Birdstrikes Evaluated

We are told by DofA that the ultimate purpose for obtaining detailed information about birdstrikes is to enable the formulation and evaluation of operational strategies and aerodrome management procedures, which will significantly reduce birdstrikes.

Even birdstrikes that appear trivial are a valuable source of essential information, and every effort should be made to report them, adds DofA.

What facts emerge from the 1980 Birdstrike Survey?

Firstly, 97 per cent of the 462 reported birdstrikes occurred in the immediate vicinity of an aerodrome.

March appeared to be the worst month for birdstrikes; the types of birds hit/collided with varied greatly.

They ranged from the expected kite, hawk, kestrel and eagle, to plovers, lapwings, galahs, pigeons, magpies and butcher birds – someone even clobbered an owl, while yet another unfortunate pilot impacted with a brolga. Another reported what should specifically be called a bat strike after he hit a fruit bat in flight. . .

When are the danger periods? Surprisingly enough, daylight (78 per cent hits); night (nine per cent); dusk (five per cent) and dawn (three per cent). Five per cent of hit times are listed as ‘unknown’.

(The placings surprised us, when we recalled the dawn and dusk danger times at Kununurra, WA, when thousands of birds would fly across the strip going to and from water).

When did the birdstrikes happen? According to the Department’s figures, 33 per cent occurred during take-off, 33 per cent during the landing run, 11 per cent on finals and five per cent during climb-out. Aircraft prone to birdstrikes: this is perhaps an unfair table, depending entirely on the routes flown and frequency and times of service. However, the facts are as follows:

Of what DofA calls the wide-body aircraft, the DC-10 had the highest birdstrike rate on percentages. The specific figures are:

Four-engine jet aircraft: Boeing 747, nine hits; DC-8, one.

Three-engine jet aircraft: DC-10, four; Boeing 727, 45; 1011, nil.

Two-engine RPT: DC-9, 76; BAC 111, one; F-28, 12; A-300

Turboprop: F-27, 56 hits.

Commuters: 20 hits.

All Australian-registered airlines experienced birdstrikes in Australia during 1980, with an overall strike rate of 4. 1 birdstrikes per 10,000 movements. A table compiled by DofA showed that Wynyard led the birdstrike-reporting stakes on a strike/movements ratio.

Of the other 26 aerodromes listed in the Survey, records are as follows on strike rate per 1000 movements:

It is interesting to note, says the Department, that although Ansett Airlines of Australia and TAA operated similar aircraft over similar routes, and had roughly the same number of Movements, AAA’s reported birdstrikes rate was nearly twice that of TAA. The proportion of the most commonly struck bird species (gulls, plovers and diurnal birds of prey), and the proportion of unknown species to the total struck was the same for both airlines.

In the commuter bracket, Air Tasmania had a high bird strike rate – but this is probably because the operator services Wynyard, Devenport and Hobart, all of which have high bird strike rates.

Who reported birdstrikes?

Ansett Airlines of Australia reported 99; Ansett Airlines of NSW, five; Ansett Airlines of SA, three; Ansett Airlines of WA, 11; East-West Airlines, three; Qantas, six; Trans-Australia Airlines, 70.

Foreign-registered airlines: Air Nauru, Air Pacific, MAS, Singapore Airlines and Thai International, one each; Air New Zealand and British Airways, two each. Commuter operators: Air Tasmania, six; Avoir, one; Bush Pilots, three; Norfolk Island Airlines, one; Opal Air, Skywest and Stillwell Aviation, one each; Williams General Aviation, two and 54 other operators reported a total of four.

What happened after the bird strike?

Seven delayed a takeoff, 13 meant an aborted takeoff, 14 aircraft returned to their aerodrome after the strike, 429 birdstrikes resulted in no disruption. . .

Where did the birds hit? Only 41 per cent of reported birdstrikes listed the part of the aircraft on which the bird impacted.

Of the reports, 56 hits the wings, 42 hit the windscreen or cockpit, 32 impacted the nose or radome, 28 hit the powerplant or prop. Nineteen hit the landing gear, and 14 hit the fuselage. flaps or antennae.

Two hit the tail assembly.

No aircraft were destroyed after a bird strike, though two Sustained substantial damage, 37 reported minor damage and 437 reported no damage after the impact.