Jodel D.150 Mascaret

THE JODEL MASCARET is the latest of the Attractive light aircraft manufactured by the Societeé Aeronautique Normande (S.A.N.) of Bernay near Lisieux in northern France, and which are handled in England by Messrs. Rollason Aircraft and Engines of Croydon and Redhill.

The Mascaret is intended by the makers as a successor to the earlier two-seat D.117 (Air Test No. 8, November 1959) but in fact it could much better be described as a sports-model variation of the Jodel Ambassadeur (Air Test No. 21, January 1965). In outward appearance the Mascaret could easily be mistaken for the Ambassadeur, and its fabric and plywood construction, with tip-tilted single-spar cantilever wing, are identical in everything but size. There are, however, some considerable differences. To start with, the Mascaret is a two-seater and the space which in the Ambassadeur is occupied by the rear Seat is taken up in the Mascaret by a large fuel tank, of 107 litres (23 1/2 Imp. gal.) capacity. With two smaller fuel tanks of 40 litres (8 3/4 Imp. gal.) capacity in each wing root forward of the spar, this gives a total of 187 litres (41 Imp. gal.) providing an endurance of no less than 8 hours and over 1,000 statute miles still-air range.

With this potential, one expects good navigation facilities and instrumentation. Putting the smaller fuel tanks in the wing roots has made additional space available between the front bulkhead and the instrument panel, which is 37 in. wide and has plenty of room for a full range of instruments and pilot-operated radio to customer’s requirements. The Mascaret used for the air-test (G-ASPG) was fully equipped for instrument flight, and had a very neat French Radiostal VHF Transceiver. Additional extras include radio, compass and VOR. Instrument lighting and navigation lights were already fitted.

Smaller wing

The second major difference compared with the Ambassadeur is a wing span of 26 ft. 11 in. Instead of 28 ft. 8 1/2 in., giving a reduction in wing area; but the Mascaret is fitted with trailing edge flaps which the Ambassadeur lacks. These flaps are operated by a lever placed between the two seats, and are much more effective than their small chord might suggest. They can be set in three positions. fully up; at 20 deg., which is normal for take-off; and at 50 deg., which is normal for final approach and landing.

The third major point of difference is the tail unit, which in addition to having a raked fin and rudder, uses an all-moving tailplane fitted with a combined anti-servo and trim tab along the full span of its trailing edge.

In most other respects the Mascaret resembles the Ambassadeur, including the engine installation, which in this particular example is the 100-h.p. Rolls-Royce Continental 0-200-A fitted with self-starter, electric generator, and screened ignition as standard.

Accommodation

Comfortable seating is provided for two people side by side. There are separate seats with lap straps, and at seat level the cabin is 42 in. wide. Neither seats nor rudder pedals are adjustable, so that dwarfs and giants are not catered for, though most normal-sized folk will find that they can fit comfortably into the fairly upright position and reach all controls without difficulty. When normally seated, the pilot’s eye is 25 in. from the nearest instrument, and the ground is visible ahead over the sloping nose of the aircraft; when in taxiing attitude, about 13 yards ahead. Behind the seats, a shelf over the rear tank extends back for 32 in. and provides adequate baggage space within the limits of total all-up weight and C.G. position.

The empty weight of G-ASPG was given as 904 lb. which included oil, radio, instruments, but not fuel. Adding the weight of two people, at a modest but conventional 170 lb. each, and the weight of fuel in the two full wing tanks (128 lb.), brings the weight up to 5,372 lb. Maximum permitted all-up weight of the Mascaret is 1,588 lb., so this leaves 216 lb. for the combined weight of fuel in the rear tank and any baggage to be carried on the rear shelf. If the rear tank is full, this would be a weight of fuel of 170 lb., leaving 46 lb. for bags. Some attention is also needed to C.G. calculation at full loads since, although both seats are close to the C.G. of the aircraft, both the rear fuel tank and the baggage compartment are behind it; thus flying with only one seat occupied will not necessarily permit carriage of fuel and baggage up to the full maximum all-up weight. Heavy pilots should also choose their companions with some eye for size. This pilot weighs 204 lb., which is a good deal more than the 170 lb. used in the weight sheet summary. But having said this, it must also be made plain that the accommodation of the Mascaret is adequate and comfortable, and capable of providing plenty of room for all normal touring requirements, combined with a range of action far superior to the majority of light aircraft.

Controls

Full dual controls are provided as standard, and since throttle, other engine controls, wheel brake handle, and flap lever are accessible from either seat, the Mascaret can be flown from either side. The only controls not easily reached from the starboard side are the tail trim, which is on the port side of the cockpit, and the main fuel cock, which is on the floor below the knees of the occupant of the port seat. Most of the engine controls are on the lower part of the panel below the instruments, and are push-pull levers in which the normal running position is pushed in. One which is open to criticism is the carburetter hot air control, which is adjacent to the identical mixture control, and distinguished from it only by the colour of the knob, dark blue, as opposed to red for mixture. It would be quite possible to grab the mixture control lever in error for the carburetter hot air. The makers recommend the use of hot air for taxiing, gliding, stalling, during the approach and landing, and in humid or icing conditions; in other words whenever anything less than normal cruising power is required, as well as in potential icing conditions.

Whether such thorough-going precautions are really necessary is open to doubt. Use of hot air when taxiing could lead to taking off in hot air - there is a noticeable reduction of power in this condition - so as part of this test, the Mascaret was taken off with the intake in hot air - and flaps full down; but although the performance was distinctly sluggish, it can be done without undue difficulty, so that the loss of power, for example in an overshoot, is not hazardous.

The other control which was irritating was the brake lever. This is a “pull-out-for-on“ with a ratchet which locks the brakes on when the handle is turned upwards. The locked-on position is such that in doing it, one’s knuckles are likely to push the throttle open, Care is needed to avoid this. In all other respects the cockpit layout is good, and the controls easy and simple to use.

A criticism from the point of view of comfort was that the cabin ventilation proved somewhat inadequate; when the fresh-air vent was closed the cabin was notably quiet; when opened it also let in engine noise but not enough cool air. Visibility from both seats is excellent, due to good quality transparencies and big windows. It was rioted that moderate rain blew off the windshield without smearing, and did not unduly affect forward visibility. Nevertheless, one would have liked to find a clear-vision panel somewhere in the canopy.

Handling

The Mascaret requires no external aids for starting up, and can be treated like an ordinary motorcar. The wheel brakes are adequate to hold the aircraft during a full power check. The steerable tailwheel, linked to the rudder pedals, gives very precise control when taxiing, and if a sharp turn is required, it is possible, using the brakes, to swivel with one wheel stationary (though this is not good for the tyres), Pre-take-off checks include setting flaps to the mid-position (20 deg.), auxiliary fuel pump ON; and putting carburetter air to COLD. The takeoff is straightforward, with no tricks and no tendency to swing. Without the use of flap, the takeoff run is lengthened somewhat, but presents no difficulty, except that premature attempts to pull the aircraft into the air result in running the tailwheel along the ground, thus making the ground run longer than necessary. A takeoff with full flap permitted the Mascaret to be pulled off the ground with the stall warning horn sounding; although not a recommended procedure, this method resulted in a very short ground run, and might be useful on special occasions. As mentioned above, a takeoff was also done with full flap and with engine power reduced by use of hot air to the carburetter. The takeoff run was a little longer than that without the use of flap, but with full power.

Once off the ground, the Mascaret climbs away well. For best gradient of climb, a speed of 70 m.p.h. I.A.S. (61 kts.) is recommended, with flaps kept at 20 deg.; for best rate of climb, a speed of 84 m.p.h. I.A.S. (73 kts.) without flap. During the climb V.S.I. readings of over 6oo ft./min. were normal.

In level flight one notices the marked change in attitude of the Mascaret at different speeds. At circuit speeds, that is in the region of 70 m.p.h. I.A.S., the nose is not very much below the horizon. As speed is increased, the angle of attack becomes very much less and the nose of the aircraft a lot farther below the horizon. The effect is much more marked than in other similar aircraft, and results in an initial tendency to gain height instead of flying level. It is here of course that the advantages of the all-moving tailplane become apparent; for whereas a fixed tailpiane can only be at the optimum angle of attack at one particular attitude of the mainplane, and something less efficient at all others, the all-moving tail can fly at the optimum attitude at all times. It was noted that in level flight at 1,000 ft., 2,300 engine r.p.m. gave an indicated speed of 120 m.p.h. (104 kts.), and 2,500 r.p.m. produced 130 m.p.h. indicated (113 kts.). The maximum continuous r.p.m. permitted is 2,750, which in this model gives a speed of a little better than 140 mph. (122 kts.) at 1,000 ft. in smooth air.

Controls are nicely harmonised, but slightly heavier than might be expected for an aircraft of this weight. The dihedralled wingtips confer a positive lateral stability, and the aircraft is also directionally stable. It was found a little difficult to trim the aircraft fore and aft to fly hands off, until it was discovered that the easy way to do this is to remove ones hands and feet first, and to fly the aircraft on the trimmer. The aircraft can then be trimmed to fly hands off at any particular speed and throttle setting desired within the normal speed range. Although rough air disturbed the aircraft when flown hands and feet off, it was found that it could be flown for long periods either bands off, or feet off, and that there was no difficulty, for example, in writing notes, and doing other things that required both hands off the controls.

Stalling

The aircraft was stalled level and power off with and without flap. There is no perceptible aerodynamic warning of an impending stall, but the stall warning horn sounds loud and clear at about 5 to 6 m.p.h. beforehand. Clean, the stall occurred at 52 m.p.h. indicated (45 kts.). With full flap it took place at 46 m.p.h. indicated (40 kts.). In both cases it was fairly sudden, rather like going over a step on a bicycle, and in The latter case the left wing dropped. A little power before the stall delayed it, but when it occurred, there was greater tendency for a wing to drop, no doubt because the outer part of the wing stalled sooner in relation to the inner part, which had the slipstream over it. In every case recovery was normal and rapid, and loss of height was not more than 300 ft. During this part of the test, the aircraft was flying at approximately 238 lb. below its maximum all-up weight, and the rear tank was three-quarters full. There was no baggage on the rear shelf.

The checks to remember on returning to the circuit are the limiting speed for flaps, which is 93 m.p.h. indicated (81 kts.); to switch on the fuel booster pump; to put the carburetter intake into hot air; and to ensure that the fuel tank selected has sufficient fuel in it. There is not much work for the pilot to do, because changes of power or flap setting have very little effect upon trim change; in fact, to be quite certain just what effect the flaps do have, it is really necessary to fly hands off and to watch. It was found that 1,750 to 1,800 r.p.m. gave adequate power to maintain level speed at 80 m.p.h. on the downwind leg, which reduced to ... at the same throttle setting, when the flaps were half lowered. Full flap produces a marked increase in drag, and in consequence a comfortably steep descent at 70 m.p.h. I.A.S., which is the recommended speed for final approach and which gives adequate latitude to round out comfortably and to cope with gusty conditions near the surface. Using more power, this approach speed can be lowered a good deal, provided conditions are right, and in this event the landing run, which in any case is short, can become very short indeed. With a wind speed on the surface of 8/10 kts., and gusty conditions on the approach, it was found that the recommended speeds resulted in landing runs of the order of 150 yards and sometimes less, according to the degree of braking used. Landing without flaps about trebled this figure; but with use of flaps and engine, it ought to be possible to land the Mascaret in any small field provided the approaches are reasonable.

The landing itself is straightforward, and presents no problems. Brakes may be used firmly when desired.

Summary

The standard Mascaret with Rolls-Royce engine, without radio, but otherwise as described in this air test, is supplied by Rollasons with French C. of A. validated in the U.K., duty paid, registered in the U.K., and ready to fly away from Redhill at £3,174. Complete with lull instrumentation, radio and night-flying equipment, the price becomes £4,062. Alternatively, the aircraft may be fitted with a Potez 4 E-20 engine of 105 h.p., in which case the lower figure becomes £3,326. One of the latter (registered G-ASKL) is already flying in the U.K., in addition to the two Rolls-Royce-engined aircraft G-ASPG and G-ASRT. Operating costs of course depend largely on the way the owner uses his aircraft, and the amount of work he is prepared to do on it himself. The best example is to quote the Tiger Club who charge their members £4 15s. per hour for the use of G-ASPG.

At £4 15s. per hour, the Mascaret is really exceptional value for money. Apart from the possibility of really long-distance touring, it is a very simple and attractive aeroplane to fly just for the pleasure of flying it; its popularity with Tiger Club members is its best testimonial in this respectùand what other vehicle at this price can give its owner a top speed of over 240 m.p.h., 20 miles to the gallon, and transport him in luxurious freedom from traffic jams, channel ferries, and other people ’s time-tables anywhere a thousand miles away in one hop?

Air Pictorial wishes to thank Mr. Michael Jones at Redhill, and Messrs. Rollasons of Croydon for the loan of the Mascaret to make this interesting and enjoyable air test.