Tiger Moth joy flights - chocks for starting?
The latest issue of the Melbourne based magazine "Pacific Flyer" has an article by well known aviation author Macarthur Job. It is called "Whirling Scimitars -and Just as Deadly" It is about the dangers posed by propellers.
Some years ago, a newly graduated grade 3 instructor at a well known aero club at Moorabbin was tasked to give a Trial Instructional Flight in a Cessna 152. The battery was flat, so the instructor keen not to lose a potential student, decided to hand start the 152. The engine of the 152 is not designed to be started by hand but pilots still do it and without formal training. On the job training so to speak. And why did the aero club allow this sort of practice when they would have known the battery was dodgy? Careless maintenance.
There were no chocks placed in front of the wheels (although there was no shortage of chocks on the tarmac). The instructor had been taught from his ab-initio days never to trust the park brake and he didn't this time, either. So he didn't even try to place the park brake to on. If it was inoperative it wasn't in the maintenance release.
Instead he told the bewildered TIF student to place his toes high on the rudder pedals and hold them down hard. He turned the magneto switch on and proceeded to swing the prop. It started alright except pity about the throttle being set to high idle. The 152 started to move quickly forward under the influence of 1500 RPM on a smooth tarmac and the frightened student took his feet off the pedals in alarm. The instructor was unable to prevent the aircraft from running into a closed hangar door. Aircraft and door sustained damage. But at least it was a memorable occasion for the TIF student.
Fast forward to an airfield in Victoria where two Tiger Moths were conducting joy flights last weekend. . A passenger paid up and was kitted out with a headset and then trussed up in the front seat. The pilot in command then prepared to start the Tiger Moth by hand as Tiger Moths are not equipped with electric starter motors. Tiger Moths don't have wheel brakes either. Some have a tail skid which acts as a rudimentary brake but useless on a hard surface. This Tiger Moth had a tailwheel which isn't much good as a brake of course on any surface.
The pilot then proceeded to swing the propeller several times clockwise and anti-clockwise to draw fuel into the four cylinders. It's called "sucking in and blowing out" in Tiger Moth terminology. Then the pilot reached over the bottom wing and turned on the magneto switches situated on the outside of the fuselage next to the open cockpits. Back to the propeller again which he carefully placed vertical and gave it the big heave-ho.
Now, according to the Tiger Moth handling notes, when starting the engine the pilot is supposed to keep the control column fully back to prevent the Tiger Moth from nosing over if inadvertant high RPM occurs. I wonder if the joy flight passenger in the front seat had been briefed to do this? But today, the pilot outside the aeroplane had set the throttle perfectly and the little engine purred to life at 700 RPM. Not enough to make the Tiger Moth move slowly forward on the grass if chocks were not in place under the wheels. Remember - no brakes.
Chocks? What chocks? If they were in front of the Tiger Moth wheels they must have been hidden in the grass? Maybe.. The pilot then walked around the aircraft with its engine ticking over and donning a leather flying helmet, swung his legs into the tiny back cockpit. All the time during the prop swinging procedure the joy flight passenger was alone in the front cockpit. One hopes she enjoyed the subsequent flight and didn't need a Barf Bag.
It got me thinking about complacency. From where this Ppruner sat in his car there was no sign of any chocks in front of the wheels of the Tiger Moth. The pilot did a propeller hand start with a passenger tied in the front cockpit probably clueless on what to do if the engine had burst into life with more RPM than the pilot expected. It has happened before and people have been hurt. The machine had no brakes and no tail skid - thus no friction drag.
It could be argued on the grounds of flight safety that as part of his team the operator of the joy flights should have provided a trained person experienced in hand swinging a Tiger Moth propeller. If there was, on this occasion he must have been off duty. It would also seem good airmanship for the pilot to have been seated in his cockpit with the fuel cock on/off availability as well as mag switches to immediate hand, in event the aircraft moved forward under its own steam after the prop was being swung . Remember - no brakes.
In other words you need a two man team (pilot and prop swinger/chock remover, for maximum safety. Then the trained prop swinger could communicate his intentions to the pilot in the cockpit re engine starting. And better still the student would not be left vulnerable and all alone.
Of course someone has to pull the chocks away after the engine is started, and the prop swinger can do that job. In the old days chocks came with long ropes attached so that the chocks could be rmoved without the person being exposed to propeller danger. Don't see that happening nowadays. Mind you there aren't too many Tiger Moths around, either. Is it too much to ask of an operator to train his staff on prop swinging a Tiger Moth and what precautions are needed when approaching the wheels to pull out each chock? Duty of care is another term that comes to mind in the profession of joy flights.
And of course, operator complacency. There are potential dangers in a one pilot - one man band operation, and the Tiger Moth joy flight operator should be aware of this. Lawyers would have a field day if mischance happens.
Last edited by A37575; 23rd Mar 2011 at 11:35.