429 - another failure?
It is quite surprising that the 429 was selected, and given its immaturity, rather risky; as a training machine it may have some value, in the same way as the good old 47 was useful as a training machine, but as a mission machine it is competing against much more capable machines.
Our organisation carried out an in-depth and comprehensive evaluation of the 429 over a lengthy period, and came to the conclusion that the 429 is still very much a ‘work in progress’, more influenced by accountants than impassioned engineers, and this was very disappointing, considering Bell’s hype.
Performance wise it is surprisingly slow with very heavy fuel consumption; at around 7000lbs down to about 6400lbs, it is achieving only 125kts at max continuous AEO power on FLI, at an average fuel burn of 600lbs/hour over a period of 90 minutes. This was at altitudes between 2500’ and 4000’ and ambient temperatures 25C to 20C.
The noise in the passenger cabin is reminiscent of the S61! A deafening gearbox howl and annoying airstream white noise. Above about 90kts the right hand door/window begins banging from the advancing blade pressure wave, and at 125 kts it’s pretty much like sitting next to a pneumatic road drill. Right hand cabin window percussion amplitudes being measured in centimeters! Quite frightening for pilots, never mind passengers.
On a positive note, the cabin and baggage area is roomy for a light twin, but is undoubtedly why the 429 is so slow and thirsty. The build quality is quite poor when compared with other types and the cabin seats are not easy to remove and refit.
Generally, apart from the cacophony going on in the passenger cabin above 90kts, the rotor vibration levels are quite good in the hover, through translation and at cruise speeds. It also handles quite well AP in and AP out, indeed AP out it is more stable than its older sister.
The EFIS system is rather dated, and not at all intuitive, the coupled functions are basic, and there are no warnings if, for example, the aircraft deviates from a selected altitude. Of concern is the use of Rogerson Kratos displays, which have established a fairly solid reputation for unreliability, and have been rejected by other helicopter OEM’s. None of the latest situational awareness avionics are available on the 429, only basic equipment, and again this is disappointing.
On the ground, 4 sets of wheels are necessary to ground handle the 429, and fitting these and manoeuvring the heli is both time consuming, potentially dangerous to feet, and challenging. The requirement to put webbing straps around the front and rear of the skids to prevent them splaying out is something you might expect of a home built, and rather ignominious for a manufacturer that once had a proud reputation as a helicopter builder. Carrying around scaffolding is bad enough but when it is not strong enough for ground handling, why not just fit wheels?
The tail rotor pitch linkage is almost Victorian in its mechanical design, and the length of the pitch links looks vulnerable and lacking in durability.
Note too that the main rotor flies in 2 distinct planes similar to the 412 and people will be familiar with the idiosyncrasies of tracking and balancing the 412.
Bell support is no longer like it was in the old days, now it is slow, indecisive and disinterested. Which is unfortunate, because the unreliability of their machines demands better support. Failures of the DAU and Rogerson Kratos displays are particularly common and Bell’s severe lack of distributed spares holding is particularly troublesome.
It is understandable that buyers are steering clear of the Bell 429 in favour of far superior machines from their competition.
Bell, at the small helicopter end of its portfolio, now appears to be directed not by engineers, technocrats or experienced aviators with design authority, in touch with the needs of the market place, but by accountants, whether internally or from Textron, and you will not find the passion for flying, design excellence, advancement, or engineering know-how that exists within their more capable competition.