Bulletproof

Of the 262 produced, it is estimated that only 40 examples remain in flying condition today, including serial number 153, registered D-EGEC, the subject of our flight test.

Externally, this aircraft has enormous presence and exudes tough, solid, almost agricultural ruggedness. Still in its military clothes and markings, this aeroplane gets the adrenalin going, before you even get in.

I will be accompanied on the flight by the owner of the Piaggio, Ivan Seach-Allan.

This aircraft is Ivan’s second Piaggio – the first fell victim to a seized engine a mere 40 hours following a rebuild. Ivan is a current helicopter instructor who recently fell through a skylight and badly damaged his back. I ask him if he will be alright doing aerobatics – “of course I will”, he says dismissively, and we make a start on the walk around check.

The all metal P. 149 airframe has a large number of camlock-fastened inspection hatches, through which useful snapshots of the innards can be viewed – for example control pushrod bellcranks, a ground power point and the oil dipstick which is on the top left side of the nose cowling.

There is one fuel filling point on the top surface of each wing, inside which there are actually two fuel tanks per side. There is just one fuel drain serving the whole system, and that is located under the centre of the fuselage. This makes drawing a fuel sample a real challenge to achieve while retaining one’s dignity, as it is necessary to lie on the ground under the belly and between the wings before reaching up to take the sample. Pilots normally emerge from this operation red-faced, mud- and grassstained and spattered with avgas.

The elevator and rudder have horn balances and the split flaps and ailerons each share half the trailing edges of the tapered wings.

Time to go

With no step provided, climbing aboard involves stretching a leg up onto the trailing edge of the wing root, reaching a hand up to a grab handle set high on the side of the fuselage, then heaving the rest of yourself up. From here, the view down into the surprisingly spacious cabin is reminiscent of a 1950s open top Cadillac, the unusually wide rear bench seat behind the pilots’ positions being the most noticeable feature.

The quality of leather used in the upholstery further boosts the likeness to quality automobiles of that era.

The rear seat back pivots forward to reveal a cavernous baggage compartment which is so vast that it could have been described as a cargo hold had there been an external door to it. Weight limit in here is 70kg.

The safest bet now is to step on to the seat, then down onto the floor. Performing the splits by missing the seat out is not recommended.

Once seated, the surroundings are unmistakably military, the light grey panel making the 149’s cockpit brighter (and in my opinion easier to read) than its contemporaries.

In fact, if it wasn’t for the three bladed propeller stuck on the front, there would be a powerful suggestion of being in a Jet Provost. Both front seats are sufficiently adjustable fore and aft to accommodate pilots of varying lengths, and we both get strapped into our four-point harnesses.

The main panel is dominated by an extremely large military G4B compass, complete with dot/cross annunciator, which suggests that it is slaved to a remote flux valve and will not need resetting in the way a direction indicator would. The other flight instruments have been placed in a seemingly random order, which is not ideal, but I’m sure we’ll manage.

Looking round the cockpit, the most noticeable features include the throttles, one mounted on the left cockpit wall, the other on the centre quadrant. These controls resemble tiny upturned lampshades, each sporting a pushbutton recessed deep into its corresponding ‘shade’. This arrangement is similar to the relight buttons found on the tops of HP cocks on elderly military jets.

They are in fact press-to-transmit (PTT) buttons. There is also a propeller pitch control for each pilot, but the single elevator trim wheel on the centre quadrant must be shared.

The magnetos are switched on by use of a fork-like prong which hangs from a small chain when not in use. To operate, insert the prong into the bottom of the slide and move it upwards through OFF and M1 to M2 for starting then up to M1+2 when the engine catches.

The fuel on/off valve is selected via a red push/pull plunger on the instrument panel next to the primer. The separate fuel tank selector is on the floor between the two front seats. The undercarriage selection is activated by a guarded switch in the centre of the instrument panel, directly underneath which are two dolls eye indicators – one for each main gear. Oddly, the nosewheel position is shown independently in a rectangular window which is flush with the cockpit floor.

The manually operated flap lever has five positions between 0 and 43 degrees and is on the floor between the seats. Behind the flap lever Ivan points out the emergency undercarriage lowering handle, casually mentioning that I will need to turn the handle 240 times to lower the gear if the normal system fails. Thinking that we could probably take it in shifts of 60 times each if the worst came to the worst I nod and say “mmm…right”.

There are two rows of switches above the windscreen which include the battery master, beacon, lights, pitot heat and radio master switch.

Starting the pressure-carburetted 270 horse (200kW) Lycoming GO-480 runs as follows: fuel pump on, prime three times, number 2 mag on the prong, mixture lean, press starter button. As the engine starts, advance mixture to rich and select mags to M1+2. Set 1200rpm on the two-handed rpm gauge (which looks confusingly like a third altimeter). With the engine warm enough, we taxi across the grass, the direct nosewheel steering and toe brakes (both sides) making light work of manoeuvring this 1800kg aeroplane.

The view is excellent all round through the sliding perspex canopy and the deep windscreen and we are soon at the holding point.

Engine run-ups and pre-takeoff checks completed, we give the photo ship Chipmunk a good head start before setting off ourselves.

Maximum engine rpm is 3400 although the geared three bladed Piaggio propeller will be turning at just over half that speed.

The pre-takeoff checklist calls for the rudder trim to be set five degrees to the right, but Ivan says it is unnecessary so we leave it neutral, increase the rpm to 2500 against the brakes, then let the aircraft go as full power is added.

Acceleration is predictably unstartling as the grass runway has a noticeable upslope, but we achieve 50kt in reasonable time and a positive tug on the stick raises the nosewheel.

A fair amount of right rudder has been needed to keep straight so maybe the five degrees trim would have been a help after all to those new to the type.

The rest of the aircraft leaves the ground at 60kt just over half way along our 650 metre runway, and I dab the brakes and attempt to select gear-up. The spring-loaded yellow and black guard has to be thumbed to one side while moving the large undercarriage switch upwards with a convenient finger of the same hand, which takes a bit of a knack to perform quickly. I’m sure this action becomes less fiddlesome with practice, and once selected up, the electrically driven undercarriage retracts with a ferocity I last encountered in a Jet Provost, taking just four seconds of clunkety-clunking from dirty to clean.

Flaps up, we accelerate to 100kt in the climb to catch the photo ship Chipmunk and set the power to 3000rpm and . 9 bar manifold. Drawing closer, the Chipmunk starts to fill the windscreen rapidly, reminding us of the 30-40kt overtake speed. Throttling back to idle avoids an embarrassing overtake but triggers the ‘gear up’ warning horn and we are soon on station – ‘loose’ echelon port for the transit.

The incompatibility in performance is now quite apparent.

In level flight the Chippie’s normal cruise speed is 90kt, the Pippi’s 130-160kt, so we are forced to maintain a higher nose attitude than our English chum, which dangles us precariously around the bottom of the drag curve, so any fore and aft corrections to our positioning requires large adjustments of power.

Also at this low speed the controls are being used in ‘stirring a pudding’ mode, such is their lack of effectiveness.

I am aware that the high work load would be drastically relieved if the aircraft was being operated in its comfort zone.

Even so, I am impressed by the way we are not once threatened with an inadvertent stall, wing drop or any other antisocial behaviour despite a fair amount of provocation.

Later on, Ivan will be showing me how viceless the Piaggio really is.

Setting us up for the head-on shot, I am pleasantly surprised by the ease with which the aircraft can be sideslipped, wings level and tracking straight. The long fuselage aft of the C of G and the well proportioned fin and rudder help with this, and soon we are leaving the Chippie by means of the breakaway shot, and heading off to explore this interesting aeroplane more fully.

First job is to unshackle the long suffering Pippi from being a drag artist into its preferred aerodynamic arena. We accelate to 130kt and set 2750rpm and 0. 72 bar of manifold pressure, which Ivan tells me is the normal cruise configuration. Apparently the mixture is adjusted automatically so we are spared the normal three-lever juggling normally experienced with constant speed propellers.

At this speed, flying the aircraft feels a lot better, but still, none of the controls could be described as ‘light’, the elevator being medium to heavy, the ailerons scoring medium and likewise the rudder. In this context the rudder feels right and as previously mentioned is nicely effective. Even though the other two controls could ideally have been lighter, I found that by the end of the sortie they felt up to the task and it was rather like getting used to a stiff clutch on a hire car.

There is sufficient adverse yaw to warrant proportional rudder input when rolling into and out of turns, and the 149D is positively stable in pitch and yaw and just positive in roll.

Its lack of twitchiness means that touring in this aircraft should be a doddle, but how will it like being thrown around the sky in aerobatic trainer mode? HASELL checks complete, we have a look at the stall characteristics and speeds.

Power off, clean from level flight, the Piaggio gives some airframe buffet at 63kt and gently drops its nose, wings level, at 58kt.

With gear and flaps we record 55kt for the buffet and 53kt for the break (more like a nod – also wings level) Taking 2. 5 times the stall speed gives 145kt, the theoretical entry speed for a loop, barrel roll and stall turn, so to begin with I try an aileron roll from the normal cruise speed of 130kt. Raising the nose 10 degrees, applying full (left) aileron and checking forward through the inverted produces a tidy enough roll, the nose finishing 15 degrees down. The roll rate feels a little slow, so I time it – eight seconds or 45 degrees per second. Similar to an Aerobat but slower than most aerobatic machines.

PIAGGIO/FOCKE WULF
P.149D
Technical specifications
Powerplant
One 270hp (200kW) six cylinder
Lycoming GO-480-B1A6 driving
three bladed constant speed Piaggio
propeller
Performance
Max cruise 156kt
75% cruise 130kt
Max manoeuvre 124kt
Vne 172kt normal category,
212kt within aerobatic weight
Stall clean 61kt
Stall landing config 51kt
Initial climb 1300ft/min
Range 560nm, no reserve
Endurance 75% cruise 4hr 20min,
no reserve
Ceiling 19,850ft
Takeoff roll 350m
Landing roll 300m
Weights
Empty 1180kg
Gross 1820kg
Aerobatic weight 1450kg
Useful load 640kg
Utility load 270kg
Fuel capacity 240 litres
G limits +6g/-3g
Dimensions
Wing span 11.13m
Length 8.78m
Height 2.90m
Wing area 18.8m2

We try a loop, this time setting 3000rpm and full throttle (. 9 bar). A firm, steady pull on the heavy elevator from 140kt delivers us to the top of the manoeuvre wings level showing 60kt on the ASI, with minimal footwork needed for balance. Round the second half, the line feature appears straight underneath us and we go straight back up into a barrel roll, which the Piaggio flies well. Before getting airborne, I noticed the absence of a g meter which struck me as odd for an aerobatic machine, but in practice, the control forces prevent you from overstressing the airframe in all but a determined effort. From a training point of view, it is useful to learn to judge the correct amount of pull by feel, but personally I would still like an accurate indication of g, not only as a reference but also as a safety net.

Having established from Ivan that flicks are approved, I decide to try an avalanche.

Entering another loop, 30 degrees before the top at 80kt I apply full left rudder and bring the stick hard back, adding a little left aileron for good measure. The Piaggio sets off round a wallowy flick roll, which tightens up nicely as soon as the control column is relaxed and recovers to a wings level inverted attitude using opposite rudder and stick central as the knife edge is passed. The rest of the loop follows normally. I feel pleasantly surprised by the way the Piaggio performed there – it is definitely growing on me.

Stall turns are straightforward, that effective rudder cartwheeling us neatly round through one-eighty then stopping the overswing to keep the figure in shape.

It is at this point that Ivan wants to show me something “interesting”, so he takes control and I take a breather. After flyingsome clearing turns, he pulls up into an off-the-vertical stall turn, except he does not kick the aircraft over at the top – instead we appear to hover in a steep nose up attitude (surely stalled) until the Piaggio eventually flops nose down. Ivan repeats this exercise in such a way as to achieve the hovering part of the performance inverted, with a backward flop to return us into laminar flight.

And the point of this demonstration of a tumbling Pippi? “You see, it’s viceless,” came Ivan’s verdict. “It’s a pussycat”.

It is true that despite the abuse – compounded by being out of balance at ludicrously low airspeeds and high power settings – there was no hint of a departure from any of the axes.

So in that respect the Piaggio is very pilot friendly – my only remaining concern being the possibility that such a clean aircraft could build up speed at an alarming rate following a botched manoeuvre such as a roll or half reverse Cuban where the aircraft can easily end up in a steep dive. This potential problem is offset to some extent by the provision of the constant speed propeller, which generates a massive amount of drag when the engine is throttled back.

Emboldened by the foregoing, I set up for a quarter vertical roll and three-quarter loop to finish. This goes well, but you do need to hit the vertical quickly and roll without delay as the speed bleeds off rapidly.

On the way down, the speed increase was easily controlled with power reduction.

We finish off with a Cuban eight, noting that the aircraft holds the 45 degree line inverted without any spluttering from the engine room.

On the way back we try an accelerated stall in a turn, and true to form the Piaggio breaks wings level. This is one safe aeroplane – all we have to do is remember to put the gear down.

Rejoining the circuit, we aim for 100kt downwind, 90kt on base leg and 80 on final. As the wind is not excessive, I am keen to try all four stages of flap and as each successive stage is selected, the nose gets progressively lower, and the flap lever becomes stiffer to operate. So much so that I almost don’t bother with the last stage.

Pigheadedness wins the day, however, and with a lusty heave on the lever we have our money’s worth. As I have now dangled a massive airbrake into the slipstream, a substantial amount of power has had to be added to stay in touch with the glidepath, and Ivan’s comment of “I usually only take two stages” now makes perfect sense.

At approach speeds, the Piaggio is as responsive to the controls as an airliner, and with full flap, any sink encountered demands an instant and aggressive application of power to prevent a premature (and hard) touchdown.

For all that, the view of the runway is excellent, and I plan to make this a touchand- go to give myself a chance to try an approach with the recommended two stages of flap.

The landing is predictably firmer than I would have liked (aren’t most of them?), but the Piaggio leaps back into the air quickly after a short roll and soon we are on the approach again, but this time with only the two stages of flap.

Sure enough, the aircraft is far more manageable in this configuration, requiring much smaller power adjustments to stay in the groove. On landing, there is a greater tendency to float without all that extra drag, and quite a large aft stick movement needed in the prolonged flare, but I am rewarded with a more pleasing touchdown despite the end of the runway being larger in the windscreen than before.

On shutdown, Ivan invites me to engage the floor mounted control lock. He thinks this is a brilliant piece of kit, and on raising it off the floor against a spring and engaging a lug into the front of the control column, I have to agree with him – simple, effective and allows the Piaggio to still be bulletproof even when left outside in the wind and rain. And the point of this demonstration of a tumbling Pippi? “You see, it’s viceless,” came Ivan’s verdict. “It’s a pussycat”.