Low flying is exhilarating and something that plenty of pilots do – or are tempted to do. Many pilots have come to grief carrying out low level manoeuvres when testosterone took over and attempts were being made to impress girlfriends.
In the air force low-flying is taught as an exercise. The effects of wind drift in turns giving rise to visual illusions when flying in a crosswind are part of the training which is not always given in such detail to civilian pilots.
In my early training days in the Air Force the lower limit of low-flying was 200 feet above ground level, subsequently raised to 400 feet, and then varied to “don’t hit the bird that was in the tree.” Of course judging the difference between 200 and 400 feet when flying over undulating ground is left to an imagination requiring some discretion.
Unseen and unmarked wires and cables, not to say lightning conductors, are only some of the hazards of low flying. Something else to consider is the single piston engined aircraft low-flying downwind, where in the event of engine failure a pilot needs to be aware that with a windmilling propeller pulling up and turning into wind can dissipate a lot of energy so that there is only time to do a 180° turn into wind followed by an almost immediate forced landing. On one occasion I was flying low-level in a Harvard over a wide area of early morning mist when I realised that in the event of engine failure I would be committed to a blind forced landing. This resulted in a speedy increase in altitude.
Low-flying in an aerodynamically clean high-speed jet aircraft has at least the advantage that in the event of a loss of power there is sufficient inertia to enable a speedy climb to a relatively high altitude from which there is time to review options available for a forced landing, or in the worst case, to use the ejection seat.
When low-flying over water, a pilot has to look a long way forward to the horizon as depth perception is difficult over glassy water. At least two low-flying accidents have resulted in aircraft entering the waters of Vaaldam. In one case a single Comanche with four people on board was flying low-level, the propeller of course being the lowest part of the aircraft with the undercarriage retracted. When a propeller strikes the water the blades become bent, losing efficiency; the engine mounts are possibly dislocated, and the aircraft slows down; generally there is no option but to enter the water. In the case of the Comanche, two people drowned.
A later case involving a Cessna 210 resulted initially in a propeller strike which also damaged the engine mounts, the pilot pulled up but was unable to maintain flight and the 210 entered the water. The three occupants exited via the baggage bay door and were rescued. The aircraft was subsequently retrieved but was severely damaged.
The insurance policy does not cover low-flying; in the first case the claim was denied because the pilot was the CEO of the insured company. In the second case the aircraft had been hired and the owner was insured. However, the pilot would have been vulnerable to a subrogation claim by the insurer. Subrogation means that the insurer is entitled to stand in the shoes of the owner and sue the guilty party in the owner’s name.
The aviation policy wordings are generally as follows: –
5. “PRIVATE PLEASURE” means use for private and pleasure purposes but NOT use for any business or profession nor for hire or reward.
6. “BUSINESS” means the uses stated in Private Pleasure and use for business or professional purposes but NOT use for hire or reward.
7. “COMMERCIAL” means the uses stated in Private Pleasure and Business and use for the carriage by the Insured of passengers, baggage accompanying passengers and cargo for hire or reward.
8. “RENTAL” means rental, lease, charter or hire by the Insured to any person, company or organisation for Private Pleasure and Business uses only, where the operation of the Aircraft is not under the control of the Insured. Rental for any other purpose is NOT insured under this Policy unless specifically declared to Insurers and the detail of such use(s) stated in Part 3 of the Schedule under SPECIAL RENTAL USES.
Definitions 5, 6, 7 and 8 constitute Standard Uses and do not include instruction, aerobatics, hunting, patrol, fire-fighting, the intentional dropping, spraying or release of anything, any form of experimental or competitive flying, and any other use involving abnormal hazard, but when cover is provided details of such use(s) are stated in Part 3 of the Schedule under SPECIAL USES.
My Capitalisation. Normally, for example, special insurance cover has to be obtained for the President’s Air Race to cover low flying.
Many years ago a bachelor group hired a Cherokee Six and took off on a trip into the then Rhodesia. They seemed to think that they were safely out of sight of our DCA but reckoned without the Rhodesian DCA. They proceeded to do some low-flying during the course of which they flew into a telephone line which cut through the leading edge and upper vertical stabiliser and very nearly took out the top rudder hinge.
Not at all abashed by this they carried out a temporary repair using ‘blik’ from an oil can, which they pop riveted in position. They continued further on their merry way until the Rhodesian DCA caught up with them at Vic Falls where the aeroplane was grounded. The pilot and his passengers had to pay for a return flight on a commercial airline and a retrieve party was sent up to ensure that the Cherokee Six was airworthy before flying back. The pilot could only pay a proportion of the repair costs as predictably he was broke.
Another serious encounter with wires occurred near Rundu on the border of Namibia and Angola when a pilot with three passengers in a Piper Tripacer flew into a cable spanning the Kavango river and plunged into the 20 foot deep water. Two passengers drowned.
A later accident occurred in the Orange River near Upington when the pilot flying a Seneca low-level along the river flew into power lines supplying a farmer’s pump. The aircraft crashed into the river and the pilot was killed.
In an accident involving a Cessna 182 in Namibia, a pilot and his two passengers flying low-level under early morning coastal fog had the top of the rudder counterbalance strike a power line under which they were attempting to pass. This caused a full rudder deflection, the 182 rolled 90°, put a wing in, crashed and burned. No one survived.
Less serious accidents involving power lines have occurred. A Cherokee 180 flying low near Bulwer cut a power line cable with the propeller. The Cherokee did not crash but landed in a damaged condition on a nearby road. The pilot was suitably chastised.
Years before, a Bonanza flying under low cloud down the Elands River valley in the then Eastern Transvaal struck an Eskom powerline spanning the valley. The aircraft sustained some damage but was able to continue to Nelspruit. In those happy days the Bonanza was repaired for less than R10,000, and Eskom claimed the huge sum of R4000 for damage to the cables.
As the years have passed better marking of power lines has occurred, but they are not always easily seen depending on lighting conditions.
Helicopters, because they do so many low-level operations, are particularly vulnerable to striking obstacles. A pilot in his helicopter was killed flying over a ridge and striking an unmarked power line, the pylons of which were not visible from his point of impact.
A contractor doing powerline inspections in a Bell 206 flew into an 11 KVA powerline which abnormally crossed over the very high tension power line being inspected below it. All on board the helicopter were killed and besides the burnt out wreck I have a lasting memory of the scorch mark for 2 km through the veld where the 11 KVA earth cable heated up as the power shorted.
Crop spraying aircraft naturally have had their fair share of encounters with wires as they so frequently operate under them. Disruption of power supply to factories and mines can result in expensive third-party claims being lodged against the aircraft owners and/or operators.
WHAT CAN WE LEARN?
Enjoy your flying but don’t let testosterone get away with you.
Low level visual perception changes the faster you fly, and there is a doughnut shaped blur zone at 90 degrees to the line of flight.