Post by volkerboehme on Jun 2, 2009 23:50:53 GMT -5
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The Breguet Deux Ponts.
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A design study for the Breguet 760 seems to have been undertaken by Breguet for the Luftwaffe as a prospective replacement for the Messerschmitt Gigant during 1944. However after D day France had no need for, and anyway could not afford, such an aircraft. The project went nowhere for several years, but eventually funding was found to build a single Breguet 760 prototype. Powered by four inadequate pre war Gnome Rhone Mistral Major engines it finally flew in February 1949.
The 'deux ponts' = 'double decker' concept with cargo loaded via clam shell rear doors to a lower deck with passengers loading through front air stairs only to the upper deck above showed promise and so Breguet decided to build three pre production Breguet 761 aircraft with early series Pratt & Whitney R-2800 engines. The new target customer was Air France since the French Air Force was receiving many transport aircraft free from the U.S. under the Mutual Defence Aid Program. However Air France showed no interest at all in the Br761 Deux Ponts as offered in 1951.
The first Breguet 761 flew in July 1951 but nobody wanted any of them. In 1952 one was leased to the colonial airline Air Algerie and they flew it Algiers - Marseilles - Le Bourget for a while before rejecting it as too big and too expensive. Then in 1953 the British airline Silver City Airways were persuaded to lease one for their car and passenger ferry service Southend - Rotterdam, but they soon reached the same conclusion as Air Algerie. Breguet responded by offering a cheaper version with Bristol Hercules engines and reduced crew cockpit as used in the Silver City fleet of Bristol Freighters. This would have been the Breguet 766, but Silver City declined the offer. They were the only non French operator of this family of aircraft (Algeria was a French colony).
Breguet then tried to sell the idea that the Breguet 761 would be an ideal maritime patrol aircraft and offered to convert the three 761s to Breguet 764 status, but not surprisingly the French Air Force preferred free Lockheed Neptunes under MDAP. Breguet were stuck with all three. However by this time the French North African colonies were beginning to revolt and the French Air Force urgently needed extra airlift capacity. They reluctantly purchased all three Br761s as mixed cargo + troop transports before the end of 1953. They were based at Le Bourget (LFPB), which was a joint domestic airfield and military air transport base. The usual trip was to Blidda (DAAB) in Algeria, but trips to Berlin (Tegel Military = EDDT) in support of the French military occupation forces in Berlin were also common. At the time 26L was probably the only runway at EDDT with the terminals to the south. As the situation in Vietnam deteriorated these Br361s eventfully made a total of three round trips to Saigon down the Air France Constellation route to assist in the evacuation of French forces and equipment.
www.airwar.ru/enc/craft/br761.html
Although Air France had rejected the Breguet 761 they needed a bigger aircraft than was available elsewhere for their high demand domestic passenger route from Le Bourget to Marseilles which continued as a branch line service to Algiers or Tunis. They could not tolerate the 5 crew cockpit of the Br761 either and they did not want a cargo deck. Then for some reason Air France also decided they wanted an extensive redesign with a stronger wing, and more powerful engines.
With those design changes in place Air France eventually ordered twelve Breguet 763 Provence with 3 crew cockpit, big upper class upper deck, lower class lower deck, and powered by four R-2800-CA18 engines as used in the Convair 240. These entered service on the routes from Le Bourget to Provence (LFML) and onward to Algiers and Tunis from March 1953. Certificated to carry 135 passengers they were actually delivered with 59 upper class seats on the upper deck and 48 economy seats on the lower deck. The lower deck was much shorter.
pagesperso-orange.fr/amisbreguet/Images/2ponts2.jpeg
www.abpic.co.uk/popup.php?q=1088901
www.abpic.co.uk/popup.php?q=1025931
www.airteamimages.com/displaybig.php?phtID=68931
After the war France invested heavily in high speed, high quality rail services. There was almost no demand for domestic air cargo, other than air mail distribution, and it was increasingly difficult to attract economy class passengers away from the railways, hence a huge aircraft with more seats in first class than in economy. The French government dumped unprofitable Air France domestic services on Air Inter, but Air France were keen to retain the high demand and high yield Paris - Provence domestic route which also fed the North African colonies.
Like the three much smaller air force mixed troop / cargo Br761 Deux Ponts, the twelve all passenger Air France Br 763 Provence were based at Le Bourget because they were part of the domestic fleet. This made interchange with international services from Orly difficult. During the piston propliner era almost all Air France and Armee de l'Air flights to and from North Africa stopped at Marseilles (LFML) which is also a joint airport and military air base. To civilians LFML is Marseilles (Provence), hence the name of this Air France all passenger aircraft, but to the military the other side of LFML is Marseilles (Marignane). At the time only RWY 14R existed and the civilian terminals were probably to the west.
Whilst the Air Force flew from Le Bourget (LFPB) through LFML to Blidda (DAAB),
www.pictaero.com/en/pictures/picture,3115
Air France flew through LFML to Maison Blanche (DAAG). I believe the western runway, aligned with the Algiers NDB was the only one present at the time. The Air France route then continued to Mascara (DAOV) located in the Atlas mountains where I believe there were French mining interests.
In flight;
www.dassaultfalcon.com/content/imagecontent.jsp?DESCRIPTION=16
After take off;
pagesperso-orange.fr/rxl.pierre/images%202/breguet.jpg
Air France flights to Tunisia were probably to Carthage (DTTA). At the time the main runway was 29 aligned with the Tunis NDB, and the old terminal was probably to the southwest of the modern airfield. A visual circuit to land on 19C was available if the wind required. The modern terminal complex and modern longer RWY 19 only came later. The French Air Force may also have flown to Carthage.
During 1955 Air France leased thee Br763s to the Air Force for emergency trooping work. The Air Force then decided it liked the Br763, but it wanted more range so that it could use a new version to Saigon and to service the French Pacific nuclear test facility via French Tahiti. Thus the Br765 Sahara came into being. It had R-2800-CB17 engines able to generate extra power from 145 octane AVGAS, as used in the DC-6A and C-118A Liftmaster. Tip tanks extend range. It also had a much stronger freight floor to take the 15 ton AMX tank, howitzers etc. Max gross was increased, but max landing weight was unimproved. The Air Force ordered fifteen Saharas in 1956, but in 1957 with the French empire collapsing they decided they only wanted four.
wp.scn.ru/en/ww3/t/1887/21/0/3
The tip tanks caused a substantial reduction in Vno, but that was not a material problem. They added a little profile drag too, but the use of 145 octane AVGAS in CB17 engines more or less compensated for the increase in weight and drag.
By 1959 there were three Br 761 Deux Ponts and four Br765 Sahara serving with the French Air Force all based at LFPB and Air France also had 12 x Br763 Provence based at LFPB. France was way ahead of the U.S. and U.K. in the development of twin engined jetliners and so by 1959 commercial passenger demand to the North African colonies was such that international Caravelle flights direct from Paris Orly began. by the end of the fifties no one wanted to travel to French North Africa via Provence, in a Provence, if they could travel direct in a Caravelle, but domestic passengers to Marseilles still had no choice and many passengers ex North Africa wished to change to a domestic flight in Provence rather than travel to the international airport in Paris.
Consequently from 1960 conversion of the Br763 Provence to Br763 Universal configuration began. This was a conversion to what Breguet had always proposed, (and had delivered in the air force Br761), with freight on the lower deck and first class only passengers only upstairs.
www.abpic.co.uk/popup.php?q=1010425
The converted Air France Breguet 763 Universals continued to serve North Africa via LFML until 1964, but now a large part of their purpose was hauling air cargo across the Med on the lower deck; departing at much higher weights.
In 1964 Air France put eight of their twelve Universals up for sale. By then no airline wanted them at any price, but the Armee de l'Air were ordered to purchase six Universals taking their double decker total to thirteen leaving Air France with only six. At some point after 1964 I believe the air force Universals were re-engined with CB17 engines to deliver commonality of spares holdings, maintenance and operating procedures with the Sahara.
The six Universals retained by Air France were no longer part of the domestic passenger fleet. They became international night freighters and so they were now based at the international freight terminal at Orly. By 1964 most major cities in Europe had banned night jet operations and most large cargo that would not fit in the baggage holds of passenger liners was hauled by propliners at night. The number of locations at which the 19 Breguets had ever been visible was very small, but now expanded slightly.
Heathrow became a primary destination for the first time as did Berlin Tempelhof (EDDI), and thus Dusseldorf (EDDL); since international airline services direct to Berlin were forbidden. Berlin was always a focus for the double deckers but the Air Force flew LFPB - EDDL - EDDT (1953 - 1972), whilst Air France operated their Berlin cargo hauls mostly LFPO - EDDL - EDDI, (probably only 1964 - 1971).
I believe the Breguet 763 Universal was the last four engined piston propliner to fly scheduled (cargo) services into Heathrow (1971). LFPO - EGLL provides a nice short classic propliner night cargo haul.
www.abpic.co.uk/popup.php?q=1003757
Simulating operations into Berlin is potentially interesting too. There were only three air corridors with a maximum altitude of FL100. The rest of East Germany was an Air Defence Interception Zone (ADIZ). Both parties accessed Berlin via an intermediate landing in EDDL and entered East Germany via the corridor which (in FS9 terms) runs direct from the (Leine = DLE) Radio Range (VOR) near Hannover to the Tempelhof (TOF) Radio Range (VOR). That route no longer exists of course. The modern German airways system is different and more complex.
www.airliners.net/photo/Air-France/Breguet-763-Provence/1240868/L/
Once they had the six ex Air France Universals from 1964;
wp.scn.ru/en/ww3/t/1887/21/0/2
Note the lack of tip tanks in the Universal. The Air Force used four of the ex Air France Universals to establish a new long haul squadron in Tahiti (NTAA). These maintained the French military Pacific services, supporting French nuclear testing, until July 1974, two years after the Saharas and all other air force Breguets based at Le Bourget had been scrapped.
The Br761/763/765 squadron at LFPB now swelled to 9 aircraft with the Saharas serving Djibouti (HDAM) and sometimes flying between France and Tahiti along the old Air France trans global propliner route. The Br763s based in Tahiti probably flew all the way to Paris from time to time as well. At LFPB replacement by C-160 Transalls took place in 1972. Air France had already scrapped theirs in 1970-71. unlike many aircraft of the Classic era they had demonstrated an exceptional safety record in both airline and air force service.
www.airliners.net/photo/France---Air/Breguet-765-Sahara/1227505/L/
Sahara tip tank close up.
www.frenchwings.net/algeria/cpg148/displayimage.php?pid=140&fullsize=1
*The Breguet Deux Ponts in context*
Aircraft need to be understood in terms of their niche in the world of aviation as it was when they were in use. We understand little about them if we do not understand what made them good or bad aeroplanes by comparison to their contemporaries which were their competitors. Every aeroplane that served for a significant period had a particular niche to which it was well fitted.
The Br761 Deux Ponts (Air Algerie / Silver City 1952 - 1953 and French Air Force 1953 - 1972) had four R-2800-B31 engines which were essentially the same engines used in the Curtiss C-46 Commando. They needed only 100 Octane AVGAS. The Br761 was limited to 99,000lbs, but could also land at that weight so it was highly optimised for short hauling.
The Br763 Provence / Universal (Air France 1953 - 1971 and French Air Force 1964 - 1974) had four R-2800-CA18 engines as used in the Convair CV240. They required 130 Octane AVGAS. Their max gross was 114,600lbs, but max landing weight was only 108,000lbs.
The Br 765 Sahara (French Air Force 1957 - 1972) had four R-2800-CB17 engines as used in the Douglas DC-6A and C-118A Liftmaster. These required 145 Octane AVGAS. Max gross became 119,050lbs but the extra weight had to be fuel for long hauling to the Pacific, (or Djibouti in French Somalia), carried in the new large tip tanks, because the wing spar could still only absorb the shock of landing at 108,000lbs.
All the Deux Ponts were unpressurised. They were limited to FL120 when carrying passengers. The engines that Air France specified for the Provence (R-2800-CA18) were closely matched to that limitation. All except the four Br765 Saharas delivered slowly in the late fifties were highly optimised for short hauling with huge loads. They barely had time to climb to high levels. The three Mediterranean crossings LFML - DAAG, LFML - DAAB and LFML - DTTA were all about 420 miles.
After Time of Descent operation of a 145 octane CB17 engine does not vary from operation of a 130 Octane CA18 engine unless we need to go around, and since the Br763 and Br765 share the same main spar, and therefore max landing weight, operating targets after the cruise phase are identical. These aircraft have only two stages of flap and each induces a significant trim change and pitch change.
Do not retract flap until 130 KIAS and 200 feet AGL. The aircraft will sink and pitch up. Both tendencies must be restrained and climb must be prevented to achieve Vx = 140 KIAS for obstacle clearance and compliance with departure restrictions. Subsequent climb is at 500 VSI making better progress down range. Do not exceed FL120 with passengers. By all means don oxygen masks and explore the limited medium level performance envelope when hauling only cargo, but this is not an aeroplane for operation around high mountain ranges and it rarely exceeded FL120 in real life.
You must achieve 130 KIAS with FLAP 1, before attempting to intercept the final approach course and you must achieve full gear extension before glidepath intercept. At most weights, with little headwind, on most approaches, FLAP 2 is required soon after G/P intercept. Like the B377 Stratocruiser careful calculation and targeting of Vref versus approach weight is essential. See 2008 Propliner Tutorial. You have been warned.
The CB17 powered DC-6A became available at about the same time as the Br763 Provence reached Air France, but in 1953 the DC-6A was still limited to only 100,000lbs for take off and 88,000lbs for landing (with pax), but this was subsequently increased to 107,000 for take off. The wing of the Provence is 36% larger than the wing of the DC-6A so a DC-6A departing at 107,000lbs needs 9% more runway than a Provence departing at 114,600lbs. Both needed more runway to depart than to land.
The DC-6A (PAA called it the Douglas Super Six) was eventually authorised to carry up to 107 passengers on short hauls and thus equipped ready for service empty weight was 64,300lbs. The Provence was authorised to carry 135 passengers but actually had only 107 seats on two decks in Air France service when its APS weight was about 74,000lbs. The additional wide body cabin volume and larger wing of the Breguet imposed a huge empty weight penalty.
An airliner's useful load is its max gross weight minus its APS weight.
Br763 > 114600 - 74000 = 40,600 useful
DC-6A > 107000 - 64300 = 42,700 useful
Br765 > 119050 - 74000 = 45,050 useful
But that is not the whole story for two reasons.
Firstly the small wing on the DC-6A required long runways to depart at even 107,000lbs. From many runways the useful load of the Br763 was actually greater because the DC-6A was restricted to less than 107,000lbs whilst the Br753 Provence or Universal could still depart at 114,600lbs. The Br765 Sahara was a superior load hauler to the DC-6A from any runway, but only over a narrow range band, and it was not available until 1957.
Secondly light is good, but strong is better. The stronger aeroplane can land heavier and to short or medium haul we must land heavy. It is all very well being able to load a trans Atlantic DC-6A to 107,000lbs for take off, but it has a weak wing spar and by the time it lands (with passengers) it must be down to 88,000lbs. Everything between 88,000 and 107,000 must be route fuel, (not even reserve fuel which we may need to land with if not used). The DC-6A handling notes disclose;
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Econ Cruise: (1100hp x 4)
COWL FLAPS - CLOSED
MAP = 34 inches
RPM = 2100
Check CHT < 232C
Plan 2100 PPH
Note - Yields 256 KTAS at FL220 @ 91000lbs
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So a DC-6A burns 2100 PPH in the cruise and a 420 mile trip across the Med will use less than 4000lbs of route fuel. If we only need to fly passengers across the Mediterranean we cannot load a DC-6A to more than about 88000 + 4000 = 92,000lbs. More than 15,000lbs of the potential take off weight are unusable on medium hauls due to the weak wing spar inherited from the 1942 vintage C-54.
On a medium haul of about 420 miles DC-6A useful load is only 92,000 - 64300 = 27,200 useful, but the much stronger Br763 can land at 104,000lbs and if we load say 5000lbs of route fuel its useful load is 109000 - 74000 = 35,000 useful; offering a huge passenger payload advantage over the DC-6A on medium hauls.
We must always fuel and payload plan very carefully when simulating the operation of propliners or we will be far above maximum landing weight at destination. To simulate the weights at which Air France operated the passenger only Provence across the Mediterranean MSFS users should remove all the wing fuel before departure (using the payload and fuel menu). To the contrary to simulate the weight at which the Universal cargo hauler was flown, by both Air France and the Air Force, all of the wing fuel should be loaded. The different typical performance envelopes of the Provence and Universal will then be apparent during simulation. Comparison with the longer range Sahara should be made by flying the Sahara fully loaded on much longer hauls, at least as far as French Somalia.
Back to our Douglas v Breguet comparison.
107 pax plus bags weigh only 21,400lbs so both airliners can cross the Med with 107 passengers. This demonstrates that the only real advantage the double deckers had was when used as intended by Breguet with cargo on the lower deck or as a pure freighter. Over 420 miles the Universal can haul several tons more cargo than a DC-6A.
For France trans Mediterranean hauls of about 420 miles were the key strategic and commercial distance during the classic phase of aviation history. This was the niche the Deux Ponts was designed to fit and it fitted very well. Paris - Provence is only 350 miles. For medium hauling cargo the Breguet Universal is superior to the DC-6A / C-118A, even over ranges somewhat beyond 420 miles, which was the longest Air France exploited in practice.
Over long ranges the Universal could not match the useful load of the DC-6A / C-118A, but of course the C-118A lacked a rear loading ramp for vehicles and could not air drop and air supply parachute forces. Remember the French Air Force used all three varieties of Deux Ponts to deploy and supply paratroop and special forces operations, not just to transport troops from airfield to airfield. The ability to drop a stick of 150 paratroopers was demonstrated. Special forces could be injected at very long range which was essential for counter insurgency operations across French Africa.
Note false URL naming. This is a Br761 not a Br765.
www.airwar.ru/image/idop/craft/br765/br765-2.jpg
There was no rear ramp. The rear clam shells opened outward and upward. The rear doors went with them. The cargo floor was at the standard tailgate height of a standard 1950s French truck. The intention was to slide loads directly from truck to cargo bay, or vice versa, but in practice standard warehouse fork lift trucks were normally used. The front doors had integral air stairs allowing the Deux Ponts to roam to places with no matching portable steps, and it never had to wait for them to arrive.
img68.imageshack.us/img68/4453/bregmn5.jpg
Cargo could be manhandled aboard over a quickly constructed rear ramp in out of the way places in Africa.
www.historyofaircargo.com/i-Example-of-rear-loading-of-a-car-into-a-.html
The Provence offered passenger friendly disembarkation in the days before airport security became a major issue in Europe.
www.airteamimages.com/displaybig.php?phtID=72317
The original Air France promotional video is here;
video.aol.com/video-detail/history-of-air-france--breguet-2-ponts/1921774869
Grainy retirement video is here;
www.le65.com/info/tv/breguet.php3
Now you understand what they are for, and where to fly them, read the supplied handling notes, in my usual format, and enjoy your simulation of these niche classic propliners.
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FS9 INSTALLATION
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Substantial familiarity with FS9 file installation and panel fixing is assumed and in this case may be complicated. These are anyway propliners that require substantial flight simulation experience to operate.
The Breguet Sahara panel, MDL and textures as used by the French Air Force are here.
library.avsim.net/download.php?DLID=84593
The Breguet Provence / Universal as used by Air France is here;
library.avsim.net/download.php?DLID=93214
In real life Air Algerie used only the Br761, This link allows Air Algerie livery on the Br763.
library.avsim.net/download.php?DLID=77494
Files with earlier dates and elsewhere may lack bug fixes. You may not be able to retrieve the files using those links directly. Once you are into the Avsim file library use the file identification numbers.
Once you have everything above installed into two folders and both aircraft have an alias to the original Breguet panel;
1) Back up both original aircraft.cfg to aircraft.old
2) Install the files from the 'Calclassic summer special'.
3) If not already installed then install the latest KMCC DC-6 panel from www.calclassic.com. Then if not already present copy (not move) the entire Z-DC6KMTG *folder*, (containing that panel's gauges), to your gauges folder.
4) The original check lists and handling notes must NOT be used in flight with my FD.
From throttle up to touchdown my Breguet 763 and Breguet 765 FD are designed to be used only with the matching and aliased handling notes. Press F10 and select lowest icon during use of FS9. The CA18 powered Br763 and the CB17 powered Br765 each have different procedures to match their different engines and weights. The original check lists cannot be used with the KMCC panel.
If you fix the original panel,(instructions follow), the original check lists can be used for start up and shut down.
The original panel was designed with an excessively aft eyepoint with a very restricted 'letter box' view. This cannot be fixed. It is usable, but requires very precise IAS targeting and flap deployment on approach.
You must achieve 130 KIAS with FLAP 1, before attempting to intercept the final approach course and you must achieve full gear extension before glidepath intercept. At most weights, with little headwind, FLAP is required soon after G?P intercept. Like the B377 Stratocruiser careful calculation and targeting of Vref versus approach weight is essential. See 2008 Propliner Tutorial. You have been warned.
Some users of the Breguets may prefer to simply alias the latest KMCC DC-6 (4 x R-2800-CA/CB) panel. Both of my Breguet FD will drive it without error. If you intend to use the KMCC DC-6 panel jump to the last paragraph of this text now.
If you intend to use a fixed version of the original Breguet panel you must install the KMCC panel and gauges as above regardless and then proceed as follows.
5) Open the Breguet panel.cfg. Substitute a suitable propliner ASI calibrated in KIAS, (as in all the real aircraft).
delete - gauge59=BR763!asi_40-300, 33,290,70,65
substitute - gauge59=Douglas_DC3!asi, 33,295,70,70
All the other gauges have excessively squashed perspective and could ideally be corrected in perspective to become more circular by equalising their depth and width as above.
6) Open the Breguet panel.cfg. Delete the original cowl flap controls and install the cowl flap gauge from the KMCC panel into the main panel. The original gauges have no control over engine drag.
[Window05]
file=OVH_C.bmp
Comment out gauges 25 to 28
//gauge25=BR763_1!CowlFlapsM2_switch, 639,502,12,28
//gauge26=BR763_1!CowlFlapsM1_switch, 627,502,12,28
//gauge27=BR763_1!CowlFlapsM3_switch, 651,502,12,28
//gauge28=BR763_1!CowlFlapsM4_switch, 663,502,12,28
the following cowl position indicators can remain and will work correctly;
gauge29=BR763_1!Cowl-Flaps12, 588,431,60,60
gauge30=BR763_1!Cowl-Flaps34, 650,431,60,60
Add to the main panel [Window01];
gauge79=Z_DC6KMTG!COWL_FLAP_SWITCHS, 86,480,120,40
Without gauge79 you will have no control over engine drag.
7) Delete the poorly located original modern pop up AP and substitute one from the classic era that works correctly and is better positioned.
Open the Breguet panel.cfg. Delete the entire original [Window02] and replace with;
[Window02]
Background_color=0,0,0
size_mm=720
window_size_ratio=1.000
position=0
visible=0
ident=50
window_size= 1.000, 1.000
window_pos= 0.000, 0.000
gauge00=Z_DC6KMTG!AP_NEW,32,630,180,60
The KMTG AP will overlay the OAT gauge and cowl flap controls when the sub panel is open. Learn to use the centre pillar AP mode switches with the KMTG AP not visible. Visible is required only to set AP pitch and bank. The KMCC AP has three AP modes that were not present in the real Br763/765 AP, (Range/LOC/LOC GS), but you are not obliged to use them. The real AP is present on the original throttle console pop up, but this is huge and it is not practical to control the AP modes from there unless you have a second monitor.
It is very likely that most / all MS autopilots will fail to cope with flap and real trim changes in the Breguets allowing excessive pitch rates to develop. The FD are intended to be hand flown and hand trimmed during flap operation.
The real aircraft did not have APR mode let alone autoland and a crash is likely if you pretend that they did. You have been warned.
8) The original panel author projected the scenery with substantial perspective errors. In the panel.cfg SIZE_Y must be set to 6144 (6K pixels per 0.6 radians of vertical scrolling scenery) and a views section to control eyeline must be added.
At bottom of Breguet panel.cfg change [Default View] and add [views] content to read;
[Default View]
X=0
Y=0
SIZE_X=8191
SIZE_Y=6144
[views]
VIEW_FORWARD_DIR=13.5
If you do those things the original panel becomes usable, but it has other bugs, which may cause inappropriate electrical or hydraulic failures, and my FD will not drive all of the original system gauges. I do not intend to add any further driver code or commission replacement gauges. Remember the MAP gauge arcs are specific to the CA18 engines in the Provence and Universal. They do not apply to the CB17 engines in the Sahara. They will show you are overboosting CB17 engines running on 145 Octane when you are not.
Objective comparisons can now be made, one Breguet versus another, and versus other propliners with 'realistic' flight dynamics and handling notes. The most interesting comparison may be Breguet Sahara versus Douglas Liftmaster, but make any flight tests departing with either the fuel needed to fly the same range with the same payload, or by simply departing both at the same weight. Please remember that neither Tom, nor I, intend to offer any support for this package or any prior Br763/5 files. This file is the support.
FSAviator August 2008.
The Breguet Deux Ponts.
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A design study for the Breguet 760 seems to have been undertaken by Breguet for the Luftwaffe as a prospective replacement for the Messerschmitt Gigant during 1944. However after D day France had no need for, and anyway could not afford, such an aircraft. The project went nowhere for several years, but eventually funding was found to build a single Breguet 760 prototype. Powered by four inadequate pre war Gnome Rhone Mistral Major engines it finally flew in February 1949.
The 'deux ponts' = 'double decker' concept with cargo loaded via clam shell rear doors to a lower deck with passengers loading through front air stairs only to the upper deck above showed promise and so Breguet decided to build three pre production Breguet 761 aircraft with early series Pratt & Whitney R-2800 engines. The new target customer was Air France since the French Air Force was receiving many transport aircraft free from the U.S. under the Mutual Defence Aid Program. However Air France showed no interest at all in the Br761 Deux Ponts as offered in 1951.
The first Breguet 761 flew in July 1951 but nobody wanted any of them. In 1952 one was leased to the colonial airline Air Algerie and they flew it Algiers - Marseilles - Le Bourget for a while before rejecting it as too big and too expensive. Then in 1953 the British airline Silver City Airways were persuaded to lease one for their car and passenger ferry service Southend - Rotterdam, but they soon reached the same conclusion as Air Algerie. Breguet responded by offering a cheaper version with Bristol Hercules engines and reduced crew cockpit as used in the Silver City fleet of Bristol Freighters. This would have been the Breguet 766, but Silver City declined the offer. They were the only non French operator of this family of aircraft (Algeria was a French colony).
Breguet then tried to sell the idea that the Breguet 761 would be an ideal maritime patrol aircraft and offered to convert the three 761s to Breguet 764 status, but not surprisingly the French Air Force preferred free Lockheed Neptunes under MDAP. Breguet were stuck with all three. However by this time the French North African colonies were beginning to revolt and the French Air Force urgently needed extra airlift capacity. They reluctantly purchased all three Br761s as mixed cargo + troop transports before the end of 1953. They were based at Le Bourget (LFPB), which was a joint domestic airfield and military air transport base. The usual trip was to Blidda (DAAB) in Algeria, but trips to Berlin (Tegel Military = EDDT) in support of the French military occupation forces in Berlin were also common. At the time 26L was probably the only runway at EDDT with the terminals to the south. As the situation in Vietnam deteriorated these Br361s eventfully made a total of three round trips to Saigon down the Air France Constellation route to assist in the evacuation of French forces and equipment.
www.airwar.ru/enc/craft/br761.html
Although Air France had rejected the Breguet 761 they needed a bigger aircraft than was available elsewhere for their high demand domestic passenger route from Le Bourget to Marseilles which continued as a branch line service to Algiers or Tunis. They could not tolerate the 5 crew cockpit of the Br761 either and they did not want a cargo deck. Then for some reason Air France also decided they wanted an extensive redesign with a stronger wing, and more powerful engines.
With those design changes in place Air France eventually ordered twelve Breguet 763 Provence with 3 crew cockpit, big upper class upper deck, lower class lower deck, and powered by four R-2800-CA18 engines as used in the Convair 240. These entered service on the routes from Le Bourget to Provence (LFML) and onward to Algiers and Tunis from March 1953. Certificated to carry 135 passengers they were actually delivered with 59 upper class seats on the upper deck and 48 economy seats on the lower deck. The lower deck was much shorter.
pagesperso-orange.fr/amisbreguet/Images/2ponts2.jpeg
www.abpic.co.uk/popup.php?q=1088901
www.abpic.co.uk/popup.php?q=1025931
www.airteamimages.com/displaybig.php?phtID=68931
After the war France invested heavily in high speed, high quality rail services. There was almost no demand for domestic air cargo, other than air mail distribution, and it was increasingly difficult to attract economy class passengers away from the railways, hence a huge aircraft with more seats in first class than in economy. The French government dumped unprofitable Air France domestic services on Air Inter, but Air France were keen to retain the high demand and high yield Paris - Provence domestic route which also fed the North African colonies.
Like the three much smaller air force mixed troop / cargo Br761 Deux Ponts, the twelve all passenger Air France Br 763 Provence were based at Le Bourget because they were part of the domestic fleet. This made interchange with international services from Orly difficult. During the piston propliner era almost all Air France and Armee de l'Air flights to and from North Africa stopped at Marseilles (LFML) which is also a joint airport and military air base. To civilians LFML is Marseilles (Provence), hence the name of this Air France all passenger aircraft, but to the military the other side of LFML is Marseilles (Marignane). At the time only RWY 14R existed and the civilian terminals were probably to the west.
Whilst the Air Force flew from Le Bourget (LFPB) through LFML to Blidda (DAAB),
www.pictaero.com/en/pictures/picture,3115
Air France flew through LFML to Maison Blanche (DAAG). I believe the western runway, aligned with the Algiers NDB was the only one present at the time. The Air France route then continued to Mascara (DAOV) located in the Atlas mountains where I believe there were French mining interests.
In flight;
www.dassaultfalcon.com/content/imagecontent.jsp?DESCRIPTION=16
After take off;
pagesperso-orange.fr/rxl.pierre/images%202/breguet.jpg
Air France flights to Tunisia were probably to Carthage (DTTA). At the time the main runway was 29 aligned with the Tunis NDB, and the old terminal was probably to the southwest of the modern airfield. A visual circuit to land on 19C was available if the wind required. The modern terminal complex and modern longer RWY 19 only came later. The French Air Force may also have flown to Carthage.
During 1955 Air France leased thee Br763s to the Air Force for emergency trooping work. The Air Force then decided it liked the Br763, but it wanted more range so that it could use a new version to Saigon and to service the French Pacific nuclear test facility via French Tahiti. Thus the Br765 Sahara came into being. It had R-2800-CB17 engines able to generate extra power from 145 octane AVGAS, as used in the DC-6A and C-118A Liftmaster. Tip tanks extend range. It also had a much stronger freight floor to take the 15 ton AMX tank, howitzers etc. Max gross was increased, but max landing weight was unimproved. The Air Force ordered fifteen Saharas in 1956, but in 1957 with the French empire collapsing they decided they only wanted four.
wp.scn.ru/en/ww3/t/1887/21/0/3
The tip tanks caused a substantial reduction in Vno, but that was not a material problem. They added a little profile drag too, but the use of 145 octane AVGAS in CB17 engines more or less compensated for the increase in weight and drag.
By 1959 there were three Br 761 Deux Ponts and four Br765 Sahara serving with the French Air Force all based at LFPB and Air France also had 12 x Br763 Provence based at LFPB. France was way ahead of the U.S. and U.K. in the development of twin engined jetliners and so by 1959 commercial passenger demand to the North African colonies was such that international Caravelle flights direct from Paris Orly began. by the end of the fifties no one wanted to travel to French North Africa via Provence, in a Provence, if they could travel direct in a Caravelle, but domestic passengers to Marseilles still had no choice and many passengers ex North Africa wished to change to a domestic flight in Provence rather than travel to the international airport in Paris.
Consequently from 1960 conversion of the Br763 Provence to Br763 Universal configuration began. This was a conversion to what Breguet had always proposed, (and had delivered in the air force Br761), with freight on the lower deck and first class only passengers only upstairs.
www.abpic.co.uk/popup.php?q=1010425
The converted Air France Breguet 763 Universals continued to serve North Africa via LFML until 1964, but now a large part of their purpose was hauling air cargo across the Med on the lower deck; departing at much higher weights.
In 1964 Air France put eight of their twelve Universals up for sale. By then no airline wanted them at any price, but the Armee de l'Air were ordered to purchase six Universals taking their double decker total to thirteen leaving Air France with only six. At some point after 1964 I believe the air force Universals were re-engined with CB17 engines to deliver commonality of spares holdings, maintenance and operating procedures with the Sahara.
The six Universals retained by Air France were no longer part of the domestic passenger fleet. They became international night freighters and so they were now based at the international freight terminal at Orly. By 1964 most major cities in Europe had banned night jet operations and most large cargo that would not fit in the baggage holds of passenger liners was hauled by propliners at night. The number of locations at which the 19 Breguets had ever been visible was very small, but now expanded slightly.
Heathrow became a primary destination for the first time as did Berlin Tempelhof (EDDI), and thus Dusseldorf (EDDL); since international airline services direct to Berlin were forbidden. Berlin was always a focus for the double deckers but the Air Force flew LFPB - EDDL - EDDT (1953 - 1972), whilst Air France operated their Berlin cargo hauls mostly LFPO - EDDL - EDDI, (probably only 1964 - 1971).
I believe the Breguet 763 Universal was the last four engined piston propliner to fly scheduled (cargo) services into Heathrow (1971). LFPO - EGLL provides a nice short classic propliner night cargo haul.
www.abpic.co.uk/popup.php?q=1003757
Simulating operations into Berlin is potentially interesting too. There were only three air corridors with a maximum altitude of FL100. The rest of East Germany was an Air Defence Interception Zone (ADIZ). Both parties accessed Berlin via an intermediate landing in EDDL and entered East Germany via the corridor which (in FS9 terms) runs direct from the (Leine = DLE) Radio Range (VOR) near Hannover to the Tempelhof (TOF) Radio Range (VOR). That route no longer exists of course. The modern German airways system is different and more complex.
www.airliners.net/photo/Air-France/Breguet-763-Provence/1240868/L/
Once they had the six ex Air France Universals from 1964;
wp.scn.ru/en/ww3/t/1887/21/0/2
Note the lack of tip tanks in the Universal. The Air Force used four of the ex Air France Universals to establish a new long haul squadron in Tahiti (NTAA). These maintained the French military Pacific services, supporting French nuclear testing, until July 1974, two years after the Saharas and all other air force Breguets based at Le Bourget had been scrapped.
The Br761/763/765 squadron at LFPB now swelled to 9 aircraft with the Saharas serving Djibouti (HDAM) and sometimes flying between France and Tahiti along the old Air France trans global propliner route. The Br763s based in Tahiti probably flew all the way to Paris from time to time as well. At LFPB replacement by C-160 Transalls took place in 1972. Air France had already scrapped theirs in 1970-71. unlike many aircraft of the Classic era they had demonstrated an exceptional safety record in both airline and air force service.
www.airliners.net/photo/France---Air/Breguet-765-Sahara/1227505/L/
Sahara tip tank close up.
www.frenchwings.net/algeria/cpg148/displayimage.php?pid=140&fullsize=1
*The Breguet Deux Ponts in context*
Aircraft need to be understood in terms of their niche in the world of aviation as it was when they were in use. We understand little about them if we do not understand what made them good or bad aeroplanes by comparison to their contemporaries which were their competitors. Every aeroplane that served for a significant period had a particular niche to which it was well fitted.
The Br761 Deux Ponts (Air Algerie / Silver City 1952 - 1953 and French Air Force 1953 - 1972) had four R-2800-B31 engines which were essentially the same engines used in the Curtiss C-46 Commando. They needed only 100 Octane AVGAS. The Br761 was limited to 99,000lbs, but could also land at that weight so it was highly optimised for short hauling.
The Br763 Provence / Universal (Air France 1953 - 1971 and French Air Force 1964 - 1974) had four R-2800-CA18 engines as used in the Convair CV240. They required 130 Octane AVGAS. Their max gross was 114,600lbs, but max landing weight was only 108,000lbs.
The Br 765 Sahara (French Air Force 1957 - 1972) had four R-2800-CB17 engines as used in the Douglas DC-6A and C-118A Liftmaster. These required 145 Octane AVGAS. Max gross became 119,050lbs but the extra weight had to be fuel for long hauling to the Pacific, (or Djibouti in French Somalia), carried in the new large tip tanks, because the wing spar could still only absorb the shock of landing at 108,000lbs.
All the Deux Ponts were unpressurised. They were limited to FL120 when carrying passengers. The engines that Air France specified for the Provence (R-2800-CA18) were closely matched to that limitation. All except the four Br765 Saharas delivered slowly in the late fifties were highly optimised for short hauling with huge loads. They barely had time to climb to high levels. The three Mediterranean crossings LFML - DAAG, LFML - DAAB and LFML - DTTA were all about 420 miles.
After Time of Descent operation of a 145 octane CB17 engine does not vary from operation of a 130 Octane CA18 engine unless we need to go around, and since the Br763 and Br765 share the same main spar, and therefore max landing weight, operating targets after the cruise phase are identical. These aircraft have only two stages of flap and each induces a significant trim change and pitch change.
Do not retract flap until 130 KIAS and 200 feet AGL. The aircraft will sink and pitch up. Both tendencies must be restrained and climb must be prevented to achieve Vx = 140 KIAS for obstacle clearance and compliance with departure restrictions. Subsequent climb is at 500 VSI making better progress down range. Do not exceed FL120 with passengers. By all means don oxygen masks and explore the limited medium level performance envelope when hauling only cargo, but this is not an aeroplane for operation around high mountain ranges and it rarely exceeded FL120 in real life.
You must achieve 130 KIAS with FLAP 1, before attempting to intercept the final approach course and you must achieve full gear extension before glidepath intercept. At most weights, with little headwind, on most approaches, FLAP 2 is required soon after G/P intercept. Like the B377 Stratocruiser careful calculation and targeting of Vref versus approach weight is essential. See 2008 Propliner Tutorial. You have been warned.
The CB17 powered DC-6A became available at about the same time as the Br763 Provence reached Air France, but in 1953 the DC-6A was still limited to only 100,000lbs for take off and 88,000lbs for landing (with pax), but this was subsequently increased to 107,000 for take off. The wing of the Provence is 36% larger than the wing of the DC-6A so a DC-6A departing at 107,000lbs needs 9% more runway than a Provence departing at 114,600lbs. Both needed more runway to depart than to land.
The DC-6A (PAA called it the Douglas Super Six) was eventually authorised to carry up to 107 passengers on short hauls and thus equipped ready for service empty weight was 64,300lbs. The Provence was authorised to carry 135 passengers but actually had only 107 seats on two decks in Air France service when its APS weight was about 74,000lbs. The additional wide body cabin volume and larger wing of the Breguet imposed a huge empty weight penalty.
An airliner's useful load is its max gross weight minus its APS weight.
Br763 > 114600 - 74000 = 40,600 useful
DC-6A > 107000 - 64300 = 42,700 useful
Br765 > 119050 - 74000 = 45,050 useful
But that is not the whole story for two reasons.
Firstly the small wing on the DC-6A required long runways to depart at even 107,000lbs. From many runways the useful load of the Br763 was actually greater because the DC-6A was restricted to less than 107,000lbs whilst the Br753 Provence or Universal could still depart at 114,600lbs. The Br765 Sahara was a superior load hauler to the DC-6A from any runway, but only over a narrow range band, and it was not available until 1957.
Secondly light is good, but strong is better. The stronger aeroplane can land heavier and to short or medium haul we must land heavy. It is all very well being able to load a trans Atlantic DC-6A to 107,000lbs for take off, but it has a weak wing spar and by the time it lands (with passengers) it must be down to 88,000lbs. Everything between 88,000 and 107,000 must be route fuel, (not even reserve fuel which we may need to land with if not used). The DC-6A handling notes disclose;
****************************
Econ Cruise: (1100hp x 4)
COWL FLAPS - CLOSED
MAP = 34 inches
RPM = 2100
Check CHT < 232C
Plan 2100 PPH
Note - Yields 256 KTAS at FL220 @ 91000lbs
****************************
So a DC-6A burns 2100 PPH in the cruise and a 420 mile trip across the Med will use less than 4000lbs of route fuel. If we only need to fly passengers across the Mediterranean we cannot load a DC-6A to more than about 88000 + 4000 = 92,000lbs. More than 15,000lbs of the potential take off weight are unusable on medium hauls due to the weak wing spar inherited from the 1942 vintage C-54.
On a medium haul of about 420 miles DC-6A useful load is only 92,000 - 64300 = 27,200 useful, but the much stronger Br763 can land at 104,000lbs and if we load say 5000lbs of route fuel its useful load is 109000 - 74000 = 35,000 useful; offering a huge passenger payload advantage over the DC-6A on medium hauls.
We must always fuel and payload plan very carefully when simulating the operation of propliners or we will be far above maximum landing weight at destination. To simulate the weights at which Air France operated the passenger only Provence across the Mediterranean MSFS users should remove all the wing fuel before departure (using the payload and fuel menu). To the contrary to simulate the weight at which the Universal cargo hauler was flown, by both Air France and the Air Force, all of the wing fuel should be loaded. The different typical performance envelopes of the Provence and Universal will then be apparent during simulation. Comparison with the longer range Sahara should be made by flying the Sahara fully loaded on much longer hauls, at least as far as French Somalia.
Back to our Douglas v Breguet comparison.
107 pax plus bags weigh only 21,400lbs so both airliners can cross the Med with 107 passengers. This demonstrates that the only real advantage the double deckers had was when used as intended by Breguet with cargo on the lower deck or as a pure freighter. Over 420 miles the Universal can haul several tons more cargo than a DC-6A.
For France trans Mediterranean hauls of about 420 miles were the key strategic and commercial distance during the classic phase of aviation history. This was the niche the Deux Ponts was designed to fit and it fitted very well. Paris - Provence is only 350 miles. For medium hauling cargo the Breguet Universal is superior to the DC-6A / C-118A, even over ranges somewhat beyond 420 miles, which was the longest Air France exploited in practice.
Over long ranges the Universal could not match the useful load of the DC-6A / C-118A, but of course the C-118A lacked a rear loading ramp for vehicles and could not air drop and air supply parachute forces. Remember the French Air Force used all three varieties of Deux Ponts to deploy and supply paratroop and special forces operations, not just to transport troops from airfield to airfield. The ability to drop a stick of 150 paratroopers was demonstrated. Special forces could be injected at very long range which was essential for counter insurgency operations across French Africa.
Note false URL naming. This is a Br761 not a Br765.
www.airwar.ru/image/idop/craft/br765/br765-2.jpg
There was no rear ramp. The rear clam shells opened outward and upward. The rear doors went with them. The cargo floor was at the standard tailgate height of a standard 1950s French truck. The intention was to slide loads directly from truck to cargo bay, or vice versa, but in practice standard warehouse fork lift trucks were normally used. The front doors had integral air stairs allowing the Deux Ponts to roam to places with no matching portable steps, and it never had to wait for them to arrive.
img68.imageshack.us/img68/4453/bregmn5.jpg
Cargo could be manhandled aboard over a quickly constructed rear ramp in out of the way places in Africa.
www.historyofaircargo.com/i-Example-of-rear-loading-of-a-car-into-a-.html
The Provence offered passenger friendly disembarkation in the days before airport security became a major issue in Europe.
www.airteamimages.com/displaybig.php?phtID=72317
The original Air France promotional video is here;
video.aol.com/video-detail/history-of-air-france--breguet-2-ponts/1921774869
Grainy retirement video is here;
www.le65.com/info/tv/breguet.php3
Now you understand what they are for, and where to fly them, read the supplied handling notes, in my usual format, and enjoy your simulation of these niche classic propliners.
****************
FS9 INSTALLATION
****************
Substantial familiarity with FS9 file installation and panel fixing is assumed and in this case may be complicated. These are anyway propliners that require substantial flight simulation experience to operate.
The Breguet Sahara panel, MDL and textures as used by the French Air Force are here.
library.avsim.net/download.php?DLID=84593
The Breguet Provence / Universal as used by Air France is here;
library.avsim.net/download.php?DLID=93214
In real life Air Algerie used only the Br761, This link allows Air Algerie livery on the Br763.
library.avsim.net/download.php?DLID=77494
Files with earlier dates and elsewhere may lack bug fixes. You may not be able to retrieve the files using those links directly. Once you are into the Avsim file library use the file identification numbers.
Once you have everything above installed into two folders and both aircraft have an alias to the original Breguet panel;
1) Back up both original aircraft.cfg to aircraft.old
2) Install the files from the 'Calclassic summer special'.
3) If not already installed then install the latest KMCC DC-6 panel from www.calclassic.com. Then if not already present copy (not move) the entire Z-DC6KMTG *folder*, (containing that panel's gauges), to your gauges folder.
4) The original check lists and handling notes must NOT be used in flight with my FD.
From throttle up to touchdown my Breguet 763 and Breguet 765 FD are designed to be used only with the matching and aliased handling notes. Press F10 and select lowest icon during use of FS9. The CA18 powered Br763 and the CB17 powered Br765 each have different procedures to match their different engines and weights. The original check lists cannot be used with the KMCC panel.
If you fix the original panel,(instructions follow), the original check lists can be used for start up and shut down.
The original panel was designed with an excessively aft eyepoint with a very restricted 'letter box' view. This cannot be fixed. It is usable, but requires very precise IAS targeting and flap deployment on approach.
You must achieve 130 KIAS with FLAP 1, before attempting to intercept the final approach course and you must achieve full gear extension before glidepath intercept. At most weights, with little headwind, FLAP is required soon after G?P intercept. Like the B377 Stratocruiser careful calculation and targeting of Vref versus approach weight is essential. See 2008 Propliner Tutorial. You have been warned.
Some users of the Breguets may prefer to simply alias the latest KMCC DC-6 (4 x R-2800-CA/CB) panel. Both of my Breguet FD will drive it without error. If you intend to use the KMCC DC-6 panel jump to the last paragraph of this text now.
If you intend to use a fixed version of the original Breguet panel you must install the KMCC panel and gauges as above regardless and then proceed as follows.
5) Open the Breguet panel.cfg. Substitute a suitable propliner ASI calibrated in KIAS, (as in all the real aircraft).
delete - gauge59=BR763!asi_40-300, 33,290,70,65
substitute - gauge59=Douglas_DC3!asi, 33,295,70,70
All the other gauges have excessively squashed perspective and could ideally be corrected in perspective to become more circular by equalising their depth and width as above.
6) Open the Breguet panel.cfg. Delete the original cowl flap controls and install the cowl flap gauge from the KMCC panel into the main panel. The original gauges have no control over engine drag.
[Window05]
file=OVH_C.bmp
Comment out gauges 25 to 28
//gauge25=BR763_1!CowlFlapsM2_switch, 639,502,12,28
//gauge26=BR763_1!CowlFlapsM1_switch, 627,502,12,28
//gauge27=BR763_1!CowlFlapsM3_switch, 651,502,12,28
//gauge28=BR763_1!CowlFlapsM4_switch, 663,502,12,28
the following cowl position indicators can remain and will work correctly;
gauge29=BR763_1!Cowl-Flaps12, 588,431,60,60
gauge30=BR763_1!Cowl-Flaps34, 650,431,60,60
Add to the main panel [Window01];
gauge79=Z_DC6KMTG!COWL_FLAP_SWITCHS, 86,480,120,40
Without gauge79 you will have no control over engine drag.
7) Delete the poorly located original modern pop up AP and substitute one from the classic era that works correctly and is better positioned.
Open the Breguet panel.cfg. Delete the entire original [Window02] and replace with;
[Window02]
Background_color=0,0,0
size_mm=720
window_size_ratio=1.000
position=0
visible=0
ident=50
window_size= 1.000, 1.000
window_pos= 0.000, 0.000
gauge00=Z_DC6KMTG!AP_NEW,32,630,180,60
The KMTG AP will overlay the OAT gauge and cowl flap controls when the sub panel is open. Learn to use the centre pillar AP mode switches with the KMTG AP not visible. Visible is required only to set AP pitch and bank. The KMCC AP has three AP modes that were not present in the real Br763/765 AP, (Range/LOC/LOC GS), but you are not obliged to use them. The real AP is present on the original throttle console pop up, but this is huge and it is not practical to control the AP modes from there unless you have a second monitor.
It is very likely that most / all MS autopilots will fail to cope with flap and real trim changes in the Breguets allowing excessive pitch rates to develop. The FD are intended to be hand flown and hand trimmed during flap operation.
The real aircraft did not have APR mode let alone autoland and a crash is likely if you pretend that they did. You have been warned.
8) The original panel author projected the scenery with substantial perspective errors. In the panel.cfg SIZE_Y must be set to 6144 (6K pixels per 0.6 radians of vertical scrolling scenery) and a views section to control eyeline must be added.
At bottom of Breguet panel.cfg change [Default View] and add [views] content to read;
[Default View]
X=0
Y=0
SIZE_X=8191
SIZE_Y=6144
[views]
VIEW_FORWARD_DIR=13.5
If you do those things the original panel becomes usable, but it has other bugs, which may cause inappropriate electrical or hydraulic failures, and my FD will not drive all of the original system gauges. I do not intend to add any further driver code or commission replacement gauges. Remember the MAP gauge arcs are specific to the CA18 engines in the Provence and Universal. They do not apply to the CB17 engines in the Sahara. They will show you are overboosting CB17 engines running on 145 Octane when you are not.
Objective comparisons can now be made, one Breguet versus another, and versus other propliners with 'realistic' flight dynamics and handling notes. The most interesting comparison may be Breguet Sahara versus Douglas Liftmaster, but make any flight tests departing with either the fuel needed to fly the same range with the same payload, or by simply departing both at the same weight. Please remember that neither Tom, nor I, intend to offer any support for this package or any prior Br763/5 files. This file is the support.
FSAviator August 2008.