Philippine Aircraft Markings, A History

19 September 2020

From Radio Call Signs To Aircraft Markings

Have you ever wondered why aircraft markings in the Philippines, particularly that of Philippine Airlines, were as diverse as the plane they have through years of its corporate existence as an airline?

Believe it or not, it all started with wireless telegraphy called "telegrams." Not the cloud-based instant messaging, video-telephony and voice over IP service app you find in your smart phone, but  the telegraph message that was directly delivered to the recipient by a messenger transmitted through telegraph codes either through Baudot or Morse codes.

For the millennial, It was like the Instant Messenger app on twitter with limited number of characters about 10-15 words or less than 100 characters. The reason why characters were fewer than a hundred was because of their expensive cost of transmission. In the 90's, the cost hovers around P5.00 per character.

And since telegraph was faster than mail, telegraphic stations across the world grew by leaps and bound that it had become unmanageable by some countries due to overlapping of frequency arising from limited radio spectrum. There were also problems associated with interconnection to neighboring countries.

As the development of the telegraph in the early 19th century changed the way people communicated on the local and international levels, like what the smartphones did today, there was need for standardize regulations of radio transmission.

Between 1849 and 1865, a series of bilateral and regional agreements among Western European states attempted to standardize international communications.

Nationality Letter Marks
To manage the radio spectrum, the International Telegraph Union (ITU) was established in 1865 to promote shared use of radio frequency by 24 (now 20) countries. The ITU then established international callsigns from participating countries to distinguish operators by their country of origin. The convention was largely European in character and influence.

ITU assigned the following alphabetical prefix letters to participants mostly beginning with the first letter of each country to identify the source of transmission.

This is where Germany got the letter "D" for Deutchland, "E"for Spain (Espana), "F" for France, "G" for Great Britain, "I" for Italy, and "R"for Russia.

In 1906, The United States (US) together with other countries Argentina, Brazil, Bulgaria, Chile, Greece, Japan, Mexico, Persia (now Iran), and Uruguay joined the International Radio telegraph Convention (French: Convention Radiotélégraphique Internationale) in Berlin, Germany.

The new participants were also allocated radio "Nationality" letters. The Convention delegates scrapped the existing call signs to create a new one-two and three-letter system that carved up the alphabet into sets of consecutive combinations and assigned them to different countries based on their perceived need. Existing users were given additional letters, and options to maintain or modify Nationality letters.

UK was provided new letters "M" and letter "V" referring to Queen Victoria for crown territories outside the UK. Japan was given "J", and the United States given "W" and letter "N" for North America as Norway wasn't using theirs. Germany also acquired letter "A" from Austria who change its letters to "HA", referring to Hungary-Austria Empire. Netherlands kept the "NL" sign.

So in 1910,  France convened  the first International Air Navigation Conference, known as "the Conférence internationale de navigation aérienne" in Paris. It was the first diplomatic conference to consider formulating international law about aviation attended by 19 European nation.

The EU Nations discussed among others, the registration of aircraft according to call sign prefixes adopted by the ITU in 1865 and 1906 as radio equipment are installed on aircraft, and the now famous freedoms of the air. While the convention was successful, the use of ITU nationality marks for the participating countries were not approved as they were never signed.

What came out from the convention however was the use of one letter identification of five superpower countries that was based on the call sign prefixes adopted by the 1912 Radiotelegraph Conference, held in London. They were Great Britain, France, Germany, Japan, and the United States.

The Philippine Islands 

The draft it produced subsequently formed the basis for the 1913 London International Radiotelegraphic Conference. The convention made a partial allotment of call letters among nations which signed the convention.The International Bureau at Berne, with the consent of those nations, modified and added to this assignment of call letters in a circular dated April 23, 1913.

It was at this stage that the Philippine Islands was recognize as country and was given the ITU sign of "PI", or The Philippine Islands.

These allocations were for use for all radio purposes - ground stations,ships, broadcast etc - aircraft not being a specific target at that time for radio equipment .In fact the use of the allocations for aircraft either as radio calls or registrations did not become widespread until the end of the Great War in 1919.

At the second Session of International Commission for Air Navigation (ICAN) held in London in October 1922, the French Delegation suggested that it would be more practical to adopt the same letters for aircraft nationality marks as those allocated for use as wireless call signs.

The N markings

As faith would have it, the United States of America never ratified the Treaty in 1912, which means that it will have to continue using the old ITU Nationality marks, which in effect affected the markings intended for the Philippines.

As "N" were chosen for American military radio stations, "W" and "K" were designated specifically for commercial use. Stations were allowed to choose the letters that followed the K or the W, and the combination was allowed to be three or four letters in length. ITU also alloted  signs beginning with KDA to KZZ to the US. "W" call signs were meant for commercial stations on the Atlantic coast and Gulf of Mexico separated by the Mississippi River, and "K" call signs for commercial stations on the Pacific coast and Great Lakes.

It is for this reason that radio station in the Philippines starts with the letter "K", as in KZRH or KZKZ, or the government''s KZRM. It was changed to DZ, DW, DX, and DY in 1946 after the Philippines acquired its independence from the United States.

Like the rest of Europe, US has treated planes as moving radio station similar to the concept of aircraft nationality following from maritime law where the national flag is used to indicate a ship’s country of registration. 

Since the Philippine Islands (PI) was a territory of the United States, the letter "N" was similarly adopted as prefix with the letter "P" as suffix, referring to the Philippine Islands. As the US FAA wanted separate codes for Puerto Rico, Marianas and the Philippines, it was assigned numbers instead of letters to appear as NP-XX. This was the marking of Philippine registered aircraft beginning 1906 to 1935.

The advent of commercial air transport prompted the US to add another suffix to the Philippine registered aircraft in 1930 that it becomes NP-CXX, with the letter "C" referring to commercial use, as distinguished from NP-XX to refer to government and military use.

The first Philippine-registered commercial aircraft was NP-C24 of Philippine Aerial Taxi Company (PATCO), precursor to Philippine Airlines, registered in 1930. The next registered plane was made in 1933 belonging to INAEC.

Only few airplanes with "N" callsigns were marked as belonging to the Philippines and they were all wipe out at the start of World War II in 1941.

A new code "PI" was however made effective before the war in 1941 after the 1912 convention was ratified by the United States, but no new plane was registered until after the war in 1946.

The coming into existence of the permanent International Civil Aviation Organization (ICAO) in April 1947 also change the marking standards.

The original Annex H - Aircraft Registration and Identification Marks became Annex 7 - Aircraft Nationality and Registration Marks. And ICAO Council adopted the first standards concerning this issue on 7 February 1949; they became effective on 1 July 1949 with the Philippines as an independent Republic finally adopting the much delayed "PI" identity.

Why PH is not the Philippines

At a convention in Paris on 13 October 1919 Netherlands decided to take the national letter "H", from the word Holland, its old name to be followed by four letters, from the national letter "NL" Nether Land, which is an English name.

As there were more countries starting with an H, such as Haiti and Hungary, Netherlands identity was changed to H-N followed by three letters, referring still to Holland and Netherlands.

It so happen that the first airline in the world is KLM. The first two planes in the Dutch aviation register were KLM’s H-NABC and H-NABD (Fokker F.II).

Following the International Radiotelegraph Conference in Washington in 1927, the Dutch registration was changed again to PH.

So there begs the question. Why "P"?

As it turn out, Netherlands wanted to have letters assigned to its overseas territories in America, Africa and Asia similar to Great Britain. Having one two-letters prefix wouldn't be enough to accommodate all the radio stations within its territory. So the ITU assigned new prefix letters that were sequentially available. The letter was "P."


The Netherlands was assigned radio call signs for its overseas territories in the Caribbean, Africa and Dutch East Indies and attached to the new station consisting of five letters which had to begin with PA-PZ.

Because the aircraft radio stations in the Netherlands were split into various ministries, multiple registrations followed: PA for the Navy, PB for the Army (later the Air Force) and PH for civil aviation. Antilles in the Caribbean got PJ, while Indonesia got PK. Suriname on the other hand got PZ. As the letter in the alphabet was not enough to list Netherlands colonies, ITU added P1-P9, with Papua New Guenea listed at P2 while Aruba listed as P4.

The other series remained unused. The PH combination was adopted in preference to PE because the letter "H" (Holland) indicates its nationality, as with French (F), German (D) and Great Britain's (G).

PAL In PH Planes 

At the beginning of jet age, PAL ordered two Douglas DC-8-53 for delivery in February and April 1962. The DC-8 was meant for transcontinental flight to the United States. At the time of loan approval in 1960, the value of the peso to the US dollar was 2 pesos to 1 dollar. For a US$6 million dollar jet, that cost would translate to ₱12 million for single DC-8 or ₱24 million for the two jet.

Then in January of 1962,  the  Philippine government devalued the peso from ₱2.00 per dollar (the official exchange rate  even  before  World  War  II)  to  ₱3.90  per  dollar to prop up its reserves which had been diminishing due to more importation activity and lesser export proceeds. 

The loan applied by PAL to the Development Bank of the Philippines (DBP) suddenly was enough only to buy a single plane instead of the ordered two as cost of the DC-8 ballooned to ₱23.4 million pesos. The peso devaluation caused the cancellation of the order to aircraft manufacturer Douglas Aircraft Corporation which put the finish aircraft to storage in Las Vegas.

The Dutch connection

It so happen that the DC-8 orders were also tied to the delivery of four F-27 Friendship developed by the Netherlands. PAL's application to DBP was for a ₱54 million loan to finance these order that has not been approved because of the peso devaluation.

Col Renato L. Barretto, the newly-appointed president of Philippine airlines, had been told by the bank sometime in January 1962 to look for other means to finance the two DC-8s and four F-27.

Dutch authorities wanting to sell their Fokker planes gave Barretto a novel idea which reverberate to this day. Lease-to-own and code share deals. While PAL knew about code sharing it does not know yet leases to own.

The Dutch government ordered KLM to buy the aircraft ordered by PAL and was registered cleverly as PH-DCP and PH-DCR, referring to PR planes, the ICAO code of PAL. What PAL did was leased all aircraft it ordered, including the four F-27. 

The Dutch however had other ideas in mind other than the leases as other countries wouldn't be deceive by the aircraft markings. The lucrative Hong Kong-Manila market, and the US West coast-Manila market was on their sight. KLM wanted to fly Hong Kong and the US, in similar fashion of what they did to KLM Asia only that it was implemented in 1995 or thirty five years later after the idea was first conceived in Manila.

Unaware of the deal KLM had with PAL in February 1962, PANAM earlier entered into similar code-share agreement with PAL for routes to Hong Kong, Japan and North America that was sealed in the first week of December 1961 by then PAL President Eduardo Z. Rumualdez before exiting the airline days later. It was agreed that PANAM would operate the lone Boeing 707 in the colors of Philippine Airlines to comply with regulatory requirements. 

It was the first "N" registered commercial aircraft to donned PAL colors that wasn't PAL as it was flown by Americans, controlled by Americans and registered  in the US. In short, its not a PAL operated plane. The deal was short lived as it was voided by US regulators by January 1962. 

PANAM wasn't so happy with the deal PAL had with KLM that in 1965 it finally filed a protest against PAL and KLM alleging that it was in fact KLM that is running the show on trans-pacific flight. 

US regulators barred PH-DCP and PH-DCR from flying Hawaii, Los Angeles or San Francisco. To circumvent the DOT ruling, KLM made another trick on its sleeves by making PAL officially register its plane under the lease to own deal where it was re-registered for US regulators to see.

The PH registered aircraft was eventually re-registered in the Philippines as PI-C801 and PI-C802 so that it can fly to the British territory and the US west coast. The very first DC-8 was named "Sampaguita" and the other one "Ilang-Ilang" that flew long range routes. Full ownership was bestowed in 1974.

From PH to N again 

Contrary to popular belief, it was not the Boeing 707 that claimed as the first "N" registered commercial jet to fly PAL because it was owned by  PANAM. That honor belongs to DC-8-50 with registration "N9608Z" (MSN 45608) that was originally ordered by PAL but was not taken up in 1962 because of the currency devaluation. PAL still ended up flying the plane two month after its supposed delivery under Dutch registry, ultimately owning it and retiring in the Philippines after 25 years of service. It was broken up in Manila in April 1987.

Netherlands involvement with PAL did not end with DC8 and F-27 as it continued leasing planes belonging to KLM beyond 1960. In 1974, KLM financed the acquisition of DC-10 fleet with PH-DTI for PAL. Two were added in 1975 PH-DTC and PH-DTK. The fourth one to arrive in 1976 was RP-C2003 ordered by PAL itself. 

In 1977, KLM convinced PAL to add 2 more DC-10 to the fleet for its expansion to Europe, with KLM purchasing the other one and leasing it to PAL while it buys another to complement PR-C2003 for US operation as the US was not letting in Dutch registered planes. Another plane was added in 1979 PH-MBP and RP-C2114 was delivered in November 1980.

Netherlands' final engagement with PAL was in 1988 when it let 10 Fokker-50 planes through third party lessor AFT, to the airline until it was hit by the 1997 Financial crisis that it had to let go all remaining frames by 1999 culminating an end to era of PH registered planes in the Philippines.

The New Society and RP

The impact of decolonization and independence on aircraft registration schemes has varied results from country to country. But none was effected in the Philippines after it acquired independence from the United States in 1946.

Most countries have had a new allocation granted usually from the new country's new ITU allocation after independence. But neither is it uncommon for the new country to be allocated a subset of their former colonial power's allocation, as was the case of "NP-XX"  and "NP-CXX" given by the Americans to their overseas colony.

However European countries already identified the Philippines as "Las Islas Filipinas" (The Philippine Islands) as early as 1903, which was fitting tribute to the "PI" code as was instilled in the 1912 Convention, had it been approved by America. But the United States at that time were notorious for not approving treaty obligation to the dismay of Europe. In fact, they were not a member of the League of Nations, a precursor to the United Nations, in the entirety of its existence.

When the Philippines finally got their independence in 1946, the PI prefix allocated by ITU and ICAN Conference, a precursor to ICAO, which has not been used at all, took effect and made effective in the Philippines.

The government of President Manuel Roxas never got the idea of "RP" prefix, meaning "Republic of the Philippines." The reason for that is because the "PI" prefix were never used. And the new Republic of the Philippines are more popularly known around the world as the " Philippine Islands." It also helped that most of the government's flying assets comprising mostly of DC-3 were handed over by the US to the Philippines bearing already the PI prefix sign.

And then President Ferdinand Marcos declared Martial Law in 1971 and instituted a change of government declaring a Fourth Philippine Republic in 1973 by the approval of the new Philippine Constitution replacing the ones made in 1935.

Consistent with the "New Republic" dubbed as Bagong Lipunan (New Society), the government changed the ICAO designation of the Philippines away from colonial identification in 1974 finally carrying the name of the Republic of the Philippines. The first aircraft to be registered under RP-C nationality markings was BAC1-11 (RP-C1184). It was retired from service in 1992 after flying exemplary flights.

The RP-C designation was not changed in 1987 following the approval of the 1987 Constitution and  it has been that way ever since.

From N To RP Finally

Then, there was this separate orders for Airbus and Boeing planes also in 1977. 

The first Boeing 747-200 plane out of the four orders was delivered in December 21, 1979. It was registered as "N741PR" in the Philippines and was the first "N" registered commercial plane in the country.

So why there was still the "N" designation? 

The US Eximbank maintained ownership over the aircraft until PAL decides to acquire it, thus the beginning of "N" registration again. It was followed by N742PR which arrive in February the following year and N743PR that arrived in March, while the last N744PR arrived in December 1980. None was acquired by PAL. 

Other B747-200 leases were however registered in the Philippines, like RP-C5745, because they were secured by Philippine Banks. And so does the first Airbus, a pair of A300-B4s (RP-C3001,RP-C3002), and the other three that followed because they were ordered by the Philippine government and paid for by government funds.

The same "N" registration was made for the succeeding Boeing 747s, including the ones acquired by the airlines in 1992, N751PR, N752PR, N753PR and N754PR. The difference this time however was they were acquired by the airline in 2009 and was registered with Philippine markings.They were retired from service in 2014.

Similar registration arrangements were made to smaller Boeing planes B737-300 and B747-400 used by Philippine Airlines in 1989 onward let from different aircraft lessors in Ireland. Some were acquired by the airline beginning 2001 and subsequently sold later to other airlines. 

The first four Airbus A320-200 planes (RP-C3221,23,24,25) were however ordered and delivered to PAL in 1997 bearing Philippine registrations, as well as the others that came later because they were all secured by Philippine-based banks and have ownership options, in what airlines call "finance lease."

The other Airbus planes (A330-300 and A340-300) were also registered similarly as they also have options for ownership, under the same concept introduced by KLM in 1962. PAL elected to acquire the planes in 2008 and retired from service in 2014.

The CAAP

The change in registration concept began when CAAP Law came into being in 2008. It subsequently  issued PCAR in June 2008 which was amended in 2011. PCAR requires all new aircraft to be registered in the Philippines while its foreign registration cancelled.

The new requirement came out after the painful experience of  local authorities regarding foreign creditors during the 1998 Receivership hearing of Philippine Airlines, where foreign registered aircraft were out of reach of Securities and Exchange Commission (SEC) which handled the airline's rehabilitation, particularly referring to the Boeing B747s, and the Airbus fleets. It was Airbus consent that authorizes rehabilitation to proceed and consequently was approved in 1999. This was one reason why PAL ditch the Boeing B737s in favor of Airbus A319s and A320s, which they are still flying today.

So when the new triple seven ordered by Philippine Airlines in 2007 arrived in 2009, it was not marked as N777PR but RP-C7777. In the same manner, all new Airbus A320, A321, A330 and A350 fleet ordered by PAL was not marked anymore with French or German registration but was immediately registered with National markings of the Philippines.