## Exemption Request FAR 91.319(c) Commemorative Air Force

Aircraft: B

- 24/RLB30 N24927 Re quest: Exemption from FAR 91.319 (c) and associated condition s in the aircraft operating limitations



## 1. Reason for Exemption: The Commemorative Air Force is requesting this exemption to provide operational relief from the restriction s of operating ov er Densely Populated Areas for our B

- 24 Liberator N529B

. This reque st is to allow participation in the flyover of the Nationa l Mall celebrating the 70 th annive rsary of the end of WW II, on 8 May, 2015. The concept of the flyover was briefed to Administrator Huerta by Congressman Grave s and summarized in the letter to the Administrator (attachment 1) . The lette r clearly establishes the event as in the Public Interest. The basis of our equivalent level of safety is focused on the fact the B

- 24 has outstanding engine reliability and also has excellent 3 engine capability for continued flight to suitable recovery bases. The B

24 operate s with a LHFE exemption (6802) and complies with the required maintenance program and crew qualifications/ training; the same as the limited category aircraft in the exemption. The oversight of the B

- 24 is focused on safe operations with checks and balances managed within the policies and procedures established in the CAF Safety Management Syst em

. 

## 2. Overview of VE Day Flyover :

WHEN: May 8, 2015 •WHY: Honor and pay tribute to our nation’s greatest generation on the 70th anniversary of VE Day •WHERE: Washington, DC and the World War II Memorial through the established “Honor Flight” model •HOW: Fly historic WWII planes over National Mall“THE PLAN”

• Capitol Mall Flyover •Trainers followed by 13 Historically Sequenced Warbird formations and concluding with a missing man formation to “taps” •Formations in 90

- second intervals •70+ planes representing the major battles of World War II, from Pearl Harbor to the final air off

ensive to defeat Japan

HISTORICAL AERIAL REVIEW FLOW •Trainer Formation “Pass in Review” (Boeing Stearmans, Piper L

- Birds, North America T

- 6s, Cessna/Beech Twin Bomber Trainers •Pearl Harbor/Flying Tigers (Curtis P

- 40 Warhawks) •Doolittle Raid (North American B

- 25 Mitchells) •Guadalcanal Campaign (Bell P

- 63/P

- 39 Kingcobras/Aerocobras) •Battle of Midway (Consolidated PBY Catalina, Grumman F4F/FM

- 2 Wildcats, Douglas SBD Dauntless) •Yamamoto Shoot down (Lockheed P

- 38 Lightnings) •Ploesti Raid (Consolidated B

- 24 Liberators) •Combined Bomber Offensive

— Long

- Range Fighter Escort/Tuskegee Airman (North American P

- 51 Mustangs) •Big Week (Boeing B

- 17 Flying Fortress) •D

- Day (Douglas C

- 47/R4D Skytrain, Douglas A

- 26 Invader) •Marianas Turkey Shoot/Battle of Leyte Gulf (Grumman TBM Avengers, Grumman F6F Wildcats, Grumman F8F Bearcats, Curtis SB2C Helldivers) •Battle of the Bulge (Republic P

- 47 Thunderbolts) •Iwo Jima (Vought FG

- 1D Corsair s ) •Final Air Offensive to Defeat Japan (Boein g B

- 29 Superfortress)

CONCLUDES WITH A MISSING MAN FORMATION TO TAPS



## 3. Route of Flight /Restricted Area Waivers

The route of flight and approvals for flight in the restricted areas are being worked thru Mr. James Johnson (703) 563

- 3118 IAW the Administra tor s’ Letter of 19 August, 2014 (attachment 2 ). The interagency suspense’s for these approvals are very close to the event and history has shown they will not become final until the month before the event , or later . However, Mr. Johnson and the General Avi ation Operations Branch, AFS

- 830 will be working together as meetings and the process continues.

## 4. Equivalent Level of Safety:

A

. Similar aircraft operation with limited /Standard certificates : The B

- 17 and C

- 47 aircraft are of comparable make, construction, and materials. The maj or reason our B

- 24 is certificated in the experimental cate gory is because the aircraft is configured differently than the original Limited TC issued in 1947 and there are no other similar standard category aircraft equivalents. The differences and modifications to N24927 with respect to LTC

- 6

- 3 issued in 1947 that were made to improve operational safety and sustainability. These differences include: The original engine configurati ons listed (R

- 1830

- 33, or

- 67) have been upgraded to newer R

- 1830

- 75 and

- 94 engines. The aircraft is operated at lower maximum power setting than stated in the 1947 document. The aircraft’s engines are no longer equipped with a high speed blower. The C AF has reduced the maximum take

- off weight of 58,000 pounds to 56,000 pounds so the maximum landing weight is never exceeded at any time.

B

. Engine Design & Reliability The B

- 24 is fitted with four (4) Pratt and Whitney R

- 1830 power plants. There were more of these engines built than any other radial engine and proved to have outstanding reliability. These are the same engines used on many of the DC

- 3 type aircraft which are primarily operated in the standard category

.C . Equivalent Level of Safety Qu estions and Answers

1 . What are the risk factors and safety issues in the LB

- 30/B

- 24A that create hazardous conditions which could impact people and property being overflown which would not be found by the operation of a similar civil type, i.e. Boein g 307/C

- 54/Limited B

- 17? There are no unique or elevated risk factors and safety issues with the LB

- 30/B

24A that would not be found by the operation of any other civilian type of 4 engine heavy aircraft. N24927’s in

- flight safety record and reliability h ave proven itself and the aircraft will present no elevated hazard for the 70 th anniversary overfly.

2. What safety data do you have concerning the aircraft while in service such as accident rate and types and classification of accidents/incidents? F or example, the accident rate in non

- combat operations (all B

- 24 versions and variants) ranged from 40 to 96 per 100,000 hours, while 300 were lost in accidents in 1943 and an accident fleet attrition rate of 30% (5,500 out of over 18,000 produced). The c auses and contributing factors are relevant to any ELoS determination. In other words, what failed and what is likely to fail, and how, and what is being done to mitigate these. For example, in general terms, how are the following B

- 24 safety issues addre ssed or mitigated by the CAF in operating N24927? Note: Some of the questions below may lead to or provide an answer.

 Advanced airfoil (Davis wing) and high wing loading;  Troublesome fuel transfer system and fire potential;  Poor

- engine out performance;  Landing gear weaknesses and hydraulic failures;  Structural weak areas affecting crash

- landing survivability;  Tail buffeting/flutter;  Flight stability and loss of control in some configurations/weights or in turbulence. N24927 is a very, very unique example of a B

- 24 Liberator. Much of her design and subsequent operation since 1941 has been civilian orientated verses the combat and fast paced war

- time training missions of other B

- 24 models this question references. Similar early Liberator aircraft s uch as the XB

- 24 and several other B

24A models pressed into civilian service as was N24927 lived long successful and accident free operational lives until their retirement. In addition, procedural improvements, aircraft modernization, an in

- depth mainten ance program and a slow

- paced operational environment today verses the 1940’s make this a very safe and reliable aircraft. No abnormal or detrimental characteristics exist with this aircraft.

3. How have you incorporated the applicable Army Air Corp s/Force Regulations and SOPs (operational) applicable to the LB

- 30/B

- 24A to CAF’s operations of N24927? Any RAF guidance? No, the CAF Safety Management System provides better guidance for operation of the B

- 24 in peacetime; our regulations are more restric tive and insure the safest operations.4. What is the technical substantiation for the modifications to the R

- 1830

- 94 instead of

S3C4G,

- 33,

- 67 engines installed in the aircraft (Possibly

- 65s as well with Stromberg PB12 Carbs.)? Please submit a co py of these materials (e.g., reliability analysis, proving & validation test data). Are the most current R

- 1830

- 94 Service Instructions being used? Does the CAF uses a QEC unit as an option in addressing engine changes and /or malfunctions? The choice of e ngines for the early Liberators was the Pratt and Whitney Twin Wasp R

- 1830

- 33 or - 67 S3C4G radial. They were equipped with a two

- speed, eleven inch diameter impeller supercharger housed inside the aft engine case; no turbo

- chargers were installed. Early Liberators had round nacelles and not the elliptical shaped nacelles of the later mass produced Liberators. The later model Liberators operated with upgraded R

- 1830

- 43 or

- 65 engines ; th is design changes giving the later models the distinctive elliptical engine nacelles were driven by the addition of turbo charging. Liberator Mark II’s were equipped with P&W 1830

- 61 engines with Curtis Electric controlled props
. There became a needed to remove the original engines because p roduction of the older

- 33 and e quivalent

- 67 models was halted by the end of WWII due to the introduction of upgraded design models. This meant the availability of the R

- 1830

- 33 and

- 67 engines steadily declined and future sustainment with this particular engine configuration would be difficult and eventually impossible. Convair removed the aircraft’s original engines and nacelles and replaced them with PBY

- 5 Catalina units that were still being produced. This is still the configuration N24927 carries today.

5. With the understan ding that the LB

- 30 and early B

- 24s, what technical data validates the combination of the Hamilton

- Standard Hydromatic propellers (both narrow and wide (paddle) types) and the

- 94 R

- 1830? Is it a sanctioned combination? Any civil equivalent? The current 23 E50 Hamilton

- Standard Hydromatic Propeller assemblies currently being used on N24927 are consistent with the aircraft’s original configuration and engine series family. We do not have the resources to account for all military and civilian aircraft utilizi ng this common propeller/engine series equivalent combination. However, two prime examples of this successful combination can be found in Aircraft Specification No. A

- 669 for the Douglas DC

- 3 and TC

- 2

- 548 for the Consolidated PBY

- 5 Catalina. Also, the CA F contracts dynamic propeller balancing to be conducted on N24927 to ensure safety and reliability.

6. Are the turbo/superchargers (GE B

- 22 type?) installed and functional? If so, what measures have been taken to mitigate the hazards these may in troduce to the operation of the aircraft? If functional, what measures are used to mitigate the defects in the buckets? N24927 is not equipped with any turbo chargers. Each engine does have an integrally driven, single stage, 7.15:1 drive ratio, single sp eed supercharger. Thisconservative configuration provides ample power to safely operate the aircraft,

increases reliability and mitigates any hazards.

7. What is the modification status of the aircraft with respect to the TCDS No. LTC

- 6, Rev. No. 3, Consolidated Vultee Aircraft Corporation, LB

- 30 (Army) dated February 21, 1947? How far from conformity with LTC

- 6 is the aircraft? Please submit relevant records especially since the conversion back to B

- 24A begun in 2006

- 08. There are some differences and modifications to N24927 with respect to LTC

- 6

- 3 issued in 1947 that were made to improve operational safety and sustainability. These differences include: The original engine configurations listed (R

- 1830

- 33, or

- 67) have been upgraded to newer R

- 18 30

- 75 and

- 94 engines. The aircraft is operated at lower maximum power setting than stated in the 1947 document. The aircraft’s engines are no longer equipped with a high speed blower. The CAF has reduced the maximum take

- off weight of 58,000 pounds to 56,000 pounds so the maximum landing weight is never exceeded at any time. Also, TCDS LTC

- 6

- 3 does not reference a B

- 24A aircraft; it references this modified RLB

- 30 cargo aircraft.

8. Have the Notes 1 through 5 in LTC

- 6 been complied with? If not, why and what mitigating strategies have been implemented in lieu of? Note 1: Detailed Weight & Balance records including equipment listings on DD Form 365’s are maintained. Note 2: Appropriate and required passenger placards are posted in accordance with current FAR’s and operating limitations. Flight deck speed verses configuration limitation warning placards are posted. Note 3: An updated, yet similar statement made by the issuing FSDO appears in the aircraft’s operating limitations. Note 4: The aircraft is no longer operated in the Limited category as referenced in this note and therefor the 337 documentation system does not and cannot apply. Detailed records of any repairs or modifications are kept in the aircraft logs. Note 5: This note no longer applies because this aircraft is no not operated for night flying as stated in and restricted by its current operating limitations.

9. Since over time Consolidated improved upon many of the deficiencies of the early B

24 s (LB

- 30/RAF Liberator I & II, B

- 24A

- D) as it developed later versions (e.g., J and H), what risks may have been re

- introduced by the CAF into N24927 by converting it back to a stock “A” model? If so, how are they mitigated? The reconfiguration of N24927 b ack to a B

- 24A model appearance was a cosmetic conversion, not a structural change, major modification, or regression in safety. No part of this project re

- introduced any hazard or risk into the operation of this aircraft. Even the hatches and windows re installed in the aircraft involved uncovering skinned

- over cover panels of pre

- existing openings; not fuselage structure modifications. Listed below are a summary of the changes made during the B

- 24A model reconfiguration:

 Replaced nose greenhouse glass I nstalled bombsite & bombardier furnishings

 Reconfigured nose gun assembly

 Relocated and installed new pitot tube assemblies

 Reconfigured flight deck instruments

 Refinished flight deck furnishings

 Installed 4 each flight deck overhead windows

 Installed flig ht engineer hatch window

 Removed flight deck cabinet and installed navigator’s seat

 Installed interior lighting system

 Removed storage bins and wooden cargo floor

 Installed 4 passenger seats in forward bomb bay

 Installed forward and aft bomb racks (non

- str uctural)

 Replaced and relocated fuel sump drain lines

 Installed bomb bay walkway

 Radio compartment floor installed in correct location

 Troop seats installed in radio compartment

 4 each radio compartment windows installed

 Auxiliary battery installed in above wing area

 Original top gunner side floors installed w/ storage area underneath

 Aft fuselage interior walkway ladder installed

 2 each top gunner windows installed

 Side hinged cargo door reconfigured to drop

- down style

 Functional RH waist gunner hatch and gun mount assembly installed

 Waist gunner flooring installed w/ storage underneath

 Tunnel gun station/hatch assembly installed

 4 each tunnel gun windows installed

 Fuselage gun storage provisions installed

 Functional tail gunner position, doors, and fu rnishings installed

 2 each aft tail gunner windows installed

 2 each upper tail gunner windows installed

 Pogo assembly rebuilt and modified to telescope

 Elevator assemblies recovered

 Rudder assemblies recovered

 Aircraft exterior painted in camouflage patter n w/ “Ol 927” nose art applied

10. What is being done to prevent a recurrence of the May 26, 2012 nose gear collapse, especially in light of the fact that this failure was common in early LB

- 30/B

- 24s? Whathas been done to prevent a recurrence of the lan ding gear failure event which took place

on September 16, 1996, in which a main landing gear brace failed? NLG collapses did occur on many B

- 24 aircraft during wartime operations, but this scenario was more common in the D & J models. Much of this was due to the much heavier weights and austere airfields they were operating out of which proved to be too much for the MLG design. In addition, the aircraft were equipped with what proved to be a sometimes inadequate NLG shimmy dampener system. The NLG shimmy damper was eventually upgraded to a much more effective later designed unit as opposed to the dual configuration originally installed. N24927 is equipped with the newer, improved design. In reference to the May 26, 2012 N LG incident several improvements and procedural controls have been implemented to mitigate any such reoccurrence. The incident came about due to a hydraulic system failure that did not fully lock the NLG in the down position. The failure point of the hyd raulic system was upgraded, additional personal protective equipment was installed on the aircraft to better handle any such scenario, procedural changes were made to physically verify the NLG is down and locked each gear cycle and the use of an additional NLG down lock tool is installed.

11. What has been done to eliminate the risk of fuel leaks in the fuselage/bomb bay areas? Does the aircraft have an early fuel transfer system (limited cross

- feed capability) or the systems installed in later mode ls? Has the fuel transfer system been modified or made inoperative? If so, how? Are potential ignition sources (e.g., hydraulic/electric motors) understood and mitigated, e.g., ventilation without the benefit of using the bomb bay? Provide technical data o n any such modifications or actions. N24927 is equipped with a very much simplified mechanical version of one of the two early B

- 24A fuel transfer systems. The system utilized 4 each mechanical valves that correspond to each engine that provide varying so urces of fuel supply to any engine from either tank, with any of the 4 electric boost pumps, or provide a fuel supply to any engine driven fuel pump as needed; the system is unlimited in transfer capabilities. This aircraft does not have the complicated f uel bladder configuration and hydraulic pump transfer system utilized on other versions of the B

- 24 (early or late models). The fuel tank and transfer system on this aircraft has been simplified and is no longer problematic or pose any fire potential. The only potentially possible ignition source associated with the fuel system is the electric boost pumps. This hazard is mitigated by pump design and flight crew awareness/system pre

- flight inspection training. Each pump is equipped with a case drain secti on that will catch and drain any fuel that could potentially bypasses the Garlock seal and enter the electric motor thereby eliminating any fire hazard. Inspecting these case drains is a specific pre

- flight checklist item to ensure safety of flight. In t he event of any fuel vapor build

- up in the bomb bay area, the aircraft is equipped with ram air ventilation on both sides of the fuselage just forward of the fuel tanks and 4 side windows to eliminate the hazard.

12. What has been done to eliminate the risk of fuel leaks in the wings (including routing inward back into the fuselage areas)? Has the fuel tank system been modified? If so, how?Are the Aux tanks aft of the No. 1 and No. 4 engines installed and functio nal? Provide

technical data on any such modification or action. Also, what actions have been taken to minimize fuel leaks related to the priming system? The aircraft is equipped with a left and right main fuel tank that extend from the wing center section outward to the inboard side of the #2 and #3 engines . Each of these is a wet tank containing no bladders each with a 1,500 gallon capability. The aircraft does have any auxiliary fuel tanks or any kind.

13. What are all of the applicable USAAC/ USAAF T.Os for the aircraft in effect at the time of retirement? Can you provide a listing and data showing that all applicable T.Os and TCTOs (to end of operational service

- 1947) have been complied with? N24927 never saw service with the USAAC/USAAF. T hough it was delivered to the British Air Ministry in May, 1941 the aircraft was returned to Consolidated in July 1941. It served throughout the war and two years afterwards in company service. Records kept of all modifications and TCTO’s were internal C onvair company documents. The airworthiness and updates of the aircraft was validated by the CAA in 1947 and the aircraft entered official civilian service.

14. What are the differences between the current AIP and the military technical guidance, es pecially in terms of inspection schedules and replacement times (life

- limits)? Does the AIP contain progressive schedules” Which inspection process is used, e.g., just annual/100 hours, 4 x 25 hours inspection covering each engine and a few major component s (right wing with No. 1 engine) at a time, IRAN, or overhaul as in C & D check

like? Any leftover processes (non USAAF) from its time under Mexican Registry? The available military technical guidance does vary from the AIP in regard to airframe and engine s and sub systems, but not so much in overall aircraft structure. N24927 was never equipped or configured with engines, systems, components and furnishings like the later model B

- 24D and J models so a majority of that technical data referencing inspection items and life

- limited parts is non

applicable to this aircraft. The criteria and process laid

- out in the current AAIP established in May 19, 1992 has proven to be adequate in maintaining the safety and reliability of this aircraft. N24927’s AIP is not on a progressive schedule; it is based on an hourly/calendar schedule. The “A” Continued Service Inspection is accomplished anytime the aircraft has not been operated in 30 continuous days. A “C” Inspection is accomplished on the aircraft, engines and propellers every 50 hours. A “D” check is accomplished every 100 hours of flight time and/or annually regardless of flight hours accumulated if the 100 hour mark has not been reached. Special inspections such as hard landings and lightning strikes are ac complished on an “as needed” basis. There are no leftover unique processes that are required or accomplished from this aircraft’s service life with Continental Can Company or its time in Mexico.

15. Has AD 2003

- 18

- 01 Airworthiness Directives; Ge neral Dynamics (Convair) Model P4Y

- 2 Airplanes, General Dynamics (Consolidated

- Vultee) (Army) Model LB

- 30Airplanes, and General Dynamics (Consolidated) (Army) Model C

- 87A Airplanes, as

amended, been complied with? AD 2003

- 18

- 01 has been complied with. In addition, an exterior visual inspection of the referenced area and the front wing spar, front spar web and lower skin of the wings from the center wing station outward to the engines on both sides of the aircraft are accomplished during each annual mainte nance inspection. To date, no discrepancies or structural anomalies have been discovered.

16. What other ADs, SBS, or other civil requirement/guidance applicable to the LB

- 30/B

24A have been considered and incorporated? No other LB

- 30/B

- 24/C

- 87 speci fic ADs, SBS, or other civil guidance beyond current FAR’s, the aircraft’s operating limitations, AAIP and technical data is available.

17. What ADs, SBS, or other civil requirement/guidance applicable to the R

- 1830, the Hamilton

- Standard propellers or o ther appliances installed in N24927 have been considered and incorporated? For example, has AD 81

- 13

- 06 Rev. 2 (repetitive, and using Hamilton Standard Manual No. 130B) been complied with? In regard to the Hamilton

- Standard propellers , AD 81

- 13

- 06 Rev 2 is complied with every 5 years on each propeller assembly. This AD was last complied with on all 4 assemblies on April 11, 2012. Also, AD 64

- 03

- 03 for solid foreign object damage is complied with on an “as required” basis. In regard to the R

- 1830 engines, we outsource major engine repairs and overhauls and rely on the subject matter experts to track and accomplish all AD and SBS; associated documentation if kept on file. The CAF’s B

- 24 maintenance program does accomplish AD 56

- 06

- 02 for cylinder flange attaching studs during the annual maintenance inspection, as well as, during any engine cylinder changes.

18. What flight emergencies, in

- flight failures, in

- flight engine shutdown and post

- flight discrepancies have occurred s ince 2006? What has been done to prevent a recurrence? Since the B

- 24A reconfiguration of N24927 there have been no other flight emergencies, in

- flight failures, or in

- flight engine shutdown s besides the NLG collapse referenced earlier in question #10. T he only other significant issue since the reconfiguration was a precautionary removal of the #3 engine for abnormally high oil consumption. Occasional minor non

- safety of flight and/or non

- mission limiting discrepancies will occur and are corrected by the appropriately A&P licensed flight engineer, or other CAF maintenance personnel. Detailed records of these minor discrepancies are listed in the aircraft maintenance log.

19. Is the fire detection and suppression system functional and properly inspecte d? N24927 is not equipped with an automated fire detection system. Fire detection is performed by the flight engineer and loadmaster/ scanner. The Halon 1301 fire suppression system is fully operational and inspected during the aircraft’s annual maintenan ce inspection. The serviceability of the fire suppression system is verified during each pre

- flight inspection by the flight engineer.20. What is the SOAP (Spectrometric Oil Analysis Program) frequency and results since

September 2010? SOAP samples h ave been and continue to be taken every 50 hours of in

- service time on each engine. To date, the results have revealed no discrepancies, or negative trends. SOAP samples will continue to be taken on this schedule and the r esults tracked throughout the li fe of each engine.

21. What are the details of the aging aircraft and corrosion control programs? Aging aircraft and corrosion control issues are a large part of the CAF’s B

- 24 sustainment program. During the annual maintenance inspection, in

- depth inspections of the wings , tail structures and lower fuselage are performed including non

- destructive inspections of spar, primary structural components and attachment points. Aircra ft secondary structures and surface skins also undergo corrosion inspections. Regular lubrication and corrosion preventative treatments are made, as well as, touch up painting whenever or where ever necessary.
22. Has the front wing spar splice in N24 927 been modified in a manner similar to the modifications made to N224J under Report No. CF

- B4J

- 44052

- 001SA? If so, is there adequate technical justification for such a major modification to the aircraft? Without first

- hand experience of the wing spar rep air made to N224J or a copy of Report No. CF

- B4J

- 44052

- 001SA referencing the splice no comparison can be made to N24927. No safety of flight defects were found on N24927’s wing spar during the accomplishment of AD 2003

- 18

- 01 . As a precaution and to ensur e long

- term sustainability, safety and operation of this aircraft for future generations, engineering was consulted and a reinforcement doubler was installed on the forward wing spar.

23. What are the configurations and redundancies installed in the aircraft? What non

standard additions were incorporated that enhance safety? Numerous redundancies and back

- up systems are built into th is LB

- 30/ B

- 24A aircraft. Today, the aircraft is operated at a much lower weight and power settings than its original co mbat design; this greatly increases the safety margin and performance aspects of the aircraft. Its configur ation has also been simplified to increase safety by the removal of such systems as oxygen, auxiliary heaters, galley, lavatory and interior luxurie s . The proven Liberator design and light operational weight make this aircraft safe and reliab le

.

24. The B

- 24 has a poor history of survivability during ditching/crash landing. What precautions have been taken to maximize survival in case of ditching or crash landing? , such as adequate passenger locations, removable stiffeners to brace lower structure/bomb bay, structural reinforcements to mitigate fuselage compression failures immediately behind the cockpit, and ditching/crash landing belts/restrain t canvas? It is very true that due to the lightly skinned and flexible 4 bomb bay doors and single keel beam design, all actual bomber versions of the B

- 24/LB

- 30 had very poor ditching/crash landing survivability. However, variants of the aircraft such as the C

- 87, RB

- 24 and RLB

- 30 (such as N24927) aircraft did not share thischaracteristic because the bomb bay door and keel structure was removed and

replaced with an enclosed, fully supported solid structure and cargo floor. This maximizes ditching/crash landing survivability.

25. Have there been any instances of tail vibration, flight control deformation, or flight control cable failures? Does the CAF restrict N24927’s maximum speed for any structural concern? For example, the H model’s speed was reduced to 300 mph to reduce the possibility of in

- flight structural failure of flight controls. Note: For safety reasons, in operating its B

- 24J, The Collings Foundation has reduced Vne to 200 mph. There have been no instances of tail vibration, flight co ntrol surface deformation or control cable failures on N24927. The CAF’s B

- 24 is a much cleaner and lighter version than that of the B

- 24J model. Consolidated also made many improvements to N24927 during its test time and operational service use with the company. In addition to the improved RY

- 3 fuselage nose section and NLG improvements the original tail section was replaced with an empennage assembly rated to 18 G’s. The CAF does restrict N24927’s maximum speed, but it is not due to structural failure reasons. There are many varying speed limitations posted in early LB

- 30A, LB

- 30B and B

- 24A technical data & the LTC, the CAF has reduced N24927’s Vne at 41,000lbs to 305 knots and Vne at 56,000 lbs to 235 knots. These restrictions are made solely to enh ance operational safety and preservation by eliminating any wear and tear on the airframe and engines brought about by unnecessary high speed operations.

26. Is the CG range maintained in a conservative range with respect to 23 percent MAC to 32 perce nt MAC (narrow CG range)? The purpose is to ensure that at all times, any of the aircraft’s flight stability issues (longitudinal) due to CG location is safely maintained. This is an issue with the “short

- nosed” B

- 24s, and in fact the nose extension in lat er models was primarily to help, but not resolve, this CG issue. Though N24927 was originally an LB

- 30B/B

- 24A short nosed Liberator Convair upgraded the aircraft with the long Liberator nose from a RY

- 3 aircraft. All Liberators have had an extremely narr ow center of gravity and Diamond Lil’ is no exception. The center of gravity on this large 67’ long aircraft is only 11’’. Loading of this aircraft is extremely critical on the ground to prevent her from falling back on her tail and maintaining her desig ned flight characteristics in the air. Each and every restoration, reconfiguration or repair project is heavily scrutinized within the very detailed CAF weight and balance program. Most impressive is the fact, that after all of her numerous configuration changes throughout her life that she still maintains her original center of gravity line at 311.5”. A detailed weight and balance calculation is accomplished by the flight engineer prior to every operation of N24927 to ensure the aircraft is within the C G limits.27. The expectation is that the most experienced LB

- 30/B

- 24 crew would be used. As

such, can you Please provide the qualifications and experienced of the proposed flight crew for the flight

– PIC, SIC, and FE? Include Total Time, Time in Typ e, ratings, currency and recency. The crew will be 6802 qualified and the pilot will be FAST qualified. The crew assignments will not be done until we get closer to the event and all crew information will be submitted with additional information required b y secret service and tsa about 60 days prior.

28. Please provide information showing that the FE assigned to the LB

- 30/B

- 24A (a required crew position) is properly qualified, e.g., experience A&P and training as a crewman? Has USAAC/USAAF B

- 24 FE trainin g been adhered to or considered? N24927 does carry a flight engineer as a required crew member position, but the Operating Limitations do not require FAA licensing, or currency requirements beyond that of internal CAF procedures. The FE position does not touch any primary or secondary flight controls or engine controls. This position is probably better described as a flight mechanic. Qualified CAF B

- 24 flight engineers must meet minimum time requirements, attend the required CAF FE ground school
course, perform OJT on servicing tasks/inspections/normal and emergency procedures, 6 (minimum) training flights and pass an in

- depth final check. Currency requirements involve an annual check ride. Some facets of USAAC/USAAF B

- 24 FE training is adhered to in re gard to system operation and emergency procedures should they be necessary

. 29. What ground crew and grounds support is used? What special pre

- flight and post

flight inspections can be performed to enhance safety? No additional ground support beyond the flight crew and the equipment carried aboard N24927 is necessary to sustain normal aircraft operations. The p re - flight and post

- flight inspections performed by the flight engineer each and every time the aircraft is operated encompass a very in

- depth,

se rious and detailed safety and serviceability inspection of the aircraft. The mechanical condition, proper servicing, safety equipment condition, loading security, weight & balance calculations and dropped object prevention are incorporated into each of these inspections prior to flight

. 30. What QC processes are used in addressing supplier and parts acquisition and use? Parts acquisition and spares serviceability are all controlled by and solely the responsibility of the B

- 29/B

- 24 Squadron’s head Crew Chief. This ensures a specific focal point of high level of experienced quality control and vendor oversight.

31. Has the CAF implemented SMS/CRM/MRM/ORM? If so, please how such does it impact the operation of N24927. Yes we have a SMS program submitted as an attachment to the B

- 29 exemption request and CRM is a module in our annual 6802 ground school.32. On the issue of engine/powerplant and propeller failure and related issues, plea se

provide the mitigating strategies for the following:

 Engine Failure & Fire; Courses of actions for these scenarios are detailed in the flight manual and emergency checklist  Putt

- Putt Fire & Containment; This aircraft is not equipped with an auxi liary power unit (putt

putt)  Propeller Overspeed and Separation; Course of action for th is scenario is detailed in the flight manual  Hydraulic & Electrical Failures; Alternate methods of energizing these systems and back

- up sub

systems are available and de tailed in the aircraft flight manual. These actions are accomplished by the FE  MEL & Flight Abort Criteria; The PIC makes the decision about aborting/diverting/making precautionary or emergency landings based upon the ma lfunction and environmental conditions when an inflight malfunction occurs. There is no way to establish criteria for all possibilities and this is true in every flight operation, regardless of aircraft category.

33. What coordination has been done with other Military/Federal entities concerning the proposed overflight? Please provide details. The coordination with all appropriate agencies is being done thru Mr. Johnson as directed by the Administrator. AFS

- 800 has been invited to the teleconferences and the meetings. Mr. James JJ Johnston Manager, National Capital Region Coordination Center FAA System Operations Security National Tactical Security Operations

34. For flight over populated areas (maximum avoidance), please discuss and provide detail on the following: The answers to the questions below are discussed in appropriate sections above. Additional detail will be available after the required coordination with other agencies managed thru Mr. Johnson and AFS

- 800 will be actively involved in working out the details for maximum safety.

  Egress/Ingress (Airports & Areas);  Ground References & Landmarks;  Formation, Mixed Formation, and In

- Trail;  Lateral Separation & Maneuvering Room; Straight & Level, Minimum Ma neuvering;  Nav and Communications;  Rehearsal, if a special event is Involved;  In

- Flight Divert Procedures Including Divert Airports (e.g. runway 19 at KDCA, Andrews AFB) and Crash/Ditching Areas (e.g. Potomac River);  Performance, e.g., (1) minimum airspee d for which it is still possible to climb away, without change of configuration, if any one engine fails, (2) symmetrical thrust should be maintained at all times, and power changes minimized, (3) glide ratio.  Conservative Performance: Please discuss reduc ed operating weights, power settings, minimum/maximum altitudes, and maneuverability restrictions. Note: For example, and for safety reasons, in operating its B

24J, The Collings Foundation has reduced max gross weight to 40,000 lb., 2,700 rpm (T.O.) and 2,000 rpm (Cru ise), and max bank of 30o



## 5. Risk Mitigation and Assessment :

The answers to the questions above touch on specific risk and mitigations requested by AFS

- 830

. However and in general terms , this assessment addresses events which pose a danger to people and structures on the ground

. The scores are listed here and the risks are shown in the Matrix. None of the risk s are in the caution or danger

zones. 1. T here is no history with the B

- 24 which s hows catastrophic failures resulting in immediate loss of aircraft control. Assessment: improbable/catastrophic 2. The most significant failure would be an engine fire and a simultaneous failure of the fire suppression system, or a fire in a component located in an area where the crew would be unable to fight the fire with onboard suppression systems. The immediate action in either case would be an immediate diversion to the closest diversion field, wh ich during the flyov er would only take 3

- 5 minutes

a nd is within the window for a safe recovery. Assessment: remote/negligible 3. Engine failures without fire, or fires successfully suppressed are managed by shutting down the engine and proceeding to a suitable airport. Three engine performance is sufficient for maintaining altitude and airspeed and normal procedures are followed for flight to the suitable airport. Assessment: occasional/negligible 4. The possibility of two engines failing is extremely remote; however, two engine performance at the operating we ight for the flyover, and other local flights
, is sufficient for continued flight to the diversion airports along the rou te of flight during the flyover and can be accomplished with a positive rate of climb at the planned altitude. Assessment: remote/negli gible 5. The possibility of a midair collision within a formation is mitigated by managing the qualifications of the pilots and the flight profiles. The pilots flying formationwill be qualified IAW FAST standards and the flight profiles are straight and

leve l point to point. Furthermore, midair collisions within a formation rarely result in loss of control, or major aircraft damage. Midair collisions within formations which result in loss of control are primarily in high “G” or highly maneuvering elements. Assessment: remote/marginal

(CONTINUED ON NEXT PAGE)

### Risk Assessment Matrix

Population/Structures in DC Area for VE Day Flyover Severity Likelihood Negligible

IV Less tha n minor inju ry and/or less than minor
structure damage Marginal

III Minor injury and/or minor
structure damage Critical

II S evere injury and/or major
structure damage Catastrophic

I Results in fata lities and/or loss of structures

Frequent = A

Continuously experienced

Probable = B

Will occur often

Occasional = C

Likely to occur sometime Engine failure

Remote = D

Unlikely , but possible Uncontrolled

fire/two engine failure Midair

Improbable = E

So unlikely, it c an be assumed it will
not occur Loss of control

(CONTINUED ON NEXT PAGE)

## 6. Summary:

Participation of the B

- 24 in the flyover of the National Mall celebrating the 70 th anniversary of the end of WW II is in t he public interest and the safety of the populati on is equivalent to previously approved flyovers with similar routes in the Washington DC area. I look forward to the opportunity to work with the Agency answering questions as they arise during the staffing of our request. Please contact

me o n my cell, or via email should the need arise.

Sincerely,

Robert A. Stenevik Vice President of Safety, Maintenance and Operations Commemorative Air Force Cell 817

- 705

- 5817 rstenevik@cafhq.org

3 Attachments:

- Congressional Letter to the Administrator

- Administrators’ Letter of 19 August, 2014

- CAF Safety Management System Guide