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Annex C: NOTES ON THE ROBIN REGENT DR 400/180

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Annex C: NOTES ON THE ROBIN REGENT DR 400/180


Annex C: NOTES ON THE ROBIN REGENT DR 400/180


These notes are for the information of Lasham Tug Pilots and give Lasham operating procedures with the aircraft type. They do not supersede the information in the Aircrew Manual for the type, a copy of which is held in the office and should be consulted from time to time as appropriate.


4.12 ROBIN REGENTs DR400 180R G-BJUD and G-BSFF. These aircraft were built by Avions Pierre Robin in France who make a number of types of light aircraft, principally those descended from the earlier Jodel series. The flying controls of the Regent are more responsive than those of the Rallye or Super Cub, and the view from the cockpit is superb. Since the airframe is lighter than the Rallye, the Regent has a higher rate of climb with the same powered engine, but due to its higher stalling speed the minimum towing speed is 60 knots. The Regent is therefore not suitable for towing the slower gliders, particularly since the climb is steeper than our other tugs, and after takeoff the transition into the steeper climb could easily be more than an inexperienced glider pilot in a slow glider could handle.

Stalling. Our two Regents drop the port wing at the stall, and if you let it go further they would undoubtedly spin. They are therefore more critical than our other tugs during the approach and require more precise handling. Too slow is obviously dangerous (if you are in trouble you need lots of power quickly), too fast and it floats a long way as it is a clean aircraft with only a small flap area (compare the Rallye with its big flaps). Don't approach too slowly; Regents have dropped a wing on many experienced pilots and they do not try it any more. This is not a Rallye, do not fly it like one. If in doubt about stalling characteristics when you are flying a tug, stall it gently at a safe height, such as during a return from a tow. But bear in mind that later near the ground you have wind gradient, turbulence, and other control movements to contend with, all of which need a good increment over the stall to ensure safety. And if you fly it on another day, the stalling speeds may not be the same because ASIs are sometimes changed, ASI tubing can develop kinks, bugs or grit, and both speeds and characteristics will be different if the wing surface has mud on it, is wet, or a repair on the leading edge has been made.

Wheel Brakes & Nosewheel Steering. The wheel brakes are operated differentially by rudder travel combined with partial brake selected on the ratchet mechanism on the brake handle, or together by centring the rudder and operating the brake handle. Directional control on the ground is also through a steerable nosewheel connected via the rudder circuit when weight is on the nosewheel. As the Regent lands faster than the Rallye or Cub, it is important not to expect too much deceleration from the brakes especially on wet grass or in no headwind conditions. Some Regents have occasionally failed to automatically reconnect the nose wheel steering on landing if the nose wheel is lowered very gently onto the ground, but a more positive nosewheel contact overcomes this problem.

Fuel System. The aircraft has one fuselage tank holding 24 gallons of which 2.2 gallons may be unusable. This is less fuel than a full Cub or Rallye, so monitor it carefully; there is also a `low fuel' light, but like all single wired systems in aircraft, do not depend on it.

Weights. The Max AUW is 2205 lbs and dry weight is about 1340 lbs, giving a total disposable load of 865 lbs. Full fuel (24 gal) weighs 173 lbs (total 1513 lbs) giving you a possible cockpit load of 692 lbs. The rear parcel shelf is limited to 60 lb of baggage. Typical towing weight is 1600-1700 lb (eg with a 187 lb pilot, 40% and full fuel respectively).

Engines - Red Arc Restrictions. On JUD the engine is an A2A with the hollow crank, but because we normally have a Hoffman 4 blade prop on this aircraft, the red rpm band restriction does not apply. However, if we ever re-fit the metal prop, then the red band becomes applicable. The engine on FF has a solid crank.

Noise. Both aircraft are fitted with special silencers, and with the 4 bladed prop this makes them our quietest tugs; the high rate of climb also minimises the noise `footprint' on the ground.

Spinning & Aerobatics. The aircraft is not cleared for spinning or aerobatics.

Retrieves. It should not be used for field retrieves due to its high landing speed and lack of drag flap. The Super Cub is always the preferred aircraft for field retrieves.

THE DI, COVERING ONLY POINTS PARTICULAR TO THE REGENT

Include the other normal DI checks as you go around the aircraft.

  1. Get up onto the wing carefully to open the canopy and enter the cockpit. The black walkway can be slippery when wet or if you have damp shoes. Note that the wing is fabric covered close to the walkway. The aircraft should be parked with the flaps down as it reduces the risk of feet damaging the flaps.

  2. Before opening the canopy, ensure no one has opened the oil filler hatch. If the canopy hits this it cracks the very expensive canopy. Get into the cockpit carefully. Regent seat backs are prone to collapse. They should not be used to help getting in and out. Hold the rear canopy frame, and try not to put any load on the seat back.

  3. Once in the cockpit, check the following:-

      CONTROLS for full and free movement.

      TRIM for movement, look back at both sides, check the indicator follows.

      FLAPS: Check they latch into the 15° and 60° positions, then leave them down to lessen the chance of treading on them as you get on and off the wing.

      CIRCUIT BREAKERS: Check that all CBs that have red trip buttons are tripped out.

      MASTER SWITCH ON: Check fuel contents, on a cold day run the electric pump and prime the engine with the throttle, leave the Master on, pump off. Key out, mixture lean, throttle back, brakes on, ready to check the engine compressions.

      LEAVE THE COCKPIT, again taking care not to strain the seat back, walk round and check the audible stall warning by operating the switch on the right wing. Reach back into the cockpit and turn the Master off to avoid draining the battery.

  4. Close the canopy clear of the cowling. Never push on the Perspex, only on the frame. Note that the front edge of the windscreen screen is painted Perspex and not metal. When the canopy gets stiff the runners need lubricating with PTFE spray.

  5. Open the engine bay access cover on the starboard side and check the oil. Close the access cover if you have to leave the aircraft for any length of time in case anyone pushes the canopy forward while you are not with the aircraft. Pushing forward the canopy while the access cover is open will twist or damage the cover.

  6. Do not remove the cowlings as part of the DI. Put your hand inside the cowling to check the clearance above the starter ring, it should be close to half an inch.

  7. The exhaust stubs move about an inch when cold.

  8. The Fuel Filter drain is under the front fuselage, and there are two tank drains near the TE of the wing.

  9. Continue the DI around the aircraft in the usual way. Note that aileron movement is less than most aircraft, about 5 inches at the root trailing edge.

  10. The flaps should have some free play in them. Check the hinges are not loose.

  11. There should be no play at all in the all flying tailplane pivot.

  12. The metal plates on either side of the hook are linked by the rope ring and should bring on the Rope On light on the top of the instrument panel. Do not worry if it flashes on and off in flight.

  13. The Spats have to be removed to pump up the tyres. It is safe to fly without the spats and occasionally we do so, such as if they have been removed for work on them.

  14. When you move the aircraft using the tow bar you will find full lock on the nosewheel puts the respective brake on, it is therefore often easier to pull down on the fin to lift the nosewheel off the ground and then turn the aircraft. You need to know how to do this at the fuel pump so cover it in the checkout.

  15. When putting passengers into the back, slide the seat adjusters back and the seats will tip forward. Anytime the seats are moved check the adjusters are pushed fully forwards or the seat may move in flight.

TAXYING. Do not try to turn in too tight a circle, the nosewheel steering allows very tight turns and you can twist a tyre or lock a wheel. This can damage an undercarriage leg and could get you grounded in more ways than one!

START UP CHECKS

NOSEWHEEL TOW BAR REMOVED RADIO OFF PARKING BRAKE.............. ON FUEL....................... ON CIRCUIT BREAKERS........ TRIPPED MIXTURE.................... RICH (in) CARB HEAT.................. COLD (in) MASTER SWITCH ......... ON (in)

WARNING LIGHTS

LOW OIL PRESS - ON LOW FUEL PRESS- ON LOW FUEL CONT OUT FLAP LIGHT OUT ALTERNATOR ON FUEL PUMP ON PRIME WITH THROTTLE MAGS...................... LEFT MAG ON *START* OIL PRESSURE Rising MAGS ..................... BOTH ON ALTERNATOR................ ON and CHARGING RADIO ON
RUN UP 1800 RPM - MAX MAG DROP 125 RPM - Typical drop with CARB HEAT is 100 rpm - Avoid prolonged ground running to prevent hot spots damaging cylinders. PRE TAKE OFF CHECKS - REGENT Mnemonic: T MM FF I HH C
TRIM.......................   SET TO 5 FOR TOWING
MIXTURE....................   RICH
                              CARB HEAT COLD
MAGS                          BOTH ON
FUEL.......................   ON, CONTENTS
                              FUEL PUMP ON, PRESSURE LIGHT OUT
FLAPS......................   FIRST STAGE
INSTRUMENTS................   NORMAL
HATCHES......                 LOCKED
HARNESS                       TIGHT & LOCKED
                              SEATS LOCKED, push adjuster fully forward.
CONTROLS...................   FULL & FREE

WARNING LIGHTS:  For Takeoff, all off except flap light

LOW OIL   LOW FUEL  LOW FUEL  FLAPS SET ALTERNATOR
PRESSURE  PRESSURE  CONTENTS     15 °   CHARGING
   OUT       OUT       OUT       ON       OUT

 
CLIMB SPEEDS,  REGENT, NO FLAP

MINIMUM TOWING SPEED          60 KNOTS

K13's                         60 KNOTS
ASTIRS and similar            65 KNOTS
Most Glass                    70 KNOTS
With water ballast            add 5 KNOTS


DESCENT - REGENT

ROUGH AIR SPEED (Vra)         140 Kts

MAX MANOEUVRING SPEED (Vm) 116 Kts. Above Vm the aircraft is only cleared for use of one third of the available control surface deflection. This may not be enough for emergency collision avoidance action.

ENGINE FAILURE `Fly the aircraft' as a first priority so that you do not, for instance, stall, or lose reference on a landing field. Only then, diagnose the fault and attempt remedial action.

LOWER THE NOSE
GET RID OF GLIDER
BEST GLIDE SPEED
FOR RANGE IN NIL WIND: 78 Kts (about 1:10 prop stopped, 1:9 prop rotating)
SELECT FIELD, TURN IF NECESSARY
R/T - MAYDAY TO LASHAM WITH POSITION & LIKELY LANDING AREA
Check:
FUEL CONTENTS & TANK SWITCH
FUEL BOOSTER PUMP - ON if not already on
MIXTURE - CHECK FULLY RICH
MAGS - TRY SWITCHING TO A SINGLE MAG
THROTTLE - EXERCISE TO TRY AND GET A RESPONSE

When committed to engine-off landing;

MAGS -         OFF
FUEL -         OFF
STRAPS -       TIGHT



       APPROACH - REGENT

FLAP LIMITING SPEED .....     90 Kts
INITIAL APPROACH;
No Wind                       60 Kts
Normal Winds                  65 Kts
Strong Winds                  70 Kts


MINIMUM THRESHOLD - FULL FLAP

Vref, speed for round-out     55 Kts



SHUT DOWN

RADIO                         OFF
LIGHTS                        OFF (if in use)
Mags                          Dead Cut check at Idle
FUEL PUMP                     OFF (if in use).
MIXTURE                       FULLY LEAN.

Engine Stopped

MAGS                          OFF, Remove Key
ALTERNATOR                    OFF
CIRCUIT BREAKERS              ALL TRIPPED
MASTER SWITCH                 OFF
FLAPS                         DOWN
BRAKES                        A/R

PERFORMANCE DATA - ROBIN REGENT

Tables are given in the Flight Manual for Takeoff, Climb, Cruise and Landing. Because of the different prop on Lasham aircraft, our performance will be somewhat different, as well as the longer takeoff and slower climb due to towing gliders of differing weights and drag. It is intended to take measurements at Lasham with a video camera of takeoffs (with and without gliders) and landings, and produce some revised figures specifically for our aircraft later. Meanwhile some figures derived from the Flight Manual are:

TAKEOFF: Conditions, smooth hard surface, 2200 lb AUW, 20°C, no wind, no slope, pressure height 600 ft. Since a normal towing AUW will be about 1650 lbs, the figures for a weight of 2200 lb roughly equate to those towing a 550 lb glider

     Unstick dist @ 1.1Vs                                =   731 ft
     Dist Unstick to 15m/ 50ft @ 1.3Vs                   =   692 ft
     Dist to 15 m / 50 ft @ 1.3Vs                        =  1423 ft

          GRASS TAKEOFF

    Short grass, add 10% to unstick, ie: Unstick         =   804 ft
                    Dist Unstick to 15m/ 50ft            =   692 ft
                    Dist to 15 m / 50 ft @ 1.3Vs         =  1496 ft

    Medium high grass, add 25 % to unstick, ie:  Unstick =   914 ft
                    Dist Unstick to 15m/ 50ft            =   692 ft
                    Dist to 15 m / 50 ft @ 1.3Vs         =  1606 ft

CRUISE: Depending on conditions, fuel consumption is between 6 and 8 imp gal per hour, endurance on full fuel between 3-4 hours and range 370 - 430 NMl. For more exact figures, consult the flight manual. Towing a draggy glider will degrade these figures considerably although modern glass gliders have very little drag, but towing a heavy glider will cause substantially more fuel to be used in any climb. LANDING Conditions: 1650 lb AUW, 20°C, no wind, no slope, pressure height 600 ft, moderate braking, runway or short grass

	  Distance from 15m / 50 ft                            =  1271 ft
	       50 ft to touchdown  =  705 ft Landing Roll      =   567 ft

HEADWIND:  Multiply Takeoff and Landing distances by:

     10 kt headwind 0.79
     15   "         0.72
     20   "         0.64 

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Last updated by John Leibacher on Friday, September 8, 1995 at 21:21


Dr. Günther Eichhorn
Springer 233 Spring Street New York, NY 10013 USA, email me