Exemption Request

Aircraft:

B‐29					N529B	

B‐24					N24927	

Request:	Exemption	from	FAR	91.319(c)	and	associated	conditions	in	the	aircraft	

operating	limitations	

Reason for Exemption:

The	Commemorative	Air	Force	is	requesting	this	exemption	to	provide	operational	

relief	from	the	restrictions	of	operating	over	Densely	Populated	Areas	for	our	B‐29	

Superfortress	N529B	and	our	B‐24	N24927.	The	inability	to	operate	over	densely	

populated	areas	significantly	prevents	the	aircraft	from	being	placed	on	display	in	

prominent	public	arenas.		Furthermore,	both	aircraft	are	approved	for	the	LHFE	

program	and	the	densely	populated	area	restriction	severely	limits	the	public’s	

opportunity	for	the	experience	supported	by	the	agency	in	authorizing	the	LHFE	for	

both	aircraft.		The	basis	of	our	request	is	focused	on	the	fact	both	aircraft	are	four	

engine	airplanes	with	outstanding	engine	reliability	and	also	have	excellent	3	engine	

operational	capability.	

Equivalent Level of Safety:

1.		Similar aircraft operation with limited certificates:

Similar	aircraft	of	the	same	vintage	and	equipment	have	been	certified	in	the	limited	

catagory	and	are	not	restricted	by	the	densely	populated	area	over	flight	rules.		

These	aircraft	are	of	comparable	make,	construction,	and	materials.		They	are	often	

produced	by	the	same	manufacturers	and	constructed	to	the	same	standards.		Often	

equipment	and	parts	for	both	airframe	and	power	plant	construction	are	identical.		

Examples	of	the	aircraft	that	are	comparable	are	the	B‐17,	B‐25,	A‐26,	&	DC‐3.		The	

Boeing	B‐17	represents	the	greatest	example	of	a	Boeing	built	product	with	4	

engines	and	similar	design	and	construction.	The	major	reasons	our	B‐29	and	B‐24	

are	certificated	in	the	experimental	category	is	the	modifications	we	made	to	

improve	engine	reliability	on	the	B‐29	and	the	modifications	to	return	the	B‐24	to	

its	wartime	configuration	from	the	modifications	made	to	the	airplane	when	it	was	

used	for		civilian	transportation.	

2.		Engine Design & Reliability

The	B‐29	is	fitted	with	four	(4)	Curtis	Wright	R‐3350	power	plants.		Each	of	these	

engines	have	been	carefully	re‐designed	and	constructed	by	industry	leaders	to	

provide	maximum	reliability	and	longevity.		Each	engine	was	constructed	from	

certificated	parts	to	provide	an	engine	that	is	de‐rated	for	the	same	equivalent	

power	output.			
In	2010	all	four	(4)	engines	on	the	B‐29	were	retrofitted	to	these	new	engine	

designs	and	were	carefully	tested	for	operation.			

The	B‐24	operates	with	Pratt	&	Whitney	R‐1830‐94	engines.		These	engines	

although	on	an	experimental	aircraft,	are	maintained	to	the	standards	of	a	type	

certificated	‐94	power	plants	used	on	many	limited	and	standard	category	aircraft,	

most	notably	the	DC‐3.			

4. Standards for Crew Training

Our	crews	train	to	the	standards	of	the	LHFE	program,	which	are	the	same	as	

standards	required	for	aircraft	with	limited	certifications	and	our	crews	have	the	

same	requirements	for	type	ratings	in	both	aircraft.	

5.		Operational Weights

Operational	capability	is	further	enhanced	by	the	low	operating	weights	of	both	

aircraft.	The	Commemorative	Air	Force	has	taken	drastic	measures	to	reduce	weight	

and	make	two	engine	operations	even	more	feasible	for	both	aircraft.	

7.		Fire Suppression and Detection

Fire	Suppression	is	provided	through	two	Halon	bottle	systems	in	each	aircraft.		In	

addition	to	this	are	highly	trained	flight	crew	scanners	who	are	trained	in	the	

detection	and	prevention	of	fire	related	emergencies.			

Summary:

The	authorization	to	operate	in	the	LHFE	program	is	evidence	of	a	recognized	public	

benefit.	The	populated	area	over	flight	restriction	severely	limits	the	public’s	access	

and	ability	to	enjoy	and	learn	about	these	aircraft	and	their	contribution	to	our	

victories	in	WW	II.	The	reliability	of	the	engines	and	the	fact	there	are	four	of	them,	

establish	the	equivalent	level	of	safety	to	aircraft	with	fewer	engines.	

I	look	forward	to	the	opportunity	to	work	with	the	Agency	answering	questions	as	

they	arise	during	the	staffing	of	our	request.	

Robert	A.	Stenevik	

Vice	President	of	Safety,	Maintenance	and	Operations	

Commemorative	Air	Force	

Cell	817‐705‐5817	

rstenevik@cafhq.org