 KCAS, and 0 feet per minute rate of

descent (ROD), pulling the thrust control lever (TCL) full aft caused an immediate

descent exceeding the 800 feet per minute NATOPS WARNING. If forward TCL is

applied at this point, an uncontrolled flight condition is possible. Within 3 seconds,

the simulator exhibited in excess of 3,000 fpm ROD.”

• Additional Recommendation - “Continue developmental testing to investigate

HROD/loss of controlled flight phenomena and determine safe flight envelope for

these conditions. Consider providing cockpit warning of this condition to the pilots

to preclude entry into unsafe flight regimes.”

• Section 4 Test and Results -”The V-22 technical documentation did not support

the operation and maintenance of the V-22. The NATOPS was plagued with

inaccuracies that degraded flight operations and still contained FSD and EMD

aircraft data not pertinent to production aircraft. Performance charts furnished by

the developer to support OPEVAL were also inaccurate when compared to actual

flight conditions and the CMS. Additionally, because of incomplete developmental

testing in the HROD regime, there was insufficient explanatory or emphatic text to

warn pilots of the hazard of operating in this condition.”

Enclosure II
Page 31

Briefing Support Material -Vortex Ring

State (cont.) (Page 16)

DOT&E Operational Test and Evaluation Report Quotes

• Executive Summary - “Vortex Ring State can occur in all rotary-wing aircraft under

similar conditions of low airspeed and high sink rate. No mechanical or electrical

failures in the aircraft were found to contribute to the mishap.... In the tiltrotor V-22,

the onset of VRS can occur in the proprotor on one side without the other side

losing lift. In such a case, the aircraft tends to roll sharply into the side that first

loses lift, resulting in large, unexpected bank angles, followed immediately by rapid

dropping of the nose of the aircraft and a steep dive. At low altitudes, there may be

no opportunity for recovery.”

• “While the possible existence of VRS in the V-22 was known when flight limits for

OPEVAL were established, the unusual attitude following entry into VRS was not

expected.”

• “In addition, testing to date suggests that should a pilot inadvertently exceed

published limitations, there may be no easily recognizable warning that the aircraft

is nearing the danger zone - and some flight control inputs; e.g., a roll or yaw

command, may trigger an asymmetric thrust condition. Such a situation can easily

be envisioned in flight conditions that place a high workload demand on the pilots;

e.g., night or low visibility, system malfunctions, hostile fire, etc., should a

breakdown of crew coordination or loss of situational awareness occur. Thus, the

first indication the pilot may receive that he has encountered this difficulty is when

the aircraft initiates an uncommanded, uncontrollable roll. High rate-of-descent

(HROD) testing continues to define the VRS phenomenon.”

Enclosure II
Page 32

Briefing Support Material -Vortex Ring

State (cont.) (Page 16)

DOT&E Operational Test and Evaluation Report Quotes

• Executive Summary - “I believe that ongoing developmental testing should

continue to explore the ability to detect proximity to the danger area in the flight

envelope, with the objective of providing meaningful warning to the pilot, or control

limitations, to avoid entry into this danger area and loss of control....This area is

historically left unexamined in other military rotorcraft which put in place restrictions

that rely on information non-specific to their particular airframe.”

• “In addition, follow-on developmental and operational tests should involve multiple

MV-22s, at heavy weights, in close time and space proximity as might be

anticipated in the conduct of a combat assault mission. Such operational test

would increase confidence that appropriate tactics exist to enable the MV-22s to

deliver assault forces to a small area in a short time while avoiding undue exposure

to enemy threats-without subjecting the aircraft to potential loss of control

situations.”

• Operational Effectiveness Areas of Concern - “As noted previously, I fully

endorse ongoing testing activities and recommend research efforts to better

understand the Vortex Ring State phenomenon and the potential danger posed to

the safe operation of the MV-22.”

• “A second, related concern involves the effects of maneuvering limitations imposed

to avoid the vortex ring state danger area...Despite the OPEVAL finding that the

restrictions had no operational impact, I am concerned that this constraint imposed

to avoid loss of control may limit the maneuver capability and hence the

effectiveness of the MV-22 in some operational scenarios. Ongoing developmental

flight testing is intended to more accurately define the danger zone beyond the

NATOPS flight envelope.”

Enclosure II
Page 33

Briefing Support Material -Vortex Ring

State (cont.) (Page 16)

DOT&E Operational Test and Evaluation Report Quotes

• “A second phase of testing is planned by Naval Air Systems Command to fully

explore the potential aerodynamic interactions between MV-22 aircraft in proximity

to each other. Until the final operational constraints upon descent rates and aircraft

separation are established based upon ongoing developmental testing, and the

appropriate tactics are confirmed in operational testing, the potential impact on the

effectiveness of the MV-22 in performing some combat assault missions must be

viewed with some reservations.”

• Assessment of OPEVAL Adequacy - “Examine thoroughly the circumstances in

which the V-22 may depart from controlled flight in low-airspeed, high rates of

descent. Investigate the potential for airflow interactions between nearby V-22s to

initiate or aggravate vortex ring state.”

• “Demonstrate the end-to-end conduct of ‘typical OMFTS scenarios’ involving

multiple MV-22s making repeated back-to-back flights in close proximity in time and

space to each other and other aircraft needed for the operations - as might be

expected during the conduct of combat assault operations.”

• “Confirm the shipboard compatibility of multiple MV-22s operating simultaneously

as would be needed in the conduct of a substantive amphibious assault.”

Enclosure II
Page 34

Briefing Support Material -Suitability

Concerns (Page 19)

JAG Report - Opinion Section Quotes

• “The maintenance/removal rate of swashplate actuators, though not causal in this

mishap, is concerning. The MOTT replaced 17 actuators during the OPEVAL

period. Given their critical role in the aircraft’s drive system, reliability of these

actuators is imperative.”

• “The frequency of servicing/maintenance requirements, for aircraft hydraulic

systems, though not causal in this mishap, is concerning. Many maintenance manhours have been spent maintaining and servicing the various aircraft hydraulic

systems.”

Enclosure II
Page 35

Enclosure III

(120039)

Page 35